just wondering if anyone could have an explanation as to why my truck quit making hp at around 5500rpms. my cam is in my sig. and it should pull well beyond that. n/a it pulled to 5900 and would have pulled farther if not for the truck intake. so why with the radix did it quit so early. it was pulling 10.5psi of boost until 5400rpms and then started falling gradually, but at 6000rpms it was still at 9-9.5psi. any opinions???

 

Are you running a 5.3, or 6.0? I've got a 3.2 pulley on mine, and I'm making 10# of boost. If you've got a 5.3, I don't think you need to go much smaller than 3.0.

 

ive got the 5.3. but i do have a big cam, and longtubes, and mild p&p of the heads, that might lose a little boost.

 

Better exhaust, yes. Still doen't explain the drop so soon. You have the springs and the Radix intake.....You should be spinning all the way up. Could it be the tune?

 

Going Lean?

 

What did your A/F ratio look like?

 

were you data loging at all? there are a few diffrent things that can make you dbw tb close and that will kill power for sure. were you on the dyno? if so is you speed limiter set high enough for the dyno runs? i would check everything in the tune.

 

i think the boost drop was due to belt slip mainly. but it should pull higher in the rpms.

 

A/F was 11.1 most of the way and started climbing to a max of 12.0 at 6000rpms when he shut it down. heres the dyno sheet.

 

yes it was on the dyno, and im almost positive that the speed limiter was set as high as it can go, this is the 4th time its been dynod. and i cant check the tune, but i will get the shop to go over it.