I'm copying and pasting what I posted on another forum, as I don't feel like typing all this out again:


Ok, I have some results at the wheels. Our local dyno said mine made 307/313. This dyno is FAMOUSLY conservative, to the point that cars with known weight could not POSSIBLY run the trap speeds they do making as little hp as this dyno says they make. Prime example: my mustang trapped 137 mph with the 393 ford that was in it. It weighed 3200 lbs with me in the car. The dyno I put my truck on today said the mustang made 546 hp.

Also, I could not dyno the truck in direct drive, which would be 3rd gear in our transmissions, because it hit the damn speed limiter! It took me a pull or two to realize that. Running it in a lower gear generally hurts results at least a little.

So, take my results with a grain of salt, as most other people would likely see higher numbers on other dynos.

 

That seems about right. The 3rd Gens put down around 260. There is lots of drive train loss on these.

 

Nice idea man...You're lazy yet brainy like me...lol

 

I just took pictures of the results from yesterday. Here they are:

 

I think the dyno in Des Moines is 60$ for a pull. I would want to do a few runs though. I think it is 120$ for an hour.

 

Ok, So I think I am missing something. As I understand it shows less then 300Hp and just over 300 lb of torque ?

How about factory 390/407???

 

Those are crank numbers. All HP and TQ numbers you get from the factory are crank. After you factor in drive train loss you have the real numbers, or RWHP and RWTQ.

Generally 15-20 percent loss is what you can expect, with the good ones being closer to 15. The Rams are known for a lot of loss.

 

It made 307 and 313 ft/lbs. This dyno is also particularly pessimistic. Have no fear, our trucks are making at least what they're rated to and probably a little more. Based on weight and trap speed, mine actually makes more like 320 or a bit over. I'd tend to trust that over a dyno that I already know reads low.

 

thats exactly why ive never had any of my cars on the dyno...i just cant justify paying that much just to know how much power my cars make. id rather get an ET and trap speed then put it into a calculator...unfortunately, too many people do the opposite...they go to the dyno, get power and weight numbers, then say "my car or truck should run these times"...

 

It is one of those things where I would pay for it "just because". I do not plan on racing my truck. Well, maybe once...