Dumb autoX question
Thread Starter
Drifting
Joined: Jun 2008
Posts: 1,495
Likes: 134
From: Blanco County, TX
Thanks JB and pauldana for sharing your setups. It gives me a good place to start. I'm really liking the Shark Bar idea, for a number of reasons. I might have to get a new cooler though.
Mashinter and SkunkWorks,
Thanks for being patient. I am hung up on this weight transfer thing. I (now) get that you are talking left\right. If you are talking about lateral (or horizontal) force, then I completely understand how stiffening the front bar can increase inward to outward force and therefore cause the front wheels to slip (understeer). If you are talking about a vertical weight tranfer, as in, "a stiffer bar causes the outside tire to have more weight (down force) on it," then I am lost. Weight to me is always in a downward direction. Force can be applied in any direction.
If I can sort this weight/force transfer issue out I think I will have come a long to to understanding the major dynamic relationships that are occuring. Getting them sorted out will take while, but it sounds like fun.
SW, thanks for the reading list and the link. For now, I guess I'm 80-90% of a BBSS guy. Maybe I need another C3. One to race, one to cruise.
Mashinter and SkunkWorks,
Thanks for being patient. I am hung up on this weight transfer thing. I (now) get that you are talking left\right. If you are talking about lateral (or horizontal) force, then I completely understand how stiffening the front bar can increase inward to outward force and therefore cause the front wheels to slip (understeer). If you are talking about a vertical weight tranfer, as in, "a stiffer bar causes the outside tire to have more weight (down force) on it," then I am lost. Weight to me is always in a downward direction. Force can be applied in any direction.
If I can sort this weight/force transfer issue out I think I will have come a long to to understanding the major dynamic relationships that are occuring. Getting them sorted out will take while, but it sounds like fun.
SW, thanks for the reading list and the link. For now, I guess I'm 80-90% of a BBSS guy. Maybe I need another C3. One to race, one to cruise.
Last edited by Kevin68; May 4, 2011 at 06:27 PM.
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
Pauldana,
My setup is very similar to yours with the exception that I don't have rack and pinion but a custom blue printed oem steering box on front but everything is similar except the front bar is the oem 1 1/8 bar with poly endlink and mounting bushings. In the rear again very similar with competition adjustable struts with heim joint ends and a 3/4 oem type bar on place of the Oem 7/16 bar. My car is VERY neutral at the limit! The car
Would understeer badly with no rear bar! Just purchased the shark bar for added reinforcement behind the seats!
My setup is very similar to yours with the exception that I don't have rack and pinion but a custom blue printed oem steering box on front but everything is similar except the front bar is the oem 1 1/8 bar with poly endlink and mounting bushings. In the rear again very similar with competition adjustable struts with heim joint ends and a 3/4 oem type bar on place of the Oem 7/16 bar. My car is VERY neutral at the limit! The car
Would understeer badly with no rear bar! Just purchased the shark bar for added reinforcement behind the seats!
.. with the stock sway bar up front and none in the back i definitely had oversteer... safe feeling, but keeps you slowed way down in the corners... put on the first set up with the larger front and back..... and well.. lets say I learned what over steer was!!!
not a fun feeling having your a$$ want to come and ride up front
.. changed out to the next size down and .....WOW... how very very
to slid around a corner at amazing speeds..... and as flat as a rug!..... BUT, one draw back.. when you break loose, you break loose on all fours... so, take some lessons at the local track if you have one and find out what that point is.... p
Drifting
Joined: Oct 2008
Posts: 1,936
Likes: 92
From: Rochester Hills Michigan
Mashinter and SkunkWorks,
Thanks for being patient. I am hung up on this weight transfer thing. I (now) get that you are talking left\right. If you are talking about lateral (or horizontal) force, then I completely understand how stiffening the front bar can increase inward to outward force and therefore cause the front wheels to slip (understeer). If you are talking about a vertical weight tranfer, as in, "a stiffer bar causes the outside tire to have more weight (down force) on it," then I am lost. Weight to me is always in a downward direction. Force can be applied in any direction.
If I can sort this weight/force transfer issue out I think I will have come a long to to understanding the major dynamic relationships that are occuring. Getting them sorted out will take while, but it sounds like fun.
Thanks for being patient. I am hung up on this weight transfer thing. I (now) get that you are talking left\right. If you are talking about lateral (or horizontal) force, then I completely understand how stiffening the front bar can increase inward to outward force and therefore cause the front wheels to slip (understeer). If you are talking about a vertical weight tranfer, as in, "a stiffer bar causes the outside tire to have more weight (down force) on it," then I am lost. Weight to me is always in a downward direction. Force can be applied in any direction.
If I can sort this weight/force transfer issue out I think I will have come a long to to understanding the major dynamic relationships that are occuring. Getting them sorted out will take while, but it sounds like fun.
Because the CG is above the ground, there is weight transfer from the inside tires to the outside tires in a corner.
weight carried by a tire affects the side force the tire can develop. I'm making these numbers up, but actual data is available in Race Car Vehicle Dynamics By Milliken
If your front axle is carrying 1500 lb. of weight and each tire only has to carry 750 lb. of weight in a corner, the front axle could develop 1500 lb. of side force at the limit. If weight transfer loads the outside tire to 1500 lb. of weight in a corner, the front axle could develop only 1300 lb. of side force at the limit.
The tire having to carry a greater weight reduces the 'g' force it can develop.
