Tim
Posted a lot
Posts: 3,340
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Aug 16, 2010 13:18:47 GMT
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Awseome project
What do the frame/cage building guys think? Lot of right angled tube joins (although i'm not saying its wrong). - they may not be part of the stressed structure
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Aug 16, 2010 13:25:57 GMT
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1997 TVR Chimaera 2009 Westfield Megabusa
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Aug 16, 2010 13:28:38 GMT
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I'm spent.....
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1997 TVR Chimaera 2009 Westfield Megabusa
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Aug 16, 2010 13:44:59 GMT
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They're like shiny little robots.
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Aug 16, 2010 13:47:24 GMT
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Some very nice work gone into this. I cannot for the life of me see any benefit in that front suspension design though! He said this: "the front suspension: in bump and droop the front end acts like a solid axle which minimizes suspension change issues, mostly bumpsteer because even if there is bumpsteer, it is identical right and left and theoretically creates no steering change. then in uneven bumps or when in roll one pushrod will push up against the shock and also against the opposite pushrod (because they are attached to each other) but the rocker slides along the shaft against the horizontal springs which push back against the car to minimize roll...essentially and infinitely adjustable swaybar. the nuts on either end can be tightened to increase the effective springrate, and the nuts can be tightened and loosened to change the level-ness of the car. hopefully that makes some kind of sense to someone besides Joe Z! also it seems there may be some similar setup in the rear suspension"
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Aug 16, 2010 14:05:23 GMT
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That's not entirely right Simon. It doesn't affect bump steer at all (as far as I can see). All it does is allow completely independent control of roll and pitch. Some single seaters use infinite or very high roll stiffness on the front (ie front wheels go up and down together) to increase stability through cornering (think 3 wheel stool compared to 4), and it can easily be combined with pitch control when using aero aids.
As far as the advantage to him.... it looks complicated, its a bit different and it shows off his fabrication skills. Disadvantages... zero damping in roll and what looks like falling rate in pitch.
It's going to be very difficult to get set up properly, but i'm guessing this car isn't being build for out right performance, more as a show piece for what he can do!
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1997 TVR Chimaera 2009 Westfield Megabusa
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Aug 16, 2010 15:12:11 GMT
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That's not entirely right Simon. It doesn't affect bump steer at all (as far as I can see). All it does is allow completely independent control of roll and pitch. Some single seaters use infinite or very high roll stiffness on the front (ie front wheels go up and down together) to increase stability through cornering (think 3 wheel stool compared to 4), and it can easily be combined with pitch control when using aero aids. As far as the advantage to him.... it looks complicated, its a bit different and it shows off his fabrication skills. Disadvantages... zero damping in roll and what looks like falling rate in pitch. It's going to be very difficult to get set up properly, but i'm guessing this car isn't being build for out right performance, more as a show piece for what he can do! That's just it... how the car is suspended doesn't have the faintest affect on bumpsteer. It's still IFS with it's addentant geometry. As for roll control... so far as i can see it would work in exactly the opposite way to an anti roll bar. When one side of the suspension is in compression, the link pushes the slider across forcing the other link down which surely would be worse for roll control? Like you say, there's also no damping in roll or in independant suspension movement. Then he says... Eh? Bumpsteer IS steering change. I'm not certain he entirely has a grasp on the way it works. I wouldn't be surprised if it's the one bit of the chassis that gets changed before it's done. Very nice workmanship on everything there so it'd be a shame to spoil it with something that's not very functional.
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1962 Datsun Bluebird Estate - 1971 Datsun 510 SSS - 1976 Datsun 710 SSS - 1981 Dodge van - 1985 Nissan Cherry Europe GTi - 1988 Nissan Prairie - 1990 Hyundai Pony Pickup - 1992 Mazda MX5
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Aug 16, 2010 15:19:17 GMT
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That's not entirely right Simon. I only posted his explanation...don't blame me. I'm not bad at working stuff out, but aside from looking pretty trick I have no idea how functional it would actually be.
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Aug 16, 2010 15:23:19 GMT
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I wasn't implying that you were wrong sorry Simon, just that what you'd copied across wasn't entirely factual
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1997 TVR Chimaera 2009 Westfield Megabusa
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stealthstylz
Club Retro Rides Member
Posts: 14,856
Club RR Member Number: 174
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The ultimate Jettastealthstylz
@stealthstylz
Club Retro Rides Member 174
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Aug 16, 2010 15:40:17 GMT
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I had a bit of a gasp at the bump steer bit too. Problem is he's written it on a forum and built something that looks good in pics so people will believe him.
He's probably right that you won't notice when you're going in a straight line if both wheels hit the same height bump at the same time. However say that when the suspension is compressed it toes out (and in when it is decompressed). Due to the ackerman angle when he goes round a corner the inside wheel will lose steering angle and the outside wheel will gain steering angle.
At the very least you're gonna end up with a situation when you greatly reduce the effect of the Ackerman angle. Gonna scrub like a mofo.
Matt
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Aug 16, 2010 16:04:59 GMT
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Matt, looking at his wishbone pick up points compared to the steering arm pivots it looks like its actually going to toe in under compression and therefore it will help ackerman.... Although you can't really see the wishbone angles from the photos. I suspect he'll be running a lot of roll stiffness and therefore wont affect ackerman much though.
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1997 TVR Chimaera 2009 Westfield Megabusa
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Aug 16, 2010 16:20:27 GMT
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thats an awesome thread, best thing ive seen and read for many a month
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Aug 16, 2010 17:46:04 GMT
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The front suspension design is an odd one. It should work like he says as long as the springs that locate the floating linkage thing are stiff enough that it will compress the shock before the link slides, in which case it will pull both front wheels up, much like an ARB. So softer locating springs will mean less roll. He does seem to have both the front and read set up with regressive spring rates though, which seams odd.
Whatever he does with the suspension though, fair play, that's some awesome fabrication!
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Aug 16, 2010 17:59:59 GMT
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His setup is basically a version of this monoshock setup as found on Goulds: However on there (as on Dallaras and Forces) the roll is controlled by bell washer stacks which give a much more precise and easily adjustable setup than his coil springs.
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1997 TVR Chimaera 2009 Westfield Megabusa
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Tim
Posted a lot
Posts: 3,340
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Aug 16, 2010 18:34:59 GMT
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Remote piggybacks rock :-)
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Aug 16, 2010 21:47:45 GMT
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How can it be the ultimate Jetta?
Where are the BBS's? Where's the roofrack full of detritus?
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How can it be the ultimate Jetta? Where are the BBS's? Where's the roofrack full of detritus? I think they are BBS. Here's some just for you:
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Why didn't they paint the bike the same colour as the car!? Or the wheels the same colour as the bike...
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How can it be the ultimate Jetta? Where are the BBS's? Where's the roofrack full of detritus? I think they are BBS. Here's some just for you: Aaahhhhh now I can relax...Balance has been restored to the world
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Aug 17, 2010 14:33:09 GMT
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lol lol
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