I know everyone here uses that dyno. Now my stepdad used it and I'm not so sure how accurate it is. His truck is a gasser: 1994 Chevrolet K3500 extended cab dually. It had a small performance chip, a K&N filter and a functioning cowl induction hood. That's it. ZERO engine mods...

The slip says 221hp and 524lb-ft of torque. I don't see how that's even possible. The Chevy guys say absolutely no friggin' way and that the dyno must be off. The motor would need some mechanical mods to hit that torque number with that hp number. Not a chance.

So with all these numbers being thrown around, how do you even know if that thing is calibrated?

I suppose it could be off, the shop is under new ownership, maybe they dont have it 100% figured out yet. My truck pulled about what I was expecting.

Who knows? The older TBI big blocks built dang good torque, but that does seem a little off. That's basically the same numbers my first gen Cummins puts down.

Is this an auto truck?

I dynoed mine there and it was exactly what I thought it should be

The HP sounds about right, but the torque is skewed. They may have had the optical sensor hosed. If the optical sensor is messed up you either get no torque reading or a skewed one.

It's got an NV4500 5-speed manual transmission in it. The torque has to be way off. The motor sounds good, but it's all bark and no bite.

Well, I was thinking with an auto truck you might have had some good torque multiplication.....it was a long shot in the dark. Sounds like your numbers got skewed somehow.

there is no way to intentionally skew #s with the dynojet 248c, nor calibrate as there is with the mustang dyno.

guessing it could be possible tom's comments on the optical sensor perhaps......

the few chev gassers our members had run on the dyno with similar hp #s sure had no where near that tq and the one i can remember with a similar tq reading to that had nearly 500 rwhp.

he may need to bring it to the march 7 dynoday and negotiate for a re-dyno to confirm that there was nothing out of whack.

now on a mustang dyno i've seen all kinds of screwy results due to bad operator input.

this dynojet has proven consistant on several rigs thruout the past almost 8 years that we have been using it for club events.

I'm with Tommy, that optical sensor can make your torque reading all sorts of screwy, does your readout show RPM? take a look at that and see if it's normal, I may guess it was only picking up scattered rpm signals and thought your engine was turning slower than it really was.

years ago I dynoed my dodge at brians tire in poky, I think it was also a dynojet, my HP was 648 but my torque was 4XX and that was at a peak rpm of something like 7000.... I was still VP powered at that time and redlined at around 3800. I think the HP was pretty close but everything else was way out there.

Good idea Muddy. I'm going to mention that to him today since we'll be wrenching on that truck. It has a miss and he seems to think it's carbon build up on a valve. It's super low mileage and from the PO's description, it could well be carbon build up. This truck has been a real PITA since he bought it.