PLEASE help with my turbo setup
 

Hello and thanks in advance,

I have a 1982 911 sc. I will be completely rebuilding the engine and trans. I will also be adding a turbo. I have a ton of questions and I know you guys will have great advice. I'm looking for 350 - 400 rwhp. I already have a T-25 turbo. I will be using Bitz Racing CIS to EFI kit.

1. What compression ratio should I run and what cam?
2. What size injectors should I run?
3. What size fuel pump?

What else am I missing???

Thanks
Rick

1. You could fit the RUF/Mahle 3.4 P's & C's, they are 7.5CR. Your stock cam is quite good, if you do want to have them reground/exchanged though then you could go for a 964 grind.

2. http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/417544-those-efi-450-rwhp-what-injectors-you-running.html

3. The Bosch Motorsport pump 044 would be a great pump for you with loads of capacity left over.

You will need an IC to run say .8bar boost pressure at that CR.

A wideband setup such as the LM-2 by Innovate.

+1 on what NathanUK wrote. He is even being conservative if you plan on running EFI.
But why a T-25? Wouldnt you want a little more top-end? For that kind of horsepower you will likely need 550 CC injectors and like Nathan said about the fuel pump is more than enough.
Keep us updated, sounds like it is going to be fun.
Pictures too if you can

Nathan, Thanks for the info. If I stick with the cylinders (in good shape) should I get some JE pistons in 7.5CR or should I go higher to 8 or 8.5CR?

930gt-40r, I got a screaming deal on the T-25 ($30) with no shaft play. Will this size work for my setup? Should I try to get something bigger?

Rick

Street car? Going to drive on the track? Do you want driveability, or a lot of HP? What kind of boost do you think you will be running? Using the stock SC heads and small port runners, or do you need the 3.2 setup to run EFI? Do you have a map of the T-25? Single plug? Why do you want to run EFI? Your ideas are going to add up to $8k before you know it...rebuild, cams, EFI, etc.

I have a small amount of SC/turbo experience, but none on EFI; mine is CIS. Let us know what you want to accomplish, and we can kick that around for a while. This turbo conversion stuff becomes a steep slippery slope.
Pat

Rick- I think you should sell that T-25 at a good profit, and maybe get a K-27 or mabye a larger garrett like a 30 or 35. A T-25 is for the likes of a stock 2nd gen Eclipse and would likely choke off your car. If you are looking for headers a good set for a good price are the GSF headers.

I would think 7.5CR is the way to go, maybe others can comment too. After all, it's what RUF used with their 3.4 Yellowbird.

If you go to high a CR you are going to limit your boost pressure and therefore limit your bhp possibilities. You only have a 3.0 so to get to 400rwhp without a low CR doesn't really seem possible to me. Hopefully others will comment.

I guess the JE pistons is a low cost answer although getting the RUF 3.4 Mahles is the better way to go.

At least with EFI you can try to get back some off boost drivability (caused by a lower CR) by optimising the ignition timing with your EMS unlike the 930 dizzy.

I run 8.5-1 JE in 98mm @ .5 bar of boost running sc cams, small port 81 sc heads matched for my 3.2 intake,twinplugged,30lb ford 5.0 injectors and Bitz's MS1 with an lc-1 wideband and a t4 to4e turbo which has plenty left at any rpm range

Pat,
Mostly street with some track. Not sure on the boost level. I know I am limited with my engine/head size. The 3.2 intake is easier for the Bitz setup I believe, plus the larger size will help. I will port the heads myself to try to help offset the small size. No map on the T-25 but I can get one easily. I have more experience with the EFI systems. You say $8k, I say $10K and I tell the wife $2K :-)

930gt,
How much could I get for the T-25 do you think? How much for the K-27 or 30?

Nathan,
That was what I was thinking on the EFI to help. I think with the Megasqurit system the tuning will be a little easier.

Hi Ben,
Have you had any problem with detonation with your setup? Do I need the twinplug system?

Thanks
Rick

Rick:
I see you are thinking clearly ;)
I'd probably go with a setup like Ben's. I would also run those stock pistons if they were in spec. If you keep the boost down to half bar or so, you have SC performance until about 3K RPM, then it's turbo. FWIW, I run DC-15 cams in my SC, they are sort of between SC and 964 grind.

400 HP is a reach; don't get blinded strictly by a number. If you get around 300, it will be very driveable and a handful on the track.

Pat

no I have not but I twin plugged it was to prevent any issues

Garret T25 turbo is good for 170-200 hp on aircooled engine. It's a small turbo used on 2L engines and there is no chance in hell you'll ever get more than 250hp-is from it. Frankly, it will mostly act as rotating plug in your exhaust system. It will start boosting very early (like 2000 RPM) and die past 4000 RPM.

Ben,

How complicated is it to add twin plug? What would you say is the cost? Machine work, new dizzy what else?

Thanks
Rick

Well machine work=$350 approx
dizzy (3.2 use 964 dizzy@600 approx) 1500-2500 depending on type
wires=350

you could use an electric edis or something for much less maybe $500-1000