74 Turbo Project

[Henry Schmidt]

We finally completed the 74 Turbo project we've been working on.
What a sweet ride.
3.0 non intercooled, twin plug turbo.
Supertec twin plug distributor w/ BurnBros Marelli conversion
Taylor wires custom made
935 pistons
911 SC cams
SUPERTEC head studs
38 mm ports In and Ex
K27
B&B headers
1 MSD 6Al triggering two Blaster II coils.

On the test drive we made .1 bar of boost @ 1800 RPM climbing my hill.
Full boost of 1.0 bar @ 3400.
No dyno sheet yet but what fun.

[eddie914]

Henry,

Very, very nice!

Eddie

'71 914/5

[89turbocabmike]

Nice Henry, I love seeing that 12 plug dizzy tucked in there. I see one in my future

[Shuie]

Nice!

Henry, would that fit under a stock flat deckild? 9 or 6 bolt crank?

[Henry Schmidt]

This engine would fit nicely in a narrow bodied, no tail car.
Sleeper?
The engine was custom build using a 1980 911SC core. 9 bolt crank.

[Shuie]

Originally posted by Henry Schmidt
Sleeper?

Yep, thats what I was thinking. thanks for the quick response.

[obrut]

henry

firstly, nice work (as always)

secondly, was there a specific reason for not using an i/cooler (classing?)

[Henry Schmidt]

First, we know turbos perform better and safer with an intercooler. That said here are the reasons.
We were trying to make 350 hp not 400+
No need for a turbo tail. sleeper
Something different.
Cool looking.
Reduced turbo lag.
This engine under load starts making boost at 1800 rpm.
Try that with an intercooler.
And the main reason we chose not to use an intercooler was that I have built several of these in the past and they're just great fun to drive.

[iamchappy]

Henry I am having my 79 3.0 SC engine rebuilt, I fabricated and turbocharged it and am using it in my 914. I added an intercooler to it and was planning on boosting it to 11lbs. I am using the stock cis and a 7th cold start injector for enrichment.
I use a MSD BTM for ignition retard with the SC distributor. K27 turbo, Tial bov and wastegate.Everything has worked very well at 9lbs without the intercooler.

? What do you recommend for piston and cylinders and compression for my set up, and should I twin plug it.
This is a street car so boost would be as short bursts now and then 350 to 400hp will be plenty for my joy rides.

[obrut]

henry: thanks for the explanation - fun ride!

[dean]

Originally posted by Henry Schmidt

This engine under load starts making boost at 1800 rpm.
Try that with an intercooler.

Just for *****s and giggles I wanted to see where my motor starts boosting.

I was in 4th gear at 1500 rpm and I booted it. At around 1800 rpm I saw positive pressure. That is my boost threshold.

I also noticed no difference when I installed a large intercooler. I think it is a wives tale that intercoolers increase lag. Kinda like the internet rumor that the G50 weighs 100 lbs more than a 915

If you think about it. The increased area in an intercooler is small and the turbo moves a TON of air. Hence no increased lag

Dean

[KobaltBlau]

Hi Henry, just found this. What compression ratio and cams did you use for this? thanks in advance.

[iamchappy]

Henry, Please let us know when the twin plug distributors are available.

[Henry Schmidt]

Originally posted by KobaltBlau
Hi Henry, just found this. What compression ratio and cams did you use for this? thanks in advance.

7.5 to 1 with 911SC cams.

[QUOTE] Originally posted by iamchappy
Henry, Please let us know when the twin plug distributors are available.
The conversion distributers are available now. Look on Ebay

[iamchappy]

Henry, do you have any recommendations as to pistons and cylinders to fit on a 79 SC engine. I would like to run up to 11lbs of boost with an intercooler.
With all of the options out there right now I cant decide. What would you fit and would you increase the displacement.

[Henry Schmidt]

The 74 project used 935 pistons and 911 SC cylinders.
I'll check my stock if you would like.
We have also built a few engines using 3.3 turbo piston on a 3.0 crank. It requires some rod modification but it is a reasonably priced option to make your engine larger. These engines turn out to be something like the 935 IMSA 3.12 liter. Those silly things made over 700 horse with IMSA legal booth. 1.4 Bar?

Just checking but do you have an exhaust (header system) or intercooler yet?
I have a 914-6 turbo header and intercooler for sale. If you might be interested I'll post pictures.

[iamchappy]

I have everything under control as far as plumbling. I like the idea of replating my existing cylinders and fit them with the 935 pistons, please do let me know if you have any nice ones and PM me with a price.

[Mr Beau]

Is there any boost retard built into the distributor?

[Henry Schmidt]

The distributor has both mechanical and vacuum advance so when the boost comes on the vacuum goes away retarding the timing

[Mr Beau]

So at 0 bar and 1 bar the advance is the same?