911SC Turbo

[iamchappy]

Hopefully this Spring I will get some time on the Dyno, I still am using the 901 with short gears and LSD with a Kennedy stage 2 clutch and pressure plate. This is the weak link, My car is mainly a street car and if I am careful it should hold up until i pursue other options.

[otto in norway]

Hi guys!
Bringing back this thread once again...
I have read a lot on this thread, and find it a bit much to take in all this info. GREAT thread, by the way!

I am thinking about doing a turbo conversion on my SC, and have a few questions:

1: From what I understand, the fuel distributor on the early euro CIS systems can deliver more fuel than the US version. Is this correct?

2: If so, how much boost can I expect to run on my '79 euro CIS, before adding a 7th enrichment injector? (I plan to boost apx. 0,5 bar)

3: Is it wise to alter the dizzy curve, just to be sure?

4: What suppliers can supply turbo conversion kits nowadays? (I am aware of Promotive, but not sure if they deliver for my engine)

5: I recently rebuilt my engine. It now has 9,8:1 CR, and 964 profile cams. How will that go along a turbo? (I probably need to replace the pistons, right?)


Otto

[spuggy]

Originally Posted by otto in norway

Hi guys!
Bringing back this thread once again...
I have read a lot on this thread, and find it a bit much to take in all this info. GREAT thread, by the way!

I am thinking about doing a turbo conversion on my SC, and have a few questions:

1: From what I understand, the fuel distributor on the early euro CIS systems can deliver more fuel than the US version. Is this correct?

Only for 930 fuel heads, and only when unmodified. Modified US 930 fuel heads will flow more fuel than modified 930 RoW heads, according to Imagine Auto.

2: If so, how much boost can I expect to run on my '79 euro CIS, before adding a 7th enrichment injector? (I plan to boost apx. 0,5 bar)

Don't run a 7th injector, don't even think about using the cold start valve. The CIS plenum isn't designed to have fuel in it. If the fueling system will support it, you should be fine with an adjustable WUR, ideally with boost enrichment.

3: Is it wise to alter the dizzy curve, just to be sure?

Sure, why not. J&S are making an adjustable CDI box with knock detection that seems really promising too.

4: What suppliers can supply turbo conversion kits nowadays? (I am aware of Promotive, but not sure if they deliver for my engine)

Swing over to the 930 forum or PM Ben (mb911). He was sourcing/making the NLA parts for the old BAE kits for a while there.

5: I recently rebuilt my engine. It now has 9,8:1 CR, and 964 profile cams. How will that go along a turbo? (I probably need to replace the pistons, right?)

I have 8:1 static C/R with 12.5 PSI with a modern turbo and a good intercooler (both of which substantially reduce charge temps). I run the best gas I can find, and regret not twin-plugging while it was apart.

That's probably just about as far as you want to go on single plug without ready access to 100 (US, e.g. RON+MON/2) octane gas.

This graph might help you:

[otto in norway]

Thanks!
I read about the guy who started this thread, wich had a 7th injector on the turbo outlet. He had been running that setup for 65000 miles, no problems. (If memory serves me) That's why I wondered about the 7th injector.
I guess this is not a good solution for longevity.

So I think I'll just have to wait a few years before I can afford a reliable turbo setup. I'll start with buying sports heat exchangers, then EFI, then pistons, and then TURBO..! (Over a couple of years)

I guess I can survive that, after all I will upgrade performance a bit with the two first mods...

[laughac]

Just had an AFR meter installed... now I'm going to play with CIS mixture for a week or two before having the turbo bolted in...

[laughac]

Still trying to get the PLX AFR meter to work properly. It has been returned twice now for going dead. Will let you know if it was a good investment if it ever works reliably! Spent about $600 on it and it's integrated boost gauge.

[laughac]

PLX didn't like my system.

[ArtMaybee]

ok, I've been lurking on this site for quite a while but haven't posted before today.
Everyone seems to have problems with finding the bonnets needed for the turbo kits.

Below is a link that shows how you can make your own if you'd like.

DIY Custom Silicone Couplers - DSM Forums

[gngrbreadman]

its been years in the making but this thing finally drives just in time to sell it anyone who,s interested can contact me at 631-392-0992 arty or on1wheel750@aol.com its a 73 looks like a 89 930 cab turbo inter-cooled 3.0 runs and drives, needs some minor finishing and love has alot of money and time invested

[laughac]

Got my turbo installed and am making some shakedown adjustments before installing an intercooler that will make everything harder to reach.

[carslutt]

good info, hope u get it dialed in soon id like to see some #'s

[iamchappy]

Ive not joined in on this thread for awhile. The only problem i have been having outside of a few oil leaks is my clutch slipping, the stage 2 Kennedy pressure plate clutch package will not hold the horsepower with much more than 10 or 11lbs of boost, i just purchased a Kevlar clutch from Renegade which i will install soon. The Kevlar clutch has better holding power but needs about 500 miles of easy break in before i can hammer it so the results may not be in for a few months.

[laughac]

I have the Kevlar clutch and have had not slippage up to 14 lbs of boost.

[laughac]

I don't want to hijack this thread but this is a rare group of the right people to help me figure out my BAE turbo problem. When the engine heats up it seems like oil is being sucked into the intake. Seems we routed the vacuum lines wrong and need your advice. I see the pics but wonder if this sounds obvious.

Is there a vacuum line to the front oil cooler thermostat, because at about 180' this problem happens? The car runs great otherwise.

[mb911]

Can you post a pic of your install? If you are getting oil into the intake track then it has to come from a turbo seals really no other way for that to get there

[patkeefe]

You may want to start a new thread.
There is no way, as Ben says, to get oil into your intake via the vacuum circuits, unless you have some ralyy bad seals. What are your symptoms? What has led to the conclusion that there is oil in the intakes?
Pat

[gsmith660]

Otto once you EFI you can turbo right away you need to lower your comp ratio but EFI gives you endless possibilities

Thanks!

I read about the guy who started this thread, wich had a 7th injector on the turbo outlet. He had been running that setup for 65000 miles, no problems. (If memory serves me) That's why I wondered about the 7th injector.

I guess this is not a good solution for longevity.



So I think I'll just have to wait a few years before I can afford a reliable turbo setup. I'll start with buying sports heat exchangers, then EFI, then pistons, and then TURBO..! (Over a couple of years)



I guess I can survive that, after all I will upgrade performance a bit with the two first mods...

[laughac]

Ok, I'll start a new thread and hope the 1 or 2 right people join the conversation.

Let me rephrase the problem. It seems like we have pressurized the crankcase PCV system.

Can anyone help us figure out which hose(s) we connected wrong?
I'll try to reach in there and start taking pics.

Thanks in advance. The power increase is great and no pinging so far.

[gsmith660]

Did you connect the oil tank vent to the intake if so you are pressurizing the oil tank and crankcase when I did that I put alot of oil into the intake and past the seals and out the exhaust as smoke.

[laughac]

Thanks all.
Found out that I blew piston #2. Broke the ring landing.

Time for a rebuild with forged pistons and steel cylinder walls.
Picking up a spare engine this week to use for a while during the rebuilt process.