How to tame brushless and LiPo in 2WD?

[ianjoyner]

I'm running a B4 with Orion Platinum LiPo, Novak GTB and 6.5L motor. Compared to running brushed I'm finding the initial torque pretty hard to deal with, especially starting from the grid without a massive wheelie!

How do people control all the torque? I don't think the slipper can be used like it may have been with brushed, it would have to slip loads. Things I thought about were:

Top speed is about right, so maybe try a 7.5L motor and gear up, hopefully giving same speed but less torque.

Would love to have a torque pot like the old brushed speedos, there's nothing in the GTB to really reduce torque, maybe I should be looking towards Tekin or Nosram?

I've never played with throttle speed on the transmitter, but maybe this is something to look at to smooth out my thumbs action.

One of the problems is LiPos have so much punch from 8.4V, this drops slightly after a couple of laps and is then fairly consistent, when capacity isn't a problem, why charge them all the way to 8.4V?

Other people must find a similar problem moving to brushless and LiPo? I know I can learn to go easier on the throttle, but seems pointless learning to control something (the torque) that is simply way more than the car can put down.

[mikeyscott]

Have you added any extra weight

[c0sie]

If its wheelieing you need to loosen the slipper off.

Get it to slip for a foot or 3 and youll be fine, add some lead to the front on the servo, or even look at getting one of the Trishbits/Ghea brass front bulkheads.

Add weight...get it heavy, back to NiMh weight and youll enjoy the experience. I remember when I went to LiPo and brushless in my B4 and I was scared whitless, now I love it

Ghea/Trishbits front and rear brass bulkheads,
Rudebits brass battery strap
Lead on the servo...

[Northy]

Move your thumb slower?

G

[ianjoyner]

I haven't really played with the weight, probably should, mine is on the limit, I know people like to run the cars heavier.

[c0sie]

Lead is the key to all LiPo related happyness

[blue_pinky]

Lead def helps for most people, I know it helps me massively, although I see some on here who are trying to run without it as well to see if a lighter car is better for them.

I'd only add that you'll find that you adjust your 'thumbs' to have trottle control that suits the new setup, brushless & lipo do respond very differently to brushed & NiMH's in all area's of driving (not just pulling uber wheelies off the line!!!), it soon becomes second nature...just let yourself get used to it!

[col300]

Try a negative throttle curve on the tranny. I always run mine at -25%, this helps smooth it out. I also run at -30% with the brake too.

[emtee]

I agree with c0sie regards the slipper.. I had to adjust mine after switching to lipo 'n BL... Have you considered one of the Novak "light" motors? I run a 6.5 light in my B4 and can recommend it greatly... no more humungous wheelies and V.quick at full throttle!!!

Have you dropped the pinion size too? I went from a 21 to a 19 after the change... seemed strange to drop pinion size but the motor/speedo temps demanded it!

Have fun dude... you won't regret the change...

[ianjoyner]

I'm already running the light motor.

Thought I'd have a play with throttle speed on the trasmitter, but turns out my 3GR doesn't have it , so played about a bit more with the slipper, pretty sure I did have it too tight, the grass I'd tested it on was no where near as grippy as the astro track, got a good few feet of slip now, I'll see if that feels a little easier, then look at the other stuff. Thanks for the advice.

[col300]

Originally Posted by ianjoyner

I'm already running the light motor.

Thought I'd have a play with throttle speed on the trasmitter, but turns out my 3GR doesn't have it , so played about a bit more with the slipper, pretty sure I did have it too tight, the grass I'd tested it on was no where near as grippy as the astro track, got a good few feet of slip now, I'll see if that feels a little easier, then look at the other stuff. Thanks for the advice.

On the 3GR, the throttle curve is EXP-TH and the the brake is EXP-BK. If you try minus 25% (-25%), this should smooth it out.

[ianjoyner]

I was interested to try speed as well as curve, but must have been my old KO that had both. I've got my throttle curve at -5%, in the past I've not got on with big curve settings, but will try more negative if I keep struggling with control.