Leaning towards GHL Exhaust???

[23109VC]

Originally Posted by jmatta

Find a welder to do this mod...for under $100, you can have a factory muffler that sounds great. I have Fabspeed secondary bypass pipes and a modded muffler; my car sounds incredible and NO resonance.

the bypass pipes are the ones that connect to the muffler?? I assume this means you have STOCK headers - not fabspeeds??

can you buy JUST the fabspeed bypass pipes but keep/use the stock muffler. I would think that would cut down the costs quite a bit...

[Cloudsurfer]

Originally Posted by 23109VC

the bypass pipes are the ones that connect to the muffler?? I assume this means you have STOCK headers - not fabspeeds??

can you buy JUST the fabspeed bypass pipes but keep/use the stock muffler. I would think that would cut down the costs quite a bit...

Yes you can. The stock muffler is actually not that restrictive, but the factory headers are atrocious.

[dja1980]

Have you seen this? I wonder if this would work on the "S" stock exhaust:

http://www.pedrosgarage.com/Site%203/DIY%20Making%20the%20PSE.html

[jmatta]

That is exactly the setup I have on my Box S factory muffler. That, coupled with the secondary bypass pipes makes a great exhaust. Look at the photos in my prior post. Don't know if it makes HP, but the throttle response is far better than stock. Downshift blips are immediate and without hesitation.

bmwm750; does anyone actually have realistic dyno results to prove the claims on the headers? Everything I've read doesn't make it seem worth the cost and hassle of CEL problems; hence, my choice not to go that route.

[Cloudsurfer]

Yes, there are a few sources of dyno results from swapping headers that do show an improvement. Both Turbowerx and FabSpeed have published dyno results of their products. Also, there have been several end users who have done the same on independent dynos.

The factory headers are horribly designed, so its not hard to see how one can get gains by getting rid of them. As far as avoiding CEL issues, I think the best solution is to load the RoW map into the car which simply ignores the secondary O2 sensors.

I am very happy with my setup. Combined with the light flywheel, it's a completely different car.

[Adam]

Originally Posted by bmwm750

The factory headers are horribly designed, so its not hard to see how one can get gains by getting rid of them. .

What?! Are you talking about these headers? I mean with the 90 degree turn into the cat and small diameter, unequal lengh runners that taper down and get even smaller before entering the collecter. I doubt there is room for improvement!

[Cloudsurfer]

Originally Posted by Adam

What?! Are you talking about these headers? I mean with the 90 degree turn into the cat and small diameter, unequal lengh runners that taper down and get even smaller before entering the collecter. I doubt there is room for improvement!

Yes those headers Apparently, Porsche must have tried all kinds of new tricks to get every last pony out of these motors with those headers LOL

[yellowboxster01]

Originally Posted by bmwm750

The stock muffler is actually not that restrictive,

True, but the stock muffler weighs a ton. When I took mine off my base 986, we put it on the scale...it weighed 47lbs. My Stebro race exhaust weighs 18lbs. I believe.

[ChrisZang]

Originally Posted by yellowboxster01

True, but the stock muffler weighs a ton. When I took mine off my base 986, we put it on the scale...it weighed 47lbs. My Stebro race exhaust weighs 18lbs. I believe.

Well,

by looking at myself I think I see a much better opportunity to save 30 lb in total weight (driver & car) w/o any mods to my Boxcar