WTH is this setup????

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DJ Dep

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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 ****....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:
 
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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.
 
Can anyone find the original post of the video at CF? Some observations were made in that thread (at least one by me) that were never answered. Now it seems to have vanished.

Poof!​
 

I just finished rebuilding the sharkbite setup for rodteq. It was originally installed on Snowman's car but he wasn't sure about using it at 140mph. He sold it to rodteq. After two passes down the strip at Bowling Green it started to bend. On the way back to Houston it collapsed.
I'm not going to go into any details on the geometry, Marck is better at it then I am. I'm sure Speed Direct has an outside company doing the work on the brackets so they are not at blame here. Here's what I have noticed:
No penetration in the welds
Brackets are welded on one side only
No beveling. Pieces are butt welded.
No quality control on bracket placement. I was given 4 brackets, 2 old and 2 new. All 4 had the arms in different positions.
My personal opinion:
The stock trailing arm cannot handle the lateral and torsional loading being placed on it. I have built hundreds of trailing arms, not referring to the assembly but the actual welding of the six parts that make up the bare arm. It it designed for compression and tension loading only. The sharkbite system puts torsional stress on the rear of the arm. These arms are stitch welded so at the very least they need to be fully welded.
The mounting setup of the bracket to the stock arm, in my opinion, needs to be welded. The current design allows movement since the main attaching point is a single center mounted bolt.
I would not use this system without a modified set of arms. Steel plate .250 versus .100 stamped sheet metal. I had Rodteq send me a set of VB offset arms and then I fully boxed the rear portion. I requested VB arms because of their stock design bushing. The other well known company in Fla still insists there is nothing wrong with theirs even though I have shown their dimensions to be up to 1/2" off.
I then had the brackets fully tig welded and mounted to the arms in the correct locations. I'm sure if someone asked Rodteq for pics of my mods he would take some.
Mike
 
Bottom line, same junk as steeroids. Those brackets are super thin cold welded by a money, no penetration pieces of crap too! Some day someone is going to kill himself with this speed direct stuff.

Can you get Rodteq to post the pics here? I'm sure ppl would be interested, i'm not going over there to post. Also, I think my half a page reply/post over there on the system was deleted. I can't find it but I know I never got an answer to all my questions and I didn't even go into the details about how iffy it was w/ the stock trailing arm, everything hanging from the trans crossmember bolt and what not.

Anotehr observation is the total lack of gussets or adequate gauge steel...in everything they build. They should invest in a bigger sheet metal brake.
 
I should see him this weekend. I may have to do the rear setup on it. I'll try to get him to post some pics here.
I have a big box coming your way.
Mike
 
Or at least a 220 volt welder.

i have a feeling that someone is cutting their stuff from thin gauge sheets w/ a laser,water or plasma cutter and someone is @ home jigging this stuff up by hand (without an actual jig judging by tolerances) and then using his 110V little putt putt welder to weld this stuff.
 
If I built and marketed something that poor I'd have been sued out of existence by now. How do they get away with it? Will they continue to deliver sub standard products until someone gets hurt or killed?
 
Just to make it clear this is not a problem with Speed Direct. It has to deal with the people actually doing the welding and assembly for them. I've never dealt with them. They could be a great bunch of guys or guy. But he/they are responsible for the final product. And any liability. In case someone from Speed direct reads this thread I will make them the same offer I made V.S. I will be happy to tell them what's wrong with their product and what is needed to correct it. All they have to do is contact me. Although I am not interested in putting this system on my car I'm sure there are people that do and I want it to be as safe as possible. Instead of talking to me V.S. chose to bash me on CF and then had the thread pulled.
Mike
 
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