dr_hfuhuhurr

iTrader: (95)

Yes, BMI is working on an upper deck (at least last I heard they were).

Blake

JDM_DOHC_SiR

iTrader: (31)

Jason.
Will it be the same size as the upper deck for the twit plate TC4?

-Dave

MartynD

Is the BMI upper deck intended to fit with the stock composite tub?

Will it be possible to purchase both the upper and lower decks separately once released?

raving-monkey

i doubt it, i guess they will make an upper deck and lower deck kit..and just the upper deck.

as i doubt anyone would want just the lower deck...it would be to flexible for any racing conditions..it would be like racing with an elastic chassis.

although if you talked to the bmi (sorry i dont know his name ) guy nicely hemight be able to do you a chassis on its own or what ever.

RCknight

iTrader: (5)

Jason! I may keep the TC4 yet if I can get just a top deck.

MartynD

Ya can see where I am going with this I hope....


Buy the upper deck run it with the tub, for perhaps asphalt or just $$ reasons, and then pick up the lower at a later date.

rayhuang

iTrader: (5)

Hey all,

I want to know if anyone else has suffered this issue with the TC4. I have had a heck of a time with one diff. It needs to be 1/4 turn from locked to be close to tight-but when it doesnt slip-it also has that molllases feel-VERY tight. but it was no problem fitting it into my diff case and setting lash, etc. So Ive been running it looser than ideal.

So I rebuilt it for the 4th time just a few minutes ago with a new diff gear and voila-problem gone. Its tight as can be and also counter rotates free as can be. It did not require any different shimming in the case too. I am happy-next time out on the track I bet the car has more rip and corners smoother now.

Anyways-anyone else or was this a fluke?

Ray

Brian McGreevy

iTrader: (10)

Ray, you got one of the thick diff gears in that were in the first batch of kits.

It's fixed now.

rayhuang

iTrader: (5)

Thanks!! Have fun this week. I wish i could make the NOvak race!!

runnin rc10

iTrader: (1)

Something Im noticing with my diffs, are that they dont feel smooth. The just kinda feel good in one area than a half turn away they seem to bind just a bit...is this the diff gears? They just feel terrible, run fine though.

rayhuang

iTrader: (5)

My front diff converted to a lt wt steel diff does that just a bit. I plan on rebuilding that one tomorrow night at track-but I just put the whole BMITC4 back together and dont want to take it apart again (now that I know I have bad diff gears)!!!

BTW-as an update on the BMI TC4-Jason tol me it was faster than his TC3 on asphalt. He ran a 8-turn and could flat foot through sweepers other drivers had to lift 3 or 4 times to get throough. And as I said on carpet-it responds to a change and you can tell after a few laps if it helped turn in-mid corner or exit or a combination of all of them.

I will do a lot of set-up changes tomorrow so anyone buying it to run on carpet-I hope I can help anser handling question. Again-I am no expert-but I will help as much as I can.

Ray

Neil

My lightend steel diff does that too. I've taken it apart installed new rings ring gear nothing helps. But the car seems fine on the track.

dr_hfuhuhurr

iTrader: (95)

Mine are doing the same thing...what I've boiled it down to is the diff spring. When I built the diff, I collapsed the spring using needle nose pliers. I think that bent the spring to one side a bit?

It's reacing but that's the best I came up with.

Blake

Fatboy Joe

Hi, I hope this tip would help those who have diff problems. The problem is not with the Diff Ring, Spring, Thrust balls or Diff Halves......it is with the diff gear itself. The face of the diff gear where the diff balls are placed are a tad thick on both sides..... what happens is when you follow manual specs on the proper adjustment, the diff halves or the outdrives tend to rub against the face of the diff gear, this gives you a not so smooth action like what you see with yoks or losi diffs. What I did was I dremeled the two sides with a flat stone grinder at a very slow speed setting and made sure that the grinding bit is squared up to get a perfect plane and just grid it around.....how much material to take out?....I didn't measure but I went around the the face grinding it for about 5 secs per side. Make sure you clean the diff gear after and take out the extra bits that where left during the grinding, most especially in the diff ball areas, use an exacto knife. Try rebuilding it again and you'll see a big improvement but if it is still gritty or not smooth, grind down some more, that means you didn't take out that much material on both sides. Word of caution: Please make sure you square up the grinding bit on the face of the diff gear to make a fine flat plane. I've done this to all my AE Kevlar Diff Gears and it always work. My diffs are as smooth as the other cars

rayhuang

iTrader: (5)

fatboy Joe-I thought about saving my gear that way. Can you desribe that bit a bit more-excuse the pun please. And I also noticed two ring marks on one dif ring-which I attributed to one ring from the balls and another ring from the diff gear rubbing.

Thanks for the tip.
Ray