26 replies to this topic

[Buzzword]

Hi there,

 

I've been trying to get my suspension setup sorted out for Autosolos and road use. Finding somewhere was a bit of a pain so I tried to learn the old string and measuring tape technique. I've got it fairly drivable but just need a little advice to finish her off.

 

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(12" Wheels)

 

I need to put less toe out on the fronts, and sort the toe in on the back (that one's a mess)

 

My real question is about the castor, as I didn't touch this - I just set the adjustables to the standard length.

So the right side in particular is a bit excessive (and I occasionally get rubbing on the arch when turning)

So I'm looking to bring both sides down to about 4 degrees all round.

 

Stupid question, but do I shorten or lengthen the tie bar to reduce the castor?

What effect is that likely to have on the camber/toe setting?

 

 

 

 

[Ethel]

Lengthen to decrease, it'll add a bit more neg camber and toe out. Looks like you could use a bit more rear toe in too.

[Buzzword]

Thanks for that.

 

Do people think I should be using longer track rod ends with this setup? Or are they only for extreme cases?

 

Cheers

[mini13]

trackrod ends are hard to say, really you need to whip them both off to check, mark the locking nut and steering rack arm with paint, and undo the track rod end off and count the turns, you want a minimum of about 8 turns IIRC, or the same distance as the diameter of the thread or more,

 

personally I tend to use  the longer ones and extend them anyway as a matter of course, a wheel nut is a good extender for welding on, even pretapered for welding... just get rid of any plating, and use a bolt to index them, and maybe a tap after if it need easing.

 

in terms of alignment, i would definatly reduce the castor, i think you'll find somthing around 4 degress better. also I would have said a bit less camber on the front, maybe a degree? and a bit more toe in on the rear, unless you do want it to be livley for  the autosolos,  also I'd aim for closer settings side to side on most things, but i do tend to run rosejoints on everything.

Edited by mini13, 29 March 2018 - 12:20 PM.

[Allrounder]

The settings I would recommend for a starter are at the front
10 minutes toe out
1.5 degrees camber
3.5 degrees caster
At the back
10 minutes toe in
1 degree camber

Been competing on solos for quite awhile now and have spent ages setting mine to fit my driving style and getting the tyre wear right. Im doing the BTRDA and CMSG solo championship this year so will be at plenty of events so come and say hi for a chat. Oxford has a event at Finmere Airfield on the 22 April.

Liam

Edited by Allrounder, 29 March 2018 - 12:51 PM.

[Buzzword]

OK, I'm getting a bit closer.

This is a bit like playing pin the tail on the donkey

 

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2 questions now.... I bought some longer track rod ends just to be safe, but they appear 'loose' like the internal diameter is wrong - even threaded on 15 turns there was play on the threads (lock nut not tightened) so I left the standard ones on, as they seem to engage enough and seem to fit better. Is that normal or did I buy rubbish?

 

When I set up my measurements at home I'm reading a fair amount of rear toe in - the lasers say no! What am I doing wrong?

I set up a perpendicular rectangle of string around the car to allow for the difference in front/rear track width.

Then I make sure the distances from the string to the centre of the wheels are the same (eg  5cm fronts/8cm rears)

Then on each wheel I measure the difference between the line and the front and back of the rim 

Is that right?

 

Sorry if that's confusing, It's a little tricky to describe!!

 

Anyway, I'll add a little more toe out on the front.

Any more thoughts on this arrangement?

 

Cheers

[nicklouse]

sounds like incorrect TREs

[Buzzword]

Liam - If I see you I'll definitely come over to say hi, I won't hake the 22nd one though as I have a few problems to sort on the car this year.

I saw you won the Abingdon Car-nival event a few years back - That encouraged me to give it a go in the first place.... I didn't do quite so well though!!!

That's what led me to sort the suspension out.

[mini13]

the loose TRE  threads is intreging,

 

where diod you get them? part no?   i dont know of another thread off the top of my head that would go on and feel baggy so I reckon they are just poor quality,

[GraemeC]

Where are you getting your reading printouts from?  And if they can do the readings, why aren't they setting the alignment?

 

How are you converting your measured values (in mm I presume) to angular values to compare with the print out?

[racingbob]

why don't you get it set up properly and then do the string thing for future reference and the broom handle trick down the side thats what i do had it to bits many times since garage done tracking etc

[Buzzword]

I got the TREs on eBay (yes...) but from a mini specific trader, I can't recall which one. Same part # as minispares. I thought they might be OK, but obviously not. I'll get in touch with the company before naming them I guess.

 

So I'm getting the printouts from the nearest tyre shop that can align 12" wheels. Tell me if I'm wrong but with the aftermarket adjustables, you can't make adjustments with the car's weight on the wheels - especially rear brackets. So my thinking was - would a run of the mill alignment shop really go to all the bother of doing a readout, raising the car to make adjustments, taking it for a drive to settle it then measure again?

(that's a genuine question by the way... I don't know)

 

Really I'd like to learn how to do it myself and so far I've spent £0 getting it set up as the shop has been happy to 'check it' (in the future it might be £10 a printout.)

 

Graeme - to convert mm to degrees I've been using http://www.trackace....rsion chart.pdf

[Spider]

Have it set up by a shop first, then if you want to make adjustments from there, just make the exact same adjustment to each side. When you get it to where you want it to be for handling and ride, take it back and firstly make sure it's all 'even steven' then get a print out for future reference.

 

I know everyone has their own ideas of how their own cars should be set up.

 

I like to get front and rear wheels with a Zero Camber - I do this for tyre life, braking and acceleration, granted, these are a compromise here are the camber will change with pitching, but dialing in any neg. camber at all on these cars reduces braking capacity. Then to get neg camber when it's wanted (cornering) dial in caster - usually a minimum of 4⁰ is needed here and sometimes as much as 6⁰, however the down side is it does make the steering heavier than it was.

 

Too much front toe in will make the rear feel 'jumpy' and any toe out on the rears will make it want to swap ends.

[nicklouse]

found this interesting.

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[Allrounder]

Depending on what lower arms you have Id be cautious as to how much caster you put on. Particularly if you still run the rubber bush type as this will try and distort the bush wearing it faster and worse case break the arm. There are offset bushes available but there is limits to these too. I now run the spherical joint type.