SSI's vs. Pre-muffler on 3.2

[ALamborn]

Much has been written here about exhaust systems, but:

I'm planning to order an SW chip but haven't yet settled on exhaust mods.

I'm interested to hear the opinions of anybody who has had the opportunity to try the SSI w/ sport muffler combination and the pre-muffler w/ sport muffler combination.

The latter is less expensive and easier, but is the performance difference with SSI's significant enough to make the cost and work (and risk of broken studs) worthwhile?

Thanks,

Andy

[dd74]

Some have said there is a difference, others say SSIs make no difference. There's a ton of information on this subject if you do a search.

Good luck!

[Halm]

ALamborn, don't you have to pass smog every 2 years? If so, are you willing to change the entire exhaust to pass and then revert to SSI's?

[jester911]

You might want to do a search and come to your own conclusion.
It seems there is pretty good evidence that there are no real gains with SSI's.

I think for the most bang for the buck it is going with a premuffler,sport exhaust and SW chip. It seems to take all three of those to do the trick.

[jimi_c]

The 993 headers with flipped flanges seems to be an interesting option. I think you need to do some back dating to the heating system and swap out the oil line for the older style as well.

I've been watching the few posts on the subject and I'm hoping that Steve W will get around to testing the headers that Tyson put together for him against his ssi setup and the premuf - sport setup that's very popular.

[PatrickB]

I'd stick with a pre-muffler, and SW chip!
Come out on any of the next SOCG fun runs, and you can check my car out!
I've heard that the SSI's really make the biggest difference on SC's!
The PITA factor isn't really worth it for a 3.2!
Get a Steve Wong chip ASAP, and unleash the beast hiding under the engine lid!!!

[mb911]

I think the best bang for the buck is the ssis. the are equal length and flow perfect for street use the only draw back is for big 3.2(3.4,3.5) at that point you need something else if running high rpms. as you will lose a bit top end but this very minimal and for the most part undetectable by a street driven let alone competition driven car unless dynoed etc. Allot of my customers start with the premuff, bypasses and go with a sport then change to the ssis after they have spent the 900 to switch those items and then go ssis and the dualinlet muffler and are happier with that in the end

[zzwhm]

Many of the posts on this topic are seat of pants stuff so out of sheer curiosity a buddy and I did a some of dyno testing last year. Maybe we had a little too much time on our hands.

We tested his 3.2 with a stock exhaust except for a bypass pipe replacing the cat then tested it again with a popular brand of headers/muffler. As I recall the HP gain with the header setup was around 5 hp.

I tested my 3.2 with a stock exhaust except for a Fabspeed premuffler and then dynoed it again after switching to SSIs and a magnaflo x-flo muffler made for the car. I got about 8 HP gain with the SSI/magnaflo setup. Just for grins I tried some different mufflers with the SSIs and found that the magnaflo got the most HP and the worst got 8 or 9 less than the magnaflo.

Later I tested the car with SSIs and cheap supertrapp knockoffs and it got about the same HP as with the magnaflo. I run this configuration for the weight savings since its a track car and the noise is acceptible.

So from all of this fooling around it seems that for my 3.2 the SSIs made very little difference by themselves and the muffler itself seemed to make the biggest difference. It also confirms that the stock system with a premuffler and good muffler is very good.

BTW my car had no problem passing the TX emissions without the cat but maybe CA is tougher.
Bill

[RideShoot&Drink]

I had SSI's on my 85 Carrera...and I wouldn't do it again as performance gain seemed very minimal.

[BReyes]

Let us know what you think. I've had ssi on SC and 3.2, magnaflow. It makes the care rock. BTW, must have the chip.

Bill. Good point with the dyno figures.

[michael lang]

Porsche had done such a good job with your car's engine and ME that you really won't notice alot of difference between SSI's and a muffler vs. a by-pass pipe & muffler set up. I thought I really wanted SSI's for my car but when a drove other cars with both set-ups I decided it was best for me to go with a Fabspeed by-pass & Bursch muffler. No complaints here. As I get more track experience I'll do something with the ME, but for now I'm happy with what I have.

[mb911]

the ssi conversion does 2 things. It allows the engine to rev more freely. It also adds heat that you could never acheive with the stock setup. As I said I feel that most of my customers wish they would have done the ssi conversion if they were allowed with emmisions etc. So if you only see 8 hp gain that also translates to quicker throttle response which is very nice to have as well..

[Halm]

As Ben said SSI’s (or headers for that matter) do more than just reduce back pressure and actually improve the actual flow of exhaust gases. I can then see how a chip helps improve performance. However I am still struggling to understand how substituting a pre-muffler for the cat would change the exhaust variable enough that a chip can make a difference. Can someone explain this too me?

[zzwhm]

The 8 hp gain was only with one of the SSI/street muffler combinations I tried which suggests that the muffler influences things more than the SSI, as others have concluded before me. But that didn't seem to be a sure thing either since some mufflers showed no Hp or torque gain at all over my stock (with pre muff) setup numbers.

I'm no expert on emissions but like I said earlier, my 3.2 passes in TX easily with SSI.


Bill

[RideShoot&Drink]

Ummm...emissions, my car has passed California smog test with SSI's, Monty and chip. Obviously, it wouldn't pass visual, but that's the good reason for the friendly shops. Otherwise, all numbers were good!

[michael lang]

Ben don't get me wrong, I really thought I wanted the SSI's, which I would still love to have and to match it up with one of your pipes would make in my opinion the perfect Porsche sound. Being practical, for the money I spent, the by-pass & muffler was the way to go based on what I felt when I compared the two set-ups. I would & probably still will order one of your 1 in & 1 out pipes to bolt to my by-pass just because I love the sound your mufflers make.

[89911]

Originally posted by michael lang
Porsche had done such a good job with your car's engine and ME that you really won't notice alot of difference between SSI's and a muffler vs. a by-pass pipe & muffler set up. I thought I really wanted SSI's for my car but when a drove other cars with both set-ups I decided it was best for me to go with a Fabspeed by-pass & Bursch muffler. No complaints here. As I get more track experience I'll do something with the ME, but for now I'm happy with what I have.

I'd have to argue the opposite. The object of an exhaust system is the rid the car of spent gases with the least amount of resistance, not to divert 2 separate banks of collectors in an uneven manner to pass through one catalytic converter. They changed this with the 964 by adding a symmetrical setup, albeit by adding even more weight. Back to the Carrrera system. I run SSI's on my 3.4 which last dynoed produce about 230 at the wheels. I suppose headers might add a few more hp's at the top end, but I'm not driving like that on the street. My current set up also uses a Magnaflow completely flow through setup with 2.5 intake and collectors. So, once the gases have the short run from the exhaust valve to the collector, they are essentially open. Other thoughts to consider are the large weight savings, stainless construction, and further weight saving with going with a backdate up top.

[mb911]

Originally posted by 89911
I'd have to argue the opposite. The object of an exhaust system is the rid the car of spent gases with the least amount of resistance, not to divert 2 separate banks of collectors in an uneven manner to pass through one catalytic converter. They changed this with the 964 by adding a symmetrical setup, albeit by adding even more weight. Back to the Carrrera system. I run SSI's on my 3.4 which last dynoed produce about 230 at the wheels. I suppose headers might add a few more hp's at the top end, but I'm not driving like that on the street. My current set up also uses a Magnaflow completely flow through setup with 2.5 intake and collectors. So, once the gases have the short run from the exhaust valve to the collector, they are essentially open. Other thoughts to consider are the large weight savings, stainless construction, and further weight saving with going with a backdate up top.

I agree totally. In is more of a principel thing then anything. I just feel that for a single in muffler and cat bypass,premuffler,high flow cat =total cost of about 900 bucks and then you could lose a bunch of weight off the back and make every thing equal for 1750 that is the way I would go in the long run,

I must say I sell 10 times the 1 in 1 out mufflers to the 2 in models but I still suggest dual in set up to anyone that can get away with it. some folks can't. some are afraid of the exhaust studs. Its is a one time shot not that big of deal granted 1750 no small amount of money but worst case you sell it for almost new prices if you don't like it