Would this setup make a good SC turbo build (260WHP)??
 

Hi fellow petrol-heads!

So I am going to build a a turbo engine based on my 3.0L engine. I have a 1980 Porsche SC, the US edition with 180HP. I want to build a turbo engine and step into the dark side!! :D

I am not in any way an expert but I know that a lot of you guys have been down this road and may have some good advice. And pointers for me to follow, and opinions regarding my build. But no it is not an option to sell the SC and buy a 930!!

This is what I intend to do:
- Swap the CIS intake with a 3.2 inlet
- Install a TEC3 engine management system
- Maybe use the K7/K9 turbo from RarlyL8 or the K7 7200 (opinions?)
- Do a custom or maybe just a stock 3.3 intercooler
- upgrade the head studs to 993TT
- Maybe upgrade the oil pump to a 965 (do I really need to change the SC pump?)
- Swap to 98mm Mahle cylinders
- Order JE pistons with 7.5:1 comp
- Use the SC camshafts
- Install 930 headers and dual muffler
- Use the stock SC heads but rebuild them

So this is what i got so far. Do you fellow pelicans think this would be a okey combo? My aim is about 250-260WHP. Realistic??

You dont need to lower compression to get 260 WHP. You can achieve that with your stock pistons and .5 bar boost and a simple bolt on setup.

No first hand experience, but lots of reading here on pelican.

I like your goal. It is modest and will prevent some of the things that inevitably will follow once your start boosting, transmission brakes etc. that is until you start down the slope :)

Didn't the 1980 SC have 188hp? And a slightly higher compression than the 78-79 SCs?

If you need a 3.2 intake manifold, I have a pelican offer:

I will sell my 3.2 manifold to you for usd 600 plus shipping. At that price we each donate 50 bucks to Mark's fundraiser. I'll do that out of the sale price of $600
I hope this doesn't come across as weird, I don't need to sell the manifold, but this way I feel it would help a pelican more than just sitting on my shelf, also helping Mark on the way.

Good luck with your project.

i am amazed at how much power a 930 has even at .5bar.

your HP to $$ ratio is not good. you can do better for the same money and not turbo and you will have a car that is WAY more fun to drive.

when i was looking for a 930 a friend told me i would have more fun in a 911 with a 3.6 in it. after owning a 930 for a year, he was right. dont get me wrong, i love my 930. but when it gets fun it gets very fast, scary and very expensive if i get caught. put it this way, there is not a road around here that i cant get a speeding ticket on in 1st gear!

its the turbo lag. you cant get rid of it. the throttle response of the 3.6 will keep a smile on your face.

Thank you for the offer but I have already bought the intake :(
And I don't live in the US I am sorry to say.

And no, not weird at all! It is important to give to charity :)

I think it is correct regarding the new comp. But they also made the airbox 3-4mm narrower and the same for the runners. At least my engine edition is only 180HP:(

That may be so, but there is just something about chasing that turbo project dream ;)

That's the advantage with working with low boost, higher compression and a 915 gearbox to begin with. It lessens the perception of turbo lag! Even though it still exists. Although I think the fun comes with the fear, diving a 930 hard and hugging the edge of disaster is what makes these cars fun to drive... Tickets??? Price of admission... Sadly (more like luckily) my tickets have all been while driving the slowest and least sporty vehicle I own at the time. I will say that I'm much more aware of what's going on around me when I'm in the 930...:D

.5 bar is all the boost you will need. You should have close to 300 WHP and if you do any more the 915 wont hold up. Just keep stock pistons, use your 3.2 intake, bolt on a turbo and go. (addressing fuel and ign of course)

So keeping the 9.8:1 compression won`t give me problems like "ping"? Is the CIS piston a good choice with a turbo conversion? Just thought the JE flat base with grooves will be a better choice?

I am not schooled on the "ping" dangers and reason why this occurs but I`v heard this is a problem with the conversion? Or is this only a problem for those who don't use IC?:confused:

I added a turbo to my 1980 SC, although mine is a euro car. The euro 1980 SC should have 188HP with 8:5:1 I think.

Not had a dyno yet but had some side by side 'tests ;)' with some friends cars (Aston Martin Vantage V8 4.7, Renault GTA V6 turbo with 275 dyno HP)
I had the Renault, I could just about pull away from him.
The Aston was faster but not as much as your'd think, my slow change 915 box and turbo lag where the issue's, when the turbo came in he couldn't pull away from me.
My car is also lightened a bit but I'm thinking it must be aprox 270-300HP.

I stuck with CIS for now with a 930 WUR to handle fuel on boost. All works perfectly.
I may go to EFI later.

Also I'm running a standard 3LDZ turbo, so K27-7200 etc should give quicker spool up (another future upgrade).

You might find my build thread helpful.

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/711757-turbo-conversion-3-0-sc-winter-project.html

with a turbo "ping" correlates to $$$ more so than a NA engine. the ping you usuaully hear is detonation, when you start playing with turbo's you start dealing with the more deadly pre-ignition

9.8? i think i would stick with the 8.5

goto one of these sites that has an effective compression ratio calculator. play around with the static CR, boost and even intake valve closing time. i am not sure on this, but you might try to stay around 12:1. its pretty fun to mess with even if you ar not building anything.