Having huge issues getting power to the wheels

[kaylon]

Been running my car indoor quite a bit and it performs okay...not quite as good as I'd hoped but okay.

However outside on the local grass track and other grass areas I get maybe 6-10 mph max, it's quite embarrassing LOL. I've checked all the gearings and they are fine and My slipper is as tight as it can go but as soon as the car hits any form of resistance the slipper kicks in and I get no power or traction.

Any ideas chaps ?

J