M 400 REAR toe in
Discussion
Just got my M400 back on the road after nearly a 2 year lay up due to a house build (236 miles in 2 years!!!). While checking it over I had a suspension geomety check (whizbang lazer affair, no more accurate than 'box stringing' as far as I am concerned but a sight quicker!!)and it all game out fine, almost exactly book figures with the exception of the rear toe angles.
My car has 0.5 mm toe in at the rear on either side so at least it is symmetrical. The book (US build manual) states that it should be 2mm to 3mm per side. This means there is a 1mm tolerence and yet it also states that 1/2 turn on the rose joint will give a change of approx 2.5mm (which seems a lot but that is what it says). It does seem odd that if the car is marginally outside tolerance one way then half a tun of the joint takes it marginally outside in the other direction! It really needs a much finer thread on the rose joint.
So the choices seem to be 1. leave it as is. 2. wind out 1/2 turn on each side and end up with 3mm each side ie total of 6mm toe in, ie the higher limit.
The last set of Corsas wore evenly so I am tempted to leave it alone even though it is outside the recommended settings.
Anyone any views please?
On a different note I had forgotten how fast these b----y things are!
Cheers Richard
Cheers
Richard
My car has 0.5 mm toe in at the rear on either side so at least it is symmetrical. The book (US build manual) states that it should be 2mm to 3mm per side. This means there is a 1mm tolerence and yet it also states that 1/2 turn on the rose joint will give a change of approx 2.5mm (which seems a lot but that is what it says). It does seem odd that if the car is marginally outside tolerance one way then half a tun of the joint takes it marginally outside in the other direction! It really needs a much finer thread on the rose joint.
So the choices seem to be 1. leave it as is. 2. wind out 1/2 turn on each side and end up with 3mm each side ie total of 6mm toe in, ie the higher limit.
The last set of Corsas wore evenly so I am tempted to leave it alone even though it is outside the recommended settings.
Anyone any views please?
On a different note I had forgotten how fast these b----y things are!
Cheers Richard
Cheers
Richard
You can turn the rose joint an additional 10deg in or out to get it a bit closer, you can get it to within 2-3mm either side, but not really a good system, i think some on here have put a rose joint on the other end aswell which allows you to just turn the strut which makes it as simple as setting the toe on the front wheels.
Thanks for the speedy replies chaps.
Interestingly there is another post on here which states that half a turn on the rose joint equals 1.5mm! This contravenes the build manual BUT the later rear wishbone set up is different from the earlier system so I might try a half turn on each and get it checked again as, if true, that would put me exactly 2mm each side. I take on board the comments about the 10% change from leaving the rose joint at a slight angle though-hadm't thought of that! Also having a rose joint at the other end (with opposite thread) is clearly the way to set it up exactly.
I was pleased that the camber angles were almost exactly book figures though, my previous M12 was a bit mor erratic!
Interestingly this toe in business at the rear was used massively on the Honda NSX to give stability on turn in. I can't remember what the figure was for the car but it was huge and resulted in massive rear tyre wear. Honda subsequently revised the figure to a much reduced figure for whatever reason. Senna didn't have to pay for the tyres when he did the original set up I suppose!!
Interestingly there is another post on here which states that half a turn on the rose joint equals 1.5mm! This contravenes the build manual BUT the later rear wishbone set up is different from the earlier system so I might try a half turn on each and get it checked again as, if true, that would put me exactly 2mm each side. I take on board the comments about the 10% change from leaving the rose joint at a slight angle though-hadm't thought of that! Also having a rose joint at the other end (with opposite thread) is clearly the way to set it up exactly.
I was pleased that the camber angles were almost exactly book figures though, my previous M12 was a bit mor erratic!
Interestingly this toe in business at the rear was used massively on the Honda NSX to give stability on turn in. I can't remember what the figure was for the car but it was huge and resulted in massive rear tyre wear. Honda subsequently revised the figure to a much reduced figure for whatever reason. Senna didn't have to pay for the tyres when he did the original set up I suppose!!
This is from the factory....
The tracking on the M400 is 1mm out each front wheel and 2mm in on the rear, as the rear can only be adjusted by half a turn on the rose joint this affects how close to 2mm toe in you can get, half a turn on the rose joint equals 1.5mm of toe at the wheel.
The tracking on the M400 is 1mm out each front wheel and 2mm in on the rear, as the rear can only be adjusted by half a turn on the rose joint this affects how close to 2mm toe in you can get, half a turn on the rose joint equals 1.5mm of toe at the wheel.
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