rear prop joint bindong unless you have drastically opened out the joint or fitted dual cardon.
The UJ's get a biggher angle than landy ones, but as with any UJ, have a VERY short lifespan at max angle(maybe 500 miles!!!!!!!!!!!!!!)
Tilt the axle so the prop nose is in line with the rear prop, and fit a dual cardon prop, and suddenly you can accelerate hard again. I did!!