Timed brushes, question
 

Hey all, I am looking for some info on timed brushes.

A guy at my track ran in the sportsman truck class which requires street spec motors but is open as far as how you set them up ( brushes etc ).

His motor was blistering fast, and the comm was the street spec kind. He told me that he used timed brushes in it.

Anyone have experience with these brushes? His speeds were close to what the pro class was doing! ( we run 19T motors ).

Yes,most of us "old" racers remember using them,the theory was (or is) that it tricks the motor in to thinking it has more timing,most street spec motors have 24 deg's of timing,with timed brushes it makes it act like it has more timing(= more RPM's)I have not seen anyone selling them,but you can make them if you have a brush jig.It's sorta of hard for me to describe(in words)on how to cut your brushes.I'll try later today.

ok, any help you can give would be great. I am thinking of trying this in my chameleon. Some racers by use are trimming off part of the brush so you don't get brush burn I think. something to that effect.

Ok,this is how we used to do it,with a file(very fine)you want to take about 40% of the brush away from the leading edge(that would be the side of the brush)about 1/8 of an inch,that would be the neg. side,on the pos. side you do the same but the trailing edge,it's been a long time so you should experiment on the brush placement,but I think I have it right.I would also experiment with brush springs and teflon shims.But remember any time you increase the RPM's you will have a reduction in torque.Good luck.

ok. sounds good. I am looking into getting one of those racetech tools that let you do this. The guy at the hobby shop also drew a diagram detailing it. So you do someting like this:


Negative Positive

_______ ______
| _| _| |
|_____| |_______|


Does this look about right?

shoot. didin't come out right. let me try this:


Negative Positive

Longer!!!! Shorter
Shorter !!!! Longer

maybe that will give it a better view.

The first one looks about right.