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Old 08-30-2004, 04:31 PM
  #1261  
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There was already a discussion about this and to be honest, I don't want to rehash and rediscuss it. Way too much typing...but here is a quote from the man himself:

"...The main reason is to maintain suspension geometry when changing toe. As you know, to add toe with the standard system you add a longer rear block which provides the toe. However, you also change the plane of the suspension arm in the process which is not always ideal. In fact, I think the adjustment contradicts one another because that direction of change of the suspension pins reduces stability while the toe overcomes it. If you look closely, my hinge pins are now swept out because I have an X block in the back and a C block in the front. Sort of a trailing arm sweep, yet the toe is maintained. I'm hoping this will allow me to use even less toe overall resulting in even more corner speed and straight line efficiency. Also, I can go as far as to add bump steer via shims to alter mid corner characteristics... and the suspension is totally symmetrical now...."

This setup is ideal for experimentation...
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Old 08-30-2004, 04:36 PM
  #1262  
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EDIT : Hmmmm, sounds interesting, now give it to us in plane english ... just kidding...

Last edited by rcspeedo; 08-30-2004 at 04:43 PM.
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Old 08-30-2004, 07:45 PM
  #1263  
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Originally posted by rtypec
There was already a discussion about this and to be honest, I don't want to rehash and rediscuss it. Way too much typing...but here is a quote from the man himself:

"...The main reason is to maintain suspension geometry when changing toe. As you know, to add toe with the standard system you add a longer rear block which provides the toe. However, you also change the plane of the suspension arm in the process which is not always ideal. In fact, I think the adjustment contradicts one another because that direction of change of the suspension pins reduces stability while the toe overcomes it. If you look closely, my hinge pins are now swept out because I have an X block in the back and a C block in the front. Sort of a trailing arm sweep, yet the toe is maintained. I'm hoping this will allow me to use even less toe overall resulting in even more corner speed and straight line efficiency. Also, I can go as far as to add bump steer via shims to alter mid corner characteristics... and the suspension is totally symmetrical now...."

This setup is ideal for experimentation...
Thanks for the Re-hash on that Rod
-Dave
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Old 08-31-2004, 03:28 AM
  #1264  
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Looks interesting I must say. I am interested mainly because when I took my car out, in the second race I had a rather tepid crash when I guy hit me from behind and it broke 1 rear upright and the ballscrew thing that sits on top of the other upright. CRAZY!! Maybe using the front suspension will be a bit more reliable from that point of view, especially since it has a bar of metal which could stop cars breaking that from directly behind the car. But, as I've found with my F201 racing, it could quite easily pop off the ball joint in an impact rather then keeping going. But, We'll only find out what its like when we all try it!!
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Old 09-01-2004, 06:16 AM
  #1265  
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i THINK it was becasue a little knock on the rear wheels meant the toe becomes retarded and could screw your whole race up
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Old 09-01-2004, 08:42 AM
  #1266  
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I personally think it is absolutely stupid to use this system. Two reasons : first it's heavier, have more parts (which induces more posibilities of breakages but also more play) and the turnbuckles design makes for more uncertainty in the toe in setting, not to mention impact breakages or bending of the turnbuckle.

Second is the most important : the front end have been designed to be used at the front, not the rear. The resulting geometry is not adapted at all. Yes, with fixed toe-in the plane of the wishbone changes, but it's a part of the setting. Using C-Hubs which includes a castor angle could be much more dramatic for the car.

Also, how can you be sure that there is no "bump toe" (variation of toe in during suspension compression) ? From what I see on the picture that rtypec has posted, the car should have less toe in when the suspensions are compressed, unless there is a massive camber change. That's it, "bump toe" will be a function of the camber change, and that's never good.

Yes, schumacher had this on their previous cars, but there's a good reason if they moved to a front C-hub / rear fixed hub system. Besides, their previous design didn't use a C-Hub but pivot blocks, which makes a helluvalot difference.

just my 2 pennies/4 cents (lol)
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Old 09-01-2004, 10:23 AM
  #1267  
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The real answer might be: DRS, Dynamic Rear Steering, same with Serpent 710.

For those don't know what DRS is, here is a link: http://www.mytsn.com/publ/publ.asp?s...d=9327&exp=109

By changing the height of rear steering joint on chassis, resulting you get more toe-in or less toe-in when shock be compressed.

Why? It give you dynamic toe-in during accelration, brake, and throttle free. So your toe-in setting might change from 1 (brake, enter corner) to 3 (accelration, leaving), give the car best agility (and more option to tweak..)


The problem for DRS is the joint play, and, for DRS behind the rear drivetrain, be rammed from rear. S710 is ram-problem-free becase DRS is in front of drivetrain, but seems EVO4 DRS will has similar problem with old NTC3, disconnect rear steering rod if you got rammed from behind...
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Old 09-01-2004, 10:27 AM
  #1268  
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btw, in case causing confusion.

Old NTC3 doesn't design for DRS, at least this is not stated on manual or anywere else officially. But the reality is by moving the angle of rear steering rod, you got DRS effect...
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Old 09-03-2004, 03:09 AM
  #1269  
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Default aluminium rear upright for evo IV

Can 53687 "TB Evolution III Aluminium Rear Upright" (1 deg.) be used with the new rear arm design used on the evo4? If not, what other aluminium rear hub carriers might be used on an evo4?
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Old 09-03-2004, 03:28 PM
  #1270  
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It can not be used unless if you grind out the arms to make them fit like they did in Europe. It would require alot of modification. See pics on the German Nats forum of Marc's 415.

I beleive Square is coming out with a set. But don't quote me on that. Dave would know more on this....
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Old 09-03-2004, 04:49 PM
  #1271  
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It's true. Here is the link
http://www.rc-square.com/news.htm

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Old 09-04-2004, 12:08 AM
  #1272  
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I took some pics of my EvoIV with the pro4 front spindle, 415 axle, and EvoIV dogbone. Here they are.

This first pic shows the Pro4 spindle with a Pro4 axle and TC3 dogbone above the stock EvoIV spindle and parts. This was before I changed out the Pro4 axle with the 415 axle and shims.
Attached Thumbnails Tamiya TB-Evolution IV-evo4pro3.jpg  
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Old 09-04-2004, 12:12 AM
  #1273  
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This next pic show the Pro4 spindle installed with the 415 axle and Evo IV dogbone. Note the .75mm shim under the spindle. And also the Tamiya silver 6mm wheel hexes. You need to use axle shims to take out the play in the 415 axle. I used about .9mm worth of shims. .4mm of shims on one side of the axle and .5mm shims on the other side of the axle next to the 6mm wheel hex. I think the best option would be to use the Square Ti Pro4 axles (non MIP style). This will eliminate the need for all those shims.
Attached Thumbnails Tamiya TB-Evolution IV-evo4pro2.jpg  
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Old 09-04-2004, 12:14 AM
  #1274  
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This next pic is for those worried about running 28mm foams on your EvoIV or 415 with LW suspension. This shows the clearance that you have with the Pro4 spindle setup.
Attached Thumbnails Tamiya TB-Evolution IV-evo4pro1.jpg  
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Old 09-04-2004, 12:15 AM
  #1275  
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This last pic is of the Team Bomber main shaft and the ring around the cup mod to prevent the cup from spreading and breaking during hard impacts.
Attached Thumbnails Tamiya TB-Evolution IV-evo4bomber.jpg  
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