DIY Transmission Dyno
Thread Starter
Joined: Jun 2014
Posts: 1,241
Likes: 47
From: Noblesville, IN
DIY Transmission Dyno So this might be a little crazy, but I want to build a transmission dyno. I have no plans to hook any external sensors up to it, but I at least want to be able to test manual transmissions under a mechanical load. (So I guess a better term would be test bench?)
My plan is to use a 5hp, 3450rpm electrical motor from a compressor, and a pulley that has been welded onto the center of an old clutch disk (or if I can get a friend to machine a splined hub onto a pulley that works as well). The trans will be supported via a plate on the front that the case will bolt to, and a stand in the rear to simulate the factory trans mount.
For a load on the output I planned on simply using a steel disk, supported on the far side (so as not to damage any bearings or seals).
My main quetion is about the size of the pulleys I should use, and the size of the steel disk. I was thinking for the pulleys something in the rang of 2.7:1-3:1. I'm torn between keeping the RPMs of the input shaft of the transmission high enough to simulate driving conditions (something like 1200-1500 rpms) while also taking advantage of the torque multiplication so that the motor has enough power to turn the steel disk.
In regards to the steel disk I am trying to find the right weight and diameter. I know that the larger the diameter the larger the MOI (which is what I want. I want to be able to turn the motor off and let the trans coast down with the motor acting as a "brake"
So, does anyone have any recommendations? Thanks!
My plan is to use a 5hp, 3450rpm electrical motor from a compressor, and a pulley that has been welded onto the center of an old clutch disk (or if I can get a friend to machine a splined hub onto a pulley that works as well). The trans will be supported via a plate on the front that the case will bolt to, and a stand in the rear to simulate the factory trans mount.
For a load on the output I planned on simply using a steel disk, supported on the far side (so as not to damage any bearings or seals).
My main quetion is about the size of the pulleys I should use, and the size of the steel disk. I was thinking for the pulleys something in the rang of 2.7:1-3:1. I'm torn between keeping the RPMs of the input shaft of the transmission high enough to simulate driving conditions (something like 1200-1500 rpms) while also taking advantage of the torque multiplication so that the motor has enough power to turn the steel disk.
In regards to the steel disk I am trying to find the right weight and diameter. I know that the larger the diameter the larger the MOI (which is what I want. I want to be able to turn the motor off and let the trans coast down with the motor acting as a "brake"
So, does anyone have any recommendations? Thanks!
TWO 45LB barbell plates. should be able to get from academy or walmart. You will need to install a clutch I would think, otherwise you will damagethe gears while shifting. yes, I know you can shift in the car with no clutch, but its a different situation than a constant load.
Thread Starter
Joined: Jun 2014
Posts: 1,241
Likes: 47
From: Noblesville, IN
TWO 45LB barbell plates. should be able to get from academy or walmart. You will need to install a clutch I would think, otherwise you will damagethe gears while shifting. yes, I know you can shift in the car with no clutch, but its a different situation than a constant load.
Thread Starter
Joined: Jun 2014
Posts: 1,241
Likes: 47
From: Noblesville, IN
Oh absolutely. Fortunately I have a friend who works in a machine shop so I can make sure any hubs that are machined/welded are centered and everything is balanced.
