One of them is me. The others I don't want to mention No offense Anyway it is enjoy share the knowleadge and info for "us " to review. end..

If my diff oil for front diff is so thicker than the rear say front 30,000 and rear 3,000wt, is my car will tend to spin into corner?

Anybody... i need handichap here!

It is possible. The front diff is designed so that the inside and outside wheels can rotate at different speeds when turning. Filling them with oil makes this effect less, ie the inside wheel will start to drag more when turning. When grip is high this is fine, there is sufficient grip to overcome the dragging wheels loss of traction. When it is low grip your car will likely lose front grip and push. However I have also encountered the front spinning out when the diff is very tight, though it is less likely.

esham,

What's the car doing wrong to make you ask that?

http://users.pandora.be/elvo

..Welcome aboard !! finally found you here.
What do you think about a "bump steer" as described in your site if it applied in the rear wheel ?

well done !! great job !!

Yea..that website already in my referance favorite quit sometime ago .. yup ..it is neat.

I ran MTX-3, Front Diff and Rear Negative Diff. Front 10,000wt diff oil and 7,000 Rear diff oil in Negative Diff. Front Toe out 1° and Rear Toe in 2°. Camber front 2° and Rear 3°. But the Rear Negative Diff is run so smooth tho.. compare than the front - manually feel. By this setup the car when into corner sharp with small radius but tend to spin out into corner like most of the weight to the front? " slip angle change"?.

So I change the front diff to lighter diff oil = 7,000wt the rest setting untouch. the " tend to spin" gone! but.... the turning radius become bigger I wonder is it really due to the weight of the diff. And suddenly spinning in my mind on this theory..." Because of the front diff oil is heavier and the tire has a good grip the turning angle will became small and slower and the light oil at the rear will turn big and faster. - This will make the car to spin out.." This is thorogh my logic thinking not math ..calc so excuse me..

So that why i ask here if that is true? Or maybe it due to my droop +5 ( probably is to musch for my MTX3 ) which make too much weight transfer to the front into cornering

My opinions, you should play with this weight transfer and not with the diff.
How far / much you want particular wheel to load and unload the traction, adjust it with the droop. How fast you want it to happen (weight transfer) you control it with your shock damping and readjusted your spring rate.
Play more attention and try to master this "weight transfer" stuff you will improve your tuning skill almost immediately.
And let the mileage hour to improve your driving skill.

Just my 2 cents.

Yup thanks Goldfinger.. seem you lean me to the priority. Thank you.

This is old forum but still I have a basic issue here to clerify .
I been told that my 2nd speed should not engage during the mid ( short ) straight/corners but only engage on the long straight. So am i have to :
1. tighten my 2nd speed clutch to engage later or
2. change gear combo ( pinion and spur ) as to let the 1st gear much longer to meet it peak.

Which one is better or more effective?

esham,

There's no absolute answer to this - either 1. or 2. may be what's needed, depending on your track.

Generally, it's best not to have a gear change during cornering as it will likely upset the balance of the car.

I'd suggest you need to tighten the 2-speed and see how it goes, first. If that leaves you short of gearing in the tighter parts of the track, try your option 2.
These things are always a compromise and your lap times will dictate what's best.

Thanks taylor.. alot rc "kung fu" that i need to learn.

Ok another one guys, What condition I should consider to tighten my engine clutch spring? More tight means difficult clutch engagement and will give more torque, loosen means easy clutch engagement but less torgue /pick up. When I should use this setting relative to a track?