Front Camber

[MikeR]

Hi all,
Assembling the front suspension can anyone give me some idea as to a starting position for the top ball joint ie number of threads to screw in etc. The car will go to marlin for final setup but would like it to be close to begin with.
Regards
Mike R

[alackofspeed]

I've done mine by eye for now, and just aimed for a roughly vertical position.

I don't think the arms, going on the sets I've have, are similar enough to be able to state the numer of turns.

[bigrich]

OK.....this will take a little explaining and gets pretty good results for DIY alignment, here goes:-

Firstly set your chassis level from left to right (use the lower cross transom that the fuel tank sits above as a reference)..use a spirit level/ camber guage and packers.

Fit your suspension links (top, bottom and hub) and set the hub approx vertical.

Next make a fixed link to go where the damper would normally go. The length of this link you need to decide depending on the ride height you want. My recommendation is to make this link the same length as your damper in MID position when on the car...this way you set the wheel in the mid point and get sensible suspension travel.

Then fit this link where the damper would normally go.

You now have the chassis level and the suspension in the position you would normally be driving in.

Ensure that the hub is in the 'straight ahead position' then using a magnetic camber gauge on the hub (Sealey £30) set the camber to req'd degree....I'd use 0 - 1 degree negative.

MEASURE the fixed link length that you have used and then when you finally get the car on wheels set the spring adjustment collar to give you the same length as the link....you have now replicated the fixed setup.

...NOTE:- your springs will settle after a few months so you'll have to further adjust the spring collar to achieve the right height again.

Hope this helps...

Rich

P.S. If you don;t have a camber gauge and your paying Marlin to set up the car jus tuse a spirit level and set it vertical.

[alackofspeed]

To add to the above - marlin use a similar method, the only difference being their device employs some stud, so they can adjust the length.

I was planning to fabricate up a similar device.

Rich - out of curiousity, have you any idea what angle one turn of the top link corresponds to?

How did you set your rear toe?

What ride height have you chosen?

How did you arrive at the settings you're running, and have you had a play to see what affect different settings have?

[craig]

It's only about £250 to get the car geo'ed at a lotus specialist with the laser wheel alignment which no matter how you do it will be 100% better then anything we can do at home.

Seems cheep as chip when you think how much the cars can cost

[alackofspeed]

Given I'm not sure there's a "correct" setting for the car, I was toying with buying my own gear so as to enable me to play.

Call it my "geeky" side, but I quite like the idea of doing a track day, and seeing the affects of adjustments.

[craig]

Front toe, in total most never be zero (and DEFINITLY NOT toe IN), should always be just slightly toe OUT, as in 1mm out (in total).

rear toe should always be IN, for a road only car 1-2mm a side is plenty.

Front camber is set by the type of tyre you have and the use you are going to give it, for a road only car, 1 degree is a good start, for A048 on track then this will need to be increased a fair bit, and with slicks a shed load more (like 3-4 degrees)

Rear Camber is much the same as front, although a start point is more like 1.5 degrees for road tyres and road use, rangeing to 5-6 for slicks.

Other thing to remeber here is that as soon as you change another part of the suspension setup, you have to re-think your geo.

for example, the more body roll you have, the more camber you need to counter it, thus a stiffer ARB will change the roll, thus change the settings.... same for stiffer springs, softer tyres, etc etc.

Got this a while back from another site thought it useful

[bigrich]

Can't remember what I calculated 1 turn of the ball joint as...although it's pretty easy to calc. Basic trig....measure pitch of the thread and then create a triangle measuring the ball joint to ball joint measurement as the other side.

Tan (angle) = thread pitch / ball joint to ball joint length.


Ride height I went with was 'mid damper' travel...I've got the measurement somewhere...I'll dig it out (I need to to reset my spring heights as the ride height has dropped with time (settling springs)


Rear toe was pretty simple......bodywork off, set the susp height (sim method to the front) then use trammels from the rims horizontally alongside the car. Then measure the distance from the trammel to the bodyside frame / panel. As the car is 'square' then for parallel toe the distance that the trammel is from the car should be equal along the length.....i set mine slightly toe in...about 1mm to allow for the toe out effect that you get on the rear of rear wheel drive cars.

..have I played with the settings....no...too bl**dy time consuming!...the Marlin design really does need quicker setting (LH / RH thread turnbuckles? eccentric fasteners etc...)...anyone got an easy mod?

...I should probably take it and have some 4 wheel geometry checks, but it handles OK, drives in a straight line and hasn't wrecked the tyres yet (1500 miles)...so must be something like?

Rich

[alackofspeed]

Rich - I've been thinking about how to make the suspension adjustable "on the fly" rather than through partial dissasembly - a pretty daft method IMHO.

Have you seen the rear toe links on the race cars?

Craig - although I've not really looked at it from a numerical perspective (x degree etc), from playing with settings in the past when I was kid competitively racing r/c cars (note I said when I was kid....!), I used to adjust all manner of geomery settings to account for the tyres, surface, roll, damper rate, spring rate etc... Which is why I was thinking it might be cost effective in the long run to buy my own gauges.

[MikeR]

Thanks guys.
Mike R

[limpabit]

Spoke to Simon at Marlin. He said set the ride height to 130mm (this is low for a trolley jack!). The set the camber etc.

[alackofspeed]

Blimey - I wonder how many speed bumps I'll beach on at that ride height.

[limpabit]

Originally Posted by alackofspeed

Blimey - I wonder how many speed bumps I'll beach on at that ride height.

I'll tell you soon!

[Jon@JNRacing.co.uk]

Mike,

After you have set it up yourself you could always call in Track Developments, they will dont a complete set up on the car for road & track, from setting ride height, to adjusting down force, not that cheap but if you feel the car doesn't handle as well as it should then it may be worth a try.

Jon