I just had my car dynoed wit a Mustang Dyno. How do the results compare to a Dynojet.
I heard they read lower but by how much?

 

about 10 to 15% lower on the mustang dyno.

 

I heard 11%

 

the best way to find out is how each of them calculate the numbers they get. in that lies your answer.

 

Not correct, its the opposite...

Actually, the Mustang dyno is very accurate, but only till around 400rwhp. It has a twin roller design as opposed to a single roller setup on a dynojet dyno, but if its a new mustang dyno they are designed for higher horsepower applications so they can be just as accurate. Demetrios K. (Reactive Racing) dynoed his car about 3 years ago on a dynojet dyno and made 500rwhp, then with the same exact setup, made no changes what so ever, dynoed the next week on a mustang dyno (same temps & humidity) and dynoed at 585rwhp.....
So it really depends on how new the dyno is and how much power your making. If your tuning on stock twins, any dyno will suffice.

 

We have an interesting thread in the Candaian forum regarding this. Out of the three rotory motors the Mustang has seen in our town two have blown up on it. Some were suggesting the additional load the mustang puts on the car might be one of the causes, anybody have any thoughts?

I know ErnieT suggests differently but from what I've seen and heard the Mustang reads lower.

 

If I recall correctly the mustangs read higher.

 

The local Mustang Dyno here reads lower than a DynoJet.

A friends BPU FD dynoed 285 on the Mustang dyno and 325 on a DynoJet.

Really is how the dyno is setup. Every dyno is different you make them read higher if you like.

 

Dyno's are very sensitive to everything. When I did my n/a FC last time, we picked up 10 rear wheel lbs of torque, just by backing off the straps that hold the car in place! 10lbs of torque, may not seem like alot, but when you have a n/a car it is! CJ

 

Higher, lower....

This whole discussion only underlines that chassi dynos are totally useless to determine exact power output. If you want to measure that exactly, put your engine in a proper test cell.

Bernd Kluesener