SSI's

[seymore]

I have a 82 SC and I'm wondering if SSI's really do what they claim to do? 10 to 15 more horses, and 30ft lbs more torque? Just Inquiring .Thanks

[Peter Zimmermann]

I don't know what the claims are, and I've never seen dyno numbers, but they are a heckuva improvement. Before your install check your state's smog laws - in CA your car would not pass without the cat & O2 sensor hooked up.

[seymore]

I have historic tags so I only had to get it inspected once and thats it for as long as I own it.

[Peter Zimmermann]

You lucky dog!!!

[Trotskyite]

I put SSI's and an M&K 2in2out on my '82 and its like a different car for sure.

[RWebb]

quite reasonable

they are also works of art - you might want to put one in the living room

[mb911]

all of my customers that have put them on and dyno'd them have shown improvements. hp levels will change with tune etc but it is a big difference in throttle response and heat for sure

[Superman]

For sure. They are heads and shoulders above our heavy, non-'tuned' exhaust systems. For heat. And also because the engine simply breathes better through them. As it turns out, the need for backpressure is a wives' tale. What helps is a tuned exhaust where the right cylinders are mated with the right other cylinders, with specific-length initial pipes. This way, the vacuum created when one exhaust valve closes helps to evacuate the cylinder whose exhaust valve is just opening. SSI's do that. Your engine will thank you.

And finally, last but not least, I would say that SOUND is at least half the joy of driving my car. The sound, with SSI's and a proper final exhaust, is intoxicating.

[GothingNC]

They look nice too !!

Check with the members up in the DC area

www.dorkiphus.net

[RWebb]

re tuned - The early cars use a stock 3 into 1 type of exhaust - this gives a bit better torque than a more highly tuned "spaghetti" header.

The SSIs are a copy of the early systems.

What we really need is for someone to make SSIs and mufflers out of titanium. That would save a nice amt. of wt. in the rear, and prevent us from being out-techno'd by 'vette owners...

[otto in norway]

Sorry, but I don't know... But I would also like to know some specifics;

How much do you actally gain?

And what's the story with different engines?

(I have a 3 litre with everything done, except the SSI's... but I guess someone else also needs to know some hard facts... -and NOT subjective)

Anyone?

[911st]

I belive that HP number gain that is bounceing around was for a 2.7 smog motor that had a very bad exaust.

From one dyno compairsion I saw for a Carrera 3.2 an SSI w sport muffler compaired to stock heater exchangers with a cat bypass and sport muffler the bot make mostly equal HP except at around 3000-3500rpms where the SSI had and advantage of 5-7HP arond the 100hp level. So I would guess about a 5% incress from the SSI's alone right were you will feel it. Add a sport muffer on top of this...

An SC might be different and may even make the CIS work better.

SSI's w a proper muffler sound the best and the bump at around 3k should feel significant.

However, for the $2k (headers, oil lines needed, and sport muffler) I would get a $100 used cat bypass and convert my stock muffler to a sport by adding second exit the the right side and put my dollars into suspention, making the car lite, and track fees.

Just my 2 cents worth.

[Bill Verburg]

Originally Posted by 911st

I belive that HP number gain that is bounceing around was for a 2.7 smog motor that had a very bad exaust.

every street 911 sold from 1975 to 1994 had a lousey exhaust system from a performance perspective.

SSI's just emulate the earlier design used thru '74 and are sized accordingly, SSI works well through 3.0 but is becoming too small for 3.2 and will totally stranngle a 3.6.

SSI's also work better w/ the lumpier early cams than w/ the later smog cams

[Joe Bob]

Just do it.....

[john walker's workshop]

too bad SSI has nothing in stock for several months due to problems beyond his control on the manufacturing side. i sure hope he stays in business.

[tdatk]

Pure sex.......Thnx Ben

http://youtube.com/watch?v=grVxwtEgZ80
http://youtube.com/watch?v=DGU2PE2C2JU

[fred cook]

I put a set of SSI exhausts and a 2 in 1 out muffler on my '80 SC coupe. The biggest difference is felt on the top end. With the original exhaust system, the engine would just quit pulling over about 6200 rpm. With the SSI exhausts I have to be careful to keep the revs under 7 grand in the lower gears. Once the new system was on the car I retuned the engine by cranking in about 2 degrees more advance and richened up the a/f to about 3.5% CO. The end effect was good bottom end and mid range torque with seemingly endless power on the top end. All in all it makes for a very pleasant driving experience. More horsepower? Couldn't say as I have not put it on a dyno. I do tend to "play" the exhaust more than the radio now!

[sepia2.4]

so if you have an older 911 say a 72 or 73 you won't notice much of an increase in hp right?

[RWebb]

none

but they are stainless

[911st]

Agreed the 75-94 exhausts were all less than optomal.

Again, I believe the 75-77 were the thermal reactor / log style and Porsches first attempt at a smog exhaust and thus the worst of the bad.

I trully think the big 10-15HP increase quoted and bouncing around for the SSI's was for the 75-76 2.7.

A 3.2 might be different but SSI's do not add any peak HP over a cat delete from the dyno numbers I have seen except for about 7hp near 3500rpms.

Go to an overlap cam and the scavenging available from a well tuned equal length long tube header should have a significant effect.

Now a 3.0 with S cams and SSI's, that would be fun.