I dont think rain hats are your issue, I run them and mine doesn’t run out of breath.

My carb setting notes-
• 38mm vents
• 160 mains (give 12.8-13.4 afr wot max, @68f air temp) , (170 mains give 12.0-12.6 afr WOT)
• 190 air
• F11
55 or 60 idle, 1.76mm IAC


Its a 3.2,dc40 cams, 9.5:1 comp, a very similar motor with slightly larger headers made ~255hp at the rear wheels which comes out to around 290hp crank.

I think there is something fundamentally wrong, spark plug wires crossed, timing way off, maybe the po installed stock 3.0 heads, cams going flat or valves need to be adjusted... or something wrong with the carbs and they are dumping too much fuel.

Been off the forum a couple days ...

I don't see anything fundamentally wrong with the setup. Sure, jetting could be off a bit, rain hats sit close to the stacks. I'm sure things could be optimized, but these things aren't costing you 100 hp. I agree with Justinp71 that something more fundamental is way off. I think taking the car to an experienced Porsche shop to do some tuning may get to it. It may be worth looking at some basics to see where things may be off. Ignition is an easy one to check - I can't recall if you mentioned what the timing is, but maybe check it with a timing light. Maybe check the spark strength with one those spark tester gizmos. Could the muffler be plugged up somehow? Monty is supposed to be a decent muffler.

What do your spark plugs look like? I was using my AEM mixture meter for tuning my carbs. What I didn't realize was that my O2 sensor was toast. My spark plugs told a different story than the air fuel meter.

Oh, I dynoed my 3.0 with and without the water shields. Back to back runs. 10hp at the top end only. One day I may switch to the ITG style or do my own thing.

Only got 1/2 day in the car today, I have an appt to take it to Aase Motors in mid June, so I wanted to look at some of the other issues plaguing the car.

Font bumper off and brakes bled.... bumper is too tight to body work, hood overlaps the edge, so I gotta put some spacers or find some dog bones to offset. Front left didn’t bleed, looks like I’m rebuilding a giant caliper... that appears to be the hanging noise I heard on track.

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Wow! Those brakes are huge!

Started to take things apart, realized after removing pads that one piston was slightly stuck (turns out it was really low on fluid) I got it loose and started looking at the bleeders themselves. Both were crudded up. Poked a needle in there and cleaned them out with carb cleaner, then reinstalled and bled out the remaining old fluid, worked great!!! No more embarrassingly loud squeak every time I touched the brakes! This should put some confidence back into my braking on track. Drove her around a bit and got some gas. AFRs are not that far off... still feels pent up, I know she wants to go fast....

Cool. Did you check the firing order is good? What was your afr at WOT?

I’m dropping off at Aase tomorrow, hopefully some answers shortly…. If anything it’ll help me reach a baseline.

Cool!

Does your car stay cool on the track? I had to open up the front of the body alot more than you to keep my temps down, but I am also running the stock GT front oil cooler.

Also how is your rear suspension setup? do you like it? Mine seems a bit soft and feel like the trail arms move some. I'm probably going to do the Rebel racing rear bushings like I did in the front.

one cam is 180 out of time,,,

Car keeps its cool so far, but without proper shrouding it appears it is really inefficient. If I make it to Fontana in aug, that’ll be the rapture test (last year it was 114 in the pits). So far my gauge is telling me the hottest it’s gotten Ian 100 deg C (212F). If I close up the hood though, I’d bet I don’t have enough exit area in the floor…

Suspension seems ok, tires are old Toyos, they seem a bit unpredictable, but prob cause they are aged out, right now these are the last of my worries, I’ll replace with new A052s when I’m ready to be competitive. I’ve got rubber bushings still (I think) but coil overs front and rear, a big sway up front (none in back) it’s a pretty stiff ride.

Funny thing is it runs pretty neutral, with a much different setup than my old narrow body race car, I guess that’s what tire width does for you.

Funny you mention this! Jeff at Aase thinks it’s a timing issue as well, but he thinks it’s due to flywheel marks being off 30 deg - but I think that was before he knew I have a vellios 915 in there.

Cool. I've noticed to me it seems when you go from 205's to 225's in the rear the car does become more neutral, but there are obviously many factors that play into it.

Also consider the BFG Rival 1.5S tire, I'm not saying its better because I don't really know but I'm running them now and they are gripping great and have great wear so far. Only 2 track days on them, but I also drive the street and drive to the track.

Cool you have coil-overs in the front. I've heard that gives more options for spring rates, amongst other things I would think.

Got a great report back from Aase this afternoon, timing was off a bit. Timing at idle was set at 8-9 deg adv, then at 3k up to 25-26 ish, then from 3k-8k was retarted back 7-8 degrees for total advance of 17-18 deg. So he pushed it back up to 26-28 deg and he said it definitely woke her up. So next step is to pick her up, continue tweaking/driving, then take to dyno for final tune. No carb changes, he felt I had her in a good spot. At least I was on the right track….

Not sure he found 100hp, but I’m hoping he woke up at least another 50hp. We’ll see what the butt dyno says tomorrow.

Well that is good. That should really help the throttle response too. Get a plate on it so you can test it on the street! Should be super easy since its smog exempt.

It does have a plate, I drove it from the shop to work, then home, unfortunately traffic kept me from opening her up much, but she now breaths easily past 5k rpm.

Time for some tweakimg!

Cool! So when is the next track day?

Not till early August, CA speedway in Fontana. Should be a hoot.

@Justinp71

How are you tuning your carbs? For some reason the voodoo of “listening” for the sweet spot is lost on me. Since going to Aase, my car runs much better, but I still feel there’s much left on the table with some tweaking.

I have an afr logger I’m going to set up this week and I’ll post results for thought/comment here.

Any additional thoughts are welcome, but not expected till I get some data posted.

I went thru the PMO notes and checked for proper float levels, fuel pressures and then the air balance between each throat. Then I just do the idle adjustment how PMO describes where you go to each carb and look for the highest idle.

Once that was done I did some runs to WOT at different air temps and just looked down and recorded the different AFR's. Then adjusted my main jets appropriately. I had gotten initial carb settings from somewhere that were close, I just needed to change my main jets in the end.

In some temps (typically cooler) it runs perfect. When a little warmer it has a few flat spots, but I think that's typical. I'm actually working on installing the X faktory throttle bodies soon, but if I had a dedicated track car they would be unnecessary.

Some helpful tips-

http://www.pmocarb.com/installation_print.htm

https://www.pmocarb.com/Images/Instructions-3.pdf

AFRs will be a great guide to tune. The basic process Justin mentions sounds about right.

Thanks, I’ve just been overthinking it. Haven’t had a chance to install my LM2 for logging. I’ll post graphs when I do…

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OK first graph, should be showing both left and right banks, but my LM2 was glitching and only recorded the right side bank. Regardless they're closely matched at the moment.

- Leaning out at higher RPMs
- Rich at cruise

I'll try a larger main jet and take another run...

AFR's probably go down when you shift from the extra pump on the acceleration pump circuit. Yes def need larger main jets, which makes sense for that beast of a motor. That will help make it feel like its not running out of breath on the high end. Looks as your cruise rpm came down to 4k then the idle afr came closer to 12:1 which afaik is as good as it gets for carbs. The problem with 3-4k cruise is the idle circuit and main circuit are typically both on for a smooth transition so cruise afr is always rich.

Increased Main jet from 140 to 150. Looks like that might have done the trick. Thoughts?

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Current Carb Setup:

46 ida Italian Webers
Venturi/Choke: 42
Main Jet: 150
Air Correction: 170
Emulsion Tubes: F7
Idle Jet: 50

Cool, alot better What's the butt dyno's opinion on the new jetting? I'm surprised how lean the low end is, does it transition good from idle circuit to mains?

All in all she feels good, no transition issues or flat spots just pulls nice though 6500, I’m carrying a lot of speed and making a lot of noise at that point so I don’t venture any higher. I’ll be out at ca speedway in early aug, there will be a dyno, so I’m going to try and get her dynoed before it gets too hot out there.

Still working on hood pins to keep the hood down, but will be looking at alignment next…

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Can’t really tell you why it took a whole day to put 2 of these on…

In for tech with younger brethren….

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Headed to small Cars & Coffee tomorrow with a few buds, we’ll see what other hardware shows up…

Cool! Making progress... it will be interesting to see how the next track day goes.

The 718 is cool, you probably have more cylinders than him!

Favorite seat, Recaro SPG! I got it a hair lower and my arms a bit further from the steering wheel as I hoped. Also got some room putting the car in 2nd gear, old seat would touch shifter. All while still using stock sliders.

I know this seat is more comfortable than the Cobra, I was in and out of both seats several times, I couldn’t stand being in the Cobra more than 20 min or so. I fell asleep in the Recaro… a few times

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A few shots from C&C, sorry not much variety in shots, my buddy’s GTL and another’s speedster , both have new motors and we’re out for a quick test before loading up for Monterey Historics.

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CA speedway in Fontana this weekend, let’s see if she’ll hit 150!

Anyone want to venture a guess on dyno numbers?

I’m going to say just under 200 at the wheels…

Shoot you better be over 260hp, this 3.2 is what I modeled mine after and its 253hp at the wheels-

http://forums.pelicanparts.com/porsche-911...fore-after.html

Thanks, keeping my expectations low. I have no idea how she’s going to perform on the track. So much different feeling than my 930. I think it has alot to do with my alignment setup…. 930 is light and nimble, power delivery is an explosion though…. My narrow body race car (blue hood) felt very light , almost formula v light on 205s…. Was set up well. This car feels piggish… heavy, slow to rev (at least prior to last tune). I don’t like caymans pulling on me in the straights…. I’ll report back after first session….

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Glad to hear you like the Recaro SPGs - I just got a set as well, about to replace some really old Cobra Suzukas that I actually like quite a bit too but are well expired and grungy.

Fun weekend, learned a bit more about my car. The bad news is with the motor, as expected, way low on power, dyno’d at 164 hp/189 tq. to the wheels. This jives with the old dyno sheet I found in the PO stash.

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Check out how early it makes torque, this explains how I was able to pull out of turn 9 hairpin at CA speedway in 3rd gear when everyone else was complaining about having to go down to 2nd.

Looks like the mixture is getting very lean between 5500 and 6500.

Dang you are missing like 100hp... Sorry to hear your track day was less than ideal.

I would start with a compression check and leak down check. Almost seems like it has an air restrictor plate in it. Seems like to me not much air volume is getting in the motor. Would make sense the cams are out of time, burned valves or cam going flat??? Maybe search on pelicanparts and rennlist to see what you can find there too. Maybe call one of the known porsche engine shops like supertec and see what they think.

Alot of low end torque and low hp points to me as large displacement with low lift, like it has a stock 2.0 cam (like the old chevy motors).

How were the motor temps?

How does it feel heavy? Lots of body roll? slow to turn in?

Justin, you are definitely in the right track. At the track I was able to pick the brain of an ex-andial engine builder. First thing he said was that there was a big restriction somewhere, gotta start looking at the heads. At the time I hadn’t realized I was making all that torque before 3500, but we did chat about the cam timing really only affecting at what rpm the tq hits (I know I’m simplifying and summarizing).

Going to start with what you mentioned and I’ll report back. I already have a private track day booked for oct, so she needs to be back in action by then, possibly just with torque curve moved to a usable rpm…

Temps were hot at the track, up to 107 on pavement per the dyno info. Engine ran a bit warm at 250, I need to shroud cooler.

She handled heavy, but I’m used to my old narrow body car, weights 400 lbs more too. No body roll but I think brakes are dragging again, need another good flush.

I see a few pages back you already did a leak down with good results. Could do a compression check and compare the numbers to other builds? The high torq on the dyno does suggest you probably have decent compression.

Hmm... What is the case number? Maybe he re-used stock small port 80-83 3.0 heads and that is restricting flow? Still should be over 165 hp... It would be good to pull the intakes off and measure the intake ports when convenient so you can get all your motor specs.

Also I think a 964 cam may be a bit mild here, that is a popular mod on 3.0's with fuel injection pistons. Still think it would make more power though. You could also take off your valve covers and measure your lift with a dial caliper. Just make sure to adjust for the rocker ratio if measuring the valve. You could really gain some power with some new DC racing cams, assuming it does not have fuel injection pistons. http://www.drcamshafts.com/911profiles.htm.

I am running a DC40 cam much less lobe separation and more duration, you could do maybe a DC60 or even more??

Are you running merged exhaust pipes?

Ready for drop, ugh, had hoped to get a bit further this weekend than just draining oil…

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Btw, what oil do you like to run? I am thinking of trying VR1 next. I'm on Mobil 1 15-50 but I have a few wet spots on this brand new motor (I like it otherwise) wondering if they will go away with VR1.

What's your plan on the motor, going to go thru it some?

VR1 20/50 changed every other race. Motor runs a bit warm with it, although shrouding around cooler is non existent now. I’ll be changing that. I get some weeping around the rocker cover nuts, but not enough to drip.

I’m going to post up to the PP engine forum, see if anyone can help. In the meantime I plan on dropping engine, doing another leak down - should be fine, but easy enough to do when out (I forgot to do a compression test before I drained the oil). Also will measure lift, maybe see what cams are in there, then finally check cam timing. Cam timing should address the early torque, but I don’t think I’ll find 100 hp there unless one is way off. Earlier, somebody mentioned one cam my be 180 deg off, that would certainly be cause for such a big loss. Will also measure intake and exhaust ports. Get an idea of what is really in there.

Since everybody loves a dyno vid, here are the three dyno pulls from the sheet above:


https://www.youtube.com/watch?v=yXccX_duoEI

What's interesting about your dyno is the horsepower is not going up at all between 3200 and 4500. You can see on this dyno of a 3.2 with bigger cams even on his first lean run in blue he gained alot of power here. Not sure what to make of it, but seems to point to something.



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That is an interesting observation, if you look at my afr graphs I have a plunge (rich spike). During that rpm range, then it comes back into “good” fuel/air territory. Perhaps too much fuel during that period?

Here we go, posted to the bird engine build forum, here’s the link if anyone wants to follow.

http://forums.pelicanparts.com/911-engine-...ml#post11432437

Any comments still welcome here too!

Cool, good place to post it. After building a few flat sixes I am curious as to what they/you find. Rennsport may be another place, not sure I don't go there too often.

Did you find much metal in the oil when you drained it? That could be a sign of a cam going flat, which could also make sense to me.