Variance Between Mustang Dyno & Dynojet

[Z28boy2000]

Just wondering what the difference is between a mustang and dynojet, my buddy dyno'd 408rwhp on a dynojet and this afternoon put down 361 on a mustang dyno. What causes the variance in the HP#'s

[00z28bubba]

dynojets are supposed to be pretty lenient with power numbers, at least that is the rumor. but mustang dynos seem to take into account more variables, maybe not but if you want a dynoqueen pull, take it to a dynojet. never really asked the question myself. i just went with the consensus.

[Mikat1]

your tune is only as good as your tuner.

[Vexzer]

difference is between a mustang and dynojet

Mustang is a "brake" dyno, meaning the motor operates against a measured load. It can even be held at a steady speed against the load. Useful for driveability tuning or simulated track testing. Imagine a Mustang Dyno as a motor-drived water pump where you can close down the water valve and make the motor work harder -or even choke down the motor, like driving a car up a steeper and steeper hill.

Dynojet is "inertial" or accelleration dyno. It calculates, rather than measures, how much power was required to speed up a known load, basically how fast it can speed up a heavy solid drum. The drum always weighs the same, but from motor to motor, power is calculated by the computer.

Both ways of measurement can be fudged by a couple of factors having to do with inputting incorrect vehicle weights and poor use of correction factors.

[Z28boy2000]

your tune is only as good as your tuner.

i strongly agree!

[Z28boy2000]

Mustang is a "brake" dyno, meaning the motor operates against a measured load. It can even be held at a steady speed against the load. Useful for driveability tuning or simulated track testing. Imagine a Mustang Dyno as a motor-drived water pump where you can close down the water valve and make the motor work harder -or even choke down the motor, like driving a car up a steeper and steeper hill.

Dynojet is "inertial" or accelleration dyno. It calculates, rather than measures, how much power was required to speed up a known load, basically how fast it can speed up a heavy solid drum. The drum always weighs the same, but from motor to motor, power is calculated by the computer.

Both ways of measurement can be fudged by a couple of factors having to do with inputting incorrect vehicle weights and poor use of correction factors.

great info

thanks

[FASTEDDIE Z]

The Mustang reads @ 13-14 % less than the Dynojet . The dynojet reading always looks better . But I believe the mustang is more beneficial when tuning .

[Mr. Luos]

The Mustang reads @ 13-14 % less than the Dynojet . The dynojet reading always looks better

Not always.
Operator can easily change factors to make it look better (on either dyno).
Had a friend dyno the exact same on a Mustang and a DynoJet. Different days though.

Ideally though, you are right with the normal variance between the two.

[Vexzer]

Not always.
Operator can easily change factors to make it look better (on either dyno).
Had a friend dyno the exact same on a Mustang and a DynoJet. Different days though.

Ideally though, you are right with the normal variance between the two.

Mustang can also test rolling resistance, emulate road course testing, and test speedometer compensation.

[Zinergy]

Mustang dynos have lower numbers but are better for testing and tuning, dynojets are for people who wanna say i made 400whp with a cam only ls1.

[Z28boy2000]

Mustang dynos have lower numbers but are better for testing and tuning, dynojets are for people who wanna say i made 400whp with a cam only ls1.

[Mr. Luos]

Mustang dynos have lower numbers but are better for testing and tuning, dynojets are for people who wanna say i made 400whp with a cam only ls1.

I personally could care less if I dyno 531 on a DynoJet or 440 on a Mustang.
As long as it is popping off upper 11's at my altitude consistently....I am good.

[LS2Tuner]

Besides the fact of the brake system versus the inertia deal they (Mustang) use a whole different calculating factor.

[carnut7202]

Yea I have a buddy that worked in a shop here in dayton ohio he said they had a dynojet and that no matter what was ran on it it always added 15-18% more than the true numbers because it soundes better