nathan96

My car seems like it has lost a lot of low end torque after doing the installs (pacesetter long tubes). I am not gettting any SES lights though. After about 3000rpm the car picks up and feels really good. Is this just normal, including the somewhat lopey idle? The car is an M6, so does it just need to be launched at a higher rpm than before? I am a bit confused if someone could offer some advise it would be great.

RamAir95TA

It's most likely normal, and believe it or not, a psychological thing.

When I added a cutout, my car certainly felt slower. Turns out I picked up .2 from the track. With true duals and long tubes, the lack of low-end is something that you'll need to get used to.

disco192

Give the car time to reset the BLMs and make adjustments for the added flow. Low end TQ will not be too bad if you did duals with X-pipe and something other than bullets or the like.

nathan96

Would an lt4 knock module be a good idea? I noticed a lot of other people had added this. There is an x-pipe, but there are just spiral-flows about 18in before the rear bumper.

brain

I doubt you have actually lost any power or torque anywhere. Either the car is not running correctly, such as the knock sensor pulling timing, or its the placebo effect. My car gained power EVERYWHERE from 1200 rpms up. I had the same feeling as RamAir when I did a cutout, it felt a lot slower, but worth a good .2 and 1 mph at the track.

nathan96

Well, the tires do not break free in first nearly as easy as before the install. This would lead me to believe that there is something not quite right in the low end, I guess the only way to know for sure is to get it dynoed and check the numbers.

disco192

you very well might have lost some low end, it depends on the setup. I would just doublecheck all your plugs and wires. Check the grounds and make sure you havent melted anything. Then get the sucker tuned. It could just be running rich and not advancing the spark enough. You also could be getting knock retard. Its hard to say without feeling it.

CamaroSS30thAnn

with the long tubes it would be a benefit of getting an LT4 KM....maybe getting some false knock from teh added noise and u are losing power.......or u can geta tune form madwolf or pcmforless.....u dont really need it but it would be to some benefit

tagz

I have the same set up... pacesettter long tubes into a 3 inch true dual with an h pipe dumped before the rear axle. Everyone gave me so much **** about losing low end power. I definatly lost some but nothing to complain about. When i get the 3.73s in there, i think it shuld pretty much even it self out with the low end.

But as you said, the car hauls *** around 3k rpm. You'll get used to it.

BadAssed93Z

its psychological like RamAir said,before your car was pretty fast and quiet, now its way louder than it is fast. my car seemed slower the louder it got.

vin1382

I posted a similar question a week ago. I installed a cut-out and noticed i couldnt even spin the tires off idle anymore. and i used to be and to punch it at 20 mph and break the tires loose. Now with the cut-out on, it feels alot slower downlow. I thought something might have been wrong...but from what i've read..this seems normal. Dyno it or take it to the track. only way to really tell.

david97gsxr

the reason it "feels" slower down low is because better flowing exhaust(or a cutout) moves the peak torque further up in the rpms. it has to do with scavenging, there is no optimal exhaust setup for an engine that has a very broad rpm range. but the best idea is to go with what makes more power in higher rpms. since, during a drag race, you're only at less than 3500 rpms once. smaller exhaust(or more restrictive), will have more of a scavenging effect at lower rpms, at higher rpms the air is trying to be forced out so fast that you really just want the best flowing exhaust possible. in general.

here is some good reading http://web.camaross.com/forums/showt...essure+exhaust

disco192

Yea, thats a good point. You will gain TQ, but it will be higher in the rpm range. I just added ported heads to my car and right now i am running open headers. I cant spin the tires when i gun it from a start and dont dump the clutch, but if i leave it in 1st around 30 mph and THEN gun it, it will spin like mad. I am pushing 400 TQ, but because of the open headers, it kills the low end TQ off the line and shifts the powerband much higher.

nathan96

I noticed when I went to put the car away last night that there was an SES, so I thought I would check to see if it was just the rear o2 sensors. Nope, it was a P0300. I must have a bad plug or wire that is causing this. I really do have a problem. I think I am still going to try and get the lt4 module, but I am going to have to pull the plugs out and check the wires to figure out where the miss is at.

got_hp?

probably getting false knock...........after my longtubes/duals, i started getting up to 7*