i saw my friends racing in ¼ of mile, one in a stock 4wd single cab 03 silveado, and the other in a brand new 07 4wd single cab silverado, the 03 beat the 07, about 3 times by a car. why is that? isnt 07 supossed to have 15 extra hp?

 

Actually from 2000-2003, the Vortec 5300 series produced 285hp. The 075.3 is pumping out 315hp. I could be a gearing issue, but I find it hard to believe the stock 03 is beating a stock 07. When I bought my truck (stock), I raced BigTexasChevy who has a 07 Z-71 and he beat the **** out of me. Even with all my current mods I'm only half a truck on him from a roll, but he kills me off the line because he has 4.10's. I'm not saying it isn't true, it is just very interesting.

I am assuming that both trucks are 5.3's. Can you find out what engines they have?

 

SC, yes sir, they are both 5.3L engines, single cabs and 4wd. i rodein my friend¨s 07 with him, and i could feel the difference between his new truck and mine. lotz of difference buddy.

 

That is really impressive the 03 was beating the 07. Man, I agree the 07 is in a league of its own of the factory line. Makes me sick how much power they have stock!![:@]

 

I heard that the new trucks have the 4,8 engines.In other words a four cylinder when going slow and a 8 cylinder when you need the power. Is this true?

 

I have heard the same rumor. I definitely want to find a way to disable that if I can. Bugs the **** out of me that my truck won't break the wheels loose from a dead stop at all.

 

The new trucks do have the option to drop to 4 cylinders, but only when not needed. For example when cruising on the highway, and no load or flat. But off the line they will always use all 8 due to the weight of the truck.

 

Cylinder deactivation technology or (cylinder-shutdown technology) was developed in order toconserve fuel. They tried it in 81 with the Cadillac however, it failed. Of course modern technology has improved this technology and it really isn't that bad. When you need power on demand (8cylinders) just press the accelerator and off you go, but set the cruise on a trip and enjoy the improved gas mileage by shutting down 4 cylinders. I reasearched and this system does not impact you performance. Here is a some excellent reading on the subject if you are interested.
http://www.sciam.com/article.cfm?cha...D083414B7F0000

By the way, the correct terminology is (AFM) Active Fuel Management, which was formerly known as Displacement on Demand.

 

ive heard my 99 has the cylinder-shutdown technology but you have to run out of engine coolent before it works. it shuts down four cyclinders to prevent heat in order to get you home/near water..

 

I think I have this on my truck too. no matter how hard I bury the accelerator i can't seem to get the other 2 cylinders to kick in. It feels like I am driving a v6 all the time.