When checking toe in/out at rear what are the best reference points on a Transformer? The longitudinal chassis side rails??
I can crank it up at the back to get more rake, but as you say I want to see what this base line feels like first. Probably will be able to get out on Thursday or Friday if the roads are dry and I have sorted the sticky throttle cable. I can reduce the camber but its a pain unbolting the bottom rose joint.....
When checking toe in/out at rear what are the best reference points on a Transformer? The longitudinal chassis side rails??
id suggest putting a string line down the centre, front to back to get an accurate datum then check that to the longitudinal rails.
How do I know where the centre is??
Run a string between the rear wishbone inner mounts, marking the same position on each side, the spacer washers are suitable, remove the string, fold in half to find the midpoint and mark that, put it back on the car checking the outer marks match where you started. Then repeat at the front. This allows you to run a third string front to back that will determine the centre line of the chassis from which you can take measurements.
Guy
So a bit of an update.
Using the parallel tub and straight edge of the rear wheel and some school boy trig I found OSR had 1 deg toe in and the NSR (in the photo!!) had zero!
So a bit of a fiddle on the nice adjustable trailing arms I got c0.4 degree toe in one both rear wheels.
Set the tyre pressure to 18 front 22 rear ground clearance front of tub (which is essentially a flat plate) 160mm, rear of tub 169mm so not pointing up!
Went for my 20 mile check run and the rear felt really planted, but am still not getting a stable front end at speed in a straight line. Steering and cornering so far feel fine but not exploring that. It needs constant input on the steering at ehem speeds in a straight line (like it is tram-lining all the time), not as bad as previously, so more toe in or less, and more caster (I am near the limit of the geometry already at around 5 degrees). I did not notice any bump steer problems.
Any chassis experts out there??
If I read your post correctly then 0.4 degrees per side is too much toe in IMHO, as stated in an earlier post rear toe wants to be in the region of 20 minutes total (10 minutes-1/6th of a degree per side)
The front of the chassis I would suggest to be 20 to 25mm lower than the rear of the chassis, normally measured at the front of the floorpan to the rearmost cross member.
I think you will always get some tramlining as the rear track of a GP4 is wider than the front track so the rear wheels will always follow a different section of the road. the wider the rear tyre the more I think it will show itself, I see you have the 295 TB15's though which shouldn't be too bad.
Constant movement of the steering wheel can be either bump steer or rear end tramlining, if you are happy that you have no bump steer then I would think that you are correct in the assumption that the rear is causing the issue.
Where are you with negative camber now?
Last edited by Strat Fan; 17-12-2015 at 17:33.
"You can lead a horse to water, but a pencil must be lead"
Stan Laurel
do you have any play in your front suspension ball joints and track rod ends?
Craig
Castor is set to 5 degrees at the front.
Camber is 1.1 degree neg front both sides, and 0.5 degree neg. - at the rear having said that after the run the rear nearside in only 0.2 neg (yes I did keep rolling the car back and forth to settle the suspension while adjusting).
So I need to go back and check this. I can also dial out the rear toe in quite easily but I note the original had a Toe out!!!! (of 2mm - which equates to 1.6 degrees toe out per side....)
The "tram-lining" feeling seems more front driven than rear but early days. Would a slightly higher tyre pressure make this worse or better??
The Transformer build manual said ground clearance 130mm but this was for 14 inch (and 205 70 tyres?) so with 15 inch wheel this will be higher, and the original Strato's had a ground clearance of 170mm at the rear of the floor plan. I dont feel it as aero lift problem but will ponder this.
Any pointers as I need to "sign Shades off" so I can get on with some other winter tasks. I hope for a few more test days in coming days to enable this.
Absolutely none. They are less than 5k miles old and were jiggled comprehensively by my MOT guy last week. Apart from the bottom suspension joint and track rod ends it is mostly rose jointed and quite quiet....But that would be a good place to look if the car had miles on it. There is no play in the steering either.
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