How much Torque???

[blacksheep4x4]

I had my 90hp injectors from Dynomite Diesel installed last week at thier shop.

They did a dyno run on my truck but the dyno sheet only shows HP. It dynoed at 347 rwhp. What do you guys think it made for Torque?

 

[gsbrockman]

Lower 700's or upper 680's +++.



Greg

 

[JGrosso]

TQ=(HP*5252)/RPM



Torque can be calculated for each RPM from the above formula.

 

[JSellers]

torque calculations

TQ=(HP*5252)/RPM



Torque can be calculated for each RPM from the above formula.

Yes, but this will be different for torque at the crankshaft, vs. torque at the rear wheels. If you use rear wheel RPM - since that's where the HP is measured - you will get a torque figure that needs adjustment by the torque multiplication of the gear ratios through the drivetrain.



You'll need to figure ratios with the specific transmission gear used in the dyno run, plus the axle ratio.



Just a caution, since the calculations can be a bit confusing.



From my reading, I thought dyno measurements also outputed torque curves, as well?



Hope this helps,

John

 

[ASchwartz]

Try the link below.



AJ Horsepower Equations



Avi



P. S. Is that dyno number with injectors only and no box? It seems a bit low for the banks system and injectors.

 

[blacksheep4x4]

Try the link below.



AJ Horsepower Equations



Avi



P. S. Is that dyno number with injectors only and no box? It seems a bit low for the banks system and injectors.

This dyno run was done on my 06 Megacab with only the injectors. Dynomite diesel did the dyno run on thier dyno. The dyno sheet doesn't even give rpms only mph. Kind of hard to figuire out the torque without the rpms. The truck made 347 rwhp at 75mph.

 

[ASchwartz]

This dyno run was done on my 06 Megacab with only the injectors. Dynomite diesel did the dyno run on thier dyno. The dyno sheet doesn't even give rpms only mph. Kind of hard to figuire out the torque without the rpms. The truck made 347 rwhp at 75mph.

Drive 75 on the highway and write down the rpms. Then use the calculation.



Avi

 

[JSellers]

Drive 75 on the highway and write down the rpms. Then use the calculation.



Avi

This torque calculation will be off by the drivetrain losses, since you need to use rear wheel RPM if the HP is measured at the rear wheel.



You need to use rear wheel RPM. If you have MPH, you can calculate rear wheel RPM from that measurement. Then use the torque equation - factoring both HP and RPM at the rear wheel.



I'm still confused that you didn't get a torque curve output from the dyno run. Does this parameter need to be enabled for all dynos? Don't the operators know to turn them on before a run?



Hope this helps,

John

 

[ASchwartz]

If the dyno does not have an rpm sensor, then the torque number is not attainable. They usually place a piece of reflective tape on a pulley or other spinning part and pick up the rpm off that part. Funny thing is they calculate the torque based on the rpm of the engine.



Avi