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Posted by: ConeDodger Jan 29 2015, 07:13 PM

I had lunch and hung out with McMark and the Original Customs crew today and an interesting subject came up...

We've all heard the old joke about how you can't turbocharge a 914. In reality, it's been done many times. Mostly badly, but it's do-able. McMark's own car is a 1.7 turbo he built as a proof-of-concept and his build has worked so well, he practically daily drives it!

I know most of you have no reference for what I'm about to say but I'll try to explain; driving a 2270 stroker TypeIV is a great big bowl full of fun. The flat torque-curve means you don't have to shift all the time, just put your foot down and go. No lug, just grunt! Driving McMark's 1.7 Turbo is like driving a 2270. That, and when I have driven it, it was only at about 6# of boost or less. Turn that up, and you've got a serious screamer on your hands...

His execution is about the best I've ever seen (as per usual Original Customs fare). Yet, having very nicely proven the concept, McMark has only built one other turbo engine. What gives? You guys don't like the idea of a turbocharged 914?

Let's discuss this...

Posted by: SirAndy Jan 29 2015, 07:20 PM

I think McMark should sell a bolt on turbo kit that fits stock engines and runs with low boost for reliability.

Posted by: Garland Jan 29 2015, 07:23 PM

Posted by: ConeDodger Jan 29 2015, 07:36 PM

that's a good idea!

Who wants one? Group buy?

Posted by: thelogo Jan 29 2015, 07:42 PM

I have my doubts about turbo and reliability in the same sentence


And a lot of guys have gone turbo , Subaru turbo w r x + s t I


But I assume premium fuel is required


And didnt the designers of the McLaren f1 specify that only a n.a engine could be used

And said that turbos were undesirable due to ,heat , complex ity , nonlinear delivery of power+accelerated wear and tear etc.

Posted by: thelogo Jan 29 2015, 07:50 PM

Here we go and I'm not against turbo ing

My dad had a 3000gt v r 4 and what a smoking engine pure launch power wow

And I love the noble m12 ,British sports car with Ford turbo v6 ??? Why




Gordon Murray insisted that the engine for this car be naturally aspirated to increase reliability and driver control. Turbochargers and superchargers increase power but they increase complexity and can decrease reliability as well as introducing an additional aspect of latency and loss of feedback. The ability of the driver to maintain maximum control of the engine is thus decreased. Murray initially approached Honda for a powerplant with 550 bhp (410 kW; 558 PS), 600 mm (23.6 in) block length and a total weight of 250 kg (551 lb), it should be derived from the Formula One powerplant in the then-dominating McLaren/Honda cars. When Honda refused, Isuzu, then planning an entry into Formula One, had a 3.5-litre V12 engine being tested in a Lotus chassis. The company was very interested in having the engine fitted into the F1. However, the designers wanted an engine with a proven design and a racing pedigree.

Posted by: thelogo Jan 29 2015, 07:53 PM

Mcmark I think from what I 've heard around here

You 've got proven designs and pedigree

Posted by: ConeDodger Jan 29 2015, 07:59 PM

Actually, this is the point. McMark daily drives his. At least in his design, you can say turbocharged and reliability in the same sentence. His design is installed on a tired old 1.7 that he had hanging around the shop. We're talking about an engine he has counted on to get him to work for a couple years. Reliably. It's even been to WCR in Oregon I think? And not on a trailer. He it there!

Posted by: SirAndy Jan 29 2015, 08:07 PM

Your 3 posts can be summed up in one simple sentence:

You missed the part where we've been talking about low boost ...

Posted by: thelogo Jan 29 2015, 08:30 PM

Lower then the fan charger that blows 1-2 bar of air in the intake ...But is only activated at full throttle ..


Heard about it hear also

Posted by: McMark Jan 29 2015, 08:39 PM

The difference is that an electric fan charger is bullshit, and a turbo is real. I push around 6-7psi of boost. I've put thousands of miles on the motor and while I've made tweaks and adjustments, I haven't dealt with any major issues so far. Actually, lets be clear, I haven't dealt with ANY issues so far. I just keep trying things because for me this is a learning project. I have to try new things and keep changing things so I know what works and what doesn't.

Next step, adjustable boost control. I'd like to try out 12psi, which is still relatively low boost.

I'd also like to clarify, that this isn't a veiled attempt to sell more motors or turbo kits. Rob and I were talking, and I suggested that I doubted if anyone would ever buy a turbo motor or kit from me. Which is perfectly acceptable. But Rob was surprised, as are a few other people I've talked to, but I'm not sure why there is so little interest.

Posted by: Black22 Jan 29 2015, 08:42 PM

He did indeed drive it to WCR in the Dalles, OR.

I saw it with my own eyes.

Posted by: McMark Jan 29 2015, 08:47 PM

That was 2 days after I fired it up for the first time.

Posted by: ConeDodger Jan 29 2015, 08:56 PM

Yup... I'm stumped. I just don't get why people who want to stay 4 cylinder aren't trying this proven method. It's absolutely as tame as the original 1.7 with an evil (reliable) secret.

Posted by: SirAndy Jan 29 2015, 09:01 PM

If i still had a /4 i would certainly be interested!

Now, can we talk about a twin turbo setup for my 3.6?

Posted by: Krieger Jan 29 2015, 09:18 PM

Mark let me drive his car more than a year ago. It moves very very nicely! There is no way in heck you'd think that is a 1.7.

Posted by: iamchappy Jan 29 2015, 09:18 PM

Just drop a 930 engine in it and your good to go.


Attached image(s)

Posted by: jim_hoyland Jan 29 2015, 09:28 PM

Haven't there been some off-the-shelf turbo kits in the past; perhaps a current member or two remember.

Posted by: McMark Jan 29 2015, 09:32 PM

Yeah, there was at least one. It stopped being produced for.....


Lack of interest.

Posted by: warpig Jan 29 2015, 09:49 PM

I rode around in it for the parade laps. SUPER FUN
Thanks McMark

Posted by: oldschool Jan 29 2015, 10:00 PM

OK I want one

Posted by: G e o r g e Jan 29 2015, 10:08 PM

The only "kit" I can remember was the one Jake Designed , built and tested, but when the 5K bolt on upgrade was announced. the interested parties disappeared.

I need to look over at your build thread to see Pictures of the install, I'm assuming no cutting involved in your setup?

At the right price a kit makes perfect since , when you can pick up running 1.7 and 1.8 motors quite cheap bolt on the kit and go. and have 140hp + or -

Posted by: Chris Pincetich Jan 29 2015, 10:12 PM

I'm saving my $$
I can go turbo after I fix about 10 other things.
...which keeps depleting the $$.

The pics I saw looked like a pretty short run from turbo, intercooler, and intake was achieved. I have a "EuroRace" header, and have seen turbo pics of this design, but with the turbo at the end of the 4->1 collector. That run seems longer than what McMark built.

The kit would likely have an ECU and coil on plug, so costs are not insignificant.

Keep up the great work

Posted by: messix Jan 29 2015, 10:14 PM

so how could this be adapted to a L-jet 1.8?

what would be scrapped and would be saved?

what would run this as far as ign and ecu f/I?

could this be used with ssi 1.7 h/e & bursch collector ?

how much do you project this "kit" would cost?

Posted by: rick 918-S Jan 29 2015, 10:15 PM

Mark, Post a link to your thread. I think we need a refresher.

Couple things I'm not sure are in your thread. Did you ever dyno test it to see what the old 1.7 is putting out now? Are you happy with where the project is now? And have you ever thought about what a kit would run? And what could a guy expect to get in terms of hp from a stock engine with a low blow kit?

Posted by: Mueller Jan 29 2015, 10:32 PM

You need to get out more.....tons of factory turbocharged cars that have driven hundreds of thousands of miles are still being driven..daily...I have one! Tons of aftermarket turbo systems installed and driven everyday!

Our daily, a '98 Volvo T5 high pressure turbo...not one single part of the turbo system has failed and it has close to 170K miles on it...

Gee...the McLaren P1, you know one of the most bad ass new supercar uses 2 turbos!

An all out race car like an F1 cannot be compared to a street car, you look silly even trying it...oh yea, the newest F1 cars are turbocharged by the way

Anti-turbo people either never owned one and heard "stories" from other owners that are hack mechanics or if they do own a turbocharged car, the failures are from a bad/hack owner/mechanic.

Posted by: McMark Jan 29 2015, 11:17 PM

I used the following:
A core 1.7 engine with good compression, but not new by any means
My microsquirt FI setup with coil on plug.
A KKK K03 knockoff turbo
A setrab intercooler
Custom exhaust built using 1.8 'log style' exhaust

It's a bolt in setup, but only reuses cooling tins, and intake path (throttle body to heads).

I haven't dyno'd it, but I can tell you the HP numbers would be deceiving. It's the torque from a turbo that makes it fun. A quick spooling, low boost turbo makes boost almost instantly and so the turbo doesn't 'come on', it just drives like a big motor.

I am completely happy. Like I said previously, I don't need to change a thing, but I'm gonna keep tinkering.

These setups are a lot of work. Expecting something in the $5k range is appropriate. But keep in mind that with this setup you're getting modern fuel injection, not just HP. Spend $5000 on a 2056 and you still need to make the engine run (exhaust, ignition, fuel). This setup kind of takes the engine out of the equation. Modern, reliable FI. Coil on plug. And turbo. In a setup that you can swap from motor to motor.

More details- http://www.914world.com/bbs2/index.php?showtopic=211954

Posted by: Mueller Jan 29 2015, 11:26 PM

I've read all of Marks thread as well as Ottos(?) and Ed Morrows threads from way back, always liked the idea of a turbo Type IV

Some rambling thoughts:

Pros:

There are few proven designs to take inspiration from.

For fuel and ignition control, Megasquirt has been proven to be reliable and very cost effective..have more money to burn, opt for a different EFI package.

eBay bought Chinese turbochargers have been proven to be cost effective and work.

Used turbochargers can be found for not much money.

Seems like there should be no reason a turbo kit should require cutting into the chassis so that if one wants the car could easily be turned back into stock

Cons:

No dyno runs..people want to see before and after results...at least an after result!

The market for a turbo kit is getting smaller all the time....it seems people are removing their Type IV and doing some other conversion on a weekly basis..

If based on the 1.7 d-jet, 1.8 people will have to source some different parts which will increase cost and frustration.

Not everyone wants a programmable FI system, if it could be truly plug and play that might ease some folks concerns.

eBay turbos again...not always reliable even for a brand new part, a few car mags have seen gains of 40 or more HP by swapping out the ebay/Chinese clone turbo for genuine brand turbo all things being equal.

Used turbos are used...lots of choices and nobody wants to buy the wrong part. Luckily it is an item that can rebuilt without too much investment.



******************************

I'd like to see more cars done, and depending on price I might be interested in such a thing since I already have a megasquirt (2 of them actually)

Posted by: ConeDodger Jan 30 2015, 12:47 AM

wait... You want to take evil fast and see what it feels like squared?

Posted by: ConeDodger Jan 30 2015, 12:50 AM

You sir will need a note from your doctor saying it's ok before McMark can take your deposit!

Posted by: ConeDodger Jan 30 2015, 12:58 AM

When I wrote the original post for this thread, I was just wondering out loud why there wasn't more interest. Seems there is at least some. This concerns me...
My car is number 11 on the Original Customs project list. I don't want that to slip back

So, move along folks... Nothing to see here.

Posted by: ThePaintedMan Jan 30 2015, 07:24 AM

I would definitely consider a turbo from McMark if offered in "kit" form. I have access to a few 1.7s and 1.8s and the cost to rebuild one as stock is one of the reasons why I'm considering going to a Suby - more power with modern features for about the same (if not less) money. McMark's turbo setup would offer a similar, albeit a little less power alternative for folks. And the BEST part is even if you did blow up the motor, you can swap in another $300 1.7 or 1.8 and transfer over all of his components and be back on the road in a weekend.

Do it Mark - I dare ya!

Posted by: Mark Henry Jan 30 2015, 07:51 AM

And I'd have to say you are right. They would never sell in the numbers needed to make the investment of buying stock. To bring the cost down you would have to sell a bunch of sets to get a break on your costs. You risk the chance of being stuck with systems that do not sell, at least not fast enough. A $5K price point you will only get a few takers at best. The 914 and Type4 is market is waining, the new generations don't want a car they want an iphone.

Another thing is you are having success because of the 1.7 smaller head bore. If you were to offer a kit it would be short order before someone mounted it on an unsuitable engine. If the power level is not enough then they will crank the boost. When it failed they would blame you personally.

Yep I'm being a downer, but I think Mark already knows these points just by his statement.

Posted by: bulitt Jan 30 2015, 08:02 AM

Most Diesel Locomotives pulling trains have turbos. They run for millions of miles and have a useful life of decades. Ok, diesel, I get it. But extremely reliable.

Posted by: rdauenhauer Jan 30 2015, 08:50 AM

CON: No Heat!

Posted by: mbseto Jan 30 2015, 09:49 AM

This really sounds like getting at least some benefit of an engine swap without doing an engine swap. Plus I get to keep some originality to the car. Staying air-cooled has some appeal to me (if I understand this, it just adds an oil intercooler?). Sounds like there's still some question as to whether this would be less money than a swap or comparable... Contingent on that last question, I'm interested...

Posted by: gryphon68 Jan 30 2015, 09:59 AM

You could skip the Premium and go straight for the E85 tune . . . .

The philosophy of cars has changed quite a bit in the last two decades since the McLaren F1. See the new P1.

Add batteries and an electric motor for even more heat and complexity. It seems to fix the whole non-linear power delivery with electrics providing "torque fill" while the engine catches up to the demand of the little pedal on the right.

Posted by: McMark Jan 30 2015, 10:11 AM

Working on that.

Posted by: r_towle Jan 30 2015, 12:51 PM

marty built a kit back in the day and if I recall from the pictures it was hanging off the stock heat exhangers to keep the OEM heat in place.

There is a paper article about it that someone posted up here at least once showing marty in his sandles working under the car.

I think his kit was at something like 4-6 lbs of boost.

Mark,
Do you have a simple way to cut a notch in the cylinders and heads for a piano wire, ala the 930 for sealing it?
Rich

Posted by: monkeyboy Jan 30 2015, 12:55 PM

One I get my Microsquirt up and running it is next on my list.

I want to throw a wrench in things and hang and Aerocharger off the end of my heater boxes. I know it's a bit more money, but it's oil less.

Posted by: r_towle Jan 30 2015, 12:58 PM

what are the pro/cons of either a jenvy throttle body, or modifying the intake manifolds to accept injectors (like SirAndy did)

Seems getting the injector closer to the valve would be better in the long run....just curious if anyone has evidence.

rich

Posted by: oldschool Jan 30 2015, 01:12 PM

yup

Posted by: oldschool Jan 30 2015, 01:25 PM

OK with all of the smart pep's that hang out here someone could maybe help Mark out with this project.....maybe a special GB to get the ball rolling.

Posted by: Philip W. Jan 30 2015, 01:46 PM

even though i am on the east coast, i am seriously considering this, and i too am amazed that more would not consider it. i have a 2.0 and am very interested in seeing this on a 2.0(1911) rather than building a 2270. i know my motor needs a refershing and would seriously consider shipping it out there to be done. or maybe a cross country drive...... the plane ticket home would be about the same as the shipping cost i suppose;

Posted by: euro911 Jan 30 2015, 02:14 PM

Posted by: nein14 Jan 30 2015, 07:31 PM

Mine has been driving and reliable for 10 years and thousands of miles

Posted by: Maltese Falcon Jan 30 2015, 08:44 PM

Rich, you had to bring up the sandals...like Hot tub time machine
And you can't turbocharge a 911 either !
It only took the factory some years honing their boosty knowledge on their force fed 917 program , then applied it to their flagship=930.
Meanwhile in the 70's there were 3 go to shops for 914 turbos: Crown , MSDS and AK Miller ent.
Crown was mail order only, MSDS was mail order / turnkey installation, and AK Miller was installation only. The first 2 shops used Rajay FB40 Rajay turbos, Miller was a Garret air-research shop. Everyone had their favorites. We built MSDS bolt on kits until the late 1980's
In this photo circa 6/76, for VW Greats magazine our 2.0 turbo (7psi) is standing in the Irwindale (real 1,320') sand pit. In the foreground is the first 930 (magazine car) into the USA. The editor Jay Amestoy could not catch us in that car. Turns out the 930 waste gate was faulty in its open cycle, not able to catch the 914 running @ 15.4 / 95 mph in the quarter.
Marty

Posted by: thelogo Jan 30 2015, 10:06 PM

Just saying f1 is faster ,lighter

Middle seat position , real clutch

Supposedly worth 10 x more then p.1

And yeh I do need to get out more

At a car show recently a guy had a twin turbo old ads
Chevy pick up , thing ran like a p-38 lightning

Gordon Murray insisted that the engine for this car be naturally aspirated to increase reliability and driver control. Turbochargers and superchargers increase power but they increase complexity and can decrease reliability as well as introducing an additional aspect of latency and loss of feedback. The ability of the driver to maintain maximum control of the engine is thus decreased. Murray initially approached Honda for a powerplant with 550 bhp (410 kW; 558 PS), 600 mm (23.6 in) block length and a total weight of 250 kg (551 lb), it should be derived from the Formula One powerplant in the then-dominating McLaren/Honda cars. When Honda refused, Isuzu, then planning an entry into Formula One, had a 3.5-litre V12 engine being tested in a Lotus chassis. The company was very interested in having the engine fitted into the F1. However, the designers wanted an engine with a proven design and a racing pedigree.[6]

Posted by: thelogo Jan 30 2015, 10:21 PM

Don't increase my tension

http://lQzTLEzU6e4

And can you can you clarify exactly what effect Turbo supercharged ing has on compression. As in low compression , low boost ,high octane And huge intercooler

Is that the kind of combo that works well together ???

Posted by: Maltese Falcon Jan 30 2015, 11:45 PM

Barrel to cylinder head flame rings, there are matching machined grooves cut into both cylinder heads and barrels . These were made at Aasco Machining. Ive held 21 psi boost with this set up.This design can be applied to the type 4 as well,

Posted by: Maltese Falcon Jan 30 2015, 11:56 PM

Compression ratio chart, or:
What happens to your total CR
(yield) when applying forced induction to your static CR
Sorry for the old scan quality

Posted by: jim_hoyland Jan 31 2015, 07:51 AM

Is MSDS going to revisit this product for a 914 ?....

Posted by: Mark Henry Jan 31 2015, 08:22 AM

At what point do you have to twin plug the turbo engine?
In a N/A six once you hit over 9.5:1 CR you are getting near the limit of single plug.
Twin plugging and fire rings would add another dimension to the turbo build.

This gets back to if boost levels are adjustable someone will push the limit, overboost and likely blame the builder.

Posted by: mepstein Jan 31 2015, 08:30 AM

thank you. that explains a lot.

Posted by: r_towle Jan 31 2015, 10:17 AM

I just cannot see that.
Do you have any better pictures of that ring in detail?

Posted by: Mark Henry Jan 31 2015, 10:58 AM

Matching groove cut into head and cylinder, the fire ring is solid.

Posted by: PotterPorsche Jan 31 2015, 11:35 AM

I believe same topic. Not a fan of bernie bergmann but i will give credit to the idea. Used stock heaters
http://www.914world.com/bbs2/index.php?showtopic=202113&st=0

Posted by: Mueller Jan 31 2015, 11:38 AM

Stuff like that is fine for a few one-off installs...it starts to get impractical and expensive.

I guess one could have a "basic" kit for with a max psi limit...

Then have other options for more boost...of course the money to HP ratio can get skewered really fast and it will get hard to justify considering all our other options if all we want is a certain about of HP for the vehicle.

Posted by: Randal Jan 31 2015, 12:06 PM

Moggy, over in the paddock section, has been hard racing (Rally) a 914 4 with a supercharger for years. He had special groves machined into his heads /barrels that seal without any issues. Of course Moggy has done a bunch of other modifications to make it all work, but it does.

Same thing could be done with a turbo, which would make an effective setup and then one could run higher boost levels.

Britain Smith has build a big time Type IV turbo motor for his 912. It works and puts out serious power.

I've thought long and hard about building an effective turbo motor. 300Hp out of a 2.0 would be excellent and would compete with the fast group with SCCA XP, in a 914, but it's likely a nose bleed from the start as no one has done a Type IV before.

FYI SCCA screws anyone using CC to compete.

If I was still going to do it I'd visit CB performance. They've build a huge number of hot turbo Type 1 motors for sand rails, etc. They have the experience and parts, likely a bunch of them adaptable to a type IV. They say 300hp is the low end of output they work with, but guessing this would be on larger motors.

It'd make sense to take Mark down there on the same trip, figure out what could be done, secure the parts and have him do it.

BTW their Type I turbo motors are reasonable.

Hi Mike. Nice to see you back on the forum.

Posted by: Maltese Falcon Jan 31 2015, 03:39 PM

Jim,
My facility has the knowledge, skill and all machinery to put kits together.
I would be in the market to offer any tuning shop/aftermarket parts co., a contract job quotation on a small run (min.25) of their turbo kit specific tubing .Tubing; intake into/ out of compressor, intake charge pipes (including intercooler piping), hot side into turbine (including headers), turbine exit +muffler, waste gate tie-in.
This is about 85% of a kit...the rest is packaging off the shelf items, and a tuning package. Those items would be packaged + provided by the turbo kit seller.
Simple as that
Marty

Posted by: Mueller Feb 27 2015, 03:41 PM

Bumping this back up to move the Subaru swap threads down the page.....

I kid, I kid

A few q's...

Think a Holset HE351Ve is too much for a 1.7? (I just happen to have a HE351Ve sitting in my garage)

If the motor is out already, worth the few hundred bucks for Raceware head studs and case kit for a type IV?

Posted by: Andyrew Feb 27 2015, 05:10 PM

I think thats too big of a turbo. I know its a variable vein turbo, but its just to big, unless you want it to spool late to keep the heat down and not use an intercooler..


The reason I say this is McMark is using a KO3 on his engine and getting a medium spool, say like an 80's turbo.

The guys that are using the Holsets on their similar Audi/VW engines that previously had KO3's are having a spool that is similar to an 80's turbo.

SO if we compound that I think you'll find that the holset will perform like a Big Ass turbo, sure it'll make a PSI or two at 3k but it wont really spool up till youve stood on it for a couple seconds or its way up in the RPM range, where the T4 doesnt do well.

I'd grab some other factory turbo off a 4 cyl. So many of them in the junkyards these days..

You could probably fund it for the couple hundred bucks you could get for the Holset..

Posted by: McMark Feb 27 2015, 08:22 PM

Yup. Keep it small. The 1.7 doesn't breathe a bunch anyway. K03 is instant boost. Just drives like a big motor, not like a 930. I turned up the boost a bit and I'm having input dyno tuned right now. It's so torquey! I really think this will be a great combo/recipie.

Posted by: Mueller Feb 27 2015, 08:54 PM

thanks....I'm missing the hotside on the Holset anyway!

Time to make ad and see if someone wants to do some trading.

Posted by: ConeDodger Feb 27 2015, 10:10 PM

There is no lag at all. Off idle you're in the boost so like McMark said, it feels like a 2270 or bigger NA motor.

Posted by: Mueller Feb 28 2015, 09:12 AM

Never driven one of those...I have driven a what I think was a nicely done 2056 and I really, really liked it, gave me a new appreciation for the Type IV in the 914.

Posted by: nein14 Feb 28 2015, 10:16 AM

my car originally has a K26 from a 944 turbo spooled between 2500 to 3000k lots of top end boost and power. I changed it out for NOS K26 from an audi 5000S spools in 1st gear @ 1800 rpm with 12lbs of boost, fall more in the RPM range of my 2.0 with 94mm P & C's with 1.7 heads

Posted by: 914forme Feb 28 2015, 10:38 AM

"Bumping this back up to move the Subaru swap threads down the page....."

Ha bump us, beat us, do what you want to us, we are the revolution!!!

I don't care plenty of room for all of us!!!

I thought you where keeping this one stock

Oh well I knew better just figured you where only fooling your self with that thought.

Mueller

2270s are a great NA Type-4 engine, the 2056 and 1911 are a sweet set of engines also if done correctly. I loved my last 1911, spun up like crazy made a great auto-x engine and not bad on the street either. But if this 12psi 1.7L feels like a 2270, you will be pretty darn happy until you feel the need for more.

Then welcome to the dark side of the force

Posted by: Dave_Darling Feb 28 2015, 11:29 AM

Hey, Mike--you might want to get the car actually running first....

--DD (calling the kettle black)

Posted by: ConeDodger Feb 28 2015, 12:30 PM

Posted by: ottox914 Mar 2 2015, 08:49 AM

Check out the build threads in my sig.

Get a snickers bar. This could take awhile...

When I did my turbo project, I had 2 goals. Use as many parts as I already had to keep costs down, and keep the engine running cool.

Phase 1 was to turbo my stock 2.0 motor. It already had SDS efi, ITB's, and a kerry hunter exhaust, so all that was to be re-used on the turbo motor. I got my hands on a used 13b turbo off a mitzu 3000gt. On paper, a perfect match for my goals of low boost and fast response. I mounted it on the back of the collector for the KH exhaust. This would keep the heat of the turbo system out of the engine compartment, and keep the intake air to the engine, as well as the cooling air to the engine cooler. There seemed to be 2 schools of thought on exhaust systems. Corky Bell supported equal length headers if you had the room, for better exhaust pulsing to the turbo, and there fore quicker response, and a log style manifold if space was tight. The 13b turbo was a turd. I rebuilt it and it was still a turd. Wouldn't boost beyond 5-6 psi, and all of that at 5k rpm.

A 13g turbo off a subi 2.0 wrx was sourced. Much better. On paper, the bigger turbo should have been a worse choice, in the real world it worked. Response was linear, smooth, and fast. I had a giant intercooler from a wrx mounted between the ITB's, and with that, intake air temps at 10psi were never more than 20 degrees or so above ambient air temp. Monitoring cht, egt, and oil temps/pressures, all were reasonable for driving around, after a good pounding all would be more elevated more than I would have liked, but all returned to "reasonable" very quickly.

So that set up was SDS, with ITB's, KH header, 13g turbo off of a wrx, BIG intercooler with a custom plenum and puller fan, oil cooler with thermostat and fan system, and lots of gauges to keep track of it all. The tune was done by me on the backroads of WI, running around 14.7 afr at steady throttle, dropping to 12.5 under boost, and going a bit lower than that at WOT. The set up was never dyno'd. All this at 8-10 psi or so, as I recall.

I had parts that worked and proof of theory. Now time to ramp things up. After a bunch of consulting with Jake and Len, a new motor was devised. Again, using as many parts as I could from what I already had, I built a 1835, which was the GA case, 2.0 crank, rods, and 1.7 cyls with custom JE pistons to get the right pin height. I already had the case, crank, rods, cyls. Len took some core 1.7Q heads and did his magic. Pistons were ordered, along with a cam Jake thought would work well for the application. The thought process was the smaller bore would seal better, the better cam and head flow would make up for the smaller displacement, and I'd have a motor that would hold 20 psi if I wanted to throw that much at it. My goals were 12-15 psi at 2000-2500 rpm and 7k rpm redline. For autox, I'd rather not have to make the 2-3 shift any more than needed, so more rpms = more speed in 2nd before the next corner.

I built the motor, broke it in, and put some boost to it. Below 3500 it was quick, above 3500 it was scenery blurring fast. Not exactly what I was looking for in an autox motor, but still very much fun. I tried the 13b turbo, still a turd. Back to the 13g. More experiments with tuning, changing timing, AFR's, plug temps, more boost, less boost, still it was a 3500 rpm motor. Tried a 3rd turbo, I don't recall the designation, I think it was a VF 11 or something. Size wise, it was between the 13b and 13g. It performed like the 13g in terms of when it would spool up, but made less boost at top end. On the positive side, with the cam and heads that had an 85% intake to exhaust ratio, the motor ran very cool. Oil temps, cht, egt all were VERY reasonable and super stable. I was convinced I had a cool running motor that would last, I just needed to find the right turbo. So overall, a little disappointed that while I was getting closer, I wasn't there just yet. No dyno on this motor either. This motor was not babied, running 12 psi and 7k rpm every time I turned the key.

Then the money shift. A friend was driving the car while I was tuning, he was WOT 3rd gear, so 13-15 psi or so and somewhere between 7-7500 rpm. I set the SDS to shut down the party at 7500. Heads should have been good to 8k. He shifted from 3rd to 2nd and that was it. The motor is now in parts. Len has the heads back to me. He thought they had been over heated due to the condition of the metal and seats. Based on my observations of egt, cht, and oil temps I don't see how this happened, but his real world observations vs my glance at the gauges, likely it did.

What have I learned. On a turbo 914, heat is the problem, and whatever you can do to control that is job #1. Had the car not been money shifted, 7k rpm and 12psi+ of boost might have been asking a bit much in the long term. The deeper you go in the rabbit hole, the crazier things get. If you are going to turbo a 914 you will need some aftermarket ECU, larger injectors, and exhaust. "Conventional" wisdom on how to size a turbo to this motor is nearly useless. All the books and internet info on turbo sizing told me the 13b was perfect, the 13g to big. 2 valve heads, air cooled, crappy exhaust port flow, lame stock cam, who really knows what the VE is on one of these old things, trial and error was a better tool to pick a turbo with. ITB's made this harder than it needs to be, but thats what I had on hand and was set up to run. E85 would be an additional layer of safety for tuning and keeping temps down.

If I were doing it again: MS was in its infancy when I started this, I went with SDS as a proven, simple solution. I'd consider MS now that it is more mature. I'd go with a single throttle body, on an OEM plenum and runners to keep that part of the deal simple and cheap. While on paper, using the late "log" style factory exhaust, as McMark did is not optimum, I'd give it a shot. I have those parts on hand, and strongly considered it, but went with the KH exhaust. I'd build in as much intercooler as I could, big injectors, and run e85, which may be easier for me in the midwest than for others out there. For the motor, i could go either way, 1.7 or 2.0. Would probably depend on the turbo. No replacement for displacement. I don't think i'd try to push the boost beyond 10-12 psi with out more of a specialty build on the motor. With a stock motor I'd stick with a stock redline. We are doing this to have some fun here, and blown up, broken down, in the garage is not the kind of fun we're looking for, right?

Posted by: Mueller Mar 2 2015, 09:12 AM

Thanks Dave,

I've gone back and read your thread and have watched all your 914 related youtube videos...thanks for the reply and input.


The car currently has a megasquirt (installed on a 2.0 bus motor with 0 compression on cylinder #3 according to the PO)

It also has a unknown header similar to the European Race header.

I have the $ saved up for a 1.7* that McMark has, while a bigger motor would be nice, the price for a decent 2.0 has given me sticker shock!


*supposed to be low miles on a professional rebuild by another shop.

E85 option is out, closest station is 15 miles away in a direction I hardly ever travel so that would be a pain (1 hour round trip due to the traffic some hours of the day)

Posted by: falcor75 Mar 2 2015, 09:32 AM

I've toyed with the idea of turbo since before I bought my 914 two years ago.
Living in "Saab town" Trollhättan in Sweden turbo cars has been the daily thing all my life. Staying with a thickwall cylinder engine sound good. I would just like McMark go with a small K03 turbo or similar sized Garret T25 unit from a 150hp Saab 9-3 (98-02 cars) The K03 kinda runs out of puff over 180 hp but that would be more than enough in our light cars. (I built a 850 kg Mk1 Scirocco with a k03 20v engine and it was fast enough.) Running E85 would be a no brainer too but it would need the tunnel fuel lines upgrades to stainless ones.

I'd love to see pics of your coil on plug setup....diving into your thread now to search.

Posted by: Andyrew Mar 4 2015, 02:50 PM

You could do what the modern FI turbo guys do and run a mix... E30 does a lot... Grab 5 5 gallon containers and fill it up every couple months..


But then there is also W/M injection... I loved it on the 944 turbo. And it kept the cylinders nice and clean.

Posted by: toon1 Mar 4 2015, 11:05 PM

Next thing you know, you'll have someone flaring the fenders for ya!!!...lol

Posted by: veekry9 Mar 5 2015, 08:01 AM

Oi,give us a hand.Grab that shovel.


TurboJet

Jettrain
https://www.youtube.com/watch?v=g4AyytkpiB0


A state of the art ambition,so many quid.

Posted by: BSACafe Feb 19 2016, 02:20 PM

Yup....I'm digging up this thread from a year ago.

McMark...are you still thinking of possibly putting together a turbo kit? I for one would certainly be interested in a reliable kit, and it seems reliability had been achieved over a year ago. Any updates?

Posted by: jmill Feb 19 2016, 02:51 PM

I wasn't into this idea until I started looking into rebuilding my 2.2 six. Prices are absolutely insane! Everyday the turbo option looks more attractive. I even have a 1.7 to base a build off of.

My main roadblock is that I have no knowledge of FI, turbos, programing, crank fire and all of the other mumbo jumbo that would make this thing tick. There's quite a learning curve involved.

I'm also concerned about the heads. How much do I need to do to them to keep them alive and what's that going to cost me?

Posted by: ConeDodger Feb 20 2016, 02:35 PM

When Mark did this, I silently said to myself, 'why, with all the parts you have on the shelf, would you go with a 1.7?' Then, I drove it.

Oh my...

Posted by: BSACafe Feb 22 2016, 12:18 PM

McMark...how many people would need to be signed up for a 'group buy' for you to put together a kit? I'm sure there would be interest out there, especially with the sheer number of 1.7 owners. Mine is a '73 and very much like the option of a bolt on kit, rather than other swaps that require a more permanent modification.

Posted by: McMark Feb 22 2016, 12:46 PM

Mine is built on a 100% stock 1.7. The idea was to make the engine 'disposable'. Also, the idea was to keep the boost low and be happy with a little extra.

I'm happy to make the setup. It's more a factor of the cost. Fuel injection with coil-on-plug ignition is about $3000 complete, turbo and plumbing is around $2000. Each unit has to be hand made and setup. I don't have any jigs or other fancy tools to help speed up the process. If I thought I might sell 10+ of these it might be worth it, but for the number of people I think might actually buy-in it's easier to just hand make them.

Posted by: Mueller Feb 22 2016, 06:22 PM

What is nice with the turbo setup is that I see no reason someone couldn't do it in stages to help with the cost...do and sort all the fuel injection/ignition 1st, drive car around for 6 months or a year then buy the turbo hard parts and install.

Posted by: euro911 Feb 22 2016, 08:06 PM

...

Posted by: r_towle Feb 22 2016, 09:06 PM

Ok,
Please post the shopping list for the EFI first.
Currently the junkyards are closed due to snow, but will open up soon enough.

Rich

Posted by: McMark Feb 23 2016, 08:03 AM

You're not wrong, I just am not set up to handle any (albeit small) volume of retail sales. Selling a $10 part takes me away from billing shop time. Now if I can grow the business a little... I could then sell packages and individual pieces.