R8 steering

[BobG]

I finally have my R8 Alpine motor running well. Now I need to work on the suspension. My first goal is to improve the steering feel. The steering is very responsive but has no self-centering. This is rather disconcerting at speed. The car want to dart left or right but with no inclination to straighten out if I let go of the wheel. So, is this normal for an R8? The car has new front shocks, ball joints and tie rods. The springs are stock and have been shortened by 1 coil. The wheels are 14x4.5 R16's with reversed centers and 165/65 tires. I've adjusted the caster to the limit. I've also set the toe to 1/16" in. Any suggestions on how to improve the steering will be greatly appreciated.
Bob G

 

[nauli]

Camber?

 

[BobG]

There's no way to adjust camber other than to use the slop in the ball joint mounting holes. I did this by loosening the 3 attachment bolts and moving the top joint as far inboard as possible and the bottom as far outboard as possible. I haven't measured the camber yet. Steve Swan (dauphproto on this forum?) has suggesting fabricating shadow plates to allow significant camber adjustment.

 

[JohnW]

Are the wheels correct for offset?

Is the caster fully adjusted in the correct direction? It can be confusing, at least to me I suppose..... Have you got the correct bolts in the correct holes for the lower wishbone pivots? There are two diameters for the lower wishbone mounting bolts - in the immortal words "don't ask me how I know this"!!

 

[Bustamif]

You need more caster to get the self centering and straight line stability you are seeking.

Use the same process you used to increase camber, elongate the 3 holes in top ball joint mount and move it towards the rear of the car. Do the same on the bottom ball joint and move it towards the front of the car. You will also have to grind a bit from the big holes for the ball joints to get the additional caster you are after.

Mine runs straight as a die at 112 mph

 

[schlitzaugen]

The self centring function is entirely controlled by caster (weird suspension geometry and rear end alignment problems aside; see below). It is the weight of the car that does the work and caster is essential to provide the leverage. No caster=no leverage, hence no centring function.

I would say you go somewhere have it measured because yours is not right even if you think it is adjusted to the limit. You may have adjusted it the wrong way or you may have some other underlying problems.

Darting all over the place however is not a self centring problem but a toe problem. If you want self centring and straight line stability you should have toe out not toe in. Rear toe has a strong contribution as well to straight line ability and here, you need toe in. Up to about 3 degrees on each side (at this setting you may see some tyre wear but all else being good your car should go like an arrow). Rear camber also helps, about 1-3 degrees negative, mind tyre wear as above. These are limits that should tip you off if you have to go over, you have some problem elsewhere.

Then there is also the question of overall alignment. If your rear end thrust line is not centred, your car will go "crabbing". You need to measure this (or have it checked by some alignment place).

Given you say you replaced the tie rods, and your toe in setting, and the reported steering behaviour, I would say your car is not responsive, but unstable. Start there. Toe out one degree per side. This should make a huge difference immediately. It may not be the best value or the final value you settle on, but it will settle the car. While you're there check sweep as well, because I remember it is adjustable on your car (lower suspension arm has an eccentric, don't remember if the front bolt or the rear one). This adjusts the position of the lower arm (angle) in relation to chassis. If you used it to adjust the caster, you've done goofed. Put it back and adjust the upper arm position to set caster.

Next, check caster.

Next, check springs. If you didn't cut the springs, check they're equal length. I would take them out, not rely on ride height because you don't know how much they are preloaded in the car.

Next, rear end alignment.

All of this assumes all your bushings are a-okay. If not, rinse and repeat.

My crapola R10 went straight as an arrow, but unfortunately I don't have the settings anymore. It was bog stock but quite a few moons ago.

 

[Bustamif]

Inadequate caster will cause it to dart around at high speed

 

[Sunroof]

My R10 does that a bit. I blame the wider than normal mags. Different to what Schlitzy said. I set the toe to in by a mm and it has stopped the darting and wandering. But I am building turn tables to set the caster and check camber. My rear springs are lower but front are stock so not sure what effect this has. I think I'll put the original springs back in the rear. Frankly if I had a good set of stock rims I'd put them on preferably with Michelins.

 

[jaahn]

Hi
Its been a while since I was under an R8 but here are some thoughts. The rack position re the height is adjustable and should be set so the steering is as designed and works evenly side to side. Lack of attention will here will cause tracking problems on bumps due to self steering on each wheel !!! People may not have heard of setting the rack height as an adjustment and have moved it over the years.
The front end may be bent or uneven due to accidents or wear or whatever. You should not start to adjust basic setting until you have checked it out. I have seen R8s back in the day with the front end straightened by heating and bending things till it looked OK for rego after accidents.
When it is all correct and steering free of play I believe a small amount of toe is correct for stability. Toe out is used for racing only, IMHO to get some handling effects.
If the rear bushes and mounts are buggered then the whole engine/gearbox/axle alignment can move around on throttle lift on/off and the rear wheels self steer. That can be disconcerting I can say from experience. Note the rear toe is not adjustable but the trunions may be stuffed too possibly as they are old cars now.
Cheers jaahn

 

[Frans]

My . First I have a question, was it like that before you changed the ball joints and tie rods?? About 6 months ago I replaced the ball joints on my car and they were extremely tight. Tight to tilt the stub and obviously tight to turn the stub in the housing. That caused the wheels not to return to the straight position when the front was in the air. This should be able to be achieved by the self-centering springs inside the rack.
You have new tie rods which will add to the friction.

It may be that a bump in the road turns the wheel slightly to a side and then it is too tight to return because of the ball joint friction.

If the tie rods are disconnected and the steering wheel is turned max to one side and you let it go, it should return to center with a speed. If not, then the rack is dry as old grease does go dry and that can be added to your problem. I do modify my steering racks even further. Above the pinion is a little piston with a V in it. The V pushes the rack down to prevent play. That tension can add to the issue. My mod is to remove the spring that pushes down and replace it with a spacer that is machined to the exact size so that the rack doesn't have a play but there is no pressure on it either. The centralizing springs remain as is.

I disagree slightly with Schlitz in that the centering of the wheels is a combination of the self-centering springs in the rack and the castor. I also run my race car and streetcar with 1 - 2 mm toe-in. My theory behind this is for the wide rims that have a slight leverage to pull the wheels out due to the tyre friction on the road and then it almost straighten them out to 0 mm. I must add that I don't use Mecapart's wishbone bushes. I make my own from Graphite impregnated nylon. The brand name in NZ is Nylatrol. This eliminates all play due to the rubber in the bought ones. The only rubber in the streetcar is in the tierod ends, but the race car is metal to metal as seen in Mecaparts catalog.

Regards Frans.

PS. remember that a positive caster is used on the R8. ie the bottom balljoint is further to the front than the top balljoint.

 

[schlitzaugen]

My R10 does that a bit. I blame the wider than normal mags. Different to what Schlitzy said. I set the toe to in by a mm and it has stopped the darting and wandering. But I am building turn tables to set the caster and check camber. My rear springs are lower but front are stock so not sure what effect this has. I think I'll put the original springs back in the rear. Frankly if I had a good set of stock rims I'd put them on preferably with Michelins.

Wider mags can cause things like that, I agree. In absence of more info, I take everything not mentioned is peachy keen, which is probably unlikely. Same for rack height, chassis state, good points there.

 

[schlitzaugen]

My . First I have a question, was it like that before you changed the ball joints and tie rods?? About 6 months ago I replaced the ball joints on my car and they were extremely tight. Tight to tilt the stub and obviously tight to turn the stub in the housing. That caused the wheels not to return to the straight position when the front was in the air. This should be able to be achieved by the self-centering springs inside the rack.
You have new tie rods which will add to the friction.

It may be that a bump in the road turns the wheel slightly to a side and then it is too tight to return because of the ball joint friction.

If the tie rods are disconnected and the steering wheel is turned max to one side and you let it go, it should return to center with a speed. If not, then the rack is dry as old grease does go dry and that can be added to your problem. I do modify my steering racks even further. Above the pinion is a little piston with a V in it. The V pushes the rack down to prevent play. That tension can add to the issue. My mod is to remove the spring that pushes down and replace it with a spacer that is machined to the exact size so that the rack doesn't have a play but there is no pressure on it either. The centralizing springs remain as is.

I disagree slightly with Schlitz in that the centering of the wheels is a combination of the self-centering springs in the rack and the castor. I also run my race car and streetcar with 1 - 2 mm toe-in. My theory behind this is for the wide rims that have a slight leverage to pull the wheels out due to the tyre friction on the road and then it almost straighten them out to 0 mm. I must add that I don't use Mecapart's wishbone bushes. I make my own from Graphite impregnated nylon. The brand name in NZ is Nylatrol. This eliminates all play due to the rubber in the bought ones. The only rubber in the streetcar is in the tierod ends, but the race car is metal to metal as seen in Mecaparts catalog.

Regards Frans.

I forgot about springs in the rack (still can't remember where they were), frankly it was so many moons ago. Still, I think their contribution to self centering in a car is next to nil compared to the weight of the front end. Not to say their health should be disregarded.

Agree with comments about toe changes on/off power. I would try to minimise these but I do realise in a high powered car like Frans' race car it may not be exactly easy.

Rear toe is adjustable a little bit with the control arms, but not much. I mentioned this more because rear toe needs checked. If bushings are worn, there can be quite a bit of play resulting in weird behaviour, including straight line stability. Thrust line ill be out of whack too. Measuring rear toe/thrust line will find the problem.

 

[dauphproto]

As a very quick and easy experiment add about 50kg of sand in the boot up front and see if it is better or worse. My old 8G had an aftermarket quickrack with no centring springs and worked beautifully and ran straight at 3 figure speeds. The Dauph is however not so friendly, it is the most camber sensitive vehicle I've ever driven. I have been over it with a tooth comb and have found no faults it is totally square and measures the same side for side. It does however run much bigger rubber than the 8 did and I put the issue down to that and being around 90kg lighter. When I took it to a local hillclimb track it felt great (no road camber)
As a general rule of thumb FWD cars should be set with a mil or so Toe out as the drive effect causes the wheels to climb in. RWD cars are the opposite and tend to be a mil or so toe in as they push out. The object of the exercise is to have the wheels as close to parallel as possible when the vehicle is going down the road. It is possible to blunt initial turn in by adding toe in and to sharpen it by adding toe out. Are the springs still in the rack? If you jack the car up and push the wheels to lock and let go it will smartly return to centre and there is a slight dead spot around centre, but only a couple of mm. I think Franz's comments bear investigation as it may be tightness in the new components causing the issue. I don't think it is a set up fault per se, because it is not a consistent fault it is not pulling one way only, just it is not centering and because of this it wanders a bit. Ballast up the front and see how it feels. If its better then there is something tight affecting the steering if it is worse then recheck the front toe with the ballast in, in fact do that anyway before and after ballasting if there is a change let us know what it is. It may be the missing piece of the puzzle (other than missing rack springs)

 

[JohnW]

My R10 does that a bit. I blame the wider than normal mags. Different to what Schlitzy said. I set the toe to in by a mm and it has stopped the darting and wandering. But I am building turn tables to set the caster and check camber. My rear springs are lower but front are stock so not sure what effect this has. I think I'll put the original springs back in the rear. Frankly if I had a good set of stock rims I'd put them on preferably with Michelins.

I thought the R10 behaved pretty well actually when I drove it to the Muster. Better than the R8, but they do have a bit more weight. I've found the 145-15 XZX tyres quite an improvement over the 135-15 ZX. The turn in is much better with no change to alignment!

 

[Sunroof]

John I think my R10 is a much rougher ride than the Floride S with 145 tyres and standard rims. Did you find it rougher than your R8?

 

[JohnW]

John I think my R10 is a much rougher ride than the Floride S with 145 tyres and standard rims. Did you find it rougher than your R8?

I'm honestly not sure. That means that if it was firmer, it didn't register much, so I guess not. I've never ridden in an unmodified Floride S mind you. The R8 has R10 rear springs (R8 R1130 springs were too soft) and Konis....

I'm in favour of standard wheels, but I'm not chasing performance. There'd be plenty around - I could have got you a set free a few months ago.

 

[BobG]

I did some measurements this afternoon. Camber is: 0 deg left side and -1 deg right side. The spec is 1 deg 40' +- 30' according to my Haynes manual. The left side is out of spec. I'll work on this later. Caster is 9.4 deg on the left side and 9.7 on the right. The spec is 9 deg +- 2 deg. So my values are bang on. I have the eccentric adjusters on the lower control arms maxed out. This rules out caster as the source of my wandering steering. I took a close look at the front suspension pieces and didn't see anything that looked bent or damaged. I also found a note that I had checked for the steering rack centering back in the Spring and it was working properly. The spring will not center the rack now with new ball joints, but it does show some tendency to do so with the wheels turned to the limits.

Tomorrow I'll re-check the toe with and without some ballast.

Regarding the possibility of the new ball joints being too stiff, I don't remember what the steering was like before I installed the new ones.

Wheel offset - my modified R16 wheels have less offset than the stock 15's so as to clear the brake caliper and tie rod end. I'll put the stock wheels on and see what happens.

More to come ...

 

[JohnW]

I gave up on the centering spring years ago and there's plenty of self-centering without it. Ditto on the 4CV.

 

[geckoeng]

I have done a number of modified racks over the years. Changing the pinion for a fast steer. This means there is no room for the self centering spring. And have never had a problem with the caster not bringing the steering back to center. One of these is a A110, which the owner said it took a bit of time to get used to but now tikes the "go-Cart" style. There were a number of A110 sold with Gordini racks that are "fast steer" and were converted by Owners, as well. So that may also need checking. The number of turns changes.

 

[dacia4x4]

There's no way to adjust camber other than to use the slop in the ball joint mounting holes. I did this by loosening the 3 attachment bolts and moving the top joint as far inboard as possible and the bottom as far outboard as possible. I haven't measured the camber yet. Steve Swan (dauphproto on this forum?) has suggesting fabricating shadow plates to allow significant camber adjustment.

i would say you have gone wrong way with camber adjustment by moving top ball joint inwards and lower outwards you are giving it a more negative camber reading which will also affect the kpi angle(or in r8 case centre line of ball joint axis) also moving it to more negative reading you would need to increase your camber angle by moving top ball joint mount point outwards. also as Schlitz said lower arm inner concentric Cam will adjust caster.i would fix camber first though as it will raise the height of vehicle slightly when moving lock to lock and having a low point at centre point, as was mentioned by another post the weight of vehicle with rack spring and camber/kpi will self centre vehicle bar any binding in ball joints /tie rod ends...... just a thought....... jim