well i finally got my pacesetter LTs and gmmg chambered all hooked up, and i dont really feel any dif. actually feels kinda slower. THat cant be can it, i hope not went from a stock monifold and flowmaster to that. also feels like something is bumping or grinding sometimes, could it be the ORY pipe or the steering column? ANyways i hope its just me thinking crazy that its slower, if nothing else, it sounds mean as hell

 

Its faster. Take it to the track, the only way to find out.

 

It may well be slower. Headers often activate the knock sensor ("false knock") and the PCM pulls timing.

Rich

 

so i need to go pick up a lt4 knock module then?, also would i be able to pick one up at the local auto store?

 

Order one from Dal. I didnt notice anything with my LT4 KM. Hook up a scanner and see if youre getting knock first.

 

Yep look at what the PCM is seeing before you start buying stuff.

It could also be and exhaust leak fooling the O2s.

 

If everything is working corretly you should feel a huge seat of the pants improvement (AKA butt dyno) over what you had. I know I did and I dont even have Lt's.

It is possible that you might be getting som timing retard, just get the LT4 KM and rule that out first. Check your plug wires real good then take it to the dyno to see what is happening.

 

...and a tune.

 

Seconded

 

Get a tune.

Funny things happen when you start modding and you don't always feel the results. My little lt1 is barely making 15lb more tq than it was same time last year. But it makes 80 hp more.

Get a tune, then get to a dyno and the track.