SSI's with a Supercharged 3.2
 

I have a Supercharged 3.2 and wanted to know if SSI's would help to increase power to the engine. I have read the many debates (discussions) regarding SSI's and "normally" aspirated engines, but how about supercharged or turbo engines?
http://forums.pelicanparts.com/uploa...1125583919.jpg http://forums.pelicanparts.com/uploa...1125583981.jpg

On a supercharged engine, ANYTHING you can do to reduce exhaust backpressure will increase power. SSIs and a free flowing muffler will make a fairly substantial difference. Not because of the tuned equal length tubes, but because of reduced backpressure.

A normally aspirated engine needs some backpressure and is dependant on scavenging, a supercharged engine does not need either.
If you put straight pipes on a normally aspirated engine you would loose torque and horsepower everywhere except at the very top end.
If you put straight pipes on a supercharged engine you will gain torque and horsepower throughout the useable power band.

I ran 2 5/8" stainless steel zoomies on my supercharged drag boat, went real fast but boy was it loud.
My friends called it the quiet boat because any time it was running everyone around was quiet, no sense in talking if no one can hear you.

kdubb, please PM me or respond via this thread. I'm in Indy too and would LOVE to see your car and see how it runs. I've been
thinking about supercharging for a long time.

Thanks,

Brandon

kdubb,
Your engine has appeared in my dreams on and off for over a year now. :D I want to do the same thing, but waiting for the time and money to line up properly.

Got any dyno HP numbers to share???

How does it drive???

Who did the installation and what brand super charger is that???

Thanks,
Dan

I have a supercharged Carrera 3.2 and use the SSIs in the winter when I want heat. The rest of the time I use a jethot coated set of racing headers into the same 2 in 2 out Dansk muffler. The headers are better but I can't drive with no heat in the winter so I lose a little power. I also run 11 psi boost on 93 octane and 16 or more on race gas. I don't see an intercooler on your engine so I guess you are running low boost. You should see an improvement with the SSIs. Good luck.

Best regards,http://forums.pelicanparts.com/uploa...1125595826.jpg http://forums.pelicanparts.com/uploa...1125596336.jpg

Looks to be a Paxton SS from SC of Knoxville. They still offer kits for these and the Wipples?

The SSI header pipe diameter of 1.5 inches is kind of marginal for a NA 3.2 engine, so I would think it would be a little restrictive with a supercharger. But it would probably be better than stock. Apparently you are not concerned about smog inspections in Indiana. Sigh.

Thank you for the responses. It is a Supercharger of Knoxville set up with a Paxton supercharger running only 5-7 lbs of boost. I know that it not a lot, but you can't tell my but that when I step on it. It will run with a turbo of the same years. At the time, it was more economical than the a turbo set up, but I'm still happy with it. SuperCharging of Knoxville claim 245hp at the engine for U.S. spec engines. Mine is a euro spec that I lowered the Compression to about 9:8. Yes they still make this setup, as well as the Whipple that cost more, but gives you much more boost.

Yup, Gerry's car is the Wipple example...nice.

Beautiful Porsche Gerry. Nice color. The whipple ain't too bad either!

That would be 345 HP not 245 HP as per Supercharging of knoxville. I had to modify their system a LOT (spell that $$) to make the big numbers. The newer SSIs have a 1 3/4 " primaries as opposed to the 1 5/8 " older ones. I have 2 " primaries on the racing headers.
This makes a difference. You must remember that flow and velocity enter the equation also the type and construction of the header sytem in relation to the type of engine.

Best regards,
Gerry

You're right. My mistake 345hp.

So would you go B&B or SSI or maybe GHL, or.....

Truthfully, I would hve a custom setup made by Jere Stahl of Stahl headers if he will do it for you. He is the father of headers and also a cantankerous individual. If you can interest him in your project then you are OK. The problem is he may need the car if he hasn't done a porsche yet and he is in York Pa.

Best regards,

You did not state if you want heat. If so go with SSI and buy racing headers for when you don't need heat. It is easy to change back and forth.

Best regards,

Why custom instead of a prefab unit? Cost may be prohibitive!!

I believe SSIs are @ $700-900/pair. My racing headers were $500/pair and then jethot coated at $250. I believe the best headers that are Stainless and beautiful are $4000, a custom SS setup could run $1000-1500 and the mild steel headers from Stahl would be @ $800-1200 add the jethot coating for $250 and there you have it. A lot of headers that are well known have been shown to be crap when put on a dyno, in fact many actually lose HP. Do your homework and don't penny pinch as you pretty much get what you pay for. I would not spend the $4000 but I do use both sets and am happy with the results for now.

Best regards,

Thank you for the info. I will look at Stahl headers and do more homework.

dang, I didn't realize this was a cross post. Here's the other post in the engine rebuilding forum:

http://forums.pelicanparts.com/911-engine-rebuilding-forum/238859-ssis-supercharged-911-a.html

kdubb, I know you're new, so no worries, but normally you should only post something in 1 forum.

Cheers,

I wonder if anyone's done a twin blower setup? i.e: A SC for low end grunt and a Turbo for top end! Now THAT'd be interesting ;)

Thanks Andy, I am learning.

Merv, I also thought of that setup as well. I wonder if there is a down side. There would have to be, because no one does it.