Went and had the truck dyno tuned today in conway at Carolina Speed shop. We didn't run it above 110mph which was a little over 4000 rpm. We were concerned with the drive shaft. So the number are a little low.
Motor is a 2000 4.8 5 speed with 35k miles
Mods-
TR224 on 112lsa
LPP long tube headers, no egr
K&N intake
Custom tune

Got 272HP at 4000rpm and 361 ft lbs of torque at 3950.

Whats everyones thought on the driveshaft? Is it safe to run it up to 140 mph to get it up to 6000 rpm where this cam will make its power?

 

Is it just me or is your A/F 15?

 

I have 3.23s and i took mine to the top of 3rd on the dyno and hit 167mph..wasnt smart, but it didnt break luckily.

 

No we got it down to 13.5 or so i think on the final run.

 

damn thats still pretty high !

 

how does the engine pull down low, cruising on the highway and whatnot? 300 lb/ft @ 3000 rpms is really impressive from a 4.8

 

Wow you put down 361 TQ? That is insane!

 

Haven't had a chance to drive it very much, just ran up to the dyno about 8 miles from the house and back. Tomorrow if the weathers nice i might take it on a cruise.

I'm pleased with the numbers for it being a 4.8.

 

Beyond insane... it's impossible. A 4.8L with a 90% VE at 4000rpm (a very stout street engine) would need to be making around 2-3psi of boost to make 360ft-lbs at the engine... let alone at the wheels.

Hate to burst your bubble, but those numbers are inflated... Look at the RPM/speed column. That number MUST be the same in each pull, as the final drive ratio x tire diameter does not change.

What size tires are you running? I'll calculate the correct rpm/speed value for you to see what it should be.

 

Thats impressive but I don't know man thats alot of torque.