4.8L Project Horsepower - One step at a time

[farmtruc]

Got a good update for you guys.
Did some real comparisons.

Here is the cam install update.
(i lost the 270hp dyno chart, not sure how, but here is the closest thing I have, it was before I started tweeking)




For this round we added the Pacesetter longtube headers, ORY (off-road y) and kept the stock muffler.

Here is the dyno chart with LT's added. Previously installed: tune,cai,220cam,stock muffler.




Here is a comparison , Cam and stock manifolds vs Cam and Longtubes (catless)
Keep in mind this is with the stock muffler and still 87oct.





I really wanted 300hp to the wheels with this setup! I knew it was possible.
Next dyno run: Final mods- tune,cai,cam,lt's,stock muffler vs removed muffler:




I didn't think this cam would pull this far out, but check it out, 7K RPMS!

[farmtruc]

Want more?

Let's recap.

We started out with a 2004 GMC Sierra, 4.8L, regcab short, auto trans.
Installed one part at a time, and following up with a dyno run for each mod.
Mods:
Stock Truck
Shiftkit-servo
Nelson Tune
UPD Cold Air intake
220 .581 -112 Comp Cam
Pacesetter Longtubes Headers

Here's a chart showing each modification and how the truck grew froma weak 4.8L to a healthy street fighter!

Next up, 3600 Yank Converter - we don't expect any power from this, just quicker 0-60 and 1/4 mile times.

[George C]

Want more?

Let's recap.

We started out with a 2004 GMC Sierra, 4.8L, regcab short, auto trans.
Installed one part at a time, and following up with a dyno run for each mod.
Mods:
Stock Truck
Shiftkit-servo
Nelson Tune
UPD Cold Air intake
220 .581 -112 Comp Cam
Pacesetter Longtubes Headers

Here's a chart showing each modification and how the truck grew froma weak 4.8L to a healthy street fighter!

Next up, 3600 Yank Converter - we don't expect any power from this, just quicker 0-60 and 1/4 mile times.

holy lean batman

it seems like decent cams in a 4.8 pull till 7k. you still dont have hte torque of tht one guy

nice progress steps

[CHEVROLADE]

DAMM REAL NICE,ALLEN YOUR GOING TO MAKE ME SWAP MY THUMPER CAM OUT lol

[farmtruc]

holy lean batman

it seems like decent cams in a 4.8 pull till 7k. you still dont have hte torque of tht one guy

nice progress steps

DAMM REAL NICE,ALLEN YOUR GOING TO MAKE ME SWAP MY THUMPER CAM OUT lol

haha, i know, i need to remove the a/f ratio from the graph.

i was thinking this cam would fall off around 6300 or so, kind of odd for a 112.
I've done comparisons with a few vettes, they act different.

chevrolade: i'm sure you're cam is making good power too. have you dyno'd it yet?

[GasGuzzler]

I used the fan description here before too...

[gmjoe2490]

So if I was to use these same mods on a 6L would I see the same results or more?

[stssilverado]

OK, now put it in a package with labor and a price and let us know how much it costs all together installed out the door. I'll drop it off next week!

[farmtruc]

So if I was to use these same mods on a 6L would I see the same results or more?

Depending on what truck it is, you should see more HP.
However, having a 6L, you'd probably want a bit more cam, also depends on how you're gonna use the truck.

OK, now put it in a package with labor and a price and let us know how much it costs all together installed out the door. I'll drop it off next week!

Ok, I'll post up a total later.

[SlvrSierra]

Why no 93 octane tune?