Originally Posted by
bkspeedo
I guess this rule would cover an actual spool like in a Touring car since Tamiya does not make one for a mini.
But if you make one from the gear diff that comes with the car this would be legal? To clarify what i've done in my car, I've placed extra washers in the gear diff so when re-assembled the diff acts like a spool, very little to no diff action. I believe most people do this today correct?
I would hope this does not fall under Rule 4, and since it's not a hop-up part it would not fall under rule 3.
When i made this setup change to the car i immediately went .5sec faster on average.
Adding an extra shim or two to the Mini gear diff to "stiffen" the diff is a common practice and will pass tech. However, locking the damn thing up will not. A diff must act like a diff.
Several years ago, super tight diffs were in vogue, but not so much any more. You only need the diff to be tight enough that your car doesn't "diff out". A nice smooth diff, tight enough to control wheel spin is much better than a nearly locked up one. Also, how "tight" the diff is built depends on the track layout, surface, grip level, etc.
In fact, guys like Calvin have more than one built up diff to tailor their cars to the track they are racing.
Glad you found a technique that gave you a half a second. That's a really big deal.