SSI's - Valuable upgrade or Nice if you have $$$
 

SSI's have been on the my list of things to add to my car.

How good an upgrade are they? Are they worth the money?

I've read about the HP gains, etc. Is it noticeable?

Thanks.

LS

Define valuable.
I put them on my SC and there was a noticeable difference but I wasn't blowing WRX STIs off the line. Maybe a few hp...better excavation... Funnt thing about "upgrades" is they sometimes cost you on resale value so keep your original if you do go that route.

It will definately sound like more hp! They are pricey, but imo well worth it. When I put them on my SC, with M&K 2 in 2 out, I couldn't stop smiling for a few days! Upper rpm's...it shrieks!

My SC has SSIs and cams. It really flies.

If you trust this old Dyno chart - they are not performance valuable compared to a chip and premuffler on a 3.2/DME car.

According to Bruce anderson 17-22hp available on 3.0 and here's another article suggesting a 964 cam as well

Cheap horsepower for CIS engines - Butzi Squared


http://forums.pelicanparts.com/uploa...1492213359.gif

From everything I have read, a cat delete (cat bypass) and chip is money better spent than SSI's

swoboda -- looks like you have a 3.2 carrera -- consensus seems to be that SSIs are a bit undersized for a 3.2 engine and, while they will provide a midrange bump, they'll also hold back some top-end.

Also, keep in mind that a) you'll need to re-route/configure the heater hoses if you want to maintain heat, b) SSIs have no provision for a cat if you need to remain emission-compliant, and c) you'll also need to buy a new muffler to work with the SSIs "2-in" configuration.

There's a few pieces of "lower hanging fruit" that, imo, are worth pursuing before exploring SSIs on a 3.2, including the cat bypass referenced above and a chip (or Sal Carceller's chip, MAF, injector setup).

OTOH, SSIs seem to provide a noticeable and material gain on a CIS-equipped 911 engine with a 1-out exhaust system.

I'm assuming there is no way to pass emissions with SSIs, correct?

That is generally correct, but would ultimately depend on how stringent your emissions testing is (visual and exhaust levels)

Few points of clarification -- a german company has recently introduced a larger diameter SSI-type system that includes a pair of high flow cats -- remains to be seen as to whether this system will provide the same emissions numbers as "new" -- further, since it looks nothing like the stock exhaust and doesn't appear to have california CARB certification, it would likely fail in states like california that have strict visual inspections.

A fellow pelican member in Colorado has also added cats to his 911SC's ssi system, but it looks like he only needs to pass emissions using a two speed static emissions test -- again, unclear as to whether his setup would pass the more rigorous "rolling road" test utilized for newer cars.

No way? Well not entirely correct. If you have a less than savvy technician he may assume that they are twin cats or not even look. The main scrutiny will be if you have a smog pump, fuel injection and other state mandated controls. Once past the visual it's the tail pipe test. Passing that is a whole other slew of threads.

Best to pre test prior to going to the State inspection.

The ?? on SSIs worth it? Back in the day, yes. Now they are quite a bit more pricey. On the 3.0 yes there is an improvement. Not so much with the Motronic 3.2. A chip and a cat mod is the better option unless you really like the look and have a hole in your wallet and want a 2 in 1/2 outlet. 2 outs tend to drone.....just my experience.

Thanks, guys. I just want a bit better sound. Currently, I have a Monty muffler and stock cat and I'm somewhat underwhelmed. I'd love a muffler that gave it a more aggressive classic sound.

Ian, I totally zoned on the username :D
Do a cat bypass and a chip.

If you want better sound, just buy a cheap 1 in 1 out muffler and gut it. That's what my brother and I both did. BTW, a "cat bypass" will give you a better sound with the Monty muffler as I understand it. I believe there are also some sport mufflers that will give a better exhaust note.

When I did my top end, I had in my opinion some modest realistic goals for bhp gain but what I was really trying to make sure I maintained was the overall reliability of my engine. So I installed the SSI's and 964 cam. More bhp, more noise, same reliability as what I had when my engine was totally stock. I will say that I was very heavily leaning towards buying a pair of Brian's headers from Rarlyl8, the only thing that won the SSI's over his pipes was the heat exchangers on the SSI's were the closest to factory heat and to me it was worth the sacrifice of a few bhp to get the roast you out of the car heat the SSI's offered. I will also say that I waited a very long time for the right pair to become available.

very personal of course...valuable or nice to have? i put them on a 1981 SC.

objectively, it's just nice to have, gotta be honest.

but if the money is not that big of an issue? you have an old rusty leaking stock system on there? i would not put any money in a second hand stock system...

SSI's...you notice them most below 4000RPM, nice little boost of torque. I went with stock steel early exhaust, and the sound is fantastic. I don't like louder exhausts.

a real benefit is easy valve clearance jobs. I have to do this at least every year with the miles i'm doing, and i'm glad i don't have to take the exhaust off anymore.