Xray XB4

[Scotty415]

Hi all,

I have a strange problem with my xb4 just not sure if it is the buggy. When I jump the buggy it will nose drive to the floor. I added 60grams on weight to rear still doesn't solve it. If I full throttle the buggy it struggles to level it's self out let alone fit the front. Is this due to the inline motor or do I have a problem.

Thanks

[luniemiester]

What springs, diff oil and drag brake are you running?

[sime46]

Sounds like either too much drag brake or a fault in the drive line slowing down rapidly when you come off throttle? Mine flys straight as an arrow without any issues. Check your settings and if nothing there then check motor. Also remove pinion and see if the transmission still rotates freely. These buggies have super free transmissions normally. Hope this helps.

[V6Jim]

I've written a whole spiel about this on another XB4 thread. I have been struggling with this too, especially off short sharp ramps. Nearly every time I popped over this particular ramp the car would just end up nose diving into the grass and ending up on it's back. I ran my spare car (Caster S10B) in alternate races and it behaved perfectly.

The upshot of all the discussion was that the car is super sensitive to rear shock settings due to it's rear end 'lightness'.

If the rear end is underdamped the suspension compresses, bottoms out and abruptly rebounds, flipping it's butt right up in the air.

The answer is to run rear weights (under Lipo, under gearbox or suspension hanger or all of them) and up the damping. It doesn't need much, just enough.

I set up a wee ramp in the garden to test this and went round and until I was dizzy! It didn't seem to matter what pistons I used, but I suspect 2 hole may be better than 3 hole. Anyway, the results seemed positive.

Jimmy

[Al3xis007]

Prob the shock set up, you might be running too soft spring and not enough pack, this makes the car bottom out on the rear before take off, I have had this at stotfold sometimes.
You could run a bigger rear wing too

[Scotty415]

Thanks for the info on this one I have checked the drive line without motor and it is very free. I am looking to go up the track today for some testing. What shock oils, pistons and springs are u guys running. As I also find the rear end on mine is very loose as well. Also I don't like running drag brake so it's always turned off. :0)

[Al3xis007]

Rear of mine has 3hole 1.4mm with 32.5/35 oil, (inner wishbone hole)
Front has 3 hole 1.3 with 45/47.5 oil. (Outer wishbone hole)
Mine has been converted to a shorty battery so it's a bit lighter