friction reduction in ring and pinion
friction reduction in ring and pinion
(OP)
We race a truck on oval tracks, it has a 305 2bbl with an automatic. I am looking to reduce friction in the rear end in order to free up alittle horsepower. Does any body have any suggestions as to how I could accomplish this? Thanks in advance.
Steve Turner
Steve Turner





RE: friction reduction in ring and pinion
Cheers
Greg Locock
RE: friction reduction in ring and pinion
RE: friction reduction in ring and pinion
These effects are on the order of 1% or less, but still measureable and not chump change when certifying for CAFE standards- maybe not for close race days too.
RE: friction reduction in ring and pinion
If the driver isn't on the gas early and hard due to chassis or skill, I'm not sure freeing up power will really help much, except maybe as a "magic feather" (Walt Disney reference).
If you are REALLY on the gas just 25% of the time you might be able to cut back on the viscosity and maybe even quantity once the gear set is broken in. Keeping a CLOSE eye on the gear faces (maybe even between heats?) might be one way to sneak up on the limits.
EP and antiwear additives might keep the gears alive when operating at the edge, but I wonder if that would eliminate the power advantage, as they are not particularly "slippery."
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"churning loss would be strictly a function of viscosity".
In my opinion, based on one or two unpleasant big-name planetary gear experiences, the oft quoted high 90's gear efficiency ignores the heat generation from churning completely. And especially at high rev low loads the heat generated (churning loss?) is 10X worse than both OEMs predicted
My current opinion is the Oil volume and lube method are mighty important too, as they effect how much not-quite-in-contact mesh is simply squishing oil, with no real purpose. Like a well submerged bath, versus a minimal spray or oil spot system with a "dry sump."
If you are running a spool, pumping oil via jets directly into the pinion and carrier bearings and gear mesh looks fairly straightforward, but if you have a differential the diff side gears and limited slip clutch pack may simply demand the oil storm provided by an oil bath.
RE: friction reduction in ring and pinion
RE: friction reduction in ring and pinion
i would like to know more about straight cut differential gears, as G-Lo mentioned. i've heard of hypoid and spiral cut, but not straight cut.
RE: friction reduction in ring and pinion
Rod
RE: friction reduction in ring and pinion
It does reduce the diff temp in a V8Supercar by 8-9C so it must do something.
RE: friction reduction in ring and pinion
Shaun TiedeULTRADYNE/LUNATI Austin,TX(stiede@ev1.net)
RE: friction reduction in ring and pinion
RE: friction reduction in ring and pinion
RE: friction reduction in ring and pinion
"automatic transmission"......that will be a huge absorber of hp....you might take a look at a higher efficiency torque converter, if you use one.
I usually tell people in your situation that it is easier to bring the driver up to speed first, then the car setup then look for the 10ths with a microscope....also try to find out what the front runners are up to in your group.
Good luck and have fun.
RE: friction reduction in ring and pinion
You will have less friction if you use differential with a lower angle on the hypoid surface (less swept area on the tooth engagment). Ford 9" differential design is used in a lot of race vehicles for light weight and strength but due to the gear angle they use as much as 15 horsepower more then most automotive differentials.
wow that is a lot.
where could i find info on how much power is consumed by various rears?
or could i calculate it from another piece of data that is easy to find?
RE: friction reduction in ring and pinion
Ford 9" -vs- Dana rear end
Chrysler recommended using the Ford 9 inch as it was definetly faster down the DragStrip
their 8 3/4" was supposedly better than the Ford 9" but couldn't holdup even under just the amount of Torque & HP they were only making back then ..it was a combination of that Torque going thru a Hi-RPM launch with manual 4-speed
that prevented use of 8 3/4..so the Dana 60 was tried & used instead..and then replaced by Ford 9 inch in Chrysler ProStock Cars after those tests.
Straight cut gears have better efficiency than hypoid gears
..you won't see any Hi-Tech Slot-Cars with hypoid gear designs :)
Most Books i've read state that Differentials have anywhere from .965 % -to- .990 % efficiency
the baseline efficiency in my Computer Program is setup at .97 % PerCent for Differentials
you can play around with this totally "Free to Public and Racing Community" Computer Program on my website
http://www.maxracesoftware.com/race_car_physics.htm
the Differential Efficiency is multiplied times the Transmission Efficiency , and inputted as one value
Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
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