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Old 03-02-2009, 05:28 PM   #1
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Default Diff fluid set up

Whats everyones thoughts on running

2 In the front
5 In the Middle
2 In the back

Or

2 In the front
7 In the middle
2 in the back

How would these set ups change my control based on what I am running now.

I am currently running 5-7-5 in my Losi 8 B and it is way too loose. I have no traction at all specially when going around a turn. The whole buggy spins out from the rear when I hit the throtle. When I am climbing the rear wheels are spinning out of control and I have to slow way down to hit a jump square.

I know the pro set up is 5 front 7 middle 2 in the back but I think this may still be too loose for me.
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Old 03-02-2009, 05:38 PM   #2
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The only way to find out is to give it a shot. But only change one thing at a time.

If you're running 5-7-5, then try 5-7-2 and see how that does. If that doesn't work, swap the front out so you're running 2-7-2. If you don't like that, swap the center for 5 for 2-5-2. My guess is that 5-7-2 would probably be good.

You're spinning out in the corners probably because the rear doesn't have enough diff action. The inside tire is pushing too much. To get more acceleration and control out of a turn, you want lighter oil in the rear and maybe in the center to transfer more power to the front wheels. If 5-7-2 doesn't do it for you, maybe try 5-5-2 rather than going to 2-7-2.
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Old 03-02-2009, 06:05 PM   #3
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I run 5-5-3 and it does fine. I had the same traction problem at my track. I was running 5-7-2 before that. 2 to 3 gave me more traction. Also move your rear hubs foward and get a 3degree rear toe in plate. Make your camber -1 in rear and check your droop and camber in front, and front toe in also. Runnint 2 in front will make the steering really inconsistent. I use 5 but 7 makes steering more stable.
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Old 03-02-2009, 06:06 PM   #4
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2-7-2 would be even worse than 5-7-2 if he is over-steering, especially on a Losi.
If you want to calm the car down go thinner in the center. 5-5-2 made the car calmer imo.

I general (according to the Xray guide),
going thicker in the front increases on-power steering
going thicker in the center increases on-power steering
going thicker in the rear will decrease rear traction

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Old 03-02-2009, 08:04 PM   #5
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I may be confused. Is this right or wrong

The thicker the oil the more traction. Thinner oil less traction.

2 is really thick and 7 is really thin. The lower the number the thicker the oil is? Since I am running 5-7-5, 5 is to thin in the back so I have to thicken it up by going with 2 which will get me more traction in the back.
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Old 03-02-2009, 08:30 PM   #6
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Just a little bit of info. Most the guys in my region that have there 8ights hooked up are running 5-5-3. Good luck.
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Old 03-02-2009, 08:57 PM   #7
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No, 2 is light, 7 is heavy. Just like a number line..

I am also confused about the rear diff. On some sites it says that thicker rear diff oil will increase rear traction, others say thinner will increase rear traction. In the Losi manual, thickerrear =more rear traction. In the xray manual, thinner=more rear traction. What gives?
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Old 03-02-2009, 09:27 PM   #8
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I try not to think about it too much.. I found the best is to start with the kit setup and after a while try out some different combos and go with what feels best/and is fastest for your particular car.
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Old 03-02-2009, 09:35 PM   #9
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Quote:
Originally Posted by Chris__RC View Post
No, 2 is light, 7 is heavy. Just like a number line..

I am also confused about the rear diff. On some sites it says that thicker rear diff oil will increase rear traction, others say thinner will increase rear traction. In the Losi manual, thickerrear =more rear traction. In the xray manual, thinner=more rear traction. What gives?
i dont run losi anymore but i liked 5 7 2 if you want more rear traction try 5 5 2 or 5 5 3
now then diffs work like this the thinner the oil the more power will go to the least frictioned side so
light in middle more power will go to front tires in on power sit. thicker you go the more the power will stay even between the front and back
in rear diff. thinner will send more power to the side with less friction thicker will make power more equal. so on high bite trac thicker fluid will make more rear traction. because both tires will get the same power from diff. on a loose track having the same power to both tires will just make it more loose so thinner will make it have more traction because the outerr tire has more friction which will mean it gets less power than the inside so the whole rear end wont step out on loose trac thicker center fluid helps to pull the car through the corner with the front end drive thicker front fluid less turn off power more turn on power just my opinion of coursde but is what i have read through the web hope it helps.
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Old 03-02-2009, 10:11 PM   #10
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Pretty good explination above jewn.Also like said above lower #= thinner fluid.The difference in what people say about diff oil changing traction is when & where.Some people say traction & they mean in a straight line,some mean in a corner & with that theres into & out of the corner & in that theres on throttle & off throttle.

If you want to have good traction coming out of corners on the gas then thin in the rear(1-2),medium in center(5) & med to thick in the front(5-7).Losi has no shortage of steering traction into a corner so thick in the front will calm down the off power steering into the corner & help pull the car from the front out of the corner on power & still give you some steering so you dont push out to the pipes. If you try 2k in the front of a losi you will spin out before you hit the middle of the corner & have no on power steering coming out of it & the front will push all the way across the track & hit the pipe.

You have to try different oils to see what works for you.Nobody drives the exact same way.They call the Hudy off road setup book the bible for a reason download it.
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Old 03-02-2009, 11:49 PM   #11
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Quote:
Originally Posted by butch man View Post
Pretty good explination above jewn.Also like said above lower #= thinner fluid.The difference in what people say about diff oil changing traction is when & where.Some people say traction & they mean in a straight line,some mean in a corner & with that theres into & out of the corner & in that theres on throttle & off throttle.

If you want to have good traction coming out of corners on the gas then thin in the rear(1-2),medium in center(5) & med to thick in the front(5-7).Losi has no shortage of steering traction into a corner so thick in the front will calm down the off power steering into the corner & help pull the car from the front out of the corner on power & still give you some steering so you dont push out to the pipes. If you try 2k in the front of a losi you will spin out before you hit the middle of the corner & have no on power steering coming out of it & the front will push all the way across the track & hit the pipe.

You have to try different oils to see what works for you.Nobody drives the exact same way.They call the Hudy off road setup book the bible for a reason download it.
yes i have heard the book is good and your info is also good light fluid in front of losi dont work to well good luck man trial and error is the best way to fig. it out start with 5 7 2 and adjust from there
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Old 03-02-2009, 11:52 PM   #12
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Thanks for the great advice above. I really appreciate the help. This can get pretty confusing based on Jewn's explanation.

Since i am already running 5-7-5 I am going to change the rear to 2 and run 5-7-2 and see how it runs. If that dosent work then I will change the middle to 5 and run 5-5-2. One step at a time makes sense.

Thanks again to all as this has been very helpful
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Old 03-03-2009, 06:25 AM   #13
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Thicker rear diff fluid can increase and decrease rear tractio depending on your definition of "rear traction". Thats why different car co. instructions can't agree on that.

Thicker fluid will prevent one of the tires from spinning more than the other. This gives the car more forward traction. But it can take away sidways traction because it'll spin both tires and lose sidebite.

Thinner fluid will have more sidebite because only one tire will spin while the other will still have good grip, so the car won't fishtail on power as much but the tire with traction won't have any power going to it so too thin will hurt accel.

It takes forever to master the rear. Just play with it and see what you like. Its preference. The center and front diff are simpler to deal with.

I'd try lighter center diff fluid in you car. 555,753,754,755,752,553.
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Old 03-03-2009, 07:02 AM   #14
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just think the thicker the oil the more that diff is going pull. if you put 7 in the rear, the car will feel like a 2wd with the rear pushing it around the track. the old standard for buggies was 572, but with the more weight forward chassy, losi,mugen,xray the rear feels loose with no weight on the rear tires. the new mbx6 calls for 752 letting the front pull the car around. you need to play with it alittle to get the balance right, the thicker the front diff the less off power steering. if you have a big jump thats hard to make, a thicker center could be what your looking for to clear it, but it sends more power to the rear which could make it feel loose. ive run the 752 and i like 742 for a slick track cause it sends more to the front and i can get to the gas faster.
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Old 03-03-2009, 07:10 AM   #15
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i found 553 with +2 hubs in the rear to be good, i found the rear to be to loose with 552
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