Every time I add a performance part my truck it loses performance. My first mod to the truck was dual exhuast. Then I added a Hypertech PP3 and it would shift from 1-2 and 2-3 @ about 6000 rpms (WOT). When I added a UPD intake and an ASP pulley, the shift points droped to around 5800 rpm. Well, I recently put on a set of Thorley headers and removed the cats and it now shift around 5600 rpm. From a dead stop, my cousins 5.3 Silverado leaves longer skid marks than my truck and all he has is a flowmaster.(same tires, same air pressure, same body style) He ran a 15.3 @ the track. I haven't taken my truck to the track. Is this torque managment? Or is my truck getting old. Here are my mods-

99 GMC RCSB 5.3
Dual borla exhaust
HPP3
Thorley headers no cats
Descreened MAF
UPD intake
ASP Pulley

I have some NGK tr55s gapped @ 58, maybe if I close the gap to around 53 it'll help a little?

 

imo--the dual exhaust has moved your power band a lot higher. and all the other mods as well. with the hpp3 the shift points should remain the same.and i think the desreeened maf is hurting you as well.

 

What Denali said. Plus, you might be runnning into the false knock issue with that 99 PCM.

 

Agreed

What year is your cousins truck? The trucks sneak up in power every year.
Opening your exhaust such as you have will kill your low end. (Great for nitrous thou) TM only kicks in at the shift, it can be seen with a scan tool as a sharp drop to 0 in the advance.

 

If your cousins truck is a 00 he is bound to beat you even with less mods. Waht is weird is your shift point. Why do you they keep on dropping with every mods you add?...

 

i bet u dont have ur hpp3 set right

 

Sorry for the late respond, I was out tonight. My cousins truck pulls pretty strong for his mod. His truck is a 2000 so he has 15 more horses. I been with him when we go out to race other trucks and his truck pulls on most of them with similar or more mods. Not too long ago we beat a 99 5.3 rcsb pull about a truck lenght and a half to about 90mph. The other truck had a borla muff so they were about the same in mods. Whats up Tiburon, have you taken the truck to the track? I dont know why the shift points drop. I was thinking that the computer felt more power and retarted the timing a little which made it shift sooner? I am going to unprogram the truck tommorow and leave it like that for some days. Im gonna try to put on the MAF screen again. (haven't heard anything good about that mod)
Thanks for the reply guys.

 

I checked for info here on LS1Tech for the best settings on the HPP3 and came up with this setting: shift points set to +4mph 1-2, +12mph 2-3 and +0mph for 3-4. I have the shift firmness on, rev limiter @ 6200, and 128mph top speed. I cant remember the rest of the questions on there but I think these are the most important. Any thought on what I should do so the shift points go back to where they were?

 

those settings seem good.


ohya, get a cam if u want to even out with ur freinds hp advantage

 

Actualy, I have not. I am waiting for cooler weather and stickier tires. I have only played with my wife's Sierra at the track.