I just got home from the Dyno a little while ago (dynojet). The mods are below. Because of my gears, the tuner only did a second gear pull. He said that in third with those gears he'd be spinning the dyno around 160mph and he didnt want to do that. The next step for me is to get 4.10s because I really think that will help, and will also give me a more accurate reading. I was a little let down with the numbers, but in a second gear pull I got 290 hp at 6100 rpm. The guys there said that a third gear pull would add about twenty-thirty hp. So I'm guessing that I laid somewhere between 310-320 rwhp with this setup. What's everyone else think? Does that seem accurate?

4.8 liter with 212/218 predator cam
Pacesetter LTs w/ ORY
Ported & Polished heads, 241 castings
Eaton Posi w/ 3.42
Dyno Tune

 

same thing i was told, i dynoed in 2nd with 3.23 gears... i just swapped to 4.11's ..

i think i made 305ish rwhp.... i put up a post a while back about it.. 3rd gear just gives you a more accurate number, because of the 1:1 ratio.. i made right at 400 on the juice... i just dont know exactly how much more you would see in 3rd?

what year is your motor?

just curious, it seems you would have made more than me.. mine has efans and magnaflows though, not much difference elsewhere... besides the CAI i have?

good numbers though man, those gears will really wake it up! i did the eaton/4.11 swap about 2 weekends ago. it goes sideways whenever i want it to now.. fun fun!

 

its just a shame the 4.8 can only see 320 ftlbs at an RPM level you will never be able to drive at.

Sounds fun though man!

 

It looks like you have the same cam I do. It's a 2001 Silverado. I get traction without a problem at any speed. With 4.10s you think it'll break them loose from a roll? It just seems like with this work I would have made a little more power. What plugs are you running? Also, how far does second gear run with the 4.11s I can take 2nd to 98 with the 3.42s.

 

Sickredsierra...How many miles does your truck have? I want to do a 75 dry shot, but my truck has 86k on it, and its been a hard 86k lol.

 

mine is an 07, with 40K miles already! i spray 100 shot dry all the time, but i went rich on my afr, kept my timing at 26* at WOT, and i run NGK TR-6 plugs gapped at .035".

and 2nd gear runs to about 88mph or so.... if i remember corectly, BUT, 3rd gear now pulls like 2nd gear used to!! it used to be a turd when it hit 3rd, but it pulls like a bitch now! i tach out in 3rd around 130ish mph.

with the 3.23's i could get 110mph in 2nd, i shift at 6400rpms though. this cam pulls hard up to 6500.

and yes, the gears change the responsiveness alot. i had one wheel puling before, so i couldnt hook from a dig on the street... but now i can... it just goes a little sideways. its fun though!

 

you're also running the stock stall. Even though the cam is not overly large, the 4.8 naturally lacks the torque that the larger CI engines do. A 2800-3000 stall and you won't be able to get traction either. Plugs won't make much of a difference, if they are old or bad, run stockers or some NGK TR55's. And honestly, I wouldn't give 2 ***** about the power made on a dyno. Get you a torque converter and some 4.10's and some damn good sticky tires, and you'll be pleased with the results.

 

Did you get it dynoed at race related on monday evening?



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yup, Jeremy tuned it, he's awesome!