SKooT1027

I've got a few exhaust questions about 944 n/a's.

1) What size exhaust come stock?
2) Do most people just leave the stock one on?
3) If you change exhausts, can anyone recommend a good one for a fair price. (Prob 3", but whatever you've found to works and sounds nice)

Macfreak007

It seems like most people here reccomend Speed Force Racing as a good supplier for an aftermarket exhaust, I'm sure a few people will tell you to go that way, and I have been impressed from what I have seen and heard from them. Personally I would just keep it stock until something goes wrong with it, or you need to replace it. Stock sounds just fine for me, whatever you do don't put anything ricey on the 944, thats the last thing you need! I vote for Stock or SFR if you want to go aftermarket.

pearldrum944

Don't be expecting much power from exhaust. I would just keep stock. I did want a little bit better sound, so I got a cone filter and adapter plate from ebay for like $20. Now I am completely satisfied with the sound.

Techno Duck

Im pretty sure most recommend not going more than 2.5 inches on the piping as you would loose a fair amount of backpressure running 3 inch pipe. The stock piping diameter is 2.25 inches.

Like Macfreak said, the SFR cat-back sounds great from the videos i have heard. Would defenetley be on my list of modifications once i have a 944. Im not sure what type of gains you would get from removing the catalyic converter. The cat. is also pretty heavy...so you will get some weight savings also .

The stock headers from what i have read are the best for the n/a engine, even aftermarkets arent worth adding.

Dave951M

Ditto on the backpressure thing. If you go too large in dia on an na exhaust, you'll gain high rpm horsepower, but at the expense of lower rpm torque. Low rpm torque is what makes a car quick, not ultimate hp numbers.

buckshot

sfr!!!!
you would'nt believe the comments i get!!
buckshot wi

Ken D

I noticed this when I ran a GHL 2.5" cat back with a high-flow cat on my old NA. Stock diameter is 2.25". The 951 runs a 2.5" and it's pushing quite a bit more power.

tifosiman

I am still waiting for a dyno chart for an 8v 944 from SFR before I crack open my wallet. I want to see a gain in HP while retaining low end grunt. I am concerned that the the power band just shifts to the higher rpms.

I can't believe with all of the group buys and people extolling the virtues of the SFR exhaust there is not real data out there on functionality. All I hear is "sounds great" and "looks nice" when it comes to the 8v.

Fishey

You will not see much hp gain when in N/A trim...

however when flow becomes a larger factor the HP gains will increase and as far as looseing low end? I think you would have to remove the midpipes with something more free-flowing before you really started to see a loss because in reality cat-back makes very little diffrence in flow compared to midpipes.

Dave951M

Ken- you'll actually see more of a gain on a turbo car by going larger since it's forced induction. The back pressure in a na car helps with cylinder scavenging (insuring a fresh charge of fuel/air mix). The lower back pressure on a turbo allows the turbo to spool up faster and be more efficient in charging the cylinders. I'm running a test pipe and 3" "cat" back, only no cat, and I'm on boost a couple hundred rpm sooner than I used to be. Not to mention that with just the turbo and a free flow Dynamax muffler, it makes some really cool noises of the good kind.

Ken D

Right Dave. I feel the stock 951 exhaust is designed very well and suits my needs just fine. I am however adding a testpipe for the reasons you stated above.
I actually went back to my stock exhaust on my old NA (kept the high-flow cat) because I didn't like the shift up the powerband.

Fishey

testpipe + Catback = TurboBack

pearldrum944

How expensive are SFR exhausts?

Serge944

I stopped even caring about hp gains for the n/a. I wont even take the time to put my custom made test pipe back on....

Youre not gonna get much out of it.

My advice is to keep the stock headers, get a test pipe, and then a nice flowmaster 50 muffler. It wont be expensive and will sound great. Just stay away from the bursch systems, i personally had a terrible time with mine.

Techno Duck

http://www.speedforceracing.com/prod...tomexhaust.php

Catback for the n/a is $600. I dont know the exact price given, but two fairly large group buys for the SFR exhaust were held a few months ago now...i dont remember what each catback system came out too but it was a pretty large discount. If another was organized in maybe 2-3 months i would defenetley participate.