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914World.com _ 914World Garage _ Ben's 914 TURBO Official World Premier
Posted by: airsix Sep 13 2004, 01:04 AM
Ok, so it isn't as cool as Chapman's 914-6 Turbo 3.0, but it's a turbo 914 all the same. Ladys and Gentlemen, at about 10:00 PST I got boost and there was much rejoicing. I took the car out, filled it with premium, tuned it with the laptop a little to make sure it got plenty of fuel under boost, and the mission was a sucess. Boost starts to come on at ~2,700rpm and is going full-steam by 3,500rpm.
I stand (ok, sit) here before you my brothers to declare that yes indeed, you can turbo a 914. 
Details:
Engine: '73 1.7, stock internals
EFI ECU: Perfect Power MIC3 (Cost ~$500 to get on the car and running 3 years ago)
Misc EFI stuff: Subaru 1.8T injectors, Holly throttle body off a 3.0 Chrysler, BMW 5xx fuel pump, foam motorcycle aircleaner (temporary)
Turbo: IHI off 1.8L Subaru (including wastegate)
Misc Turbo stuff: Bosch blow-off valve (for a Saab I think). Cheap. Plastic. Works great.
Total cost to add turbo: $175 (EFI was already on the car. Use Megasquirt+turbo and you can do this for <$400 easy)
I tried to modify my fuel pressure regulator with a boost-reference port like the in the http://www.dune-buggy.com/turbo/ but I broke off a wire guage drill bit about 1.5" deep into the bolt. Dang. Only had about a quarter-inch to go too. So I just bolted it back on the car and set the fuel pressure at the 30psi I have the ECU turned for. I tried to crank up the injector pulse width under boost to compensate, but they hit 100% duty cycle at 5,000rpm because at that point they only have 20psi effective pressure (because there's 10lb of boost by that point). So I'm keeping it under 5k rpm until I get a rising-rate pressure regulator. The wideband O2 says mixtures are just fine below that point. I estimate I'm getting 110hp (That's not a WAG. I really did the math) which doesn't sound like much but is sure better than the 80hp I had before. I would still like to add an intercooler which could put it in the neighborhood of 130hp without getting too boost-happy. Even as it is now I would say it's 100% more fun to drive. I'm really happy about it. I'll get the pressure regulator issue squared away so I can run it up to 6k and I think it'll keep me happy for quite a while.
Rick said "This thread is worthless without pictures" so here's the best I could do. If you missed the earlier thread I'll throw in one of the earlier pics too. I tried to make a video but all you hear is wind noice and the blow-off valve between shifts.
Posted by: airsix Sep 13 2004, 01:06 AM
Ok, here's the one some of you already saw - the completed exhaust from Friday.
Attached image(s)
Posted by: airsix Sep 13 2004, 01:09 AM
Here's the best shot I could get of it on the car. It's on the passenger side tucked up there right at the front of the tranny. The intake side just peeks throught the engine tin enought to get the intake plumbing into the engine bay. Oil return drains almost striaght down with a little 'L' where it goes into the pass-side valve cover. The orange hose is for cooling air to the bearing housing. I'm running a 1/2" hose from the vapor-canister port on the impeller housing on the engine to the water-jacket on the turbo bearing housing. It's definitely not as good as running water through it, but has to be better than just plugging it off. There is a decent amount of air-flow out of the hose anyway.
Attached image(s)
Posted by: redshift Sep 13 2004, 01:23 AM
YES! Good job! I'd do that.... that looks fun.
M
Posted by: airsix Sep 13 2004, 01:44 AM
YES! Good job! I'd do that.... that looks fun.
M
Thanks!
I almost forgot my credits:
Thanks to Sammy Gore for setting out to disprove the myth. The first guy I know of to do a DIY 914 turbo.
Thank you to Jeff Shyu (Jenny's brother). The first DIY intercooled 914 with D-jet.
Thanks to Ed Villela for showing us how it SHOULD be done. The most elegant 914 turbo.
And Ed Morrow, with his CIS-from-scratch 1.8 turbo. (Two Ed's w/ CIS injected turbo 914's!)
Three cheers for the fathers of the 914 turbo-4!
I probably wouln't have ever got around to doing this if Sammy hadn't once said something to the effect of "A lot of people talk about building a 914 turbo but most of them are never going to do it." I had been one of those people "talking about it" and that comment nagged at me for 3 years. Thanks for the motivation Sammy. I probably never would have gotten around to finishing this project if you hadn't said that.
-Ben M.
Posted by: SpecialK Sep 13 2004, 01:58 AM
Congratulations Ben! 
Nice fab work too! Now it's off to the dyno right?
Posted by: iamchappy Sep 13 2004, 02:20 AM
Great work, you have seen the light. Turbo on brother.
Posted by: ejm Sep 13 2004, 04:35 AM
Nice job.. Welcome to the club 
Posted by: Evill Ed Sep 13 2004, 05:23 AM
YES! Good job! I'd do that.... that looks fun.
M
Thanks!
I almost forgot my credits:
Thanks to Sammy G. for setting out to disprove the myth. The first guy I know of to do a DIY 914 turbo.
Thank you to Jeff S. (Jenny's brother). The first DIY intercooled 914 with D-jet.
Thanks to Ed V for showing us how it SHOULD be done. The most elegant 914 turbo.
Three cheers for the fathers of the 914 turbo-4!
I probably wouln't have ever got around to doing this if Sammy hadn't once said something to the effect of "A lot of people talk about building a 914 turbo but most of them are never going to do it." I had been one of those people "talking about it" and that comment nagged at me for 3 years. Thanks for the motivation Sammy. I probably never would have gotten around to finishing this project if you hadn't said that.
-Ben M.
Ya Done Good there Ben
Now the real addiction begins!!
Ed
Posted by: Racer Chris Sep 13 2004, 05:44 AM
Good job Ben!
Posted by: nein14 Sep 13 2004, 07:32 AM
Congradulations!!! from one 914 turbo owner to another , Kudos to Evil Ed and Sammy for proving to all the NON Believers it can be done!
Posted by: airsix Sep 13 2004, 09:02 AM
Thanks Ed, I forgot - you also did a CIS/turbo!
/me goes back to edit earlier post...
-Ben M.
Posted by: fiid Sep 13 2004, 09:50 AM
NICE JOB!!!! Serious Kudos to you.
I think you can improve your engine-turbo exhaust plumbing though - by running it all the way to the back of the car and then forward again you are allowing the exhaust to cool some, which means it is shrinking and hance it takes more of it to push the turbine around. That's a little fab project that you can do later though.
Drive it for a while and enjoy. My car has been on stands forever, and I miss it :-(
Posted by: Root_Werks Sep 13 2004, 10:14 AM
Couple of buddies of mine and I have thought about doing this. Any words on the performance? Was it worth it? 
Posted by: airsix Sep 13 2004, 12:04 PM
You are exactly right. This was my biggest concern and the subject of much debate (in my head). I had originally planned to chop up my heat-exchanger tubes and use them to make a header with the distance between the heads and the turbo as short as possible. I decided it would add at least 3 or 4 weekends to the length of the project. So I bagged that idea and did what you see in the interest of time. There is a good chance I'll build up a decent header (really short) this winter.
-Ben M.
Posted by: airsix Sep 13 2004, 12:22 PM
Performance isn't earth-shaking, but it's definitely fun - and about what I was hoping for (I had realistic expectations). It was definitely worth it. 2 weekends and $175 for about 30% more power? No question it was worth it. When this 1.7 heaves it's last breath maybe I'll drop in a 2.0 or...
Hey, thanks for all the kudos, guys. It means a lot. When I said "2 weekends" I meant that was the execution part. The planning took a lot longer. I slept like a baby last night - first time in forever that I wasn't staring at the ceiling all night trying to figure out some part of this project.
-Ben M.
Posted by: andys Sep 13 2004, 12:22 PM
You are exactly right. This was my biggest concern and the subject of much debate (in my head). I had originally planned to chop up my heat-exchanger tubes and use them to make a header with the distance between the heads and the turbo as short as possible. I decided it would add at least 3 or 4 weekends to the length of the project. So I bagged that idea and did what you see in the interest of time. There is a good chance I'll build up a decent header (really short) this winter.
-Ben M.
Ben,
I'd simply wrap the exhaust with header wrap and avoid all the extra header fabrication work. It'll really help hold the heat in, and I'll bet the turbo will come-in sooner too (2700 RPM is kinda high, but easier on the rods). How much boost are you getting and/or what's the waste gate set to? On my turbo 914 (circa 1975), I had to fab my own heater boxes on the Crown turbo headers, which wasn't a whole lotta fun; though they did work well.
Andy
Posted by: red914 Sep 13 2004, 12:59 PM
Ben, that thing looks awesome! any chance of coaxing you over to this side of the mountains so we can all ogle it close up sometime? we'd probably buy you a beer...
Posted by: Root_Werks Sep 13 2004, 01:25 PM
I agree with Shane, if you come on over to the west side so some of us teeners can check out your car, I would be in for a beer.
I use to, mind you use to have an article from the early 80's "VW&Porsche" I think? That had a stock 2.0FI with KKK turdo from a 924 I think? The guy didn't have to do much as I remember. That has always haunted me to do one ever since. Just seemed cool. 
Posted by: airsix Sep 13 2004, 02:21 PM
You guys are great. Thanks for all the comments.
Header wrap: That's exactly what my engineer Dad said. I said, "yeah, but the pipes are still long" and he reminded me that the pressure response between the head and the turbo is speed-of-sound, so keeping the heat in is really the only issue. I'm not worried about header-wrap rust. I don't drive in the rain, and being a turbo these pipes will rust from the inside out before header-wrap rust is ever an issue. (Dad asked why I didn't do the whole thing in stainless and I said "Because you aren't paying for it".)
Thanks for the west-side invites, guys. I cringe though at the thought of letting you look closely. he he. I plan to weld on the SC flares and paint the car this winter/spring. If I do that and tidy up some wiring ugliness maybe I will bring it over if there is a gathering next summer.
-Ben M.
ps - Wouldn't you know. It was raining cats and dogs this morning. Had to drive the pickup. First rain in a month or more. I was so pumped to drive the 914 today too. 
Posted by: airsix Sep 13 2004, 02:27 PM
Anyone who has pulled it off knows it aint as easy as you make it sound. Tonight when I get home I'm going to offer a toast to the north with a frosty beverage.
Thanks Sammy. Anybody can follow. You were the one who blazed the trail. And yeah, it's hasn't been easy, and it's not over yet - I call this a major milestone, but not the end of the project. Still got some issues to shake out, but it'll get there (in one piece I hope). You are still THE MAN. Cheers.
-Ben M.
Posted by: Eddie914 Sep 13 2004, 02:46 PM
In what part of Eastern Washington State do you live?
My mother has lived in Spokane for nearly 50yrs. I get over there regulary.
Regards,
Eddie
Posted by: TimT Sep 13 2004, 03:11 PM
Kewl!!
nice job Ben....You may want to run it without the muffler. We run 930's all the time on the track and street without mufflers and havent had any problems with noise..
No muffler is lighter, and will allow faster spool up of the turbo
Try it you may like it !!
Posted by: andys Sep 13 2004, 03:42 PM
nice job Ben....You may want to run it without the muffler. We run 930's all the time on the track and street without mufflers and havent had any problems with noise..
No muffler is lighter, and will allow faster spool up of the turbo
Try it you may like it !!
TimT,
That reminded me of something we did in the early days of street turbo's without waste gate controls. We controlled the boost with the exhaust by restricting it with different sized mufflers (or as you suggested, no muffler at all). Crude, but effective.
Ben, if you used thin wall muffler tubing for your fab, keep a close eye on it. It will likely crack. It's perhaps one reason your Dad suggested stainless. Again, in the early days, we used heavy wall (.125") carbon steel weld together steam pipe fittings. Actually worked out quite nice, as there are 45's, 90's, and reducers available with beveled edges for welding.
Andy
Posted by: airsix Sep 13 2004, 04:15 PM
I'm in Kennewick, WA. (2 hours South of Spokane). Anybody's welcome to come visit. The problem is this place isn't really "on the way" to anywhere.
The avatar pic of the Tetons that says "home" is misleading - that's where I grew up.-Ben M.
Posted by: Andyrew Sep 13 2004, 04:25 PM
I want to see that intake setup!!!
Asside from that..
GOOD JOB!!!
My thoughts for a turbo was a built bottom end (bus stuff... on a 2.0) k26 sized turbo (heck I have one on my desk.. lol) water injection and short exhaust pipes... Then a Mass air flow (for da sound of course...) And maybe 7-10 psi...
BUT That will be later.. Maybe on this sbc 
Andrew
Posted by: airsix Sep 13 2004, 05:30 PM
There is no way I'm letting any of you see the intake setup! It's too ugly. It's made from stuff bought at Home Depot. It would make the average PCA member faint on sight. It's just a proof-of-concept prototype. I will make a REAL intake this winter and then I'll show you pictures.
-Ben M.
ps - I haven't given up on the idea of making a short video if someone's got a place for me to upload to.
Posted by: Brando Sep 13 2004, 05:36 PM
Next up, twin turbo?
Run a turbo off of each side... Cyls 1,3 & 2,4
Very impressive work done there. Bravo!
Posted by: Gint Sep 13 2004, 06:15 PM
Nice goin Ben!
Ever going to dyno it?
Posted by: rick 918-S Sep 13 2004, 09:29 PM
That's what I'm talking about! 
Posted by: echocanyons Sep 13 2004, 10:15 PM
Damn fine work!
Posted by: Jake Raby Sep 13 2004, 10:19 PM
The one big key is that you kept it a 1.7
Every Type IV Turbo that I have been able to keep together used the 90mm bore.
Good job, I'd really like to see what your head temps and EGT run for comparisons with two that I built last year.
Posted by: Britain Smith Sep 13 2004, 11:49 PM
Every Type IV Turbo that I have been able to keep together used the 90mm bore.
Good job, I'd really like to see what your head temps and EGT run for comparisons with two that I built last year.
What about a 98mm bore with nikki's? You think that will work?
Posted by: nein14 Sep 14 2004, 07:30 AM
As the proud new owner of Evil Ed's 2.0 914 Turbo , he built it with 94mm P & C's, 71mm crank and 1.7/1.8 heads.
Boost its set at 9lbs. for the street and come on at about 3000 rpm's. He also installed Carroll Water Injection system for running 14lbs. of boost on 100 octane race fuel
when he was doing track events at Watkins Glen.
The head temp rarely gets above 180- degrees. The car is an absolute blast to drive even in 5th gear it has grunt!
Posted by: Evill Ed Sep 14 2004, 11:43 AM
As the proud new owner of Evil Ed's 2.0 914 Turbo , he built it with 94mm P & C's, 71mm crank and 1.7/1.8 heads.Boost its set at 9lbs. for the street and come on at about 3000 rpm's. He also installed Carroll Water Injection system for running 14lbs. of boost on 100 octane race fuel
when he was doing track events at Watkins Glen.
The head temp rarely gets above 180- degrees. The car is an absolute blast to drive even in 5th gear it has grunt!
Hey John, I think it was the oil temp that rarely goes over 180f
The heads never go over 325 or 350f, I forget.
BTW- I think John drives it alot harder than I did, on the street anway. I don't recall routine 100 mph blast to my barber shop
Ed
Posted by: nein14 Sep 14 2004, 12:25 PM
HI Ed
Your right, my mistake I was referring to oil temp. The head temp doesn't go above 325 to 350 degrees.
BTW, the last run up to get a haircut was 110mph with a BMW 325 trying to catch me. 
Posted by: Jake Raby Sep 14 2004, 02:29 PM
Nickies solve the sealing issues- period. Any size will work unless you get stupidly thin.
Posted by: jkeyzer Sep 14 2004, 02:32 PM
I was just wondering, is it really ok to run a water cooled turbo without water cooling?
Are they set up for adequate cooling with oil alone?
Posted by: lapuwali Sep 14 2004, 02:49 PM
Wondered about that myself. As I understand it, the primary reason water-cooled bearings came into being was that even the oil-only turbos had cooling problems, esp. on shutdown. The oil would fry once the pressure went away after shutting off, coking to the bearing. I supposed what one could do is use a small heat exchanger (like an oil cooler) with lines to and from the bearing. If you mounted the cooler more or less level with the turbo, there would be some thermo-siphoning effect to keep the water moving even w/o a pump, and this would work even with the engine off. Would work best if you ran the hoses parallel to each other, one above the other, so one was the "cold" hose, and the other was the "hot" hose. Hot water would rise in the bearing housing to the hot hose and sink in the cooler as it lost heat, pushing the cooled water at the bottom of the cooler along the cold hose into and up into the bearing housing. Pretty cheap to do. The air hose from the fan housing currently blowing air through the bearing housing could instead blow it against the cooler.
I have no idea if this would be adequate, but it sounds like it would be better than just relying on the oil alone.
Posted by: Evill Ed Sep 14 2004, 03:22 PM
Are they set up for adequate cooling with oil alone?
Yes, it is fine. The cooling jacket is to help prevent oil coking (sp?).
Ed
Posted by: ArtechnikA Sep 14 2004, 04:22 PM
Run a turbo off of each side... Cyls 1,3 & 2,4
have a look at the sizing and the firing order before deciding this is a good idea ...
Posted by: airsix Sep 15 2004, 02:11 AM
UPDATE:
Well, I drove it to work today. I'm really liking this boost thing. But the 'not going past 4k rpm' part got old real quick because that's when thing are just starting to really get fun. If you recall this is a self-imposed limit because I haven't finished converting the fuel pressure regulator with a boost-reference port and the injectors can't keep up past around 4,700 rpm. So tonight after getting home late from work, and spending time with Jamie and Kimberly I went back out to the garage to try to figure out a way to get the broken drill bit out of the fuel pressure regulator adjustment bolt. No joy. So after wasting a bunch of time on that dead-end I scrounged up an 8x1.25 bolt and made a new one (square cut threads and all). This time I drilled it right by making a tooling plate to hold the bolt perfectly vertical. That worked. Bored it straight down the center. I then drilled the head of the bolt to press-fit a piece of tubing for the vacuum hose. So far so good. I got it back on the car and adjusted the pressure to 30 psi. Went to hook up a vacuum hose and the stinkin tube pulled out. Ok, going to have to solder it. Can't believe it pulled out. I had to press it in with an arbor press. Oh well. I need a vacuum hose 'T' anyway (I was going to temporarily steal the line to the BO valve). Tomorrow I'll grab a 'T' on the way home from work, solder the tube into the bolt head and see how it works.
This boost stuff is really a new tuning experience. I thought I had my ignition advance curve roughed in pretty good but I found out today that it'll need some more work. I had roughed it in by doing some second-gear pulls from idle to 5k rpm. But what I found out today is that I'm going to need to refine the boost-retard settings further because If I rip through the gears there is more boost the second time through the rpm range. For example if I'm loping along in 2nd @ 2,000 rpm and floor it I might have around 3 lb. boost by the time I get to 3,000 rpm. If I take it up to 5,000 rpm and grab third I find myself into a lot more boost than I was at the same rpms in second.
Ed(s), and others who've done this sort of tuning... What kind of advance settings are/were you using? My ECU will allow me to subtract from the advance angle at various manifold pressures. I put in a linear boost-retard from 0 at atmospheric to -10 at 10psi. (For example the advance angle at 3,000 rpm and 10 psi would be 27 - 10 = 17 degrees). I really don't know if this is even anywhere near close. (no intercooler)
Thanks for keeping the chatter up. This is fun.
-Ben M.
Posted by: Evill Ed Sep 15 2004, 05:15 AM
Well, I drove it to work today. I'm really liking this boost thing.
But the 'not going past 4k rpm' part got old real quick because that's when thing are just starting to really get fun. If you recall this is a self-imposed limit because I haven't finished converting the fuel pressure regulator with a boost-reference port and the injectors can't keep up past around 4,700 rpm. So tonight after getting home late from work, and spending time with Jamie and Kimberly I went back out to the garage to try to figure out a way to get the broken drill bit out of the fuel pressure regulator adjustment bolt. No joy. So after wasting a bunch of time on that dead-end I scrounged up an 8x1.25 bolt and made a new one (square cut threads and all). This time I drilled it right by making a tooling plate to hold the bolt perfectly vertical. That worked. Bored it straight down the center. I then drilled the head of the bolt to press-fit a piece of tubing for the vacuum hose. So far so good. I got it back on the car and adjusted the pressure to 30 psi. Went to hook up a vacuum hose and the stinkin tube pulled out. Ok, going to have to solder it. Can't believe it pulled out. I had to press it in with an arbor press. Oh well. I need a vacuum hose 'T' anyway (I was going to temporarily steal the line to the BO valve). Tomorrow I'll grab a 'T' on the way home from work, solder the tube into the bolt head and see how it works.This boost stuff is really a new tuning experience. I thought I had my ignition advance curve roughed in pretty good but I found out today that it'll need some more work. I had roughed it in by doing some second-gear pulls from idle to 5k rpm. But what I found out today is that I'm going to need to refine the boost-retard settings further because If I rip through the gears there is more boost the second time through the rpm range. For example if I'm loping along in 2nd @ 2,000 rpm and floor it I might have around 3 lb. boost by the time I get to 3,000 rpm. If I take it up to 5,000 rpm and grab third I find myself into a lot more boost than I was at the same rpms in second.
Ed(s), and others who've done this sort of tuning... What kind of advance settings are/were you using? My ECU will allow me to subtract from the advance angle at various manifold pressures. I put in a linear boost-retard from 0 at atmospheric to -10 at 10psi. (For example the advance angle at 3,000 rpm and 10 psi would be 27 - 10 = 17 degrees). I really don't know if this is even anywhere near close. (no intercooler)
Thanks for keeping the chatter up. This is fun.
-Ben M.
Ben, 1 degree of retard per pound of boost is a good guide line.
I found that I needed to be at 24 degrees for anything over 8-psi. Your system is more adjustable than mine was so you will have to experiment. I would start a little higher, 24 vs 17 and back it down as necessary. Too little timimg is no good either and will cost you power.
Regards,
Ed
Posted by: Mark Henry Sep 15 2004, 06:05 AM
Congrats Ben, nice job!
Are you using a 2 bar MAP sensor?
Posted by: iamchappy Sep 15 2004, 06:35 AM
Ben, have you considered a 5th injector ( cold start valve) that would richen up the mixture. Fire the injector at 3 to 4lbs by a pressure switch.
That is what I did with my setup and found no need to retard the timing more than a few degrees if any even at 9lbs boost.
With the map sensor you have great tune ability but the extra fuel getting thrown down it's throat brings on measurable performance you can feel and detonation safety, this can be easily plumbed into the system.
Posted by: airsix Sep 16 2004, 12:52 AM
MORE UPDATES:
Wow, thanks for all the great tips guys. Yes, Mark, I'm using a 2-bar MAP sensor. Ed, thanks for the info on ignition angles. Wow! Sammy, you are right (more on that in a second).
So yesterday and early tonight I worked on modding my fuel-pressure regulator for a boost-reference port. I got it finished around 9:00pm. It works perfectly. Fuel pressure rises pound-for-pound in synch with the pressure on the reference port. So now I've got 30psi fuel pressure off-boost and up to 40psi when on-boost.
So I set my pressure to 30psi and went for a drive. I had to back-out a whole lot of boost-enrichment I had programmed in before fixing the pressure regulator. I did some low and mid-range off-boost tuning to smooth things out because there was some part-throttle bucking in one spot where it was going rich. Got that resolved and it drives pretty nice now. Ok, time to really get on it. I went to some isolated road (Ha! I remember Sammy talking about his special tuning road. 
) and started pulling some full-throttle runs, watching the WB-O2 and laptop to tweak the boost-enrichement where needed trying to at least get somewhat of a constant mixture. At this point I was just trying to get the mixture at WOT roughed in to between 11.0:1 to 12.0:1 across the whole rpm range because when I started it was all over the place (mostly rich). This process was easy at first, but as I got the mixture closer and more constant the power just started to POUR ON. It was getting harder and harder to tune further because there is enough power now that things are happening too fast to drive, watch the WB-O2, and laptop at the same time. Cool. I've now got the mixture hovering around 11.5:1 under all boost conditions (and around 12.7:1 off-boost). Any thoughts on optimum boost mixtures? I don't figure 11.5:1 is optimal, it's just a target I used tonight to rough things in.
It looks like I might need to go to larger injectors. The Subaru injectors I'm using are now hitting 100% duty cycle at around 5,900 rpm. I might try a few more pounds fuel pressure but that's not going to be a permanent solution. I think that will be easier to deal with than a 5th injector. At least now I can run the engine up to almost 6k rpm under full boost. WOW! I honestly NEVER thought I'd like this 1.7, but I can't deny that I'm having a ball with it now. Sammy, you are so right about the torque curve. I'm used to the power dropping off rapidly above 4,500 rpm, but now it just keeps getting stronger. The higher it gets the harder it pulls! Its really a new experience. (I can only imagine what Chapman's car is like!)
One other thing that was a pleasant surprise - after working the mixtures into the ballpark I started getting boost much earlier. I'm now seeing possitive manifold pressure as low as 2,200 rpm!!!!!!
Ok, it can't all be good, right? The bad new so far is:
1) two small oil leaks (will fix Saturday)
2) choking on the price of synthetic oil
3) burning through a tank of gas this week faster than I can say "YEEEEEeeeee HaaaaAAA!!!!"
Posted by: iamchappy Sep 16 2004, 06:43 AM
Turbo 914's are way to much fun. The air has been cool and damp the past few days, I cant get enough of the extra grunt the engine exhibits under these conditions.
I know what you mean in regards to keeping an eye on the laptop and gauges. My first few runs all I had to watch was a tach, boost and a/r gauge and wasn't able to, when I finally stared at the boost gauge I was seeing 18lbs of boost due to the wastegates lines hooked up wrong. Running at 9lbs made it easier ( 18lbs was just insane ) to catch the readings on the gauges, All I watch now is the tach. Quarl gave me a red led instrument light which I wired into the 7th injector to let me know when it fires. At night I think the cops are on my ass as it floods the whole interior with red light. He thinks they need to be brighter 
Keep up the good work Ben, enjoy the new found toy. 
Posted by: airsix Sep 16 2004, 09:31 AM
Thanks Chapman (or do you prefer to go by "chappy" or Loyal, or...?)
I know this is just a meager 1.7 that is probably only making "2.0 w/ cam & headers" type power, but you have to understand that for 12 years (off and on) I've only driven 80hp 1.7's. Never rode in a 2.0, a six, or any other non-anemic 914. As I've worked on my driving and improved the handling of the car it's made the power issue all the more frustrating (the better I made the car handle, the more gutless it felt). I know this little turbo isn't going to set any land-speed records, but it's so much more enjoyable to drive now there's absolutley no comparison. Guys with warmed-up 2.0's might be thinking "big deal", but it's all relative. I've been underpowered for so long that I feel like I've been let out of a cage.
-Ben M.
Posted by: fiid Sep 16 2004, 11:43 AM
Aye, Ben,
Do you live at any kind of Altitude?? It strikes me that you may not have even been developing 80HP if you are at a few thousad feet. The turbo will also provide atomspheric compensation for you :-).
Seriously cool that you are realising actual performance gains. Do you have a GTech or something that you could get a quantitative read from?
Posted by: airsix Sep 16 2004, 12:15 PM
Do you live at any kind of Altitude?? It strikes me that you may not have even been developing 80HP if you are at a few thousad feet. The turbo will also provide atomspheric compensation for you :-).
Seriously cool that you are realising actual performance gains. Do you have a GTech or something that you could get a quantitative read from?
Nope, no altitude here. I'm at only 550 ft above sea level. I can't imagine driving a 1.7 where I grew up (5,000ft ASL = 75% power x 80hp = a scorching 60 hp)
I don't have a G-tech, but I do have 2 things that might get us some real numbers. A few years ago I bought the "road dyno" software that lets you record a sound file off your ignition pulses and plots a torque/hp curve based on your inputs (final drive, gearing, tire diameter, frontal area, etc). I had a heck of a time trying to get a clean enough recording though. Now that I'm running electronic ignition I might be able to get it to work. Recording the electronic ignition with a digital cam-corder should be clean.
The other option is that I've got the rpm cable for the LM1 wideband sensor. It will log rpm over time and dump the data to excel. If I knew the math I could extrapolate hp/torque from that using the same inputs as the "road dyno" software. Anybody care to give me some tips on that front?
I'm still going to try making a video of a run so you can see/hear it. I took my Dad for a ride (he drives a 300zx) and he got a real hoot out of it. "Do it again, Do it again!!!"
Now he wants me to turbo his pickup and he's eying a supercharger kit for his 'Z'.I'm having a great time with this, but in the back of my mind I can't help but think about the Subaru motor you're working on. That gives me goosebumps.
-Ben M.
Posted by: lapuwali Sep 16 2004, 12:20 PM
How much boost are you running? I thought you'd said somewhere you're running 10psi, but you also say you think you're getting only 30% more power. 6psi should give about 30%. For 10psi, 50% sounds closer to the mark, unless you also substantially lowered compression to get it to run 10psi of boost w/o an intercooler. If the internals are stock (which it sounds like they are) and you are running 10psi, then you should be getting something close to 120hp, which is pretty damned impressive.
Posted by: airsix Sep 16 2004, 01:52 PM
I used Ray Hall's turbocharger calcualtors to estimate the power. What I did first was put in the bore, stroke, # of cyls, max rpm, compression ratio, and ZERO boost. Then I adjusted the volumetric efficiency number until it showed power output of 80 hp. That was my "stock" baseline.THEN I added boost to the calculation to get my hp estimate. If I recall it showed 114-116hp (no intercooler and my WAG for the compressor efficiency). With intercooler the estimate jumped up to 145hp. So, it looks like I've got to figure out how to get an intercooler working!
I figured the 116hp was a "best case scenario" so I said 110hp. I don't exepct anything to come out as good as the calculations since this is all home-spun by some dope with a hammer and a welder.I checked my datalog and the wastegate is keeping boost at 1.621 bar, so I'm not at the 10lb I stated. It looks like it's closer to 8.9-9.0. I haven't rigged up a boost controller so it'll stay at that level for now. I might leave it there permanently. The engine might be living on borrowed time as it is. Giving me a boost-knob to play with might not be wise.
-Ben M.
ps - Some kid in a Mazda-something heard the BO valve this morning on the way to work and tried to get me to play. Too bad I'm more mature than that and just ignored him. (Ok, I really REALLY kicked his ##s, but don't tell
)
Posted by: cha914 Sep 16 2004, 02:09 PM
UUUUMMMM...
1.62100 bar = 23.5106173 pounds per square inch
I hope that is a typo...or I am real interested to see how long this motor lasts
Great stuff, keep us posted!
Tony
Posted by: airsix Sep 16 2004, 02:27 PM
1.62100 bar = 23.5106173 pounds per square inch
I hope that is a typo...or I am real interested to see how long this motor lasts
Great stuff, keep us posted!
Tony
Nope, not a typo. Remember, you are breathing 1.0 bar right now. Add 9 pounds to that and you've got 1.621 bar.
-Ben M.
Posted by: lapuwali Sep 16 2004, 02:55 PM
MAP is 1.6 bar, not "boost". You're running 0.6bar of boost. Terminology can be confusing. Interesting calculations. I was basing my 30% number on what other cars have done with a 6psi non-intercooled supercharger or turbocharger on the dyno. However, you're right in that the VE for a Type IV is actually fairly low. A 1.7 should make a lot more than 80hp unboosted. 50hp/liter is 1950s level efficiency, and most of the figures I was using for comparison were at least 1980s level efficiency.
I wonder how much improvement there would be in increasing exhaust flow, a known sore point on the Type IV. A bit of port work on the exhaust side could pay big benefits, and would probably improve cooling even with the turbo. Still, 110hp is something to be proud of with such a simple setup. You've certainly got me thinking, as I also have just a 1.7, and don't want to spend big dollars on a Big Four, or a Six, nor do I really want to go water-cooled with a Soob or the like.
Posted by: aufaber Sep 16 2004, 02:56 PM
Wow, great job!
You probably want to loose that red oil line asap though, we had two 914's blow that exact same hose. We lost one engine because of it. That hose's out sheathing gets very gummy and soft when hot and just ripped.
i know Jeff had a custom hose made up pretty cheap for the supply side of his Turbo.
-Aaron G>
Posted by: airsix Sep 16 2004, 03:22 PM
Hi Aaron! Actually I've got a real oil-line (hard-line w/ banjo fitting on turbo connected to a section of 12,000psi flex-hose on engine side). The red hose is just a piece of heater-hose I'm using for a lame attempt at cooling the bearing housing. One end is connected to the evap-canister port on the impeller and the other end is connected to the water jacket on the turbo. The engine fan forces a fair amount of air through the hose for what I hope is a little bearing-housing cooling benefit. Yeah, I know. My Dad's response was "nice try".
-Ben M.
Posted by: airsix Sep 16 2004, 05:25 PM
Sorry about that Tony and James. You are right, I should have said my manifold pressure was 1.6 bar, or said my boost was .6 bar. My bad. (I think Tony was hinting to me about my error and it went right over my head).
-Ben M.
Posted by: jkeyzer Sep 16 2004, 05:58 PM
What is the effect of compression ratio on the max. boost you can run? Why are most turbo motors ~7-7.5:1?
Would a 73 1.7 with its reduced compression ratio be better than an early 1.7? I think it's 7.5:1 vs. 8.5:1 or something like that.
Posted by: ArtechnikA Sep 16 2004, 06:07 PM
it's complicated but it comes down to a couple of things. first - it's all about cylinder pressure, and when you start out with a compressed mixture it's like having more mechanical compression.
second - since the supercharged mixture is A Good Thing, and the more of it the better, high compression ratios require small combustion chambers which doesn't leave much room for mixture. with a larger combustion chamber, there's simply more volume in which to cram the air/fuel mixture.
Corky Bell's "Maximum Boost" and Hugh MacInnes' "Turbochargers" are excellent resources for independent research.
Posted by: airsix Sep 16 2004, 06:15 PM
'73 1.7 has 8.2:1 compression, so yes, it may be better suited to turbo applicaitons than a '72, but not by much. 8.5:1 is still plenty low for mild turbo-ing IMHO.
-Ben M.
Posted by: lapuwali Sep 16 2004, 06:18 PM
It's not really the compression ratio that's the problem, it's maximum cylinder pressure, which, all else equal, is higher with a higher CR. Add boost, and you're raising the peak pressure, since the starting pressure is higher. Ultimately, the limit is detonation/spark knock. Lowering the CR lowers the peak pressure on-boost to keep the engine below the detonation limit. The disadvantage to that approach is you also kill power and efficiency off-boost, which is where a street engine spends most of its time, anyway.
Older OEM turbo engines often had low CR as a conservative safety measure. It allowed an idiot owner to put regular gas in the car and not kill the engine completely, just cause enough knock to remind them not to do that again. It also allowed the car to be run at very high ambient temps with the AC on while driving up a steep grade, the worst possible combination. With modern engine controls, spark timing can be retarded and boost regulated more effectively to keep cylinder pressures down while still having a high CR. This kind of thing was hard to do in the 80s, and pretty much impossible in the 70s, so early turbo cars just ran low CR. With a knock sensor, you can control knock pretty well and keep CR and boost relatively high, and still allow an idiot owner to put in a tank of regular on a 100 degree day while getting ready to drive west out of Denver and keep the engine safe by just disabling most of the boost. It's the advent of these electronics that are allowing turbos to reappear in OEM apps after they nearly vanished for awhile. Modern systems are now so good that turbo lag is nearly gone completely, and it's often hard to tell the turbo is there at all.
Ben did absolutely the right thing in getting a programmable engine management system on the car first, and getting used to working with it, before attempting a turbo. He can get fuel and spark set perfectly and responsive to boost w/o too much worry of melting things.
Posted by: Mr_Chu Sep 16 2004, 08:14 PM
Before I comitted to a 6 conversion for my car.. i thought if turbo would work in a 914. I had so many negative responses about it... but damn.. for those who have the 914 turbos, you really proved them wrong. I would have totally went with the turbo system instead of a 6...
But since i have the 3.0 liter 6 waiting.. i have to steer that way..
Posted by: iamchappy Sep 16 2004, 08:51 PM
3.0 - 6 Turbo, if you still choose to steer in that direction Mr. Chu.
Posted by: Andyrew Sep 16 2004, 09:23 PM
Theres no substitute for Cubic inches except forced induction...
Hecks ya when you mix em..
Posted by: airsix Sep 16 2004, 11:04 PM
James, that was some great info about turbo application history. I always wondered how it was that late '90s turbo's like the Eclipse and Supra could run such high boost levels and such high static compression ratios. What you say makes sense.
Thanks for the compliment about my strategy. I'll tell you what, many times over the past 2 years it didn't seem like the right thing. It's been a steep learning curve dealing with the EFI and learning to tune with it. I think the best money I've ever spent was that LM1 wideband O2 sensor. Tuning without the wideband was like taking tests and only being told if you passed or failed, never knowing what you did right or wrong. Using the wideband O2 is like getting your test back so you can see what problems you missed.
I hope others do this sort of project. If anyone else wants to do a turbo-4 I think you could do it very inexpensively with a good junkyard turbo and megasquirt EFI. I am happy with my EFI, but I bought it pre-megasquirt. Is Kit Carson's EFI going to support forced induction? If so, I think one of those two systems would be the way to go if you're on a tight budget (Perfect Power makes some nice mega-feature ECU's if you want to spend a few $100 more). Let's say you go with megasquirt, a junkyard turbo, and an LM1 wideband O2 for tuning (I can't stress enough the value of the LM1). You could easily keep the whole project under $1,000 if you do the fab work yourself. My total cost to date including the EFI is about $750. Megasquirt would have been a couple $100 less. That's cheaper than carbs! Don't underestimate the cost of "the little stuff". After the EFI was on and working it cost another $175 to do the turbo install. Only $50 of that was the turbo its self. $125 was all the little bits and pieces of nickle and dime stuff (hose clamps, fittings, exhaust tubing, etc).
-Ben M.
ps - so what do you guys think? Intercooler or water-injection? (The age-old problem: I just can't think of a practical way to get airflow over an intercooler)
Posted by: redshift Sep 16 2004, 11:49 PM
Holy shit dood, you just made my ultimate puking scenario into a painting!
m
Posted by: Andyrew Sep 17 2004, 12:26 AM
Intercooled and water injected.
Intercooler will work just like an oil cooler, it doesnt NEED extra air flow.. it just could really benifit from it..
A fan would be a good choice... like a 70% throttle switch or WOT switch to turn it on...
Water injection is another safe guard, and for oh 300 bucks your good
Andrew
Posted by: lapuwali Sep 17 2004, 08:37 AM
I'd do an intercooler first, and just lay it across the top of the engine, or across the front of the engine bay. Perhaps do a GT-style all-mesh engine lid to help with temps. If you look at a number of the "across the top of the engine" OEM intercoolers (2nd gen RX-7 turbo, turbo Soobs), they have a scoop to get air in, but no where for the air to GO afterwards. Measurements on the RX-7 setup showed the scoop could basically be closed off with no real difference. Airflow would be nice, but just the intercooler itself will help. Ducting more air into the upper engine bay is (and should be) something to do, anyway, and can be done w/o ugly scoops visible from the outside. Adding one would cost much less than $300. There are lots of junkyard intercoolers out there, from any number of Japanese turbo setups. Some are pretty small, too. If you wanted to get quite fancy, you could try to obtain (or even fabricate) a water/air intercooler. Build a watertight box around a regular air/air intercooler, and circulate the water with an electric pump to a small radiator (oil cooler type) mounted more into the airflow. One possible place for it is directly in front of the engine, below the front shelf. You'd catch under car airflow (which is considerable), yet be in front of all of the exhaust heat, and no having to carve up a trunk or run really long hoses.
Water or alcohol injection always seemed like a drag-racing hack to me, and I think is mostly suitable if you're running really high boost for short spurts. An intercooler will improve VE some, and should allow a modest boost increase. 12psi with good VE should give you 150hp or so, which I'd think would be plenty from an elderly 1.7.
Posted by: andys Sep 17 2004, 10:42 AM
Older OEM turbo engines often had low CR as a conservative safety measure. It allowed an idiot owner to put regular gas in the car and not kill the engine completely, just cause enough knock to remind them not to do that again. It also allowed the car to be run at very high ambient temps with the AC on while driving up a steep grade, the worst possible combination. With modern engine controls, spark timing can be retarded and boost regulated more effectively to keep cylinder pressures down while still having a high CR. This kind of thing was hard to do in the 80s, and pretty much impossible in the 70s, so early turbo cars just ran low CR. With a knock sensor, you can control knock pretty well and keep CR and boost relatively high, and still allow an idiot owner to put in a tank of regular on a 100 degree day while getting ready to drive west out of Denver and keep the engine safe by just disabling most of the boost. It's the advent of these electronics that are allowing turbos to reappear in OEM apps after they nearly vanished for awhile. Modern systems are now so good that turbo lag is nearly gone completely, and it's often hard to tell the turbo is there at all.
Addition to the history:
The '63 and up (not exactly sure of the start date, but that should be close) Corvair Corsa had only a pressure retard diaphram on a Delco mechanical distributor. 6 degrees retard is what I recall. Carburetion was a side draught Rochester single barrel ahead of the turbo. No waste gate. CR was I believe 8:1 with open chamber heads, and a nitrided crank;the later Corsa's were making 180HP. This, on a '60's vintage air cooled motor. They were fast with a few easy mod's.....'65 Corsa with wrapped exhaust, and a two barrel down draught carb on an ICO manifold, and this thing was as fast as an stock early Z28. Ran El Mirage at 131MPH in a standing start one mile run; that was in '68 or '69.
The '63 Olds Jetfire had an aluminum 215 cu. in. 215HP V8, 10.25:1 CR, and 8 lbs boost. It too had a Rochester side draught carb ahead of the turbo, but with an elaborate alcohol injection system. Dash pot on the trottle plate kept it from snapping shut under declleration to keep from pulling down the turbo and avoiding pulling oil through the carbon seal on the impeller shaft. Featured a water cooled impeller housing, and a differential pressure waste gate. It was manufactured by Air Research. I ran one of these set up's on a six cylinder '69 American. A friend owned the Jetfire, and it was really quick in it's day (it was what was considered at the time, a compact car). Had AC, no knock sensors, no electronic boost or timing controls, and no detonation.
Lots of other turbo stories, but this will do for now.
Andy
Posted by: lapuwali Sep 17 2004, 11:08 AM
All very true, but in 1963 the gasoline coming out of the pump wasn't 85 octane fuel with a 10% alcohol content, and they could run the thing at 10-11:1 AFR w/o altering any smog police, as they're weren't any.
GM fooled around with turbos in the mid-60s (and were pioneers largely forgotten today by some who think it was Porsche and BMW who brought turbos to the street in the 70s), but they'd given up on them for a very long time, not to reappear on gasoline engines until the 80s, and even then I can only think of the GN. American Iron is not my subject. It's also interesting that it still took 25 years for turbos to appear on cars at all, since they were first developed in aircraft applications before and during WWII. Perhaps they were still classified post-war (they certainly were during it).
The history of turbos on production cars is an interesting one, with lots of ups and downs. Big hit in the early 80s, then they died off again for awhile (partially replaced by superchargers), and are now making a comeback.
Interesting you should mention the '63 Olds engine, since that's the Buick/Rover V8 so beloved of many Brit-car fans. All aluminum pushrod V8 of modest (by American standards) displacement that was very light (less than 300lbs). If it would fit, it would probably be an excellent 914 engine.
Posted by: andys Sep 17 2004, 12:16 PM
Well, the quality of the gas is certainly a factor. That 11.5:1 Z28 I mentioned would be tough to find gas for these days, no question. Turbo's didn't take in the '60's because big cubes were by far a lot cheaper to produce than were high tech high HP small motors. If you notice, that was the evolution back then (US cars). Turbo's re-appeared in an effort to bring small (fuel) efficient motors to a higher HP/performance level.
The '63 Olds had different (and better) heads than the Buick version. The only reason the Buick heads became popular as a retro on the Olds, was that they had smaller chambers (Buick used dished pistons) and you could get way more compression for cheap. Another reason the Buick got attention, was that it was easy to swap the dished pistons in favor of the Olds flat top's. Consequently, the Buick was more popular amongst the backyard hotrodders. Notice however, that the racers of the day tended to use the Olds motor. It really was a sweet power package. The NA 215 V8 four barrel motor was rated at 195HP.
As a 914 swap, these were somewhat popular early on....maybe someone here can chime in with who made the adapters. In the mid '70's, the woman that cut my hair had such a 914 with the 215 aluminum V8 motor (her husband built it, and she occasionally drove it.......I still have the vision of that car; it was a green '73).
Andy
Posted by: aufaber Sep 17 2004, 06:44 PM
ps - so what do you guys think? Intercooler or water-injection? (The age-old problem: I just can't think of a practical way to get airflow over an intercooler)
Air-Water intercooler...
http://images.earlyapex.net/Jeff%20Turbo/mvc365f.jpg
Posted by: ArtechnikA Sep 18 2004, 04:01 AM
http://images.earlyapex.net/Jeff%20Turbo/mvc365f.jpg
Jeff never did post any delta-T numbers on that, long-term or short-term, so i must remain skeptical on the implementation.
water/air intercoolers certainly can be made to work -- 934's and early 935's had them...
Posted by: airsix Sep 18 2004, 09:48 PM
UPDATE:
I got mixture and advance angle squared away today and started paying some attention to other things. Did a WOT blast from a dead stop through tripple digits and logged the data from the ECU. Intake temps hit 158 degrees F (ambient temp was 76 F). How much do you think I could knock off that number with an average-ish intercooler? 2 years ago when I got the turbo I also picked up an Eclipse intercooler I have not installed. I'm still trying to figure out how to get some air over it once I put it on the car. I'll try to figure something out this week. I'll keep you posted.
-Ben M.
ps - Sammy, I'm glad you commented about Turbomania - I didn't realize it was dedicated to vw forced induction. I always assumed it was about turbo's in general and didn't know it was focused on aircooled vw applications. I'll have to get a copy of that one.
Posted by: Mueller Sep 19 2004, 09:06 AM
congrats Ben....I'm jealous..
according to Corky Bells book, water-injection is a "band-aid", and that you must have something wrong with the system if you need to use it...the biggest gripe I have with his statments about it is that he does not go into any detail why.....I do know that the water will displace air/fuel which is not a good thing powerwise
here is a link with some more information from a company that favors water injection
http://www.rbracing-rsr.com/calculations.htm
Posted by: airsix Sep 20 2004, 09:15 AM
Hey Mike,
Hope you had a nice vacation. Don't know if you've really got anything to be jealous about - YOUR daily driver has more than double the power! It's fun though. Much better than before.
-Ben M.
Posted by: Mueller Sep 20 2004, 02:04 PM
the 911 is an okay daily driver, but I "really" miss driving the 914
I played with the 914 yesterday...had it running good for about 20 minutes then the damn ECU starting resetting itself causing it not to run anymore....the only thing I can think of is that it has something to do with heat...the ECU never got hot and was far away from any heat sources...I don't know, mabey once the coil gets hot it builds up resistance that could be freaking out the ECU signal
I plan on installing the crankfire ignition this week.........
I have another one of those turbos you are using, think you can plumb both of them* and run them in parall using a "Y" ???
*use the one exhaust outlet like you have, but have a "splitter" to drive each turbo and then have the compressed air meet up again...let me know if you want to try it, just pay for shipping and it's yours to borrow
Posted by: airsix Sep 20 2004, 02:56 PM
Wow, great info Sammy!
Mike, I forgot to warn you - you are going to need to make a heat-sink for your wideband O2 sensor. Just cut a 4 or 5 inch square of copper plate, drill a hole in the center just large enough for the sensor threads and then bend two sides up at a slight angle. (This is per Klaus @ inovate) Then sandwitch it between the sensor and the bung. I did this and all is well now, but without the heatsink my sensor was freaking out if I was hard onto the boost for more than a few seconds. I'd get "Sensor Timing Error 08" and have to reset the controller, but with the heat-sink installed now it's fine.
-Ben M.
Posted by: lapuwali Sep 20 2004, 03:22 PM
If it is heat, I'm thinking it's more likely to be heat from the board itself. You say the ECU never got hot, but what about the individual components? If the processor gets too hot, it will reset. If the injector drivers are getting very hot, they may be driving up the temperature of the processor.
Are you running resistor plug wires or resistor plugs? Still have the case open on the ECU?
I'm in the middle of assembling my MS. Perhaps trying a different unit might help pin down your problem. Once I manage to get it completely assembled (still have to hunt down some parts that didn't show with the order), I can bring it by and we can see if it also has the same problem.
Posted by: Mueller Sep 20 2004, 03:42 PM
Ben,
yea, I've seen the copper heatsink in the docs of the LM-1...where is your O2 reader mounted? It is "behind" the turbo correct?
James,
My resistors for the injectors do get hot, but they are a good 2 feet from the ECU, I have not checked the ECU components for excess heat, I'll try that next.....yep, ECU is still "open" but there is nothing around it so I don't know how a cover could help......like I mentioned, it starts fine if sitting for a day or so and runs great for about 20 minutes before the VE table resets itself
Posted by: lapuwali Sep 20 2004, 03:59 PM
I meant the FETs powering the injectors, which should be mounted directly to the MS board and may get fairly hot. The resistors limiting the current to the low-impedance injector should get hot, and should be mounted far away from the ECU.
Having the cover off means you're exposed to electromagnetic interference from the ignition system. The same thing that causes static on the car radio if you don't run resistor wires and/or plugs can cause havoc with any computer system. Every component on the board, esp. the metallic leads on things like resistors and capacitors, will act like a tiny antenna and pick up the EMF coming off the plug wires. A metallic case will help shield the ECU from this interference.
When you see the reset, you see the VE table is empty (or scrambled)? Hmm. Do you have to re-upload the VE table to get it to work? This is ringing a bell. What *should* happen in a simple processor reset is that it will simply boot again, and copy the config data from FLASH to RAM, and it runs out of RAM. When you edit the tables, it just edits the RAM copy, and when you "save", it's copying the data from RAM back to FLASH. A reboot will literally take milliseconds, so you'd normally have a hiccup while it's booting again, but then it will keep running after it's re-copied the FLASH data to RAM (which will have been erased during the reset). If you see the copy in FLASH going away, then the processor is somehow corrupting or clearing the FLASH. I seem to recall this being a known problem that's been fixed with newer code. I'll have to do some reading on the MS boards to see if I can find this again...
Posted by: airsix Sep 20 2004, 09:23 PM
Yep, it's down-stream from the turbo. A good 2 feet behind it. I thought that would be far enough down-stream not to need the heat-sink but it wasn't.
-Ben M.
Posted by: Mueller Nov 11 2004, 05:50 PM
Hey Ben...it's me again asking questions
what did you do to mate the turbo plumbing to the throttle body?
do you think you are loosing any boost out of the bushings for the throttle shaft?
Posted by: airsix Nov 11 2004, 08:36 PM
what did you do to mate the turbo plumbing to the throttle body?
do you think you are loosing any boost out of the bushings for the throttle shaft?
Hi Mike,
I'm not using a stock TB. I pulled one off a turbo Chrysler (it's a Holley) that was sized right - just 2mm larger than stock. It's nice and tight, so no leaks. Nothing fancy on the plumbing. Just tubing and a rubber coupler at each end. Made a little 'T' midway between turbo and TB for the BO valve, which is just attached with clamps and a stubby piece of hose.
I'm using the stock runners, but I modifed the plenum. I cut and reformed my plenum to point the TB straight up (stock 1.7 points to the driver's side). I did that so it was easier to plumb from the turbo to the TB. I also made a flange for the new TB and welded it to the plemum in place of the stock 'cone'(over the top of it actually).
-Ben M.
Posted by: Mueller Nov 11 2004, 08:42 PM
when you ran your LM-1 for setting up your tables, did you data log all the inputs or just RPM, MAP and the O2?
thanks for the info....you da man
Posted by: airsix Nov 11 2004, 10:45 PM
Definitely not the man, but thanks.
When tuning with the LM-1 I only datalog rpm and mixture. I don't have it set up to log throttle possition and map. I'm too lazy. I can also data-log from the ECU to capture temps/TPS/MAP/RPM/timing/injector-dwell. Then I just eyeball it against the LM1's rpm/mixture log. If I wasn't so lazy I'd integrate them but at this point there's not a need. Mixtures are good and the car runs great.
I had all my tuning done (except on-boost enrichment) before adding the turbo. So, when I added the turbo it was real easy to add enrichment on the possitive side of MAP. That part was a piece of cake actually because the only thing I had to change from my NA map was add boost retard on the ignition table and add boost enrichment on the possitive side of the MAP table. Everything else stayed the same and it runs great.
So, you getting close? Sounds like it.
-Ben M.
Posted by: Brad Smith Nov 12 2004, 08:53 AM
Run a turbo off of each side... Cyls 1,3 & 2,4
have a look at the sizing and the firing order before deciding this is a good idea ...
Yup. If you were doing a twin turbo you would want to pair the front as one pair and the rear as another. The turbo will respond better if the pulses are even.
Brad
Posted by: Brad Smith Nov 12 2004, 09:17 AM
Water or alcohol injection always seemed like a drag-racing hack to me, and I think is mostly suitable if you're running really high boost for short spurts. An intercooler will improve VE some, and should allow a modest boost increase. 12psi with good VE should give you 150hp or so, which I'd think would be plenty from an elderly 1.7.
This is wisdom. Listen to him. Being an RX-7 guy, I can tell you that the scoop does almost nothing- it's actually located in a low pressure area, so the low pressure is trying to suck air out, while the direction of airflow is trying to push it in. Not much airflow through the doggone thing.
Note that, based on some tests done of airflow and cooling capacity, one of the best intercoolers that can be had cheaply is from a turbo Supra. Not so great for that big six when they pass about 400 hp, but great for the stock levels of the Supra and a little beyond. You aren't planning on over 300 hp are you? They're cheap and relatively easy to find. They also are not monsterous in size, and they're easy to plumb and mount.
Put on the "GT style" engine lid (that is what it's called, right? The one with twice as much grill area) and stick it in the front corner out of the way. Use an electric fan that comes on under boost. (Use a pressure sensor to trigger a relay- or just forget the electric fan. It doesn't take as much airflow as you think... you aren't cooling the whole engine, just the intake charge. A dinky little electric fan that some cars use on the air conditining (like the late 80's RX-7 for example) should do nicely.
Here's a Supra intercooler auction on ebay:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7933619562&category=46096
Note that this is the Mk III Supra that I'm talking about, not the later model ones. Current bid is $41. They commonly sell for $100 to $200.
Here is a website comparing flow numbers for various intercoolers from production vehicles, and compared against 1 Spearco core.
http://www.gusmahon.org/html/cooler%20test.htm
Note that the Supra core fared VERY well, as it didn't have much restriction internally OR for cooling air through the core.
Cheap intercooler tubing? http://home.earthlink.net/~turbogus2/cooler.html
Note that the author of this website is deceased. (go to the main page for info on that.) Many of you may have seen the "mean mini" sub-13-second minivan- this is the page for that guy.
Good luck, and I hope this is helpful.
Posted by: soloracer Nov 12 2004, 11:04 AM
I've seen video clips of that mini van. Pretty impressive to watch a soccor mom van from the 80's taking down a newer style camaro. Too bad about Gus though. Doesn't seem right sometimes the way things go.
On the intercooler side I bought 2 Porsche 944 Turbo intercoolers. I'm not sure of their flow rates as compared to those in the charts Brian posted but they are a sturdy bar and plate unit and I believe they are good for 400 hp each as well. They are shipped more like a brick than a tile so their mounting positions would be different. Some RX7 guys have used them as well. I'm thinking of welding these two together and having custom end plates made. I just have to find a good place to mount them now. I'm thinking somewhere in the rear trunk and have the air "dragged" through them as opposed to front mount where it is rammed through. The exit venting would be either out between the tail lights or the trunk floor. Here is a pic of one sitting on the floor underneath my car. Don't use the tires for size comparison - they're a little bigger than stock....
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Posted by: Brad Smith Nov 12 2004, 11:36 AM
Nice pic... makes me feel like singing...
"I like big butts and I cannot lie..."
oops, I mean rapping.
What flares are on there?
Posted by: airsix Nov 12 2004, 01:54 PM
http://www.gusmahon.org/html/cooler%20test.htm
Note that the Supra core fared VERY well, as it didn't have much restriction internally OR for cooling air through the core.
Cool. Thanks for posting this info. I've got the little Eclipse/Tallon IC that he tested. (not on my car yet)
-Ben M.
Posted by: Mueller Apr 15 2005, 06:29 PM
doing "research" for some odd reason 
and thought I'd ask if you installed the IC yet???
Posted by: iamchappy Apr 15 2005, 06:35 PM
Then theres my idea for the intercooler using fans and a fresh air source.
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Posted by: iamchappy Apr 15 2005, 06:36 PM
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Posted by: iamchappy Apr 15 2005, 06:37 PM
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Posted by: iamchappy Apr 15 2005, 06:41 PM
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Posted by: airsix Apr 15 2005, 09:33 PM
| QUOTE (Mueller @ Apr 15 2005, 04:29 PM) |
| doing "research" for some odd reason and thought I'd ask if you installed the IC yet??? |
Hey look. A thread back from the dead.
Nope, no IC yet. I've been totally consumed by other non-914 projects since November. Hopefully sometime this summer I'll get around to it. Keep us posted on your project. Looks VERY interesting.
-Ben M.
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