Mods in sig, but problem is when running around 75 or 80mph...stand on it so its WOT, the rpm's jump to 5000 and run up to 6100, and it shifts. well at this point I am right around 100mph, but when it shifts, it drops to around 36 or 3700rpm's and it takes it FOREVER! to get on down and around to 120mph...? what is causing this and is there anything that can be done about it relatively cheap....? Thanks in advance!

 

it is normal on these trucks. if you want more topend, put a cam in it

 

The shorties don't help much and the superchips should be replaced with a custom tune to take full advantage of your engine throughout the rpm range. I noticed a huge difference when I changed from a handheld tuner to a custom tune. I got more power everywhere. Topend was perfect. I also noticed the SOTP difference when changing from Flowmaster to Magnaflow. And the drone at highway speeds was gone which is what I wanted in the first place. I was like alot of newbie's I bought a handheld tuner, Granatelli mass air , throttle body spacer, shortie headers, these things did not do much for performance and now I know better NOT to spend my money on crappy products. My 0.02

 

 

HANDHELDS & SHORTIES LONGTUBES & CUSTOM TUNE