Blown motors at the Runoffs

[kr]

Not sure if it applies to other types of gearboxes, but SADEV USA in North Carolina offers gearbox dyno services at their rebuild shop.

KR

[Hardingfv32]

To properly dyno the FV trans requires that it be powered by approx 60 hp. That is a serious electric motor and measurement system. The internal loads have to be accurately applied inside the trans to learn anything.

Both the power source and axle outputs have to be measured with load cells. I would use a race engine for the power source. It would have to be on a gimbled frame to take a load cell measurement of its output. This engine cell is mounted on the trans test chassis. The axle outputs need to be controlled by water brakes and measured with load cells.

All this is doable at a reasonable price but would require a sizable test stand/chassis.

Brian

[BLS]

To properly dyno the FV trans requires that it be powered by approx 60 hp. That is a serious electric motor and measurement system. The internal loads have to be accurately applied inside the trans to learn anything.

Both the power source and axle outputs have to be measured with load cells. I would use a race engine for the power source. It would have to be on a gimbled frame to take a load cell measurement of its output. This engine cell is mounted on the trans test chassis. The axle outputs need to be controlled by water brakes and measured with load cells.

All this is doable at a reasonable price but would require a sizable test stand/chassis.

Brian

And if you are going to do that at normal max RPM then with the ratio required for a 4 pole electric motor of 1:2, you will need a 120hp motor and drive... Pretty pricey stuff.

[Mark_Silverberg]

To properly dyno the FV trans requires that it be powered by approx 60 hp. That is a serious electric motor and measurement system. The internal loads have to be accurately applied inside the trans to learn anything.

Both the power source and axle outputs have to be measured with load cells. I would use a race engine for the power source. It would have to be on a gimbled frame to take a load cell measurement of its output. This engine cell is mounted on the trans test chassis. The axle outputs need to be controlled by water brakes and measured with load cells.

All this is doable at a reasonable price but would require a sizable test stand/chassis.

Brian

Yes, this is absolutely true if you want to understand the absolute power absorption of a transmission. If, however, the objective is only to make a comparison between two configurations an inertia dyno could be used and, assuming the input torque remains the same, a time to RPM plot of the transmission output would show which configuration has less drag.

[Hardingfv32]

A question that has taken up room in my head for 30 or 40 years.... For instance, I've always wondered if there really is an advantage to using the ball style pinion shaft bearing vs. the roller style, how worn the syncros should be, or which is the best lube. Thoughts?

Ball style pinion bearings: Moot point. Unless you find NOS there are no ball bearings worth using. I have collected them for 30 years and have never found one that was not micro pitted or worse. A pitted bearing is not efficient. A correctly made NEW bearing is most efficient when new. All that loose bearing or trans axle setup stuff is a myth. New bearings and the thinnest oil you can find. Do not worry about wear in your racing life time.

Brian

[Hardingfv32]

"I assume some people are playing with one race oils..."

I was told by a top end runoffs competitor several years ago that he was using a one race oil (and a one race engine for that matter).

He was blowing smoke! How in the world are you going to damage the syn oil in one event without first damaging the bearings from too much heat. How else do you damage the oil without 250 deg plus heat?

One race engine: Could be some lose in cylinder sealing during one event depending on your setup.... in theory.

Brian

[Hardingfv32]

Since FV is supposed to be about driver ability rather than car prep, and since we are stuck at RA for the next two years, how about every car run a long box with a 1.26 3rd, and 2 hours before the race, every car line up and be filled with the same weight motor oil and tranny oil.
ChrisZ

Pointless... What you have to control is the viscosity of the oils... the temps they are used at. Everything you mention does almost nothing compared to the use of the monster manifolds.

Brian

[BLS]

He was blowing smoke! How in the world are you going to damage the syn oil in one event without first damaging the bearings from too much heat. How else do you damage the oil without 250 deg plus heat?

One race engine: Could be some lose in cylinder sealing during one event depending on your setup.... in theory.

Brian

What was meant was the engine was only good for the one race using a zero weight oil.

[Hardingfv32]

What was meant was the engine was only good for the one race using a zero weight oil.

IF you can get the oil system correct, using zero weight oil would have very little effect on 'race' engine longevity. The big problem to solve is low rpm oil pressure. Our oil pumps do not pump enough volume at low rpm. Using a very high volume pump uses more power than the use of zero weight is saving. The OEM's use a variable output pump to solve this issue.

Brian

[BLS]

IF you can get the oil system correct, using zero weight oil would have very little effect on 'race' engine longevity. The big problem to solve is low rpm oil pressure. Our oil pumps do not pump enough volume at low rpm. Using a very high volume pump uses more power than the use of zero weight is saving. The OEM's use a variable output pump to solve this issue.

Brian

Yes, I understand.