Thread: 3" DP = no lowend myth...

I agree with you guys that once your IN the throttle hard it will make power. What most people complain about, and I can vouge for this on the supercharged engines, is that in town driving in light throttle situations the car may feel a bit more lazy. Most guys that install headers notices this right off the bat if they do a lot of stop and go driving where you arent using much throttle and the responce falls off. WOT is a different story and the power gain is usually worth the offset down low during normal driving. Some people are just more picky than others, I have heard from a lot of people locally about how they didnt like the loss in low end driving around, but everyone is going to have their own opinions.

Originally Posted by 99GT2dr

I may not be noticing this because my cruise timing is bumped up a lot. With stock timing, I imagine light throttle would be lacking in power. But who are we kidding? Nobody modded drives around at "light throttle" anyways.

Um, I do? I certainly don't feel the need to get into boost from every stoplight.

I will say, though, that when I was running non-boosted I didn't notice much of a reduction in off-idle response when I went with a 3" Random Tech downpipe and converter. My first "setup" was the Wizair, UD pulleys, and U-Bend removal with a SLP Loudmouth cat-back. Now THAT suffered off the line and I didn't gain jack up top to make up for it, really.

I went back to a stock cat-back and then went to the downpipe and dropped two tenths while picking up 1.5mph over a downpipe that already had the u-bend gone. With stock mani's and cat-back I didn't notice any low-end loss, but you could probably credit the stock exhaust for that. I think with a 3" downpipe and open 2.5" exhaust that off-idle response would suffer.

It DEFINITELY did once I went with TOG's. They absolutely killed any feeling of torque that the L36 had and I actually got slower by a tenth. Even with the M90 now it still feels a bit soft on the bottom end. Ah well.

I've experienced the lack of lowend torque on both an 05 3.8 NA and my 04 3.8 SC when opening up the exhaust. However as, Dave has pointed out this is low throttle positions, low rpm situations.

Originally Posted by 99GT2dr

Are you guys tuning your car yourself, or are you just running a canned PCM? A lot of people that complain of the lowend loss also don't tune their cars, just bolt this or that on and expect more power.

Going from stock to a 3" DP and PEM's or headers definately requires a tune, that's a BIG jump over the stock setup.

I was merely running a canned DHP 1.0 at the time.