Put my 6.0 on the Dyno!

[Dirty_Stroke]

I finally got a chance to put my truck on a dyno, Saturday. I have alot of questions and I am also posting a video because the dyno operator wasn't sure how to dyno the truck and I wasn't either. The truck kept trying to downshift so he had to run it from like 80mph and up to keep it in Overdrive. The dyno was a Dynojet but it was a 3000lb roller and we made the dyno pulls on a 20% load. I was told after the fact that most diesels are dyno'd on a 5000lb roller and the 3000lb roller was inaccurate and showed low hp numbers??? So my questions are:

1. Was this the correct kind of dyno?
2. Is Overdrive the correct gear to make a run in?
3. The guy gradually rolled the pedal to the floor on all runs. I thought you was suppose to stab it to the floor and hold WOT to get a correct number?

My truck made 460 hp and 910 lb-ft. I thought both numbers were low considering I've seen a couple trucks with stock injectors and the SPD tune lay down 450/980 or so.

[windrunner408]

I would say your numbers are about right considering your turbo is stock right? JMO.

[Six0~Stroker]

I THINK you guys did it wrong..... You need a custom Dyno tune that locks the tc early (like in third)



It is NOT supposed to try to downshift during the runs... That will spike the hp levels and give an inaccurate answer.

[TheFordman87]

I think you do it 1st - 3rd thats some of the runs I've seen. But as well maybe even all gears. If I remember correctly the one guys had his tact out but he had his rev limiter set to 3500 rpm and he said it was hitting the rev limiter at 13x

[Dirty_Stroke]

Originally Posted by windrunner408

I would say your numbers are about right considering your turbo is stock right? JMO.

Yes the turbo is stock. But would a 460rwhp truck run 8.6 1/8th mile times?? That doesn't seem right. I figured it would be around 490-510 range. Also FWIW, my bro in law put his Cummins on the same dyno right before me and it laid down 411hp. He called his EFI live tuner and the guy swears the exact tune he is running laid down 467 on a DUALLY and that the dyno is off. Does the smaller roller effect the numbers? I would assume it would.

[Dirty_Stroke]

The truck got up to 147.8 mph!!! I thought that was pretty cool lol

[windrunner408]

IDK man. Maybe try it on a different dyno.

[Dirty_Stroke]

Is Overdrive affecting my numbers too? I do plan to put it on another dyno soon. But I want to make sure how to "properly" dyno.

[MWilbur516]

First off, your dyno operator was clueless. Second, you don't need a dyno tune with a properly equipped and knowledgeable dyno operator. They can lock the TC and hammer down without down shifting. If the truck down shifts the numbers will be affected.

That being said, I think your numbers look pretty close to what I would expect. Maybe a little low, but 155's aren't putting out much more fuel than stock, especially if you still have the fueling limitations set in your FICM's stock tune. I would expect about 460-475rwhp from your setup. Thats just my opinion. You need someone to dyno your truck who dyno's diesels and knows the in's and out's. Congrats on the numbers BTW, they are very respectable. And remember, if it runs good and turns good track times, don't worry about the dyno numbers.

[toren302]

I started a thread about this issue too. My numbers were low. I had vivian write a dyno specific tune, that would lock the converter early and it wont shift out of 4th. With all of that it only gave me 30hp. Went to the track today and based on the times and using power hungry's calculators I am putting down 475. the best dyno run I had was 402. My next step is a FICM tune.