XRAY - Model racing cars

My son generally runs 19T and I've always tried to have the belts like sloppy sphagetti, but I understand that mod requires tight belts...

1) why?
2) what happens of I leave them as is?
3) I have the adjustable top deck but don't run the belt tensioner as the belt keeps coming off, would this be good in mod?

Muchas thanksyou's

Hi
1) because the modified motors habe more power.
2) the worst thing that could happen is that the belts start to skip.
If this is very much, the belts and pullys wear very quickly.
3) This isn´t just a belt tensioner. If you run your car and watch the belt (of courese not on the track, because you can´t see the belts) you will notice that the belt starts moving up and down.
With the "pelt tensioner" in the top deck this vibration is much smaler and the drivetrain works better. You could set the "belt tensioner" that it just tuch the belt.
Stocki

I run my belt the same tension in stock and mod and it's a bit lose for stock. The belt only skips when I run a normal front diff or a spool (any diff that allows full braking) but most of the time I run a oneway. You may only need to tighten it if you use full braking because mods have a lot of braking power.

dave, i have run mod all year with my belts set 1 position looser than stock with no problems at all. the front and rear belts have been changed once and so have the pulleys, when we race at norwich (indoors on astroturf) using low wind motors we have had no belt skip at all.

thanks for the replys guys, we ran with the belt tensioner and all was ok