This is something I have been toying with for sometime in my head and on paper.
It is the front suspension on my car RF105.
In general I thought the look let it down it has a degree of bump steer which is not a large amount and can be sorted easy with the original set up.
I have been told the Ackerman is out so with layout I can bolt a steering arm onto the front face which will fix both these.
The bearing is a modular bearing with ABS senser for traction control or speedo.
One of the other reasons for the change I feel that a wheel alignment should be a simple job as the service side of the car should not be a hassle.
I have put external adjustment for camber and a caster adjustment in the top arm with a 5/8 clevis.
The top arms can be spaced up or down from the upright to adjust roll the centre.
I have prototype arms top and bottom I am happy with them in general but will source some suitable ball joints instead of the spherical bearings.
I have found the housings and spherical bearings are restrictive in droop in a race car it would not be a issue but more street than track it will be.
I could move a few things here and there to get them to work but you seem to run a fine line but with the ball joints I feel I will have more scope for changes.
One thing I have done with the upright is offset the top and bottom holes to make it easy to make this gives me the inclination of 7.5 deg which is as per the STD stub axle.
I am thinking I may half this as it may not require this much.This I would like feed back on.
In turn I would have to lengthen the top arm in turn reducing camber gain but with the small amount of travel on these cars I don’t think I will see much anyway.
The longer arm may work in my favour as far as ride and feel. This I would like feed back on.
I worked out the angle through the ball joint centres but the bolts run parallel to each other with the top set back in toward the chassis
So in effect the ball joints are not on the same axis but it does not seem to have any ill effect if anything I think it is pulling more neg on turn in than the STD set up,This I would like feed back on.
I have notice manufacturers doing some odd stuff with front ends (2 upper ball joints 2 link set ups and seem to get the same effect as I think it may induce caster on turn in hence neg also.
I still need to finish the top link to take some readings as it goes through its motions so I need to confirm that yet.
(yes the upright is wood its cheap and easy to make changes)
The main reason for this post is that when I posted my rear end I learnt a lot from members on this site.
I realized how much there is to learn.
So knowing suspension is all about compromise I would like to get some feed back on what I am doing to iron out any major issues that I may not see.
I can give more specific figures when I finish the top caster link I can then strap it all down and get accurate readings and post them over the next day or so.
The car will see some track work on road tyres Im hopping to get 16" rims over the brakes.
Some road rallies ect
I don’t know spring rates yet as would like to scale it first but I don’t want it to stiff.
Jim
A thought on the 2 upper links with 2 ball joints on the top off the upright.
If one link ran forward as per top arm in pic then another ran at 90 deg to the wheel back to the chassis I think this would allow you to run less neg camber but on turn in it would increase caster and camber allowing you to run less static neg.
The offset being the steering may get heavier on tighter turns ?.
It is the front suspension on my car RF105.
In general I thought the look let it down it has a degree of bump steer which is not a large amount and can be sorted easy with the original set up.
I have been told the Ackerman is out so with layout I can bolt a steering arm onto the front face which will fix both these.
The bearing is a modular bearing with ABS senser for traction control or speedo.
One of the other reasons for the change I feel that a wheel alignment should be a simple job as the service side of the car should not be a hassle.
I have put external adjustment for camber and a caster adjustment in the top arm with a 5/8 clevis.
The top arms can be spaced up or down from the upright to adjust roll the centre.
I have prototype arms top and bottom I am happy with them in general but will source some suitable ball joints instead of the spherical bearings.
I have found the housings and spherical bearings are restrictive in droop in a race car it would not be a issue but more street than track it will be.
I could move a few things here and there to get them to work but you seem to run a fine line but with the ball joints I feel I will have more scope for changes.
One thing I have done with the upright is offset the top and bottom holes to make it easy to make this gives me the inclination of 7.5 deg which is as per the STD stub axle.
I am thinking I may half this as it may not require this much.This I would like feed back on.
In turn I would have to lengthen the top arm in turn reducing camber gain but with the small amount of travel on these cars I don’t think I will see much anyway.
The longer arm may work in my favour as far as ride and feel. This I would like feed back on.
I worked out the angle through the ball joint centres but the bolts run parallel to each other with the top set back in toward the chassis
So in effect the ball joints are not on the same axis but it does not seem to have any ill effect if anything I think it is pulling more neg on turn in than the STD set up,This I would like feed back on.
I have notice manufacturers doing some odd stuff with front ends (2 upper ball joints 2 link set ups and seem to get the same effect as I think it may induce caster on turn in hence neg also.
I still need to finish the top link to take some readings as it goes through its motions so I need to confirm that yet.
(yes the upright is wood its cheap and easy to make changes)
The main reason for this post is that when I posted my rear end I learnt a lot from members on this site.
I realized how much there is to learn.
So knowing suspension is all about compromise I would like to get some feed back on what I am doing to iron out any major issues that I may not see.
I can give more specific figures when I finish the top caster link I can then strap it all down and get accurate readings and post them over the next day or so.
The car will see some track work on road tyres Im hopping to get 16" rims over the brakes.
Some road rallies ect
I don’t know spring rates yet as would like to scale it first but I don’t want it to stiff.
Jim
A thought on the 2 upper links with 2 ball joints on the top off the upright.
If one link ran forward as per top arm in pic then another ran at 90 deg to the wheel back to the chassis I think this would allow you to run less neg camber but on turn in it would increase caster and camber allowing you to run less static neg.
The offset being the steering may get heavier on tighter turns ?.
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