I have a 05 Silverado with a LM7 5.3. I recently installed a 228R Comp cam in it along with
1.) Ported 706 heads w/ pac 1218
2.) 30Lb Injectors from an 8.1
3.) Cats punched
4.) Ls7 lifters and chromoly pushrods
I have 4.11 gears as well. I took it to go get tuned, on a dynojet i believe, and it only made 270 rwHp. Forgot the torque. Is this normal?? I feel like it should be a lot more. There was a guy on another forum that made 351 rwhp. Why such the big difference? This is really bothering me. Anyone have any thoughts! Thanks

 

Probably a mis-match of parts. I have a few questions.

Tire size?

No headers?

Stock torque converter?

Cold air intake/modded stock airbox?

How high (rpm) was the pull on the dyno?

That's a pretty large cam in a small 5.3, and I'm assuming it doesn't have all the supporting mods it needs. If you have tall/heavy wheels & tires, it's probably the wrong cam choice for you.

 

Thanks for the reply! Tire size is 33x12.50. It is a pretty big tire. It shouldn't make that big of a difference on the dyno with 4.11 should it?
Stock Manifolds
stock torque converter
stock air box
The rev limiter is set at 6300 rpm this is where it stops making power. The guy that made 351 rwhp everything else stock as well with less mods. Still confused as to why there is such a big power difference.
It will get a stall converter after transmission goes out.

 

You just listed your shortcomings on those dyno numbers. A shorter & lighter wheel and tire package by itself might net you another +50 hp or more. And you at least need to mod the stock airbox, let that thing breathe! I bet it makes power past 6300 if it can get some air!

 

About right for stock manifolds with a big tire. Put a set of LTs on there and it will pick up tremendously.

 

yeah man that truck isn't breathing at all... You need full bolt ons and a great exhaust for sure... I know you probably got excited over a cam, but you should have done CAI, LTs, and exhaust first.

 

For example, i'm pushin 260 rwhp on my 06 silverado cc on 20x12" rims and 32x12" tires and all i have is CAI, TBS, LTs, exhaust and a tune. everything else is stock

 

Thanks for the feedback guys. It's kinda sounding like 270rwhp is all that i'm going to get with the set-up right now. What are your recommendations on longtube headers and cold air intakes? What's the best for the truck? Probably not any ebay cheapies huh

 

Ebay headers work fine. You might want a stall to for the big cam

 

Best bang for the buck by far!
Seems to be in stock, grab a set while you can.
Speed Engineering 25-1012+25-1014 - Speed Engineering Truck SUV Longtube Headers & Y-Pipe (1999-2006) | Speed Engineering

Do alil work and seal it up to hood and its good to go.


Catbacks, if you dont already have a decent setup.
http://www.amazon.com/s/ref=nb_sb_no...p%20cat%20back