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Old 01-06-2010, 06:53 PM   #1
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Default Does thicker diff. fluid= less power?

I want to thicken my center differential fluid to transfer more power to the rear wheels.. will this reduce my torque or top speed?

Also how much thicker than stock should i go beings my fronts are ballooning WAY more then the rears..

Thanks
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Old 01-06-2010, 07:00 PM   #2
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I want to thicken my center differential fluid to transfer more power to the rear wheels.. will this reduce my torque or top speed?

Also how much thicker than stock should i go beings my fronts are ballooning WAY more then the rears..

Thanks
It will not reduce your torque or your top speed. If you are just playing around and not racing try out soe 10000 in the center 7000 in the front and 5000 in the rear.
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Old 01-06-2010, 07:03 PM   #3
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Id like it to be about 60/40 (front/rear) what would your recomendation be?
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Old 01-06-2010, 08:05 PM   #4
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Id like it to be about 60/40 (front/rear) what would your recomendation be?
You can't really get power distribution like that with diff fluid changes. All the center diff does is allow different rotation rates when the front or rear are in different traction situations. In other words, if the front tires are slipping, heavier fluid will help slow the slip by keeping them more closely matched to the speed that the rears are turning. Lighter fluid would allow an easier transition or differential between the fronts and the rears. Hence the name differential. Same thing with the front and rear diffs when comparing the available traction or turning radius of the left and right tires.

Using different weights front to rear only changes how easy each of those transitions occurs between left and right on it's respective end.

In a perfectly straight line, with good traction at all four wheels, differentials are basically not doing anything. They could be filled with cement and work the same. (assuming that the gear ratio front and rear are the same)

Now if you wanted a differential in the speed front to rear, that is what you would need is a different gear ratio on the front gearbox from the rear. Mugen had that in the 5R I believe.
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Old 01-06-2010, 08:06 PM   #5
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In buggy I usually run 5,7,3 right now in my Ve8, once I get used to it I will go to 5,5,2. I have used 10,10,5 though before but what Badass said try 1st get used to that then go to 5,7,3 for racing. For bashing your better off with thicker oils anyway because you dont have to change them as often. I find heavier oils make the car alittle more managable also, and once you get the feel for everything lighten it up a bit. All cars are different too so you just have to experiment.
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Old 01-07-2010, 02:28 AM   #6
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Thicker center diff oil will alow the vehicle to pull harder.

it will however lose rotation, it wont steer as good as with thinner oil.

also harder to drive.
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Old 01-07-2010, 05:24 AM   #7
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Wow, not even one page and this one's already full of misinformation. Yes, if you put heavier diff fluid in the center diff, you will have more power at the rear wheels and less center diff action under acceleration, which will keep your front tires from ballooning when you get on the throttle. You pretty much have the right idea.

The viscosity of the fluid in the center diff WILL have a profound effect on the front to rear power distribution and wheel speed. Thinner fluid will bias the power dramatically toward the front end under acceleration and the heavier the fluid, the more you reduce the amount of differential towards the front end under acceleration. On paper, if we were driving on velcro tracks with velcro tires and there was no slippage what so ever, then the theorists among us would be partially correct, but on real tracks where we race and tires slip more often than they grip, that all goes right out the window.

And just for clarification, the car will rotate like crazy if you go with thicker fluid in the center diff. Thin diff fluid sends more power to the front end under acceleration, so the rear end maintains more traction and the front tires will spin wildly and cause the ballooning you experienced. As you go heavier in the center diff, the more the power distribution becomes equal from front to rear, making the rear wheels more likely to spin and lose traction, causing the car to rotate more in the corners - possibly too much. I used to race buggies that had no center diffs - trust me, you don't want to use too heavy a fluid in the center diff. The car is all over the place and much harder to control.

You car has two spider gears in the differential, so I would go with slightly heavier fluid than in typically used in the 7.5 to 777 cars. A center diff with four spider gears would normally use 7000wt center diff fluid, so you should use 10,000 as a starting point (especially if you're somewhere that's cold), and possibly 20,000 during the warmer weather. If you're compelled to install the two extra gears in the diffs, order the IF102 gears and the 97001 gear shafts. The car will run fine without them, but there's the info if you need it.
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Old 01-07-2010, 06:27 PM   #8
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Wow, not even one page and this one's already full of misinformation. Yes, if you put heavier diff fluid in the center diff, you will have more power at the rear wheels and less center diff action under acceleration, which will keep your front tires from ballooning when you get on the throttle. You pretty much have the right idea.

The viscosity of the fluid in the center diff WILL have a profound effect on the front to rear power distribution and wheel speed. Thinner fluid will bias the power dramatically toward the front end under acceleration and the heavier the fluid, the more you reduce the amount of differential towards the front end under acceleration. On paper, if we were driving on velcro tracks with velcro tires and there was no slippage what so ever, then the theorists among us would be partially correct, but on real tracks where we race and tires slip more often than they grip, that all goes right out the window.

And just for clarification, the car will rotate like crazy if you go with thicker fluid in the center diff. Thin diff fluid sends more power to the front end under acceleration, so the rear end maintains more traction and the front tires will spin wildly and cause the ballooning you experienced. As you go heavier in the center diff, the more the power distribution becomes equal from front to rear, making the rear wheels more likely to spin and lose traction, causing the car to rotate more in the corners - possibly too much. I used to race buggies that had no center diffs - trust me, you don't want to use too heavy a fluid in the center diff. The car is all over the place and much harder to control.

You car has two spider gears in the differential, so I would go with slightly heavier fluid than in typically used in the 7.5 to 777 cars. A center diff with four spider gears would normally use 7000wt center diff fluid, so you should use 10,000 as a starting point (especially if you're somewhere that's cold), and possibly 20,000 during the warmer weather. If you're compelled to install the two extra gears in the diffs, order the IF102 gears and the 97001 gear shafts. The car will run fine without them, but there's the info if you need it.
Awesome info! Do you think the diff gears in the inferno ve will hold up against the MM2200 and larger pinions?
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Old 01-07-2010, 06:45 PM   #9
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correct me if im wrong... but the bigger the number, the thicker the oil right?
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Old 01-08-2010, 12:43 AM   #10
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correct me if im wrong... but the bigger the number, the thicker the oil right?
Yup
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Old 01-08-2010, 07:50 AM   #11
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Go to google and type in the following: "Triple diff basics". The first hit in google should be rcm. In that thread there is a very good post on diffs and oil. I'd post a link, but I don't think I'm allowed to post a link to a different forum. I'd post the text, but it was written by RC Driver and I don't want to infringe on their writings.
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Old 01-08-2010, 05:24 PM   #12
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I found with changing diff fluids also infects the temp of the motor/esc/battery. When running 1/8 buggy I found 7/10/3 to be the best all round.
Xtreme RC did a article on diff fluids - http://www.rc411.com/pages/howto.php?howto=24&page=5
And another aritcle about grease/oils - http://www.rc411.com/pages/howto.php?howto=26&page=5
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Old 01-08-2010, 06:28 PM   #13
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GREAT links!!!

Any on rebuilding diffs? Or rebuilding shocks?

I've done both, but I still don't know if I did it right (no issues though).

Cleaned out and added diff fluid for diff

changed out o-rings/washers/oil for shocks
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Old 01-08-2010, 06:52 PM   #14
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i got 120k on my center diff i like that set up,y give 50-50 power !!
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Old 01-08-2010, 07:29 PM   #15
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GREAT links!!!

Any on rebuilding diffs? Or rebuilding shocks?

I've done both, but I still don't know if I did it right (no issues though).

Cleaned out and added diff fluid for diff

changed out o-rings/washers/oil for shocks
Link for shimming diffs - http://www.rc411.com/pages/howto.php?howto=35&page=4

Building Shocks - http://www.rc411.com/pages/howto.php?howto=31&page=4
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