Originally Posted by Billup

Gundo hack if you don't feel like forking over big money, but, I did just install a Billy Boat Engineering exhaust just yesterday, and I'm pretty pleased with the sound over stock and install was really pretty simple. Did it on the ground in the parking garage of my apartment complex. The full kit was about $1,300 I believe from LMPerformance. Only thing that really sucked was it took almost a month to get here.


With that said, I originally bought Agency Power muffler bypass pipes (remove muffler and run open cats), drove it for one single trip, went back in the garage and put all the stock stuff back on and ordered the Billy Boat. Way happier than running open cats, and the exhaust itself didn't really break the bank. Next step will be headers and go piece by piece.

Originally Posted by Schnell Gelb

Replace with stainless steel studs. There are kits on fleabay if you measure thread pitch/ length/diam. Get serrated flange nuts too.

Originally Posted by David993S

Keep in mind that just adding headers does not make an engine breath more fully. If the engine isn't taking in more air, headers aren't going get more out. I'd suggest some kind of loud muffler if loud is what you're going for (and a different muffler isn't going to give you more hp either......contrary to claims from some performance muffler builders.)

Originally Posted by murphyslaw1978

Well, stock 996s are really quiet. Straight pipes are extremely loud. Stock 996s are actually quite "flowing," and you're not going to get a lot more horsepower adding headers and changing the whole exhaust. 996s already have headers.

I performed the gundo hack on my car, and it's not quiet anymore. It's actually decently loud. So you could do headers and mufflers that are lite and open, and it will sound great and loud.

Originally Posted by Hotrodaxel1976

Hey thanks for this information, sounds like this is a great option. If I had my car here I would know what To order and remove. But she is still at the Indy.

Originally Posted by johneecatt

I street/track a 99 996 and to track, we put on 997 headers and straight pipes (with oxygen sensors = no CELs). Did a light chip (for pump gas - in CA it's 91) and it dynos 260 (228 torque) to the rear wheels. But it's REALLY loud - cup car loud. So for the street, we put on a Supertrapp rig (yes - like the bikes). So it's still loud - but not 'get ya pulled over' loud (at least I never got stopped). And you can change the Supertrapp off and on in about 10 minutes, when you're on the track.
As for the chip - it's invisible. Put back the stock exhaust and it passes CA DMV with flying colors.
With the Fister cans, I have 4 exhaust options. Works out great!!

Originally Posted by Billup

As long as you know what year and whether its a C2, C4, C4S, etc., then you'll be good to order.

Before installing I put a scale up to make sure both inlets were the same diameter as stock, everything checked out. After removing / adding / removing / then adding exhaust one more time, the whole thing took maybe an hour and a half with hand tools start to finish.

Originally Posted by johneecatt

I street/track a 99 996 and to track, we put on 997 headers and straight pipes (with oxygen sensors = no CELs). Did a light chip (for pump gas - in CA it's 91) and it dynos 260 (228 torque) to the rear wheels. But it's REALLY loud - cup car loud. So for the street, we put on a Supertrapp rig (yes - like the bikes). So it's still loud - but not 'get ya pulled over' loud (at least I never got stopped). And you can change the Supertrapp off and on in about 10 minutes, when you're on the track.
As for the chip - it's invisible. Put back the stock exhaust and it passes CA DMV with flying colors.
With the Fister cans, I have 4 exhaust options. Works out great!!