why does the two dynos have a hp difference? which one is more true rwhp? what one is better? thanks, mike c.

 

i know the mustang dyno has 2 rollers while the dynojet has 1 roller, so since the car has to spin 2 instead of 1 thats probably why a mustang dyno will show less RWHP.

the mustang dyno will give a more realistic dyno numbers, like a car cutting through the air and as the car is moving, a moving car has a downforce on the road. (for me its hard to explain someone else can do a better job)

like i said the mustang has a more realistic reading BUT most people use the dynojet and if you wanna compare numbers a dynojet might be better for that.

 

Mustang dyno is a much better tuning tool. they set the resistance to your cars weight. that allows the engine to perform under the same load that it would see on the road. A dyno jet provides a set amount of resistance that has no relationship to what the actual engine load on the street would be. I believe (and could be wrong) that the resistance on the Dyno Jet is equal to a car weighing 2100#
Use a Dyno Jet for Dyno Queens The mustang is the real tuners tool.

 

either way they both will show gains made. One just makes you feel better than the other!

 

Mustang measures torque and computes horsepower as HP = torque * RPM / 5252 while the Dynojet measures the acceleration (difference in RPM) of the drum and computes horsepower from that with a much more complex formula.

The Dynojet will have an increasing error as the horsepower goes up. For instance, you dyno stock and get 310 HP, then do heads, cam, boltons, etc, and dyno 450 HP. That number should be higher because the greater amout of power accelerates the drum more rapidly, throwing off their power calcualtion. Even as a tuning tool, the numbers should be taken with a grain of salt. The Mustang does not suffer from this phenomenon.

In theory, the Mustang should be closer to "true" horsepower.

 

well put critter they also refer to the dynojet as an accelometer

 

do you still start from a low rpm and pull though the gear on a mustang dyno.

 

The typical way was to record in steps - 2000, 2200, 2400, etc. That can be easily done with a computer these days, and I understand that the Mustang can do that. I've heard that you can program the Mustang to simulate a dragstrip, where you start from zero and run up through the gears, and I believe you can program it to ramp up from a low RPM much like a Dynojet, except that you can program the ramp rate in RPM per second.

 

I have run a 1/4 on the mustang and it was within a tenth of what i actualy ran at the track N/A, when i tried it on the juice my car jumped and wheel hopped like a mother so i wont be doing that again. you can also do 0-60 and im sure some others i dont know of. When tuning i always just start at a low RPM and run it up just like a dynojet.

 

thanks for the replies,my car made 430hp on a dynojet.how much power would it make on a mustang dyno? THANKS.

 

It will make less Mike on a mustang dyno.

 

mustang dynos can also use 50 inch rollers similar to a dynojet instead of pinching the tires.