exhaust / cutouts / variocam

[Johnny Danger]

Virtually every aspect of the oem exhaust system is in some way restrictive . When you refer to the term "tuned", I don't think Porsche had performance in mind as much as they did keeping things OBDII compliant and Uncle Sugar off their back as far as emissions were concerned .

[Jake Raby]

Originally Posted by Johnny Danger

Virtually every aspect of the oem exhaust system is in some way restrictive . When you refer to the term "tuned", I don't think Porsche had performance in mind as much as they did keeping things OBDII compliant and Uncle Sugar off their back as far as emissions were concerned .

But you'd be amazed at how well they work.. even when adding up to 400ccs of displacement via big bore hotrodding.

Not a single engine of mine received any aftermarket exhaust system in 2010... The data supports my decisions.

[Idaho Red Rocket 3]

Jake,

Are you saying keeping the entire stock exhaust system on a 2000 S is the best choice ?

I was thinking of eliminating the main cats and keeping the stock header with the built in cat. Or... would it be better to get a set of tuned headers and keep the main cats ?

Is there a loss in low end torque with either of these mod concepts ?

[Johnny Danger]

Originally Posted by Jake Raby

But you'd be amazed at how well they work.. even when adding up to 400ccs of displacement via big bore hotrodding.

Not a single engine of mine received any aftermarket exhaust system in 2010... The data supports my decisions.

Jake,

With all due respect, I experienced a marked improvement in performance over the oem system after I upgraded to a set of custom headers that utilized equal length primaries, a merge style collector, along with a set of 200 cell HJS tri-metal cats, to include deleting the secondary cats and replacing the oem muffler with a custom cat back exhaust. This led to a significant increase in horsepower/torque throughout the entire power spectrum as evidenced through dyno testing. However, there was a substantial price tag attached to all of this, and it involved two very well respected "tuners" in Germany - M&M Exhaust and 9FF. Prior to this, I experimented with all sorts of configurations. For example, deleting the pre-cats and leaving the secondary cats in place, and vice versa . Or, going completely catless and alternating between the oem muffler and an aftermarket catback; so forth and so on. In most cases, my vehicle lost low end and mid range torque. Moreover, all of these approaches proved to be futile in terms of reliability (keeping the vehicle OBDII compliant and avoiding CEL's ect..) and making strides toward better performance. It wasn't until the latter was accomplished that I achieved positive results . In any case, I'll concede that unless someone is willing to commit the time and money necessary to improve the oem system, things are best left intact. Still, I can't help but emphasize the overall restrictive nature of the oem system. Especially, the superfluous function of the secondary cats and the equally inefficient design of the oem headers/pre-cats.

[Gator Bite]

Originally Posted by Jake Raby

But you'd be amazed at how well they work.. even when adding up to 400ccs of displacement via big bore hotrodding.

Not a single engine of mine received any aftermarket exhaust system in 2010... The data supports my decisions.

Perhaps the variables are different on your 996 and 986. On my 987, I did dyno testing before and after each of the three exhaust systems I installed. Each of them delivered about 15+ RWHP.

I changed the system more than 8 times, putting the stock exhaust back on between each install, in an attempt to cleanse my sonic pallette so I could best compare the new system to stock. The difference between the stock 987 exhaust and any of the aftermarket systems I tried was absolutely undeniable. In my experience, I didn't feel any difference down low, but from 5,000 up, the stock system just holds the car back. It's most noticable when you go back to stock after having driven the aftermarket for a while.

Believe me when I tell you, I'm not one of those guys that's going to tell you that my car felt so much faster after desnorking or performance air filter installation. I've tried those things and felt absolutely no difference. I'm a pessimist and it shows in my butt dyno.

[Johnny Danger]

Originally Posted by Gator Bite

Perhaps the variables are different on your 996 and 986. On my 987, I did dyno testing before and after each of the three exhaust systems I installed. Each of them delivered about 15+ RWHP.

I changed the system more than 8 times, putting the stock exhaust back on between each install, in an attempt to cleanse my sonic pallette so I could best compare the new system to stock. The difference between the stock 987 exhaust and any of the aftermarket systems I tried was absolutely undeniable. In my experience, I didn't feel any difference down low, but from 5,000 up, the stock system just holds the car back. It's most noticable when you go back to stock after having driven the aftermarket for a while.

Believe me when I tell you, I'm not one of those guys that's going to tell you that my car felt so much faster after desnorking or performance air filter installation. I've tried those things and felt absolutely no difference. I'm a pessimist and it shows in my butt dyno.

Gator Bite,

I concur with your assessment. However, in the case of my vehicle, there was marked improvement in low end torque "right out of the chaulks".