1977 911 SC Porsche/WRX STI RALLY Turbo

Recently I purchased a 77 911SC,number 000031,an early Wide body car, that had a blown 2.7,imagine that. The car was fitted with a EJ257 2.5 Ltr. turbo from a rally prepared car. The engine was hand built, balanced, blueprinted etc. and is running 310RWHP at 12boost,available 500hp up to 28 boost. I'm currently having the car rewired, dyno'd and spec'd out for performance by a subby race technician.Has anyone actually done this conversion? I need to get an exhaust system fitted,do I need it fabbed out ? Any ideas advice or wisdom appreciated. My goal is to have this car as PORSCHE as possible. The suspension has been uprated,billsteins,corner balanced,weltmeisters,sway bars etc. so it can handle the power,w/295's on the rear to apply it. HELPPPPPPPPPPP

Convert it back to Porsche power. Sell the Subi engine. You are ruining the value of a collectible.

In reply to TxCoyote: thanks for your advice, since I already have 3 early 911's I think i'll allow myself something different for a change.If you've driven these cars the only thing they lack is HP,plus this is being done carefully with the ability to change it back.

ducs wrote: Recently I purchased a 77 911SC,number 000031,an early Wide body car, that had a blown 2.7,imagine that. The car was fitted with a EJ257 2.5 Ltr. turbo from a rally prepared car.

Smoke's been blown up your arse. Rally cars in NA cannot have engines larger than 2.3l if they are turbocharged, unless they are 2WD.

Unless they meant they had the EJ257 lying around the shop after they pulled it out to put the rally spec engine in...

Lots of guys have put an ej motor in a porsche. Don't worry so much. You don't have an actual rally car engine so there is nothing special to worry about. The ej257 is a regular passenger car engine and it will work just fine.

This swap isn't too hard to find in the engine swap section on nasioc. MS even has a PNP option for Subarus on their website. KEP has adapters. Wiring isn't can bus so no biggie.

Porsches have gotten so expensive lately that few do the swap anymore. And of course the exhaust is custom, but you said this is being done by a shop so what do you actually need help with?

It's come to my attention the 2.5 are RA-legal now.

The power figures still sound like a stock engine though, not a high compression engine built to suck through the 34mm soda straw.

Also, I have a lot of doubt about a 500hp subaru motor.

They just dont make big power. Most people even with built motors never see more than 450 crank hp.

In reply to HiTempguy:

Yup, lots of dudes make foolish decisions pushing for max hp numbers. I think it is better to have a reliable 400 hp than a time bomb 500 hp.

HiTempguy wrote: Also, I have a lot of doubt about a 500hp subaru motor. They just dont make big power. Most people even with built motors never see more than 450 crank hp.

The hook that set me for turbo AWD BOOOOOOOST was a ride in an STI that made an honest 500 crank HP on low boost - high 300s at the wheels. Low being 17psi. The engine was slated to run 28psi or so with water injection, and had the ancillaries to feed and support the kind of power it could make (IIRC he was shooting for 600 at the wheels, but I figured if he saw 550 then he was doing good).

It was weird. It was raining and he rolled into the throttle and there was no noise, no tirespin, just Star Wars hyperspace effect as the world started streaking at me really quickly.

Knurled wrote: It's come to my attention the 2.5 are RA-legal now. The power figures still sound like a stock engine though, not a high compression engine built to suck through the 34mm soda straw.

IDK about stock engine. A stock EJ257 puts down about 250-260AWHP running 15lbs of boost (at most). So if it is actually putting down 310 at the wheels on a legit dyno, at only 12lbs, then it's a ways from a stock engine.

That said, no way in hell I'd be running 28lbs if you want any longevity.

irish44j wrote:

Knurled wrote: It's come to my attention the 2.5 are RA-legal now. The power figures still sound like a stock engine though, not a high compression engine built to suck through the 34mm soda straw.

IDK about stock engine. A stock EJ257 puts down about 250-260AWHP running 15lbs of boost (at most). So if it is actually putting down 310 at the wheels on a legit dyno, at only 12lbs, then it's a ways from a stock engine.

I'm figuring the effects of a low-restriction exhaust (it's in a 911, the exhaust is probably 3 feet long), assuming a catless uppipe, and banking on the fact that it's not powering through the STI transaxle and an AWD dyno. Then it's a tune and maybe a little dyno optimism away from 310 at the rear wheels.

Mind you, this is still more power than a 930 made, and probably with a lot less tail weight too.

HiTempguy wrote: Also, I have a lot of doubt about a 500hp subaru motor. They just dont make big power. Most people even with built motors never see more than 450 crank hp.

I'm at only ~450-ish crank because I run out of injector. Same built engine package (minus slight piston spec difference for race vs street) in the Element Tuning STi racecar has been laying down 600awHP for a few years now. Just because some people can't do it right doesn't mean nobody can do it right.

And I wouldn't exactly call a 911SC a "collectible."

Why keep it as much Porsche as possible? That would be mean nearly stock everything. You've got a package that can make similar power to a 3.3 turbo for FAR less money (just make sure the pistons get replaced with some forged ones if you want to go for big power).

Thanks for the feedback, the intention is to run the car at 16-18 boost,for 380-400 hp. not pushing it. The pistons are forged and the crank was balanced and engine built by race mechanics.2.5's are legal, I'm wondering where I might get an exhaust setup? Or has one been built that I can spec out or order? Also the car has been built to be reconverted back to a 3.0-3.2 Carerra engine should I decide to go that way. Any recommendations appreciated. Tks Will

In reply to HiTempguy:not your out of the box 2.5 lol

In reply to irish44j:tks, but I planned on running 17-18 for about 380-400,no interest in anymore power as I want the car trackable when dialed in.

are you planning on campaigning it in rally? I'm asking as you mentioned about the 2.5 legality in RA. As for power boost to 19-21 with more then enough fuel headroom and be safe and happy. As for the SC, a quote from someone who campaigned one in the Mexican 1000 is "there isn't a tougher car on the planet then SC911". If you're looking to campaign it in RA or Nasa Rally Sport I encourage you to email me davidz@national.pca.org as I have some contacts to pass along to you who have campaigned 911s on stage and can help provide you with insight and assistance on setup, problems and concerns, fixes to said problems and concerns and all sorts of other assistance.

(Suspension wise the big issue is bumpstops and travel btw, my one contact is currently working on a solution of their own and I have an option B to consider as well).

Knurled wrote:

HiTempguy wrote: Also, I have a lot of doubt about a 500hp subaru motor. They just dont make big power. Most people even with built motors never see more than 450 crank hp.

The hook that set me for turbo AWD BOOOOOOOST was a ride in an STI that made an honest 500 crank HP on low boost - high 300s at the wheels. Low being 17psi. The engine was slated to run 28psi or so with water injection, and had the ancillaries to feed and support the kind of power it could make (IIRC he was shooting for 600 at the wheels, but I figured if he saw 550 then he was doing good). It was weird. It was raining and he rolled into the throttle and there was no noise, no tirespin, just Star Wars hyperspace effect as the world started streaking at me really quickly.

You'll likely be in custom exhaust territory, but should be pretty reasonable if the turbo is in a stock location. That will allow for aftermark headers and uppipe, if they aren't already fitted. ECU tuning is very important, so take care to do that correctly. It's capable of the higher numbers, but for longevity, best to take it down a notch. Take a picture of the intake, that angle will show many things suggesting build quality. If you see this, , you should be smiling.

In reply to ducs:

lets see i have a 72 911e,a 73 alfa gtam,and a bmw 3.0cs,so i'm not real worried,tks for the advice though.

In reply to sachilles:

my mechanics are investigating certain issues associated with the wiring,have you completed this conversion yourself,how did you set your car up? Any help appreciatted.

I think you actually will want a custom exhaust that matches the engine, even if something off the shelf is available. If there was - and I doubt it - it'll probably be geared towards a stock Subi engine and won't help you make the most of the engine you have.

Haha, love the dead thread revival. Some of you guys are on glue with your claims of 500+hp on a Subie motor (where is the rofl smilie when you need it??).

Can it be done? Sure, with about $30k and running race fuel.

jsquared wrote: I'm at only ~450-ish crank because I run out of injector. Same built engine package (minus slight piston spec difference for race vs street) in the Element Tuning STi racecar has been laying down 600awHP for a few years now. Just because some people can't do it right doesn't mean nobody can do it right.

Post dyno sheets or gtfo. Pretty simple concept.

Jack Burns of Burns Stainless is your friend. He can fab an exhaust for just about anything....and does exceptionally high quality work too!

http://www.burnsstainless.com/

He speaks Porsche too---- so I'd give him a call. Tell him you read GRM / CMS as he's been an advertiser for years.

HiTempguy wrote: Post dyno sheets after 20k and not blowing up the EJ or gtfo. Pretty simple concept.

fixed. although without wanting input from competitors who have or currently campaign aircooled 911s in rally regarding setup and suspension, I'll sit back and enjoy this thread like Michael Jackson with some popcorn from hear on out.

I'd like a built thread with pictures as well.

Knurled wrote: The power figures still sound like a stock engine though

At 12 PSI instead of 16-18 or whatever the STI runs usually.

edit: Tricked by a necro