Solid thrust arm bushing and spherical bearing monoballs - street ride?
#16
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BGB for the win
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I wanted to resume this discussion and share what I have found. You have rubber inner control arm bushings front and rear; you have a rubber lined caster puck in the front and an aluminum one in the rear. When we first started engineering these cars for Pro racing we struggled. I had ZERO support and while parts or money would have been great, even information would have helped us save in testing costs. One night while in my Cayman laboratory the light bulb went off that we were experiencing toe deflection. I had some of the best sports car drivers in the country struggling with this car and I stared at the 911 and then the Cayman and then the 911 and BOOM, divine inspiration occurred. The series gave us monoball rear toe links but we had to use rubber rear control arm bushings. In the back, a Cayman has 3 links vs the 911's having 5 and it finally occurred to me that a hard mounted toe link needs a spherical monoball control arm. Without it, the rubber inner control arm bushing gives up when it's loaded. The 911 has the upper dog bones to rely on for this. I made a rules request, got the inner monoballs approved and the radio chatter went silent. Suddenly "that's how this thing should have been handling all along."
I was concerned last week that by selling you all aftermarket toe links I was recreating the problem but it already exists from the factory given that the front and rear OE toe links are spherical in nature and the control arms are not. I was sort of shocked to learn this last week as I studied my car on the lift. A lot of folks don't like monoball inners because of the road noise but I think that as you all outfit your suspension wish list, you need to consider upgrading the inners. The car has such an abundance of rear tire that it isn't the ill handling car that our GS race cars were running 245/275 tires with a soft sidewall but if you are thinking about going to a more track oriented suspension package, it's worth considering. My $.02.
I was concerned last week that by selling you all aftermarket toe links I was recreating the problem but it already exists from the factory given that the front and rear OE toe links are spherical in nature and the control arms are not. I was sort of shocked to learn this last week as I studied my car on the lift. A lot of folks don't like monoball inners because of the road noise but I think that as you all outfit your suspension wish list, you need to consider upgrading the inners. The car has such an abundance of rear tire that it isn't the ill handling car that our GS race cars were running 245/275 tires with a soft sidewall but if you are thinking about going to a more track oriented suspension package, it's worth considering. My $.02.
Your advice and experience is like gold! Thanks. This sheds a lot of light on what and why we need some of these components. Based on this here is my suspension mods plan:
1. Rear inner lower control arm monoball (spherical bearing) ends. Not adding the monoballs to the front at this point for better NVH
2. Front and rear solid thrust arm bushing (front adjustable)
3. Adjustable front and rear drop links
4. Adjustable front tie rods
5. Adjustable rear toe links
6. DSC controller
7. Lower all three corners by three turns (will see if that works on Long Island streets...)
8. Aggressive alignment/Corner balancing
I saw that usctrojanGT3 added 450lb/550lb front/rear springs. While clearly this adds some H (from NVH) given he says it rides like OEM sport mode. Is it worth the tradeoff for the track?
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^ rear thrush bushing is already metallic not rubber
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I got the RSS system from BGB for my 987.2 before.
It was extremely good.
No noise, well maybe a tiny bit, but only on track ang on a nasty dipper.
No wagging, even on 1.5G load.
No wheel hop!! Well, 90% fixed.
Brilliant on the street.
No downside other than cost.
I'd do it again on the GT4.
It was extremely good.
No noise, well maybe a tiny bit, but only on track ang on a nasty dipper.
No wagging, even on 1.5G load.
No wheel hop!! Well, 90% fixed.
Brilliant on the street.
No downside other than cost.
I'd do it again on the GT4.
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Do RSS and Tarett use the same LCA bearings? I've found that it can make a big difference on how long they last before they start rattling.
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