So I went to the dyno today and I was expecting A LOT more tan what I had. It was an inertia style dyno and it said I was putting down (RWHP)297.8 @ 70 MPH??and 710.9 ROLLER torque @ 70 MPH. It doesnt show a RPM on my paper just MPH. I have a 302 bored to a 310 with all hyperutetic internals, 10:5:1 compression, MSD ignition, full exhaust, matching heads, cam, and intake (eldelbrock) Holley 650 double pumper, 373's in the back with an 8.8. I mean this thing gets up and goes but I thought it would have a lot more than that. I have beaten everyone that I have raced and one of which was a high 12 sec (like 12.9) truck. So what gives.I was expecting like 350-400?? The onlt time I jumped above 300 was when I shifted my self and then it hit 314 hp....any help or does this sound right??

 

From what i remember reading somewhere, you should avoid them inertia type dynos. I dont remember the reasoning but im sure you just experienced it [:'(]. Hope it didnt cost you too much....

 

So long as your wheels aren't slipping, RPM & MPH are a fixed ratio for each gear. That means you can go out and drive your car at 70mph and see what the RPMs are in each gear at that speed. It will always be the same ratio (unless something is slipping). So you should have no trouble figuring it out yourself.

 

I thought it was the drum style ones to stay away from. Where you are hooked up to a heavy drum and have to pull it.

 

From what I've heard, they actually overestimate your power.
Don't forget that Ponylove, you are talking 297.8 hpat the wheels which should be about 340 at the crank. For a 302 that sounds about right. Give us your full engine specs and so we can get a better idea.
BTW, my basically stock 289 (mild cam, headers, 4 bbl) puts down 190 rwhp, so you are putting down an extra 110 over mine.

 

Yeah, definatly stay away from the "drum" dynos. Ive just heard to avoid the inertia ones. But if you live in the boondocks like i do, you cant be picky unless you plan to have a road trip.

 

What is the right kind of dyno that gives the most accurate reading?

 

There are actually ALOT of dyno machines out there. From what i hear, its The Rototest Dynamometer which can be found here; http://www.rototest.com/index.php?&D...&Visitor=2

In my opinion, its either a Dyno Dynamics ora Dynapack.

 

For a 302 I'd be more than happy with that.. I'd be horribly skeptical if it was 400hp on a n/a 302.

 

You have two basic types of dynomometers,Dynojet and a Mustang Dyno. You are describing dynoing on a Mustang dyno which will always read lower than a Dynojet.Most speed shops in DFW have the Dynojets. If you were to dyno on a Dynojet, you would probably see closer to 330-350 rwhp.

297 on a Mustang dyno is a decent number, nothing to be concerned over and probably rightin line with your mods.