XRAY - Model racing cars

my set up:




im losing grip in chicanes
car is just spinig out imidietly

also my car is spining out in fast corners


what should i change in my set up?

Hi,

could be that you are too soft with the damping in the rear for running without antirollbar(s). I would mount the 1.2mm antirollbar in the rear or go to 500/550cst in the rear. If you would keep it really soft in the rear I would use the outer camber link position on the rear hub. With the inner position on the rear hub and a soft rear setup it could be possible that the camber increases too much during faster cornering.

i have anti roll bars
i just missed them during filing the set up sheet-.-
sory
on rear i have 1.2mm
and in front 1.4

my friend told me that i have to tight diff
i have a tight diff(really tight),because its just sinkin'-.-
its not transfering all the power to rear which is aplied

can you help me with this BALL diff?
how to build it in the best way?
can you give me some advice?

im waiting for gear diff,but i wuold like to make this diff run fine:)

Yes, it also could be the ball diff. If you have very low grip then a tight diff will end you up in spinning suddenly. In the same way, if you have a lot of grip then it could bring understeering (I mean the grip that the rear of the car can provide).

When building the diff it's important to assemble the cone washers correctly and fully tighten them at the first time (same as with springs). Once tightened you can set the preload that you want. Then I only use ball diff grease. With other grease there I got lots of slipping. To set it I hold the spurgear and one rear wheel, then turn the other one and tighten the diff as long as the one wheel turns pretty hard ... like you tighten the top of a PET-bottle to describe it maybe.

That's basically the point I'm starting from. But if it's too tight then it's the best to untighten it step by step by 1/4 of a turn.

A ball diff must be run in when new with less preload. Then you can tighten it more and more.

My bal diff building process is

strip everything into a pot of brake cleaner , remove the thust bearing using a set of C clip pliers

i then use 1000 sand paper to sand the diff rings so there is no sign of the ball marks on there

Clean the pulley and the bearings well , then add a small amount of grease on the diff outdrive (this only holds the diff rings in place)

add oil to the bearings then build them onto the diff half with the pulley

Clean the diff balls and pick up with a small screwdiver with some diff grease on it and place them in the pulley(i like MR33 diff grease , the Xray stuff is a bit thin)

then add a small layer of grease to the othe diff ring and build this back together , this is that part done , then assemble the thrust bearing using thrust bearing grease(black type)

tighten only enough to feel the diff being a little tight , put it into the car and hold one wheel and give LIGHT THROTTLE holding 1st the left then the right wheel , then tighten till you cannot move the spur gear whist holding the rear wheels , then the 1st battery i do i will listen to the car and see if the diff is slipping and adjust if needed , i find the diff will need a slight tweek tighter after rebuld

check out this video (i know it is a Tamiya but diff building is the same)

thanks,i will try this

Regards

Nice video. If you use brake cleaner make sure it's a good one that could be used on plastic and rubber, too.

brake cleaner have inside feul and alcohol.....
so its obvious its not for rubber

haha

I allways clean my RUBBER tyres with brake cleaner !!!!!!

it doesnt matter for ball diffs there is no rubber in them

the best brake cleaner is Loctite brake cleaner as it doesnt leave the tyres greasy , BUT it is 8 euros a can i only use this for tyre cleaning , cheap stuff for other uses

cleaning tyres with brake cleaner destroys them:D
i use only brake cleaner for tyres before big race or somethin'

hahaha

never destroyed any of my tyres !!!

I think he means that brake cleaner can 'dry' the tyres out by the nature of it's degreasing properties.

If you want a cheaper alternative, use lighter fluid, that cleans the tyres up far better and lasts a lot longer.

i heard people use WD40 too , but i never tried it , my tyres never last longer then a day , 6 to 7 batterys on sorex32's and the lap times drop off by 1 second over a 18 second lap

I then give my old tyres to the young kids at the track to keep them racing

only indoor do my tyres last longer then i never notice any bad problems with cleaning with brake cleaner

wd40 is grease,so if you are using it for longer time your car is drifting:D

but wd 40 is another oil:)
if your doors or somethnig does not works u use a little bit wd 40 to make it run smooth:)

Some brake cleaners are really suited for rubber, too. Nigrin and Motorex i.e. are one of those. I use Nigrin all the time on front bearings, carburetors and on a towel for cleaning my rubber and foam tires. On the other hand there are brake cleaners for 2€ that even discolour cooling heads. I think Nigrin is at 6,50€ and Motorex at 12 to 13€ ... but REALLY good.