View Full Version : True or False?


darkcrave
09-21-2008, 02:48 AM
found this while on another form:confused:

"DynoJet Dyno's simply use a large drum, of know mass, as its rotating resistance...Then rwhp is calculated based on how your "acceleration/unit of time" of the drum occurs...

From what I am told the Mustang dyno gives you a "true" or real world rwhp... i.e. my '00 FRC put down 307 rwhp stock, using 12% drivetrain loss and that is 348 flywheel hp (factory rated 345 hp)...My '02 Z06, on the same Mustang dyno, put down 348 rwhp stock, divide that by 12%, using the same 12% drivetrain loss is 395 fwhp (factory rated at 405 hp)

Dyno Jet Dynos give more of a bragging rights rwhp...

The difference between the two is about 10%...Dyno Jets registering the higher hp readings...

Yours for example...358 rwhp Mustang Dyno vs. 405 rwhp DynoJet...358/405=.884...Pretty close to the 10%...

Last comparison one of the F-body guys posted on LS1.com was the something like the following...338 rwhp Mustang vs. 378 rwhp DynoJet...338/378=.901

On the Mustang dyno that I go to...Stock LS1's in F-body cars dyno in the 280~290 rwhp range...Yet nearly every LS1 F-body that posts rwhp using DynoJet Dynos are in the 310~320 rwhp stock...285/315=0.905

Again...285 rwhp using 12% drivetrain loss gives 324 fwhp, factory rated 320 hp...If you use the DynoJet hp, then you get the following...315 rwhp with 12% drivetrain loss gives 358 fwhp, factory rated 320 hp...So you see, it sound great to think these engines are putting out this kind of power, but it's just not as realistic of a number as you get with the Mustang Dyno..."

SUCK MY SS
09-21-2008, 02:57 AM
mph can always back up hp claims...

Vndcatr
09-21-2008, 03:00 AM
So, Something that takes horsepower to spin it(mustang dyno -load bearing) .. Is considered true ?..

But yet something that spins by rotating mass.. (dynojet) is uncorrect..

I think it should be flipped around. Mustang dyno's are some power robbing dyno's..

z28berryhill
09-21-2008, 03:12 AM
they have nothing to do with each other but we are dealing with the word mustang here guys

BS@PMS
09-21-2008, 03:56 AM
mph can always back up hp claims...

Thats more of a gearing game too. Some cars are decieving.

travie319
09-21-2008, 11:41 AM
It sound as if someone is trying to justify his or her own numbers.

hlaalu
09-21-2008, 11:59 AM
How does a dynojet not account for drivetrain loss if it is measuring power from the rear wheels? Does the engine connect right to the rear wheels?? :lol:

Dissident
09-21-2008, 04:50 PM
There's several factors in dyno's which is why everybody says it's nothing but a number to tune by. Even dynojet's have different versions of dynos. On top of that, there's a variance if they're corrected or not, or how they're 'corrected'.

Add in the difference in drive train loss between cars and you can see how much variance there is.

My point is this. You put a car on a dyno to help you dial it in. It doesn't really matter what number your car makes (provided it's dialed in correctly) because it'll still run the same regardless what another dyno says. The idea is to get it dialed in.