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dameetz
2008.05.30, 10:42 AM
I have 2 ASF cars with same problem. When I accelerate hard from stand still it always veers to the right. I have to counter steer to the left when coming hard out of corners. Both my cars are fully ball bearing, one has Atomic ball diff the other has Kyosho diff, Atomic motor pods 98mm, 2deg and 3 deg knuckle, 0 toe, Atomic T2 and Stock R motors, Atomic DPS. And I do check and recheck the front and rear bearing smoothness ,the T plate straightness as well as steering trim. What could have caused this problem?

mleemor60
2008.05.30, 11:09 AM
48 or 64 pitch gears? When installing 64P on standard shaft you can wind up with a little bind in the Dif causing somewhat erratic operation. Just a thought.

dameetz
2008.05.30, 12:04 PM
I m using normal gears which is 48p I guess.

Tjay
2008.05.30, 12:42 PM
most importantly. work on one car only. adjust your tx till the car goes straight or till you cant adjust anymore. Then work with you mechanical parts.

Make sure:
-diff is not too tight.
-nothing is rubbing on the wheels
-motor wire is not binding (check motor mount if it's tweak because of the wires)
-your toe doesn't bind on the front knuckles

hope this helps. good luck!

F_Zero
2008.05.30, 12:56 PM
What kind of Pinion Gears? Plastic, aluminum, steel?

Honestly, one of side of your Mini-Z is acting perfect, that is why it is moving to the left, so maybe, you can try fixing the opposing side? Try a looser fitting rear diff. Ceramic Diff balls might help reduce play. Also try centering the rear diff shaft. check out AtomicMods.com for turtorial.

Also try higher front grip tires. The more grip up front will counteract the rear diffs steering. As more weight is directly transfered into the car upfront, the rear ball diff will automatically have to counteract this.

Aurora
2008.05.30, 01:25 PM
Not sure it will apply to 02 as much as AWD, but sometimes when my AWD ride height with shell is too low, the (rear end of) car does touch ground during hard acceleration, which might cause it to steer to one side.

And I know it probably is not a 'trim' problem, since the car track straight when the throttle is applied slowly.

dameetz
2008.05.30, 07:48 PM
What kind of Pinion Gears? Plastic, aluminum, steel?

Honestly, one of side of your Mini-Z is acting perfect, that is why it is moving to the left, so maybe, you can try fixing the opposing side? Try a looser fitting rear diff. Ceramic Diff balls might help reduce play. Also try centering the rear diff shaft. check out AtomicMods.com for turtorial.

Also try higher front grip tires. The more grip up front will counteract the rear diffs steering. As more weight is directly transfered into the car upfront, the rear ball diff will automatically have to counteract this.

I m using HPI steel pinions.I post the picture of one of my car in the '2.4 post your car pic' thread if you want to see the detail.

dameetz
2008.05.30, 07:50 PM
Not sure it will apply to 02 as much as AWD, but sometimes when my AWD ride height with shell is too low, the (rear end of) car does touch ground during hard acceleration, which might cause it to steer to one side.

And I know it probably is not a 'trim' problem, since the car track straight when the throttle is applied slowly.

Even with the body off it still steer to the right during acceleration.

cowboysir
2008.05.31, 02:06 AM
I;ve has a similar problem in the past when a motor with too much torque causing the chassis to go a bit sideways under acceleration...try a bigger pinion to reduce the initial torque of the motor.;)

Aurora
2008.05.31, 10:35 AM
Even with the body off it still steer to the right during acceleration.

Hmmm, I guess what I was trying to suggest is to find out whether it is something more related to radio setting or more mechanically based issue.

If the steering right only happens during hard acceleration, and will not happen when you slowly accelerate or when the speed is constant, then I suspect it might be more mechanical (suspension setting, binding, etc)

But if the problem always happen, regardless how fast or slow is acceleration or speed, and get worse when the car is faster, unless it is a binding issue, I would guess the problem might be able to be fixed by trimming. :)

F_Zero
2008.05.31, 11:37 AM
All of the things I can think of...

- Try Ceramic Diff Balls, a smoother diff might tolerate more or less.

- More grip for the front tires.

- Go back to the stock Motor Pod, the Alloy MP could be causing the weight difference in the T-Plates or rear of the car

- Finally, get right of the HPI Steel Pinions! Use Delrin, Plastic or Alloy or Titanium! Those Steel Pinions are knocking the Spur Gear around. The Weight is to heavy and causing the rear to be off balanced for sure! try some stock ones It should work. ;)

dameetz
2008.05.31, 11:38 PM
Ok I ll try to get the ceramic ball diff and try every advice that you guys give. Will let you know soon.

benmlee
2008.06.02, 01:13 PM
Try putting a washer under the T-plate on the right side between the T-plate and motor pod if everything else are ok.
BTW, there is nothing wrong with the HPI pinion. They last a long time. Maybe a tiny bit more weight. Doubt you will feel that in acceleration or corner. However, since PN has promatch pinions now, the HPI steel pinion is obsolete.

Tjay
2008.06.02, 02:40 PM
somemore...

Check your motor mount and make sure it's square. No tweaks.
Don't over tighten your lug nuts.

dameetz
2008.06.03, 06:35 AM
Try putting a washer under the T-plate on the right side between the T-plate and motor pod if everything else are ok.
BTW, there is nothing wrong with the HPI pinion. They last a long time. Maybe a tiny bit more weight. Doubt you will feel that in acceleration or corner. However, since PN has promatch pinions now, the HPI steel pinion is obsolete.

If i put the washer as you mention wouldn't it make the motor pod tilted a bit? Anyhow any advice on how thick the washer should be?

color01
2008.06.03, 12:57 PM
Yes; it's like corner-weighting your real car by altering the preload on each end. ;) The thinner washers you can find the better, sometimes you'll end up using newspaper if the problem is really that fine. :)

benmlee
2008.06.03, 01:03 PM
If i put the washer as you mention wouldn't it make the motor pod tilted a bit? Anyhow any advice on how thick the washer should be?


That is the whole idea, to tilt the motor mount so that one wheel drops more than the other. The wheel that drops more, and put more pressure on the ground will have less traction as strange as that sounds. What you are trying to do is to put a bias up front so that the outside wheel and inside wheel have even pressure in a corner, and hence more traction. More traction up front means less traction in the rear, so it steers more in one direction.

Use a standard thin 2mm washer. If one washer does not work, use 2. If you need more than 2, then something else is wrong.

One more thing to check is to make sure the distance from T-plate to the wheel is same on both sides. I found sometimes it is off by as much as .5mm. Use some bearing shims to even it out.

chung3j
2008.06.15, 02:08 AM
If you are using CF H-plate, get PN's H-plate holder to correct thrust angle. A problem I had with my own car that caused the same problem was thrust angle. Weight biases doesn't do as much damage as a bad thrust angle.