A tune.

 

A cam. With a cam you will probably need a tune. Headers vs cam is an incredible price difference though and you won't even feel the full power of a cam without headers so.....

In response to TooTall's reply I would not get a tune if you are thinking about getting a cam in the future, you might as well wait

 

Depending on the cam you probably want to do cam and headers at the same time, as the new cam (depending on how aggressive it is) will be pushing more air. You'll need a tune to tie it all together.

Gotta pay to play, OP.

 

Chevy's specs say the engine produces 355 HP @ 5600 RPM.

What am I missing here, and why is more power necessary? I understand better performance, as I have a tune, but more power?

 

That 355 is at the crank, that's where all manufacture hp ratings are measured.

318 at the wheel is a pretty good improvement.

As a stock truck is below 300 at the wheel.

Sent from my iPhone using Tapatalk

 

Chevy's specs say the engine produces 355 HP @ 5600 RPM.

What am I missing here, and why is more power necessary? I understand better performance, as I have a tune, but more power?

Big car go vroom

 

Depending on the cam you probably want to do cam and headers at the same time, as the new cam (depending on how aggressive it is) will be pushing more air. You'll need a tune to tie it all together.

Gotta pay to play, OP.

Yes I been told that, I was going to add headers only but I seen and was told get both and get it returned again. We shall see thanks.

 

Watch this

. Richard Holdener is by far the best source of GM power on YouTube.

 

20% + or - a little is the usual loss when comparing "engine HP" vs. "rear wheel HP"

 

Chevy's specs say the engine produces 355 HP @ 5600 RPM.

What am I missing here, and why is more power necessary? I understand better performance, as I have a tune, but more power?

Wat

 

Thanks

 

Watch this

. Richard Holdener is by far the best source of GM power on YouTube.

how is he getting 398 hp and 427 tq out of "stock 5.3"

 

Nitros and that's at the crank.

Sent from my iPhone using Tapatalk

 

no, that was his baseline before headers and before nitrous. with headers and nitrous he got 600 and 550

 

Premium fuel and all the ignition advance it can take. He also was under near perfect conditions in an air conditioned dyno room. Remember when GM stamps a power rating that engine needs to do that at any altitude and at the highest temps. Also keep in mind the amount of weight a truck has. That effects how much ignition timing you can throw at the engine on low octane fuel. Richard just shows you the max on an engine dyno. My guess is he was running every trick in the book to show just how much better the LT engines are.

 

Texas speed had an L83 on the dyno that was also stock. It made 410hp and 430ldft of torque. They show the graph of that engine and compare it to the cams they offer.

 

Premium fuel and all the ignition advance it can take. He also was under near perfect conditions in an air conditioned dyno room. Remember when GM stamps a power rating that engine needs to do that at any altitude and at the highest temps. Also keep in mind the amount of weight a truck has. That effects how much ignition timing you can throw at the engine on low octane fuel. Richard just shows you the max on an engine dyno. My guess is he was running every trick in the book to show just how much better the LT engines are.

got it, thanks. do you know what altitude they are rated at? is it the same across all manufacturers?

Texas speed had an L83 on the dyno that was also stock. It made 410hp and 430ldft of torque. They show the graph of that engine and compare it to the cams they offer.

I guess that is also with premium and ignition advance?

+45-55 hp and tq still seem like a lot off of premium and advance. if that's it, why don't tuners (diablo) advertise gains like that?

also, to achieve that, are they loosing low end tq, ie 2,000 rpm and below?

 

The old saying was 20% loss through the drive line. This is starting to be proven wrong. The major engine dyno experts are now on a thought of 100hp plus 1-5%. So if the OPs truck put down 320 to the wheels this lines up with what the engine dynos are showing. The L83 is just under rated from the factory. It's more common than you think. They just rate them low so the can't be sued. The low end torque would not be effected. The VVT is still active. Most dynos don't work well at low engine speeds. It causes some type of loading issue from what I have been told. That's why they typically start at 2500-3000. Also the big thump stick graphs would make people cringe when they realized that cool sounding cam lost 50-100lbft of torque at 2000 and below. The major cam companies would never show you that on a dyno graph even if they could.

 

So what type cam would you suggest? My 5.3L is a 2000 model. Chevy Silverado 4WD

 

You might make a new thread with your vehicle info and what you want to do, as your engine is very different from the o.p's, even though they are both 5.3's...