Help with exiting corners

[barry]

Hi,

My Tamiya TA-05 spins very easily coming out of corners on my local asphalt track. As someone who has been away from the hobby for a while, I could do with some help. I've altered droop, toe-in, and camber, but still can't seem to solve this. I've heard of people changing to a lighter grease in their diffs to make it less likely to break traction - can anyone tell me if this is worth the effort? Is it possible to 'loosen' my rear diff somehow?

Many thanks,
Barry

[cjm_2008]

the first thing I'd look at is driving technique mate. it's an easy place to start. are you trying to nail it before the apex?

slow down. practice each corner individually each lap - build up speed gradually.

if it isn't your driving, you obviously need to gain some rear end grip. this could mean softening the springs, using a lighter grade shock oil, or using a piston with more holes. try one thing at a time.

[qatmix]

Here are some settings from ta05

I would set the front camber to 0degree, and the rear to around -3 degrees.

I would move the rear shocks into the most inward postion, the front ones more outward.

As to the diffs, you actually would be best to tighten the front up slightly. All you have to do is turn the diff screw about 1/2 turn. I wouldnt do any more as you can break them if they get too tight. Try it and if its still to loose, turn it again another 1/2 turn.

But as has been mentioned, the real key is to slow down into the corner and power out past the apex.

Cheers

[barry]

Thanks both.

I really appreciate the advice. I probably am giving it too much throttle too early.

Barry

[sosidge]

I would set the front camber to 0degree, and the rear to around -3 degrees.

I would move the rear shocks into the most inward postion, the front ones more outward.


That is VERY extreme camber and not something I personally would ever consider using. 1 degree negative all round is usually in the ball park, with the aim of getting even tyre wear.

Diff should be set a little tighter at the front, rear should be set to rotate smoothly and relatively freely. A tight or notchy rear diff will cause no end of traction problems.

I found the TA05 to have a fair amount of steering. Just running a stiffer grade of spring on the front seemed to calm it down a fair bit, say Tamiya blue front and yellow rear.

There are lots of other things to check too, obviously make sure the car is in good mechanical condition and that all the parts are aligned and move freely. Something as silly as a loose steering part will ruin the handling. If you find yourself a bit lost on setup go back to kit settings and start again, really you shouldn't need to veer to far from them to get the car to your tastes.

Oh, and tyres matter too!

[barry]

Diff should be set a little tighter at the front, rear should be set to rotate smoothly and relatively freely. A tight or notchy rear diff will cause no end of traction problems.

Thanks for the advice. So just to be clear, I can tighten/loosen the diffs by tightening/loosening the screw that holds the diff together (a long cap screw on the TA05, rather than having to change grease? How loose/tight can I go:)!?

Cheers,
Barry

[sosidge]

Thanks for the advice. So just to be clear, I can tighten/loosen the diffs by tightening/loosening the screw that holds the diff together (a long cap screw on the TA05, rather than having to change grease? How loose/tight can I go:)!?

Cheers,
Barry

That's right.

Diff tightness can be anywhere between very tight and free spinning, but you should never be notchy and always have zero to very little slip. A setting for rear diff would be free to rotate but not spinning free if you spin the wheel. A setting for front diff would be a little tighte, turning with a little resistance by hand, but not notchy.

Ball diffs are something of a black art, a little time to learn their nuances and effect on car handling is time well spent.

[Al3xis007]

while you're there take the diff balls out of the front diff and try a spool, then you can be a throttle jammer :-)

i always look at the problem the other way; if the rear's kicking out change the front

(a pikey solution without seeing it is shortening the rear wheel base)

[qatmix]

Spools are the tool of the devil! ;)

I should have said that my regular course is a small technical circuit, so I need to try to get as much speed as possible whilst accelerating out (with a car with lots of acceleration, little top speed) so thats why I have 2.5 -3 degree camber. (as to most of the other guys). On a large outdoor circuit it will not need to be as extreme.. although it will still work.

Also check your droop, if you have alot of it at the front, you will throw a lot of weight to the front of your car when braking, on teh ta05 with the weight in the middle this can be quite dramatic.

what is important though, is to do all of these things one step at a time. if you do them all and the car doesnt handle well, you wont know what was the problem.

[barry]

That's right.

Diff tightness can be anywhere between very tight and free spinning, but you should never be notchy and always have zero to very little slip. A setting for rear diff would be free to rotate but not spinning free if you spin the wheel. A setting for front diff would be a little tighte, turning with a little resistance by hand, but not notchy.

Ball diffs are something of a black art, a little time to learn their nuances and effect on car handling is time well spent.

Just to clarify some terms...
* very tight - wheels stop spinning immediately when spun by hand
* free spinning - opposite of above
* very little slip - not sure what this means

Thanks for the help,
Barry

[barry]

while you're there take the diff balls out of the front diff and try a spool, then you can be a throttle jammer :-)

i always look at the problem the other way; if the rear's kicking out change the front

(a pikey solution without seeing it is shortening the rear wheel base)

What do you mean by short rear wheel base? I thought wheel base was the distance from rear to front wheels.

Cheers,
Barry

[qatmix]

What do you mean by short rear wheel base? I thought wheel base was the distance from rear to front wheels.

Cheers,
Barry

On the Ta05 you can change the suspension blocks that the arms go into. If you put the smallest blocks in, you would shorten the rear width of the car. this would make you turn easier. But you dont need that. You just want to hold speed in the corners.

[qatmix]

Just to clarify some terms...
* very tight - wheels stop spinning immediately when spun by hand
* free spinning - opposite of above
* very little slip - not sure what this means

Thanks for the help,
Barry

A ball diff should never spin once you release it like a loose gear diff.Its more how it feels when you turn the wheels. If you tighten it you will just need to use a little more force to spin it. loosen it, a little less.

Its important you never tighten it too much as it will just break the diff, as i said before, just try 1/2 turns on the diff screw, then try it on the track etc. Its a bit of a lengthy process at first, but you will soon get used to the diff settings you prefer.

[sosidge]

Just to clarify some terms...
* very tight - wheels stop spinning immediately when spun by hand
* free spinning - opposite of above
* very little slip - not sure what this means

Thanks for the help,
Barry

Slip would be when the plates and the balls in the diff slide against each other rather than grip. You can test it by holding one wheel and the spur gear in your hand, then try to turn the other wheel. It should take a generous amount of force before the diff slips (if at all).

A very tight diff may have almost no diff action at all - although running diffs that tight will tend to break them.

[sosidge]

What do you mean by short rear wheel base? I thought wheel base was the distance from rear to front wheels.

Cheers,
Barry

I think he probably means adjusting the wheelbase using the spacers on the rear wishbones. Shortening it like that helps to put more weight over the rear wheels which will aid traction. There are other effects of a short wheelbase though - less stability and a tighter turning circle.

[chickentikka25]

It sounds like your rear diff may be too tight - a tight rear diff tends to make the car slide (by breaking the traction of the rear tyres) out of corners, a loose one will make it slide when entering, or mid-corner.

You could also try some pro-squat (I run a TC5 and can mount the rear of the rear wishbones higher than the front of the wishbone). That promotes on power rear grip. I find it useful as it also ever so slightly dumbs the front end down when powering away so you can make rapid direction changes under power without spinning.