I got one of these DBR 12 about a week ago because I thought these things on Carpet would be good practice for what I primarily run, 1/8th scale onroad.
I received the car (pre-built by Jason) on a Friday and proceeded to race it the next day. I'm kind of new to 12th scale for the most part. Although, I did dabble with an L3 back in 2004... breifly. It was nice when it wasn't tweaked, but somehow it was always not right, and I quickly gave up due to the maintaince. So when BMI introduced a car that you can't tweak, I was like...yeah!
I take one with tires please. Anyways, back to the race... As I've said, its been a while... The first time out, I forgot to tape the battery,
then there was gearing, and meanwhile the all the screws in the pivots worked their way out.
That last one was ugly!.
By the time I had everything worked out, I felt that the car was very drivable, nothing weird like I remembered about these cars. But the stock setup was hurting for steering,
a disavantage that would put me at more than a full second off the pace. My competition was a contingent of OD 12 team drivers, and they were dialed. So I turned to Jason for his insight and expertise on these little electric cars. After defining the problem as well as I could, Jason prescribed some changes to my setup. I raced again yesterday, I am happy to report that I went from being more than a full second off the pace to within 2 to 3 tenths. That's with no practice, nonetheless. I wish I could say that this thing was dialed right out the box, but anybody that races knows that this is never the case. There is just too many variables. What is important is that the BMI concept is for real. My car was never tweaked. More importantly, this chassis responded very well to setup changes. By that, I mean my car never lost its composure when I dialed in more steering. It just kept asking for more. When this thing is properly setup, it is an absolute beauty to drive. It's only going to get better as I learn. Thank you Jason for everything.
Here are the changes I made to my set up. in the following order
10K in the damper tubes (more stable and responsive in the turns)
1.5mm beneath the shock ball mount. (slightly improved on power steering)
caster shims in the back (more overall steering)
copper rear spring (not Jason's idea, but man, it was nice!!!
Things that didn't work
10K on the king pins (a little twitchy)
less pod droop 1.5 to .5mm (lost a lot of off power steering)
Things that I will try.
20k 30K in the tubes
Extra thick side flex plate.
Narrowing the rear.
Things I am afraid to try.
Has anyone tried to shim the arm mounts to lengthen the upper arm? I am thinking this will reduce the amount of camber gain. might be good...