915 power loss: regular VS Swepco 201 gear oil

[Litle brother]

....

[Rawknees'Turbo]

Would the power loss be measured in 10ths of a horsepower? I can't imagine that gear oil, other than maybe if cement was used in the box, would create much measurable resistance.

[Litle brother]

....

[ClickClickBoom]

The difference is Racing is one thing; driving is another. Racers will always trade logivity beyond the next race for a 1/10th here and there. Question is, how often do you want to overhaul your trans?

[Litle brother]

....

[Litle brother]

....

[ClickClickBoom]

Frustrating isn’t it when racing teams won’t reveal the results of thousands of dollars in research so their competition can be on par.
Suggest SAE:
Focus on drivetrail loss. Membership is reasonable and access to the pubs is awesome.
https://www.sae.org/publications
I can recommend the History and Development of the Pratt and Whitney R-2800 book, shows the testing to destruction of an aircraft motor design.

[ClickClickBoom]

Originally Posted by Litle brother

....

I am sure you could measure the centistokes of both fluids, and do the calculations, it is after all, just physics. My neighbor has a PhD in physics and specializes in fluid dynamics, I asked him the same question he said “give a grant for 2 mil, and a year and I can give you a pretty good approximation” He works at NASA as a theoretical physicist, on rocket motors. I would question anybody who says they have an exact number. PM Matt Monson, he will be the closest answer you will get here.

[ClickClickBoom]

Originally Posted by Rawknees'Turbo

Would the power loss be measured in 10ths of a horsepower? I can't imagine that gear oil, other than maybe if cement was used in the box, would create much measurable resistance.

Windage is a huge concern, from NASCAR to F1.

[dreichman]

Originally Posted by Litle brother

As the head line indicates I wonder if anybody has experience reagarding 915 drive train loss measured on the dyno using regular/factory gear oil VS the thick Swepco 201?

I have read on the "Great www" that thinner gear oil has been used in race cars during qualification to make better times than oil used during races.

I have also read that running with 10-20mm lower oil level in the 915 also contributes to less drive train loss.

So can one, in light of the above(among many other factors) assume that running the Swepco 201 results in a bit more more drive train loss?

Cheers
Eskild

I think it would be a distinction without a difference. Maybe measurable in mathematical terms but Not by the seat of the pants method, LOL

[LJ851]

Originally Posted by ClickClickBoom

Windage is a huge concern, from NASCAR to F1.

I think Rawknees got banned for too much windage a little while back.

[Rawknees'Turbo]

Originally Posted by LJ851

I think Rawknees got banned for too much windage a little while back.

Ha ha - ain't dat' da' truth! Maybe I shouldn't use Swepco when posting!

[Litle brother]

....

[ClickClickBoom]

Originally Posted by Rawknees'Turbo

Ha ha - ain't dat' da' truth! Maybe I shouldn't use Swepco when posting!

Like a fart in an elevator....

[pmax]

Originally Posted by Litle brother

As the head line indicates I wonder if anybody has experience reagarding 915 drive train loss measured on the dyno using regular/factory gear oil VS the thick Swepco 201?

Actually, factory recommends 90 which is thicker than 201.

[patkeefe]

I think the variants in ingredients of gear oils have to do with the variety of dissimilar metals found in a gearbox, ie, hardened steel gears, brass synchronizers. Evidently SWEPCO was formulated by request of a Porsche race team.

That said, I did have to learn about this stuff once in engineering school, but thankfully, I've mostly forgotten it. I'm sure it is quantifiable. I do think it is a mistake to equate "thicker" to "more resistance", especially at room temperatures.

The old timers told me that during the second war, farmers used to put sawdust in the gearboxes and differential to quiet them down. Good gear oil must have been hard to obtain back then.

Also, you could also consult API and ASTM.

[Rawknees'Turbo]

Originally Posted by ClickClickBoom

Like a fart in an elevator....

I tried to hold it in, I swear, but that black bean and egg burrito would not be denied!

[winders]

If you are racing, use Swepco 210......actually, I would use it my street car too if I had one with a 915.

Only racers with big budgets and in-house mechanics would risk running oil that it too thin just to gain some HP. In other words, the typical club racer would not use thinner oil just to gain a few HP.

[GH85Carrera]

Go on a diet and loose 10 pounds. No cost to do, and it will make your car faster in every aspect than thin transmission oil. But hey, it is your transmission, not mine. When the engine and transmission are at full operating temp, that oil is not that thick.

[Geary]

Thinner gearbox / diff oils are for drag racers. They run their gearboxes cold, and only a few miles per year.