Author Topic: Rear end efficiency  (Read 65262 times)

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Offline desotoman

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Re: Rear end efficiency
« Reply #90 on: March 24, 2011, 07:30:07 PM »
That overdrive uses more HP than a standard Quick Change gear set does, since it has a double sets of spur gears. Then add the offset of the 9 inch ford rearend. Sparky I bet you are close on your estimate.

Tom G.

PS. Why doesn't someone build one using belts instead? Much more efficient.
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Offline Nexxussian

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Re: Rear end efficiency
« Reply #91 on: March 25, 2011, 03:08:53 AM »
PS. Why doesn't someone build one using belts instead? Much more efficient.

While that is possible, and cleaner (no oil to drop during the change :) ), wouldn't that be even more bulky than the quick change unit added to the 9"?
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Offline johnneilson

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Re: Rear end efficiency
« Reply #92 on: March 25, 2011, 11:12:56 AM »
Guys,

has anyone done any work with lubricants?
Or any testing with REM and other surface treatments?

John
As Carroll Smith wrote; All Failures are Human in Origin.

Offline fastman614

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Re: Rear end efficiency
« Reply #93 on: March 26, 2011, 09:05:01 PM »
I have played with some of the "snake oil" additives over the years. There was a company called Bitron.... it wa of course, a network marketing type outfit that pretty much ensured the failure of all of their distributors.... the guy who helped me out with the additives used to give them to me at his cost or as trades for welding, tube bending or other favors....  I never was able to quantify the difference of "before" and "after".... I do know, though, that the gasoline additve, which claimed to have the super slippery compound in it and was recommended for electronic injectors, did give my Corvette a noticeable improvement in the fuel economy - like more than 10% improvement. Whether it was due to the injectors themselves or some unknown oxygenator, though, I do not know.

I did have some of their two stroke oil additive and the gasoline additive at Bonneville one year... I was trying to get Rick Gold to use the gasoline tester on a before and after gasoline sample... I figured he could have told me something about the gasoline stuff anyway, although probably not about the super slippery part of it.... but with the oil additive, I was not able to get anyone from among the competitors with 2 stroke bikes to try it....

The only anecdotal evidence I can talk about with regard to their gear oil additive is that we had a gear reduction unit at the plywood mill that was, due to its design constraints, way too small and, thus, constantly overloaded. We tried many oils and additives. This product brought the heat down from about 160F to under 135F..... the test was all but forgotten about and, 8 or 9 months later, after 2 oil changes and no additive replacement, the gear box was running hot like always though... and then being rebuilt or replaced annually again. And, oh yes, we do use it to this day in our diff and transmission, although I only have enough for about one more application of it.
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Offline desotoman

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Re: Rear end efficiency
« Reply #94 on: March 26, 2011, 09:43:20 PM »
PS. Why doesn't someone build one using belts instead? Much more efficient.

While that is possible, and cleaner (no oil to drop during the change :) ), wouldn't that be even more bulky than the quick change unit added to the 9"?

I think area wise, it could be made  the same or smaller, just depending on the HP you would be putting through it. I would use 8mm pulleys and belt so you could get some small incremental changes in the gear ratio. JMO

Tom G. 
I love the USA. How much longer will we be a free nation?

Asking questions is one's only way of getting answers.

The rational person lets verified facts form or modify his opinion.  The ideologue ignores verified facts which don't fit his preconceived opinions.

Offline johnneilson

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Re: Rear end efficiency
« Reply #95 on: March 27, 2011, 12:40:07 AM »
The silence here is deafening.

In some circles, the REM finishing is a must. Though I ask for data, none is presented.

A few years ago we were running a Rx7 at California Speedway. I had the data from previous sessions and had just done a trans and rearend oil change with lube from a friends sponsor. The car was down about 500 rpm thru the banking and looking like it was parked. Not believing it could be the oil, I did the rotor test, plugs and checked the fuel pressure. Another session and same result. Set the car up on stands and changed the trans and rear end back to my synthetics. Problem fixed and back to form. I will not mention names or brands, but the difference was between synthetic and conventional oils of the same vis.

John

As Carroll Smith wrote; All Failures are Human in Origin.

Offline jimmy six

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Re: Rear end efficiency
« Reply #96 on: March 28, 2011, 12:04:34 PM »
There are NASCAR teams that have trans and rear gear oils just for qualifying at Taladega and Daytona only. The lubricants are thrown away after the 5 mile run.  When you looking at parasitic load reduction you look everywhere.....Good Luck
First GMC 6 powered Fuel roadster over 200, with 2 red hats. Pit crew for Patrick Tone's Super Stock #49 Camaro

Offline johnneilson

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Re: Rear end efficiency
« Reply #97 on: March 28, 2011, 02:00:47 PM »
There are NASCAR teams that have trans and rear gear oils just for qualifying at Taladega and Daytona only. The lubricants are thrown away after the 5 mile run.  When you looking at parasitic load reduction you look everywhere.....Good Luck

I do know that some years ago hybrid bearings were the rage (ceramic/steel). I destroyed many of them.
Another detail was to reduce the gear section to the minimum width and reduce the pumping action from the gears meshing.

John
As Carroll Smith wrote; All Failures are Human in Origin.

Offline John Burk

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Re: Rear end efficiency
« Reply #98 on: April 25, 2011, 05:17:43 PM »
 
My friend who has an engine shop in Charlotte sent me this:

To answer your question, some of the Nascar teams have the gears micro-polished.
Some of the big teams that have a wire EDM machine can lighten the ring gear about one lb.
 I am not sure if coated gears are legal now in Nascar
I know it would also be very very expensive for the hundreds of ring and pinion ratios they have for each different tracks
 
Alot of the dirt late model teams with quick change rears have the gears micro-polished, then DLC coated (same type of coating I told you about they coat titanium valves with)
 
I know of one team I built heads for that did a bunch of chassis dyno tests back to back.
They ran with std. ring and pinion, then changed to the mico/ DLC coated rear gears and picked up 8 HP
They told me with the coated gears they could put lighter weight gear oil and less amount of oil.
The DLC coating is supposed to let gears run cooler,  as well as decrease wear.

Offline The wonderful One

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Re: Rear end efficiency
« Reply #99 on: April 25, 2011, 09:05:03 PM »
For my two cents worth you may want to call Clark Kibler (B-Vill record holder and Mobile Oil engineer/ retired) (803) 992-2177. He is very good. The Wonderful One

Offline Bob Beatty

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Re: Rear end efficiency
« Reply #100 on: April 25, 2011, 09:39:36 PM »
Fastman,

To answer your original question, my '57 Pontiac pinion measures 1 1/2" vertical offset from the ring gear centerline.
Bob Beatty
 
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Offline fastman614

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Re: Rear end efficiency
« Reply #101 on: April 27, 2011, 10:11:31 AM »
Okay... thanks, Bob.... 3/4"  (the vertical difference between the Olds/Pontiac pinion offset dimension and the pinion offset dimension of a Ford 9" rearend) in my lakester is doable without any re-setting of the height of the running gear. I had originally placed the rear axle centerline for using a 30" tall tire and when I went to 28" diameter, I discovered a 3/8" height difference from front to rear- with the front being higher. I have lined up some Pontiac/Olds items amongst which are 2.69 and 2.56 gears.

I have also, in the meantime, made a deal to use some 30" tall tires (I had the tires- I needed to get rims and MOON discs) and I have procured a set of 2.86 Ford gears and I am working on getting some 2.80 gears as well. Doing it with the taller tires and Ford rearend is a bit less work and, overall the equivalent ratio is very close- as in less than 1/2 a percent.
No s*** sticks to the man wearing a teflon suit.