Observations From Dyno Day

[AndyClary]

We ended up checking eight cars, I’ll just opine about the “standard” T’s. One car has a stroker crank, A manifolds with a zenith carb and a Z head. This was built for cross country touring and pulled 28HP. The other five cars were very similar. All had been rebuilt at some time and were in good mechanical condition. Three had Z heads, one had a Prus head and one was a 15 with a standard low head. The low was a tick under 18 and the high was a tick over 20. I would consider this to be about normal for your average modern T built for touring.


Andy

[TXGOAT2]

Rear wheel horsepower?

[AndyClary]

Yes. Tested on a Dynojet Dyno.

Andy

[TXGOAT2]

Not bad. The Ford driveline is fairly efficient, it seems.

[Kevin Pharis]

Chassis dynos have a correction factor to add in the HP lost between the flywheel and ground. Some may have this number dialed in, but suspect with our T’s it’s just a WAG. This example is set to 8%

[big2bird]

The high head had 2 hp more than the low head?

Lots of other factors like valve grind cam, fuel delivery, ignition,timing, balance, age, blah blah.

[AndyClary]

I think the five cars were really close to the same combination with the low head being the outlier. They all ran good, no misfires, carb adjustment close but all were a tad rich. Coils or distributors didn’t seem to factor in. I think it was a good selection of the typical T owner. Note that the car with the big crank and carb made fairly decent power. I’ve driven this car and it does run good.

I agree with Kevin that there is probably a correction factor involved.

Andy

[Dodge]

The normal accepted power loss thru the drivetrain in modern car is 15% on average. Thats going thru a hypoid rear end and big fat tires.
I'm guessing our Model T's with skinny tires (less drag) and straight cut gears in the rear end is somewhere in the 8-10% range.
Looks like a great day on the dyno for all.
I can see why the Mercury never knows its going up a hill.....

[TXGOAT2]

Automatic transmissions can consume significant power, too. Taking advantage of modern lubricants can cut parasitic power losses in Model Ts. Radial tires, if available, might further reduce power loss.