Pillowball/Hardened Runner Hybrid Approach

[TmZer0]

Suspension Component Question

Looking for some feedback based on people's experiences!

I know this has been loosely covered in other threads but I can't find any direct answers/experience.

I'm up for some bush/rod replacements and was interested in a hybrid approach between hardened rubber and pillowball kit.

Why not choose one or the other? Well, this is for my daily driver, which I track once or twice a year. I like a stiff car and a sporty feel but I don't want to compromise the chassis too much with 100% pillowball gadgetry. 

I know from experience and a tonne of reading that not all components affect ride quality in the same way - eg. in my case, coilover top mounts should be hardened rubber as pillowball transfers way too many undesirable qualities and doesn't have much more upside than a good hardened rubber. But, pillowball tension rods translate to much better turn-in/steering response and make the car significantly sharper, without negatively impacting ride quality in a significant way. 

I'm not TOO bothered by NVH (to a degree).

So, with context out of the way, does anyone have any experience with a hybrid approach as mentioned above? I'm going to replace all components over time so am seeking guidance on:

- front tension rods
- upper camber arms
- rear lower control arm
- rear traction rod
- rear upper camber arm

- rear toe adjuster rod 

Secondly, is there any reason why this is a bad idea? Or any other info/wisdom that I might not be considering.

Cheers 🫶

Edited April 28, 2024 by TmZer0

[GTSBoy]

1 hour ago, TmZer0 said:

I don't want to compromise the chassis too much with 100% pillowball gadgetry

What is the "compromise" that you think will happen? Are you thinking that something will get damaged?

The only things you have to be concerned about with spherical jointed suspension arms are;

• Arguments with the constabulary wrt their legality (they are likely to be illegal for road use without an engineering certificatation, and that may not be possible to obtain).
• A lot more NVH transmitted through to the passengers (which is hardly a concern for those with a preference for good handling, anyway).
• Greatly increased inspection and maintenance requirements (see above points, both).

 

It is extremely necessary to ask what car you are talking about. Your discussion on strut tops, for example, would be completely wrong for an R chassis, but be correct for an S chassis. R32s have specific problems that R33/4 do not have. Etc.

I have hardened rubber bushes on upper rear control arms and traction rods. Adjustable length so as to be able to set both camber and bump steer. You cannot contemplate doing just the control arms and not the traction arms. And whatever bushing you have in one you should have in the other so that they have similar characteristics. Otherwise you can get increased oddness of behaviour as one bushing flexes and the other doesn't, changing the alignment between them.

I have stock lower rear arms with urethane bushes. I may make changes here, these are are driven by the R32's geometry problems, so I won't discuss them here unless it proves necessary.

I have spherical joints in the front caster rods. I have experienced absolutely no negatives and only positives from doing so. They are massively better than any other option.

I have sphericals in the FUCAs, but this is driven largely by the (again) R32 specific problems with the motion of those arms. I just have to deal with the increased maintenance required. Given how much better the front end behaves with the sphericals in there.....I'd probably be tempted to go away from my preference (which is not to have sphericals on a road car, for 2 of the 3 reasons in the bulleted list above), just to gain those improvements.

And so my preference for not using sphericals (in general) on a road car should be obvious. I use them judiciously, though, as required to solve particular problems.

[Duncan]

To add to that very useful summary, even in the race/rally r32 gtr I have good quality, new(ish) poly bushes everywhere because that is what rules require, and the handling is excellent. Of course, the car doesn't do many klm but I'd still expect poly bushes to last better in road use than sphericals (especially as I have a couple of klm of dirt road to stuff sphericals up)

I would change the front upper arms to spherical if I was allowed to, because the poly bushes flog out often, but otherwise new bushes (and ball joints) and a good alignment can make a world of difference