alconk

iTrader: (1)

Hello, I just changed the cam in my 2001 GMC Sierra RC 2wd stepside and it feels lazy??? These are my modifications done. LQ9 6.0, LT headers w/ electric cutouts, 4.10 w/ Eaton posi 3500 stall, shift kit in tranny w/ cooler. I bought the LQ9 as a new crate motor then installed Thunder Racing 224 .563 at 112. This also has the Beehive springs and there pushrods. This setup made this truck perform amazingly fast. It had excellent response and a nice lopey idle but more to the mild side. Well, I decide to change the cam one more time so I went with Texas-Speed Comp TQRV2 cam which has a 232/234 and a .598 lift with a 113 LSA. I had them also retune the PCM. I just started it tonight and drove it for about 25 miles and I'm somewhat disappointed. It feels kinda lazy compared to the other cam and it's not much bigger. I just wanted more of a racy idle which also is kinda the same also. What has happened?? Do I have to give the computer time to adjust?? Please if anyone has any suggestions please send them my way.

rollinna65

iTrader: (18)

There's nothing wrong with your truck, the cam you swapped in just has a different powerband than your last. The TR224 is known for being a very torquey cam which is exactly what you want in a heavy vehicle like your truck. Your new cam should make more power up top but your going to have to wind it out more to feel it. You could either swap the 224 back in(which I doubt you'll do) or you could throw in a bigger stall so you don't notice the midrange power you're missing with the new cam. Did they set your shift points higher when they retuned the computer?

Gold Z

iTrader: (3)

Rollinna65 pretty much nailed it. The bigger cam makes less horsepower in the lower rpm range which makes your truck feel sluggish down low. The tradeoff is more horsepower in the higher rpm range. Your gas mileage should be lower now too.

alconk

iTrader: (1)

Shifts points are still at 6 grand or maybe it's 6200. They told me that I would notice more mid and loose some bottom end which I was willing to sacrifice (it's all over the road until around 40mph). I did notice the speedo climbs faster from 70 on up but just don't feel it??? It that true about the PCM learning the new program?? They told me it takes about a hour of driving to do so???

alconk

iTrader: (1)

THis truck isn't a daily driver and more for show go gas mileage has never been a issue. It's actually put up for the winter now but had to take it out to test the new cam.

GTObsessor

iTrader: (2)

if you wanna get the most out of it, get it up on a dyno and have a pro tune it.

rollinna65

iTrader: (18)

Maybe they're supposed to be lower since you're driving a truck but those shift points seem kind of low for a cam that big. Have you dynoed the truck with the new cam in it yet to see what the powerband looks like? I bet it peaks a little bit above 6200 in which case your shifting too soon to get the most out of that cam.