Light steering
Discussion
I have had a problem with this for a while and tried lots of different options
the issue is light pas steering at high ish speed ?
If I give a list of what I have done trying to fix the problem in no order and see if I have missed anything as even various TVR dealers cant fix it either ?
20mm drop front to rear
24 psi on the front on 16" wheels
Ball joints replaced (not track rod ends)
New racing reds
Various splitters
New power steering pump
Tracking
Spacers
I have heard there is a spring in the pump that can be reduced in lenght to make the steering heavier ?
the issue is light pas steering at high ish speed ?
If I give a list of what I have done trying to fix the problem in no order and see if I have missed anything as even various TVR dealers cant fix it either ?
20mm drop front to rear
24 psi on the front on 16" wheels
Ball joints replaced (not track rod ends)
New racing reds
Various splitters
New power steering pump
Tracking
Spacers
I have heard there is a spring in the pump that can be reduced in lenght to make the steering heavier ?
Hi there, im no expert but the way you have worded your problem doesnt seem right.I totally understand how you could have a problem with light steering at speed, but not how the power steering part fits in. The P.A.S does not work in direct relation to the cars speed [slow manouvering and parking being the exceptions]it merely aids the effort needed to turn the wheel.
Have you tried with the front tyre pressures even lower. Try it with standard 15inch front wheels and see if the problem still exists. Have a full geo check on the front especially and see if that makes any difference.
I know when i first started to drive my chim, i made a mistake of putting 30 psi in all 4 tyres and the car was an absolute dog to drive. The steering was light and skitish, the car tramlined terrible and i thought "o my god what have i bought"
22 psi in the front and 24 psi in the rear, a full geo set up by Trackvroad and the car is now in a different league.
Have you tried with the front tyre pressures even lower. Try it with standard 15inch front wheels and see if the problem still exists. Have a full geo check on the front especially and see if that makes any difference.
I know when i first started to drive my chim, i made a mistake of putting 30 psi in all 4 tyres and the car was an absolute dog to drive. The steering was light and skitish, the car tramlined terrible and i thought "o my god what have i bought"
22 psi in the front and 24 psi in the rear, a full geo set up by Trackvroad and the car is now in a different league.
How high is "highish"?
What width of tyres do you have on the front?
You could try more negative camber on the front wheels. Possibly more castor (if you have the adjustment available).
Do you know what camber and castor you have at the front?
As TJC46 mentioned, probably best to get your geometry checked to see what you have at present.
What width of tyres do you have on the front?
You could try more negative camber on the front wheels. Possibly more castor (if you have the adjustment available).
Do you know what camber and castor you have at the front?
As TJC46 mentioned, probably best to get your geometry checked to see what you have at present.
When they replaced the top ball joint, were all the spacers put on the rear, both or front side of each ball joint? As I found out, it matters as when I replaced mine I put one spacer either side, and this had the effect of light steering at speed. (non-pas for me) I can't remember which side is correct without looking ta the car.
Stock clearance for spacers are 8mm, the single spacer being placed forward of the hub mounting spigot.
Some comapanies supply 2 x 3mm spacers, 6mm total. Spacer thickness whether single or multiple should always be 8mm total thickness.
If fitting 6mm spacers (3mm forward 3mm behind) they can have the affect of moving the hub spigot forward by up to 5mm due to the 2mm width deviation. This is tooooooooooo much reduction of castor and will lead to high speed instability.
Suggest you remove spacers and try without.
Some comapanies supply 2 x 3mm spacers, 6mm total. Spacer thickness whether single or multiple should always be 8mm total thickness.
If fitting 6mm spacers (3mm forward 3mm behind) they can have the affect of moving the hub spigot forward by up to 5mm due to the 2mm width deviation. This is tooooooooooo much reduction of castor and will lead to high speed instability.
Suggest you remove spacers and try without.
CHGRIFF said:
Stock clearance for spacers are 8mm, the single spacer being placed forward of the hub mounting spigot.
Some comapanies supply 2 x 3mm spacers, 6mm total. Spacer thickness whether single or multiple should always be 8mm total thickness.
If fitting 6mm spacers (3mm forward 3mm behind) they can have the affect of moving the hub spigot forward by up to 5mm due to the 2mm width deviation. This is tooooooooooo much reduction of castor and will lead to high speed instability.
Suggest you remove spacers and try without.
Not strictly true CHGRIFF, it all depends on build tolerances in both the upper wishbone and the upper balljoint - if the wishbone is welded so the outboard end (where the balljoint fits in) is only 1mm narrower and the balljoint is 1mm wider you will only have 6mm space. A prime example is when earlier this year I replaced my wishbones, the originals had an 8mm spacer with, I presume, the original balljoint but the new wishbone with replacement balljoint only allowed a 6 mm spacer. Some comapanies supply 2 x 3mm spacers, 6mm total. Spacer thickness whether single or multiple should always be 8mm total thickness.
If fitting 6mm spacers (3mm forward 3mm behind) they can have the affect of moving the hub spigot forward by up to 5mm due to the 2mm width deviation. This is tooooooooooo much reduction of castor and will lead to high speed instability.
Suggest you remove spacers and try without.
Forcing in an 8mm spacer would have stressed the wishbone, but with a 6mm spacer the bushes were spaced correctly fore & aft at the inboard end and the scpacer slid in nicely at the outboard end.
I'm not saying that 8mm in itself is wrong, I am saying don't force a spacer in there.
It is for that reason I avoided saying how thick a spacer must be in my original post.
Ged
Yeh, I had this spacer nightmare when having a mix of new and old wishbones, with a new set of ball joints. Could not re-use the original thick spacer, and also found that the 2 3mm ones were too thick when combined. Ended up grinding down one of the 3mm spacers to fit.
Anyway, just put all the spacers on the correct side for caster.
Anyway, just put all the spacers on the correct side for caster.
I have no idea on how the spacers were set up I trusted all was well and locked the car away for the winter ! and sadly tvr at henley went under,
I will take the wheels off over the weekend and have a nose and time for a read of the bible...... but sounds like a job for someone with geo set up ?
I will take the wheels off over the weekend and have a nose and time for a read of the bible...... but sounds like a job for someone with geo set up ?
Mr Haribo said:
I have no idea on how the spacers were set up I trusted all was well and locked the car away for the winter ! and sadly tvr at henley went under,
I will take the wheels off over the weekend and have a nose and time for a read of the bible...... but sounds like a job for someone with geo set up ?
If I were you, I wouldn't even bother taking the wheels off unless you have a castor guage and know how to use it. I will take the wheels off over the weekend and have a nose and time for a read of the bible...... but sounds like a job for someone with geo set up ?
You could measure the camber on each of the front wheels using a spirit level.
The only real way to find out what camber, castor and toe you have on your car is to have a full geometry check on all 4 wheels.
The camber and toe on the rear axle will have some effect on the feel of the steering, although admittedly not as much as the front axle geometry, it is still all part of the whole steering feel.
Once you know what the geometry is like, then you can start adjusting to get the feel you want.
As a start point, you may wish to set your geometry to the settings below
Hope this helps
Ged
P.S. it would be interesting to see what the current settings are. Would you be able to post them once you have them please?
ETA Personally I would set the front toe to parallel
Edited by J400GED on Tuesday 13th September 23:35
Hi I had the same problem and was thinking of selling my car after takeing it to verious places and being told there was nothing wrong with it I thougt I would give it one more try and took it to Castle tvr they did a wheel alignment and now its like a different car if I had of lost the faith I might have been driving a s2000 now.
They seem to be light at the best of times, even at 60-70 they feel too light!
I have seen 150+ superleptons on a 3 lane private track at night, best kept in the middle lane!
I believe the lightness at speed is inherent for many reasons not least, probably including the following;
Cheap P/S rack with little thought to design relating to feel at speed.
Aerodynamics of the car generally.
I have seen 150+ superleptons on a 3 lane private track at night, best kept in the middle lane!
I believe the lightness at speed is inherent for many reasons not least, probably including the following;
Cheap P/S rack with little thought to design relating to feel at speed.
Aerodynamics of the car generally.
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