Bump steer

[J.Kirkman]

Hi, I have been running with the standard 10 degree castor blocks with the 25 degree kick-up shim and have been finding the car hooks terible mid corner. So I tried to get some 5 degree castor blocks but everywhere was out of stock. So I fitted some 3 degree blocks but now have massive amounts of toe out when the front suspension is compressed. I removed the washer under the ball stud on the steering block which improved this but I still have loads of bump steer and no way of getting the ballstud any lower. Is this a fault with the 3 degree blocks, can they only be used with the 20 degree shim? (I havn't tried this yet but dont want only 23 degrees of castor anyway!)

Any help or experience much appreciated.

[jaydits]

hi i have put the little grooved ring thats between the arm and the hub in front of the hub and thats curing it almost

[J.Kirkman]

Cheers, but you shouldn't need to mess with the front wheelbase. I'm loosing the love for my new Losi

[The Pookster]

Have you tried running it with some toe out bumpsteer? This actually works quite well...

[J.Kirkman]

Yeah I found it very unpredictable through the bumpy back section at Southport. I've just tried to alter other things on the car such as front hub hight and moving it backwards also tried it with the 20 degree shim which makes it crazy bump steer. There is nothing else that can be done within the standard geometry of the car so I do feel Losi are taking the p*ss when they sell 0 and 3 degree hubs. I wounder if they even tried them before putting them into production!!

I'm going to try and modify the steering arm so that the ballstud can sit 1mm lower but im going to have to strengthen it on the underside to compensate for removing the upper material.

[Legacy555]

Originally Posted by J.Kirkman

no way of getting the ballstud any lower

Remember that you can put a washer under the ballstud on the steering rack too, having the same effect as lowering the ballstud on the spindle.

[J.Kirkman]

Originally Posted by Legacy555

Remember that you can put a washer under the ballstud on the steering rack too, having the same effect as lowering the ballstud on the spindle.

I'm afraid this is wrong. Adding a washer here does the oposite to what you say and increases bump steer as the ballsud is upside down when compared to B4 ect, I've tried this already.

[Chalkie]

You need to lower the height of the ballstud on the spindle, if you've taken the 2mm spacer out from under the spacer then you could try putting all of the spacers on the kingpins bellow the spindle to lower the height of the whole spindle.

[J.Kirkman]

Originally Posted by Chalkie

You need to lower the height of the ballstud on the spindle, if you've taken the 2mm spacer out from under the spacer then you could try putting all of the spacers on the kingpins bellow the spindle to lower the height of the whole spindle.

Done and done. Seriously guys the only way around this was to remove material from the steering arms to lower the ballstud. This has improved things a lot but still isn't perfect but I'll try it with a little bit of bump steer before removing any more.

[Legacy555]

Originally Posted by J.Kirkman

I'm afraid this is wrong. Adding a washer here does the oposite to what you say and increases bump steer as the ballsud is upside down when compared to B4 ect, I've tried this already.

You're absolutely right - was thinking of my old CR2 there. How about getting hold of some short-neck ballstuds? Or dropping the spindle spacing?

[Tom3012]

John could you not put the ballstuds on the underside instead? Not lookes so just guessing?

[steveproracing]

Again an idea that I've thought of without a car in front of me. But can you put left arm on right side. Ie turn them upside down to lower the ball height???

[J.Kirkman]

Originally Posted by Tom3012

John could you not put the ballstuds on the underside instead? Not lookes so just guessing?

The ballcup hits the wishbone on lock. In reality Losi should not have maufactured the 0 and 3 degree blocks as the cars geometry can't be adjusted to suit.

[J.Kirkman]

Originally Posted by steveproracing

Again an idea that I've thought of without a car in front of me. But can you put left arm on right side. Ie turn them upside down to lower the ball height???

Not done this but the steering arm is offset to go over the wishbone. Fliping them upside down will result in major contact.

Thanks for the ideas tho guys.

[J.Kirkman]

I'll look for some short neck ball studs as this sounds like it could do the job. I only need a bit more as the mighty file has done some correction!!

[Chalkie]

Well if you still need to drop the ballstud a little lower I'd be tempted to grind the 5.5mm hex off and use a die to run the threads up further. That way you don't weaken the arm, and you should be able to move the ballstud upto 2mm lower which should be enough to use even the 0 degree blocks.

[Chopster]

Originally Posted by Chalkie

Well if you still need to drop the ballstud a little lower I'd be tempted to grind the 5.5mm hex off and use a die to run the threads up further. That way you don't weaken the arm, and you should be able to move the ballstud upto 2mm lower which should be enough to use even the 0 degree blocks.

Good idea, bonus being there isn't a 'hex' as such as you use the Allen key to fit them... So can still be easily fitted/adjusted

[Tom3012]

Or use a longer turnbuckle with a shock end screwed on to that side then screw into the hub? If that makes sense?

[J.Kirkman]

Some great ideas there guys. Thankyou. The rose joint shock bottom is prob the easiest and I'll try that when I get home, just not sure it will allow enough for the angle changes of the steering linkage but only one way to find out.

Give yourselves a pat on the back from me