Jake951

Check out this article. Do you get the feeling they don't like the Dynojet dyno's?

pk951

Interesting article what to make of all that info? Are they saying that a lot of the claims people make about hp is way over inflated thats how i read it.

toddk911

Interesting as I just watched a car show recently and one of the well respected tuners said they only use the Mmustang as it gives more realistic numbers, which I know many in here say they give too low of a number.

Maybe it's not low but more realistic and the dyno jet is overly optimistic in it's results.

macnewma

It really only matters when you are looking for a number to brag about. If you are looking to tune your car it is all relative and should be used for benchmarking.

Max

OriginalSterm

agreed, good way to base any improvements made by modifications or changes made in a/f ratio or boost.

rage2

I hate quoting numbers on the net (especially the Honda forums)... it sucks. If I don't post numbers (ie I beat a viper at the track posts), people don't believe the power and want to see numbers. If I post numbers, I'll be met with an onslaught of "the numbers look wrong" when I post a car with big numbers. It's a lose-lose situation.

When tuning, I use the same dyno and look for changes between runs. That's what dyno's are intended for. Unfortuantely, people want a comparison with other vehicles, and thus we're all forced to post dyno numbers. Mustang dyno's 13% lower than dynojet, dynojet 16% lower than flywheel, Mustang 31% lower than flywheel... it confuses everyone.

I personally prefer the Mustang dyno over the Dynojet dynos. The mustang dynos are way more accurate in reproducing real world loads, and have the ability to "hold" certain rpms (well, wheelspeed) to allow you to complete a full map in really short amounts of time.

Jeremy Himsel

Agreed. A mustang dyno is without a doubt the better dyno to tune on as it comes the closest to simulating "road driving" conditions.

Dynojets on the other hand comes very close to representing factory BHP claims (if that's what you're after). On a dynojet, a new ZO6 will put down about 350 RWHP (the ones I watched were lightly modded and made 360). Take away what you lose in the driveline from the factory numbers and the DJ is pretty close.

rage2

Yea, there are several conversion factors that I mentioned that are fairly close for most cars. I spent a day last year dynoing several cars on the same day on several dynos to come up with the numbers.
Your Z06 example of 350whp, multiply by 1.16, you'll get 406hp flywheel. Run it on a Mustang dyno, and I'll bet it'll get close to 310whp (350 / 1.13). Good enough for any bench racer!

fast951

The best way to use a dyno is for a before/after graphs... A load dyno, such as the mustang, is much nicer for tuning.

rage2

IMO, a loaded dyno is a REQUIREMENT for tuning, especially with turbo'd cars. On a dynojet, I have a tough time getting enough load to make the same amount of boost I do on the street, without resorting to tweaking the boost controller.

Jake951

I've noticed the same thing. Boost builds more slowly at lower rpm's on the Dynojet than it does on the street. As a result I think the Dynojet underestimates power/torque in the boost rampup region (around 2500-3500 rpm in my car). On the high end I have to readjust my boost controller by about 1-2 psi to get the same boost as on the street.

K27

Don't even get me started on some of the hp claims I hear on speed channel from guys that have not even been near a dyno
there was one last night, he said to the presenter, this car is makin 400......er 500 hp.
Well which one is it ?, surely if you dyno a car you are not out by a hundred hp ??, obviously he had no idea and had simply sat down with a calculator and added up all the advertisers numbers for all his bolt on's

jsonnen

IMHO the only true dyno is a chassis dyno......no slippage whatsoever......and no BS!