[Dave]

My '92 F-stock/daily driver has a few cracks in the exhaust. What's the common wisdom for replacement on the 968? I have heard there is no performance improvement, true? Best sound? Borla? B&B? Custom?



I do not mind if it's a bit loud as the car is a fully caged track beast that still has tags and does commuter/airport duty frequently.



Any and all suggestions welcome.



Thanks in advance,

Partial Post: Please Login or Register to read the full post.

[ds968]

I LOOOVE the sound of my BB catback ( no resonator option ) as have most 968 owners, and many others who listened to it. I understand Borla produces a very similar sound to the BB, but have not heard it myself.



Performance improvement has been the subject of much heated debate on these forums, and no one so far ( from what I can tell ) has been able to either validate OR disprove the manufacturer's assertions relative performance gain.

Partial Post: Please Login or Register to read the full post.

[Dave]

Thanks Dan. Any other insight from the esteemed 968'rs out here?

Partial Post: Please Login or Register to read the full post.

[flash]

working on new design - works on paper - still a couple of weeks from prototype though - these systems are very critical - more so than any other engine i've worked with - they work closely in conjunction with the intake - messing with the pulse timing results in torque dips - turbulance messes with the pulse timing - back pressure is also critial - unlike a turbo, reducing back pressure results in torque loss



having played with a couple of different things now, and seen the effects of a few different systems, it looks like we've figured it out - will be working on prototype the moment the roll bars are done



film at 11

Partial Post: Please Login or Register to read the full post.

[Eric_K]

The B&B has worked well for me. Its at least 20 lbs lighter than stock and sounds a lot better. I don't think you'll notice any other differences.



Eric

Partial Post: Please Login or Register to read the full post.

[Larry Currie]

I'm well pleased with the sound of the B&B.

Partial Post: Please Login or Register to read the full post.

[RS Barn]

I'm working on a cat back as well. Mine will be a little quieter than B&B. The muffler I use is high flow but not straight through. It keeps the correct back pressure and there isn't any resonance. Car goes to fabricator Wednesday.

Will update.

Pete

Note: Can add more noise for racecar. Doesn't add more hp.

Partial Post: Please Login or Register to read the full post.

[RS Barn]

Had car at fabricator today. Finsihed prototype and drove. Deeper sound at idle. Growl on acceration and quiet on cruise. Nice polished stainless tip. I will publish pricing and pictures next week. Will be very affordable.

Note: Can add more noise but without any HP gains

Partial Post: Please Login or Register to read the full post.

[flash]

sorry - won't get to mine for at least a week - gotta get the "chassis brace" project out the door first



this is fun though (how warped is that?)

Partial Post: Please Login or Register to read the full post.

[RickP]

Quieter than BB, correct backpressure, no resonance-quiet on cruise, deeper sound at idle, growl on acceleration, polished SS tip and affordable? Sounds like the perfect exhaust.



Rick

Partial Post: Please Login or Register to read the full post.

[kgain968]

Any more news on this?

Partial Post: Please Login or Register to read the full post.

[Brian]

i feel like i'm going to post this in several places, but i'll go ahead.

i bought pete's full exhaust from rs barn.

just got it finished up last night.

i could only drive it for a few minutes because the gasket sealer had to cure.



there is a definite performance gain. i'm just a novice, so i don't have any test results.

the thing really flies. i didn't notice any dips anywhere. the engine runs like a top.

it's got a very low, deep sound at idle. duriing accel, it really growls, but in a good way. not a mazda with a glass pack. more like an angry lion. (cheesy, i know). during cruising, it's not even noticable.



i'll take it out again tonight and really get into it since all the sealers will have cured.

it was very expensive. i'm sure that a cat back will be much cheaper. not sure the performance difference. this was my christmas splurge for myself.



i have a post around here somehwere else i'll update

Partial Post: Please Login or Register to read the full post.

[Alter Ego]

I also recently purchased the RS BARN CAT-BACK EXHAUST as well. My biggest concern when looking at an aftermarket exhaust was the issue of any droning at highway speeds. I must say that this is the quietest aftermarket exhaust while cruising on the highway that i have ever heard. And I have heard many over the years.



It is definitely louder at idle as well as when you are hard on the gas. But, not overwhelming. (Some more induction noise would be welcome - maybe need a proper cone-type intake filter with a velocity stack) This is a very nice understated exhaust with a bit more attitude versus the stock. The tip looks perfect on our cars and updates the rear a bit. With the windows down, the car definitely sounds like it means business. But, not enough to catch the attention of every car for miles around you. Unfortunately, I cannot compare to a B&B.



As for seat-of-the-pants power gains, it does seem to have more top-end power. This should pay some dividends at the tracks with long-straightaways.

Hope this helps.

Partial Post: Please Login or Register to read the full post.

[Greimann]

Just to add to the DNA of this discussion, I just saw a new product that Summit Racing sells. A slick setup with an electrically operated butterfly. A clever bunny could use this as a variable backpressure / noise control device that is either driver operated or actuated by some kind of control circuit based on operating parameters. They are originally intended as a cutout bypass, but used inline could be the basis as an adjustable exhaust system that is good for low and high RPM power. Just floating some ideas.







Summit Racing Cutout

Partial Post: Please Login or Register to read the full post.

[bob blackwell]

Thanks for sharing Dave. That looks like a very well made piece that will last for a while and it certainly will be more convenient than my Supertrapp was to vary exhaust back pressure as well as sound. There would be a weight gain with the extra pipe. Good luck, bob Blacckwell.

Partial Post: Please Login or Register to read the full post.

[S_Cal968]

Hmm, I can't imagine that elect. butterfly as being reliable. I'm very familiar with that motor and gearbox. Unless it's in cool air or very well insulated, it won't last long. Interesting idea none the less...

Partial Post: Please Login or Register to read the full post.

[Charles Geer]

I have a ceramic coated header back exhaust that hit me for 900 bucks. We lost 3hp and 3 ft pounds of torque but we gained enough noise to have me removed from several tracks...Great for shifting gears to the high pitched sound track but that's about it.

Partial Post: Please Login or Register to read the full post.

[RS Barn]

Charles,

If you are still going to campaign your car you should look for a used B&B or my cat back. I did lots of testing before offering. I can doccument my results.

Pete

RS Barn

Partial Post: Please Login or Register to read the full post.

[Charles Geer]

Pete Thanks:



I will be racing the 968 again first thing 2007. My exhaust will have to safice for now, mainly because I need to feel I got my money's worth. It does fine, we are pretty competitive in the car...no thanks to the exhaust. I'll let you know if I need to buy yours, I've got your number.



Again, thanks.

Partial Post: Please Login or Register to read the full post.