Problem with power
 

It seems my E-Maxx runs faster going in reverse.

Is this because my diffs need swapping over?

Probably not. I'd check your throttle centering and EPA...

The throttle seems fine, I reprogrammed my 9920 and still the same problem. What's the EPA?

End Point Adjustment. It sets the max and min values of the throttle and reverse/brake respectively. If your reverse/brake EPA is set to 100% and your throttle set to 60%, then you will go quite a bit slower in forward. EPA is sometimes called "travel adjustment".

That is if you have an aftermarket radio. Doesn't apply to stock Traxxas radio.

Yes, that's true. :dft001: It's been so long since I used the stock Tx/Rx, I almost can't remember them anymore.

Nick: Is there any difference in drivetrain drag if you spin the wheels manually one way and then the other?

I use a Spektrum DX3, I don't think it has EPA?

The diffs roll fine. I can literally wheelie in reverse but not in forward - I'm using 6s on a 7XL!

Well then, I know the Spektrum has it because I use that as well. On the Spektrum, it's called travel adjustment, but abbreviated on the little screen on the transmitter. I would definitely look into that. Maybe you switched models on the Tx by accident (each model can have different settings)?

6s on a 7XL!? Doesn't that run a tad hot?

Thanks I'll check it out.

It might be a problem with one of my Lipos actually, one of them seems dead. :(

Yes, that would be a problem, but not likely the problem.

I've given it another run. It is just as fast forward or reverse except it wheelies in reverse.

I guess it's just grip with my tyres or how it has no stearing in reverse at the front. My batteries are poor quality, I'm sending them back, well... getting rid of them anyway and buying some proper ones.

If it's just a matter of wheelies, that could be a couple of things. Weight distribution of the truck, and maybe some of the power control settings on the ESC.

Yea. Its not the batteries I don't think...