Dyno questions???

[B767DRIVER]

A couple questions relating to the dyno...

1. If I change my 3.07 gears to 3.55 will it effect RWHP/RWTQ numbers? If so how?

2. If I change to a lightweight flywheel will it effect RWHP/RWTQ numbers? If so how?

I know the effect of these changes on the car. I have a friend who has both and have driven his car. I'm just curious how these changes will translate to dyno numbers?

Thanks!

 

[GR8_ASP]

First question is what kind of dyno and under what type of test.

If it is an inertial dyno (like a Dynojet) then the answers are:
1. yes, it will reduce the measured torque and horsepower as more of your engines energy will go into accelerating the drivetrain (fatser rate of drivetrain speed increase)
2. Yes. It will reduce the drivetrain inertia and appear like an increase in torque and power.

If it is on a power absorption dyno, the results will depend on the dyno test but in general will not impact the results (if it is near steady state or controlled based on the dyno schedule then they will have no effect).

 

[B767DRIVER]

First question is what kind of dyno and under what type of test.

If it is an inertial dyno (like a Dynojet) then the answers are:
1. yes, it will reduce the measured torque and horsepower as more of your engines energy will go into accelerating the drivetrain (fatser rate of drivetrain speed increase)
2. Yes. It will reduce the drivetrain inertia and appear like an increase in torque and power.

If it is on a power absorption dyno, the results will depend on the dyno test but in general will not impact the results (if it is near steady state or controlled based on the dyno schedule then they will have no effect).

Thanks..I use a Dynojet. Are we talking single or double digit changes?

 

[Viper X]

Check the archives, but I'd guess your readings on the dynoject would go down about 3% when changing from 3.07's to 3.55's. I think Sean Roe commented on this subject a year or more ago.

 

[steponz]

Larry Macedo has said the same thing... Its around 3%.

joe