I got my truck on a dyno jet eatlier this week and it put down 230hp and 260tq. The truck is a 99 with a 5.3, 4x4 vinci 062(210/218 .551/.551 112lsa), thorley headers, custom cat back, nelson 91 octane tune, 4.56s and 265 tires. all run were made in 3rd gear in tow/haul mode with the air temp being 84* and 55% humidity. and the a/f was 14:1 all through the run, thats with the cats still on the truck dont now if that will change my a/f or not. so was i expecting to much from my motor or whats going on. I know its lean from the a/f reading i got.

 

HMMM,yeah seems low to me.My 03 tahoe stock with a 5.3 2wd put down 245rwhp and 284rwtq

 

Those numbers may seem a little low but dont use a dyno tune to deside how much power your truck has. A dyno is best for tuning, than pulling, and tuning some more to make improvements, other than that the numbers dont mean ****. If it feels like its running good and your tune is dead on, I wouldnt worry too much about it. My truck with mods in sig made a measly pull of 320hp and 320 tq, when most are putting + 40 to the ground with similar mods. My truck pulls like a raped ape, runs and sound great so I dont let the numbers bother me.

 

numbers do seem low. with the same cam in 110*+ ambient, pig rich i put down 290/318. get the 14.0:1 down to 12.8:1 - 13.0:1 and it should pick up power. how much timing are you running? this cam does seem to like a little timing, especially down low.

 

I dont have the capability to look at the tune all i can do is tell nelson what its doing and hope he makes the right changes to the tune. i need my own setup. another wierd thing is i had some pacesetter headers on the truck with offroad-y and it seemed to pull alot hard then it does now with the thorleys and cated y.

 

Was the converter locked?????!

 

The 4.56's could be throwing off your numbers as well, i know when i dynoed my truck i wasn't too happy with the numbers either but my tuner mentioned that the 4.10s were probably distorting the numbers a bit, along with my 20's.

Dyno numbers really don't mean anything anyway, its what it does on the track/street that matters. I had a 2000 z28 that only dynoed at 348 rwhp and ran faster than other cars that were putting down over 400. Dyno queens suck!

 

I would definitely start with getting your A/F a little richer. That is way too lean.
But like "OrlandoFL4.8" mentioned don't get too stuck on the number. Use the dyno to tune your truck to the best that it can do. There are too many variables involved, especially as the motors age. Something as simple as putting in the good gas, tune up and oil change can bring you up.

The gearing and the gear your truck is run in can make a difference.

I am looking at a 99 Tahoe Dyno (right now) with an intake and it is in the 220-230 Peak HP Range. So I would definitely say don't worry about it and use the dyno as a tuning tool.

 

Gearing should have no bearing on output numbers. If you put 3.73's it should read the same a 2.96's or 4.88's...

 

my truck in sig with the stock exhaust and no efans only put down 270/301 with about 10* of timing left in it. this was in june so i dont remember the temp but it was hot. like the others said, dont worry about numbers except track times and trap speeds