WTH is this setup????

DJ Dep

refugee from the other place
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It's advertised on CF for a group purchase. They call it a "Sharkbite kit". Anyone know what it's for and if it does anything besides adding extra weight to the car? The price is pretty steep, to put it mildly.

rear_coilovers.jpg
 
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Marck had a discussion about this one before. Did you watch the video?
 
Marck had a discussion about this one before. Did you watch the video?

NO, I haven't seen shit....love to see his comments though....

I suspect it's more sales hype than actual STREET performance gain either in ride quality OR performance, with street tires.....

surely someone with a balls out racer must see something differant, not sure what, though....

about all I can do to understand SLA theory, after that, maybe as well as blowing smoke....I think from time to time I may even understand ackermann angles, but then when going back again....I don't, or forget to remember, whatever....

:devil::hi:
 
IIRC, Marck's main issue of contention with that setup was the rocker ratio between the wheel and shock (not much shock travel compared to wheel travel).
Please correct me if I am recalling this incorrectly.
 
Is there any other "slick" modern suspension setups that have been developed for the C3 in the last couple years? Last time I looked around, all you could do was use the VB&P stuff, like monoleafs and what not, but the basic setup and geometry was all the same. The only other alternative was a Guldstrand 5 link, virtually identical to a C4 suspension as I understand it. Just wondered if anybody developed anything to work with the C3 chassis. Probably some fundamental limitations. Out of my depth on this one.

Of course you can always go for an Art Morrison chassis and use the C5 stuff I guess. ;) Way out of my league.
 
The only other alternative was a Guldstrand 5 link, virtually identical to a C4 suspension as I understand it. Just wondered if anybody developed anything to work with the C3 chassis. Probably some fundamental limitations. Out of my depth on this one..

I believe the same guy that designed and was part of the original group marketing the "RPF" 5-link designed the C-4 rear suspension....famed race car designer Bob Riley. RPF was Bob Riley, Protofab and George Foltz.
 
IIRC, Marck's main issue of contention with that setup was the rocker ratio between the wheel and shock (not much shock travel compared to wheel travel).
Please correct me if I am recalling this incorrectly.

That's exactly the issue, the rockers have a funky ratio, the wrong way around. Normally with limited wheel travel you use a ratio-ed rocker to increase shock travel for instance 2:1 so the shock is more effective for little suspension travel. This system works the other way around, the rocker reduced spring & shock travel, eyeballing I would say around 1:1,5 or so, this means that the shock will not be able to control tiny movements as effectively and it also means it becomes 1,5 times less efficient in damping rates and spring rates. You'll need much stiffer springs and stiffer shocks. I asked them what was up on CF, they never answered. Testament to my concerns were the fact that in their vid they had a set of nor mal shocks in the stock location along with the setup above. Not sure if the final version has 2 sets of shocks.

I also wrote about the angles that the linkage makes with the cam. From bump to compression ideally the cam linkage should swing from one side tpo the other when it comes to angle w/ the cam picot to linkage eyelet centerline, this gives the best distribution around the pivot center and the least angular effect. The way this is set up on the wheel side, the linkage makes an angle and when in bump the angle becomes worse, it only goes through perpendicular when in jounce. I know it's probably a design compromise but it comes forth from the cam ratio. Had they used a different (maybe 1:1) ratio and some kind of bracket on the trailing arm to bring the linkage inboard it might have been a lot better (but then the arm would probably not be strong enough and need reinforcement), the cam ratio is extended on the outboard side so that the linkage to the trailing arm has a satisfactory angle (but it still could have been shorter, check the pic, the linkage points outboard, if the rocker was a little shofter it would have pointed straight up or a little inboard and would swing over on bump compression)

Last but not least, it must be me but the bracketry looks mighty flimsy, just like on the steeroids. Maybe their fab equipment can't handle heavier gauge stuff..not sure but a susp can get accelerated to what..2g? Now imagine the rocker ratio and the (most likely) super stiff springs and stiff valved shocks. Those brackets are under a lot of strain.
 
I don't care for how the spring pushes sideways on the crossmember. As the suspension is loaded more on one side in a corner, the crossmember is going to move some due to the factory bushings, which will move the pivot points of the camber links.

Seams to me this is all show, and it wouldn't help at all when driving the car hard.
 
IIRC, Marck's main issue of contention with that setup was the rocker ratio between the wheel and shock (not much shock travel compared to wheel travel).
Please correct me if I am recalling this incorrectly.

That's exactly the issue, the rockers have a funky ratio, the wrong way around. Normally with limited wheel travel you use a ratio-ed rocker to increase shock travel for instance 2:1 so the shock is more effective for little suspension travel. This system works the other way around, the rocker reduced spring & shock travel, eyeballing I would say around 1:1,5 or so, this means that the shock will not be able to control tiny movements as effectively and it also means it becomes 1,5 times less efficient in damping rates and spring rates. You'll need much stiffer springs and stiffer shocks. I asked them what was up on CF, they never answered. Testament to my concerns were the fact that in their vid they had a set of nor mal shocks in the stock location along with the setup above. Not sure if the final version has 2 sets of shocks.

I also wrote about the angles that the linkage makes with the cam. From bump to compression ideally the cam linkage should swing from one side tpo the other when it comes to angle w/ the cam picot to linkage eyelet centerline, this gives the best distribution around the pivot center and the least angular effect. The way this is set up on the wheel side, the linkage makes an angle and when in bump the angle becomes worse, it only goes through perpendicular when in jounce. I know it's probably a design compromise but it comes forth from the cam ratio. Had they used a different (maybe 1:1) ratio and some kind of bracket on the trailing arm to bring the linkage inboard it might have been a lot better (but then the arm would probably not be strong enough and need reinforcement), the cam ratio is extended on the outboard side so that the linkage to the trailing arm has a satisfactory angle (but it still could have been shorter, check the pic, the linkage points outboard, if the rocker was a little shofter it would have pointed straight up or a little inboard and would swing over on bump compression)

Last but not least, it must be me but the bracketry looks mighty flimsy, just like on the steeroids. Maybe their fab equipment can't handle heavier gauge stuff..not sure but a susp can get accelerated to what..2g? Now imagine the rocker ratio and the (most likely) super stiff springs and stiff valved shocks. Those brackets are under a lot of strain.

Thank you for the explanation. I might even understand some of it. ;)

So, in your view, what is the best possible rear suspension setup for a C3 chassis? Is the Guldstrand 5 Link, taking it to basically C4 territory or are there other packages I don't know about I wonder?
 
The guldstrans setup is a lot better, that shark bite kit does nothing for the biggest proble, toe control/torque steer. it's just a fancy shock/spring setup. The best I would be tempted to say mine LOL but commercially available (used to be), the greenwood double a arm, hands down.
 
The guldstrans setup is a lot better, that shark bite kit does nothing for the biggest proble, toe control/torque steer. it's just a fancy shock/spring setup. The best I would be tempted to say mine LOL but commercially available (used to be), the greenwood double a arm, hands down.

Makes sense to me. Ferrari and Jaguar did it that way. Hell, the front suspension on a 4 wheel drive Dodge truck is done that way now.:smash:
I believe the T/A setup to be a inherently poor/cheap design.
 
The guldstrans setup is a lot better, that shark bite kit does nothing for the biggest proble, toe control/torque steer. it's just a fancy shock/spring setup. The best I would be tempted to say mine LOL but commercially available (used to be), the greenwood double a arm, hands down.

There was a rear SLA for the C3 chassis! I had no idea. Did it require tons of modification and welding? I'll have to look it up. Someone should license and reproduce it. . .

So hey, if your rear suspension works on a C3 chassis and you need some live testing, I could help you out. Just say'n :)
 
I dunno, FB007 on the CF is probably gonna get sent to banned camp for negative comments about a supporting vendor. He is not humping leg with the rest of them!

Hey Marck, maybe you should send him an invitation....:stirpot:

I watched this video a few months back on this suspension set up. I am no M.E. but it sure looked like a bunch of hype to me.
 
I dunno, FB007 on the CF is probably gonna get sent to banned camp for negative comments about a supporting vendor. He is not humping leg with the rest of them!

Hey Marck, maybe you should send him an invitation....:stirpot:

I watched this video a few months back on this suspension set up. I am no M.E. but it sure looked like a bunch of hype to me.

FB007 is a member here.
 

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