.50,1/16,5/65,3,32 allens
1/4,3/16 nut driver,wheel nuts are a 11/? cant remember

did you mean 3/32? Also, I thought the nuts holding on the shocks were smaller than 1/4?

Allen drivers will be .050", 1/16", 5/64" and 3/32
Nut drivers will be 3/16", 1/4" and 11/32"

There seem to be a lot of gearing questions lately... and unless 2 people run at the same track, its hard to be specific. Back in the day, the motor pinion on brushed motors could usually start at a certain number of teeth "over" the motor turns. So for example, if you were running a 13 turn motor, and were gearing "8 over" for that car, you could start with a 21t pinion.

Any thoughts on how this would apply to a brushless motor in a b4.1? It seems like its not quite as simple of a calculation, but I my best guess was (1.5*turns)+5 would be a good starting point without boost. That's a 31 on a 17.5, 25 on a 13.5, 21 on a 10.5... Any thoughts?

would be roughly the same as dropping one tooth on the pinion...

81/22 = 3.68~

84/22 = 3.81~

81/21 = 3.85~

it's not exact but in a pinch 3 teeth on the spur gear equals 1 tooth on the pinion..

As someone just learning brushless, this information would be invaluable to me. It will give me a baseline to start with for when I get to a track.

Thanks Racer & Smoke! I changed to 84 over the w/e felt really good about it!

I picked up a T4 and plan on running a D3 - 13.5. Per the manual, AE suggests 87/18 gear but I don't think the math = the FDR of 7.80:1 as stated in the manual.

What gearing would someone suggest to start with for a T4 with a 13.5? (Med indoor clay track)

I recall 24/81

18/87 is more of a 12.57 FDR.
I ran that same size gearing on my B4.1 with a Novak 13.5T and it would do 12 O'clock wheelies in the street. I would tame it down to a 7-8 FDR

a 24/81 is a 8.78 FDR and may work depending on track.

Does anyone use Stainless steel screws on the b4.1? and if so what advantages/disadvantages are there?

I use some of them, but local sponsored guys like Numan in So Cal uses all of them and I just think that they look better, I dont know if they have any performance aspect

They look better and dont rust, but are typically softer. Someone mentioned to run the stock screws on the shock mounts earlier in the thread, and I though it was BS, but sure enough I noticed my stainless front upper shock screws were bent recently.

They are stronger than aluminum, but not as strong as the original steel.

Larry (pops) posted this on the 17.5 thread on the Mike's racing local forum:
"B4.1 gearing 75-34 final drive = 5.75 that will work"

The 2nd double in the middle is the only jump that requires any skill on that track layout. Stay left and land as close to the inside pipe in the off-camber section as you can. The gap is farther between the jump and landing on the right side. You will see people case that jump all day even in 4wd mod. I have no experience with 17.5 but I suspect the thing is to backside the 1st double or land with as much speed as you can so you can clear the 2nd jump. Good luck out there and if you need help with secret gearing still give me a PM. I asked 3 people but I'm waiting for their response.

Jeff K

i just followed racer 53 "how to build a ball diff" to the T. the only problem is i do not have the "FEELING" for when the diff is correct. when i get to the part to set the slipper i can not get the front tires off the ground. there is a loud honking sound from the car, i think it is the diff. not sure if it is to loose or to tight? i do not want to tear up anything so if you guys can help out and tell me which way to go.
by the way that is a great video and once i get the feeling i will be good.

thanks for the help in advance.
scott ross