A friend of mine has a 2004 Reg Cab GMC with 5.3L, G80, and 3.42 gears. Only mod he has is a predator programmer. My 2005 Crew Cab feels faster, goes through the gears quicker, shifts firmer and quicker, he even drove my truck and agrees that my truck feels faster. At the Track his truck went 15.10 @ 91.x and my truck went 15.22 @ 90.9 this was on the same night. The time slips were almost identical in 60ft 330ft, and 1/8th mile and he was just a lil quicker in the 1/4 mile. I'm trying to figure out why my truck feels faster than his but the track times show different. Is it weight, or maybe gear ratio, or ? any other suggestions?

 

I'm no guru, but I would think it is b/c your gears are shorter than his. Shorter gears do get the engine's rpms up quicker, which should make your engine work a little less to get the truck up in the powerband.

Question... did the power rating change b/t '04 & '05? There's possibly some PCM config changes too. Can anyone answer that question?

 

a louder motor/ride will throw your butt dyno all out of whack. im willing to bet that noise is the culpret.

 

I think the motors have the same power rating but they did go to the e-fans in 05 so that should account for a lil more power.

 

I am guessing that your lower gears give more of a push in the back at certain points in the torque curve of your engine. His engine may have a more linear (constant) torque curve. He is pulling less weight than you are, but his taller gears make up for his weight advantage so that you both accelerate at the same rate over a distance.

Mike

 

I wanna know why these new crew cabs are so damned fast with very little mods? lol

 

Three83, does your truck have that 310 HP, all aluminum 5.3? If so, this could be one reason why your truck feels faster. Your 3.73 gears may have something to do with the power too. You could be a better driver...

 

I tell you this much.....The first 05 Crew Cab I test drove had the 3.23 gear and I was very disappointed. Then I came across this one and it just happened to be the exact truck I wanted and it had 3.73 gears. When I went test drive it there was a night and day difference.

There is also a night and day difference in good air and bad air. When I ran these times I heard someone say the DA was like -200, the temp was in the upper 50s, and it was one of those rare days where the humidity wasn't near has high as it generally is here in Louisiana. My previous truck was a 00 Ext Silverado with K&N FIPK, Hypertech, 160 t-stat, and flowmaster and had a best of 15.30 @ 89.8mph in the same type weather mentioned above.

My goal is mid 14s on motor (without internal motor mods) and mid 13 or faster on spray. Headers, ORY-Pipe, Yank TT2600, Under Drive Pulley, Volant Air Scoop, and a 75 - 100 hp shot should get me there. Just gotta save the money to do it. I'll be sure to have it on video for the non believers. I know a few people that have <certain type truck I won't mention the name of> and they think this puny 5.3L isn't cable of running such times.

 

I don't think it is the 310hp motor, I think those only come in the 4x4 trucks. I'm sure this is the 295hp motor.

 

Do the two trucks have different seat styles? I ran into this while trying to figure out why my Honda *felt* faster than my truck, even though speedometer rates of climb and 0-60 clockings indicated very much otherwise. It turns out the truck seat backs are concave, and give very good support to the upper back, so that my body barely moves under acceleration. OTOH the Honda seat backs were convex, with support ending about midway up my back. My upper torso was thus free to be pushed back even under the slightest acceleration. To test the theory, I put a small (12") pillow against the seat back of my truck, so that it would support my lower back only, and leave the upper part of my body free to move. Believe me, it felt like I gained 200 HP. Not sure if this is what is going on, but it might be a possibility.