It's funny this conversation is just hitting the forums. I have been chatting some with James about moving the b/l motor over. I was not aware the Jason was looking at it too and I have been talking to him as well. Just last night, I looked at the weight balance point of the b/l vs the brushed. Looking at OD's numbers, they are very close to mine. My scale only weighs in 5g increments. My Neo 4 Star weighs 165g w/o the harness. I have two Orion 9t that weigh 170 and 175g. Since b/l is only legal in mod (right now) I am only concerned about correcting a mod car. I found the balance difference between the two types to be 3.6mm... the b/l has it's balance point 3.6mm further away from the diff side then the brushed motor.
So, as much as a pain as it is, I am making up new upper and lower plates to move the motor mount over 3.6mm and then spin up a shorter diff hub of the same dimension. Then I will have to make a new diff thrust sleeve to soak up the difference (I know the manufacturer!
). I completed the lower plate tonight, the rest will get done in the coming days. I loosened the tweak screws and so far, it feels right on. Both sides feel about the same when you give it the light touch.
I have a Regional Race coming up at the end of the month I can do some testing. Then the bigger challenge will be seen in ND the week after.
For those that are thinking that they can just add a little wieght to the rear pod instead of going through all this.... it will take roughly 1/4ou added to the outter edge of the diff side tire to correct it. Of course it does not make sence to add weight to a tire. It would take over a 1/2ou if you stuck it to the outside edge of your motor mount. My personal hunch is that it will do more harm then good trying to add weight in this manor.
If you are going to tweak the car with a b/l system, leave the rear wheels on the stationary part of the tweak bar. That way, the weight imbalance will not show up when you tweak the front. You wont be able to spin the car around then with the rears on the moveable bar and get a flat result... the diff side will show light.