Any thoughts on my camber/Toe?

[AarhusTr6]

Hi all

I rebuilt my front end and put the car into one of those fancy shops that does all the measuring.  Any thoughts on the results and what actions (if any) should take?  Steering feels a wee bit light at 75mph on motorway but back country road with nice swerves etc it is quite good.

Edited August 24, 2022 by AarhusTr6

[John L]

If the tracking people put in the spec for your car correctly, the items in red are not correct, and should be adjusted.

the rear I believe should have some toe in,  and the overall alignment should put the car straight, which its showing now, as not so.

I would ask their opinion.

John

[Bfg]

AarhusTr6,

I guess it depends on whether you feel like tinkering. Other factors like wheel section and tyre choice, tyre pressures, steering rack mounting, which bushes you have in the suspension pivots, any slack in the steering-trunions, and the car's ride height and load condition .. will each effect the feel of the steering and handling.  Very likely you are rather focused on the feel of the car's steering and handling ..much more so than you will be in a few months time. 

Steering feeling a little light above 70mph would not be a problem to most of us nowadays, and as you describe yours as being "a wee bit" then it suggests that it's not really an issue for yourself ..unless perhaps you find yourself in a transcontinental hurry and blustery cross winds.  You also seem happy with the cross country handling, so although the figures suggest adjusting things, I wonder if in the real world - you'd actually notice much difference. ?  The figures given would not  imply terribly uneven tyre wear.  

The little lack of toe-in will be mostly noticeable as bump steer, both front and rear, particularly if your car's suspension bushes are soft. You have made not mention of that being an issue. 

A little more castor balance may aid straight line stability. The figures in grey perhaps imply this is not adjustable or is within acceptable parameters. However, from the figures given, I'd expect if ;

• on the LHS, there were one less shim behind the front-suspension's lower-wishbone forward-most bracket - it would add a little more to the castor, and slightly reduce the negative camber. The toe in would adjust the wrong way but that of course is easily adjusted by taking in a turn at the track-rod-end. 
• on the RHS, an extra shim behind the front-suspension's lower-wishbone forward-most bracket would slightly reduce the castor and would add a little more negative camber and toe-in.  

I'm sure someone will come along soon to check my 3d geometry thinking. Hopefully I've not got it wrong.

I suspect half a degree toe-in overall (ie., -0 deg 15' on either side) would be about right, if the suspension has been reassembled with moderate to firm polybushes.

At the rear, your car has toe-out on the LHS and zero toe-in on the RHS. This would contribute to the car feeling tail-end floaty at higher speeds. The toe-angle will change for the better, to negative toe-in under acceleration, but be worse under braking. Removing one shim from either side's outer-most (next to the sill) trailing-arm-to-chassis-bracket would improve that.  Whether you feel it or not in the real world is of course another matter.  

If and when you do this, then I'd highly recommend you slightly slacken the inside arm-to-chassis bracket bolts as well, and (with safety blocks under the chassis) jack under the rear of the trailing arm ..so that corner of the car's weight is fully carried on its road-spring. Only then should the trailing-arm-to-chassis bracket bolts be tightened up. This helps the inner and outer pivots (trailing arm bushes) to axially align with each other.  The camber on the rear RHS is a little excessive but until the pivots are axially in line your really don't know by how much, and I again doubt whether most drivers would feel the difference if corrected.  If you want to correct this, then it is corrected by choice & orientation of the notches on those brackets.  < This >  is adjustments and thinking on my own car. It's a TR4A but the suspension geometry is the same as on the TR6.  

Hope that helps,

Pete.

[Robert Price]

Spring lengths and rating can affect camber. One of my 6's had a lot of negative camber and was low at the front, I spoke with Revington about the dimension range from the ground to bottom of the chassis measured between the wishbone. Bought some new springs and it corrected the height and camber, but the issue maybe different from car to car.

Rob