I can't see it being the exhaust...I still have the cast manifolds and y w/ cats on my LS1 and it pulls like a raped ape up top. I have the TR 224. I would think it's something other than the exhaust holding you back.

Did you put springs in w/ the cam? Maybe you're getting valve float up top? I'm wondering if it isn't a valvetrain issue somehow...

 

And, I'm still running on the stock 4.8 tune for the most part (all I did was bump the rev limiter and shift points up IIRC.)

 

Yup put in CC 918 springs. Weird, maybe it is just the tune. Guess I'll find out this Friday after the dyno tune.

 

Any chance a crank relearn would be causing this? I was just reading an old thread about it and problems it causes. Right now I keep getting a P0300 misfire detected code, which I assume is from the cam almost killing the engine at low rpms. Also I used the cam & crank sensor from the LS1, instead of swapping the ones from the 5.3.
Are the sensors possible different?

 

I don't know. I used all of the truck sensors on my swap. If you have no tune at all, it might feel sluggish b/c it's shifting so early. You'll need to run it up to 6400-6500 or so to really feel that cam.

Best of luck w/ the tune. Post up your b/f and after #'s.

 

Maybe I'll try swapping the sensors tonight.

Right now I'm shifting at about 6K. I'll get the numbers posted up after I get back.

 

Their ya go, or be like me and unbolt the exhaust before the muffler and ride. Keep us updated!
Philip S.

 

Well I did the crank relearn yesterday and modified the Main VE table. I blended the 5.3 and LS1 tables together, since I'm kind of running a hybrid. On the way to work today it drove much better, had a lot more high end than before.
So I can't say if it was the relearn or VE table that did it for sure since I did them at the same time.
But either way I'm happier with it. Can't wait till Friday.