What? Are you stupid? Turbo on a 911SC

[patkeefe]

If I were doing this project, I would be running all this in a spreadsheet to consider all the options.

There is a guy selling a 930 on the forum who has a $100,000 plus car that you could pick up in the 40's. If it were me I would sell my SC and watch for deal. They happen all the time here.



Les, I had my engine out anyway for a rebuild, so I considered the cost per HP options (the spreadsheet), and decided to go turbo.

Anybody can go buy a 930 if they want a turbo. Like Ben says, I'm more of a DIY guy...

Two roads diverged in a yellow wood
And sorry I could not travel both
And be one traveler, long I stood
And looked down one as far as I could
To where it bent in the undergrowth

Then took the other as just as fair
And having perhaps the better claim
Because it was grassy and wanted wear
Though as for that, the passing there
Had worn them really about the same

And both that morning equally lay
In leaves no step had trodden black
Oh, I kept the first for another day!
Yet, knowing how way leads onto way
I doubted if I should ever come back

I shall be telling this with a sigh
Somewhere ages and ages hence
Two roads diverged in a wood
And I took the one less traveled by
And that has made all the difference


Robert Frost



Another reason is because people told me I couldn't do it.

[RarlyL8]

My suggestion would be to directly e-mail the folks who have successfully done this conversion. They will be more likely to open up to any pitfalls and helpful hints off-forum rather than open themselves to ridicule. I know many extremely knowledgeable folks who simply will not post due to the BS on these forums. It's a damn shame and hurts us all.

If you actually read the words you will see that BS has nothing to do with opinions and everything to do with ridicule and being a smartass to others. Many folks simply won't tolerate it and don't post because of it. And yes, that hurts us all.

Yes I ran out of 'rhoid cream and I'm a bit touchy. Now back on topic.

Here's my bastard. An SC with a 930 engine. If I had it to do all over again I would have turbocharged my 3.0L SC engine. I knew what I had and it was good. I bought the 930 engine thinking that was the best way to go. Total scam, had damage and needed rebuilt.
A turbocharged SC can be more fun than a 930 in some ways. With a narrow body, skinny tires, turbocharger, and the 915 you have the best of both worlds.

[turboteener]

I don't know where all this talk about "high compression" motors is coming from, the 81 SC has a compression ratio of 8.5:1. Not high at all. You can easily do 6 psi on that and the engine will last forever. Plus it will get much better gas mileage and have better drivability around town because it is not a 6.5 or 7.0:1 engine.

If the kit uses a Rayjay turbo you probably should look into getting something a little more modern. You can have a flange for a Garrett, KKK, Mitsubishi, BW, IHI, etc welded to the header, so you can use a much more modern turbo. It would also help you get better drivability.

An overboost switch would not be hard to wire into your system. It is not a complicated device.

[turboteener]

Oh, yeah, Brian that is a hideous car you should give it to me so no one will see you driving it around town. (Just Kidding, of course)

[copbait73]

Originally Posted by turboteener

I don't know where all this talk about "high compression" motors is coming from, the 81 SC has a compression ratio of 8.5:1. Not high at all. You can easily do 6 psi on that and the engine will last forever. Plus it will get much better gas mileage and have better drivability around town because it is not a 6.5 or 7.0:1 engine.

If the kit uses a Rayjay turbo you probably should look into getting something a little more modern. You can have a flange for a Garrett, KKK, Mitsubishi, BW, IHI, etc welded to the header, so you can use a much more modern turbo. It would also help you get better drivability.

An overboost switch would not be hard to wire into your system. It is not a complicated device.

I twin turbo'd a '81SC. The C.R. is actually 9.3:1 which requires a little less boost however the point is still vaid. I loved my creation. It was still responsive yet it had an alter ego once the boost guage went past 0 plus the '72 with full IROC body probably only weighed 2150#.

[turboteener]

Damn bet that was a really cool street car. Lightweight and responsive. Very cool.

[mb911]

Originally Posted by turboteener

I don't know where all this talk about "high compression" motors is coming from, the 81 SC has a compression ratio of 8.5:1. Not high at all. You can easily do 6 psi on that and the engine will last forever. Plus it will get much better gas mileage and have better drivability around town because it is not a 6.5 or 7.0:1 engine.

If the kit uses a Rayjay turbo you probably should look into getting something a little more modern. You can have a flange for a Garrett, KKK, Mitsubishi, BW, IHI, etc welded to the header, so you can use a much more modern turbo. It would also help you get better drivability.

An overboost switch would not be hard to wire into your system. It is not a complicated device.

not true 81 sc engines are either 9.3:1 or 9.8:1 but ran small ports

[turboteener]

Your right, I messed up. The early 3.0 engines had 8.5. The later engines were a little higher like Ben mentioned.

[germaniac]

Yeah, I understand I could sell a few of my cars, get a small loan and drive out with a built 930 or even a nice 965...but the point is, I love my little SC, it is solid as a brick but in order to keep our affair goin', she needs to cough up a little more power...that's all -- she isn't stock in the cosmetic sen se anyway, so selling her isn't really a viable option if I wanna see my investment back...the car is a C2 conversion with a 993 interior, well except door panels which are RS, oh and the 930 steering wheel..oh and the...so you get the point.

I figure if I like this car and it has proven to be a solid drive (all paperwork for the last 18yrs or so) having a low boost kit installed wouldn't be a bad thing if done right. I have worked out the payment with the mechanic, I have the kit, and I just wanna make my car a tad more powerful.

I won't be hitting the track in this car, I won't be dragging kids light to light, I just want a little bit more excitement out of a very predictable car (for a 911).

As for being "bolt on", I understand that it really isn't a lego kit with minor assembly required. I am simply referring to the fact that on this particular kit, there is little to no fabrication involved as the guy is providing all the custom hardware he had manufactured.

Again, I admit my shortcomings on the knowledge side of this issue, that's why I turned to the board. I also am smart enough to appreciate all sides of this one...

Hey Ben, you have that parts list I emailed you? (lol)

[RarlyL8]

My car was sitting in your parking lot a couple of weekends ago Bret. Your buddies enjoyed it, ha!

The SC engine had several different versions throughout the years of '78 and '83. Euro/US/ROW/different years, all had different C/R and CIS systems.

The first things I would do is run the engine type number and see exactly what you have. Then use Marty's cool boost graph and see how much you can get away with. Start out with the lowest boost possible and work up to the target point.
Run the A/F ratios and see if you need more fuel, check the timing vs knock.

It's just not that difficult dealing with a low boost application. The devil is in the details. Take your time, be conservative, make a checklist and check everything twice. I'm sure the fellows that have done this will be happy to help you along if you post your progress and questions.

[germaniac]

Brian,

Thanks for the support, it's really welcomed. Down here in S. Florida, a helping hand is hard to find! Luckily, I am moving back to my atlanta home soon...whooohooo. Thanks again, all of you guys.

Rob

[turboteener]

Yeah but Ben likes Pintos, so what does that say?

I agree with Brian, watch the details, and work slowly when tuning and you will have plenty of success. Of course boost is addictive. You won't be happy with "just a little". You will get in and drive it and then have to have more, so be prepared. It is worse than crack.

[RarlyL8]

Yes I saw the Pinto, man did that bring back memories!

When I first built the 930 engine I worked up to 1.0bar boost. The first time I spun the cold tires on an off ramp at 90mph was the last time that engine saw 1.0bar. It took 3 shots of Jack to release the seat cushion from my sphincter. Sometimes the crack habit isn't so hard to kick.

[patkeefe]

Originally Posted by RarlyL8

Then use Marty's cool boost graph

Brian, where can we find this?

[copbait73]

I love home grown TURBO applications, always will. For me, they are a cheap way to big power but the devil is in the details.

Here, study this and kick me for awhile...... all for fun!

[RarlyL8]

I don't see an MFI pump, are those carbs?

[mb911]

Originally Posted by RarlyL8

I don't see an MFI pump, are those carbs?

yup carbs but wait you can't do that what Pinto are you talking about Me???

[copbait73]

Originally Posted by RarlyL8

I don't see an MFI pump, are those carbs?

It was my first Porsche and first homegrown TURBO Porsche (after a banzai TURBO VW), engine was a 2.0L '69T, pressurized Webers. air/water couple intercooler, fabricated blow-off valve, adapted INDY car W/G (massive), Schwitzer 3LDA, 3" tailpipe - straight thru. Roughly 150HP (did I claim BIG POWER?)

[copbait73]

Originally Posted by mb911

yup carbs but wait you can't do that what Pinto are you talking about Me???

Ben, I drove Pintos also. At one time the Pinto was the family car and I had my 911.

[mb911]

Originally Posted by copbait73

Ben, I drove Pintos also. At one time the Pinto was the family car and I had my 911.

Yeah guess I am missing something here but oh well