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Author Topic:   Trailing Arms- Do You take out the Rubber Bushings
hughes
Dirt Maniac

Total posts: 141
posted November 25, 2001 09:39 PM
If a 1/4" of wheel base makes a big difference, I'm pretty sure that between both ends (rubber bushings) of a trailing arm, that under torque those bushings could easily compress 1/8" on both ends maybe even a 1/4" on both ends under torque. That could give you a 1/4" - 1/2" under racing conditions on one arm, then you add the other three trailing arms and that could equal some speed.

juni
Dirt Full Roller

Total posts: 73
posted November 25, 2001 09:59 PM
Run hard ones in the left lower and stock in the right . I been told that this will work well . MY question is if the rear end is pushing the car forward wouldn't the right side get shorter ? And make the car tighter?

racer17j
Dirt Forum Champ
Total posts: 1565
posted November 26, 2001 12:51 AM UIN: 54865418
i've always seen guys want the stiffest they can get on the lowers and then softer ones on the top i would try poly 's on the lowers and stock on the top

Oldsmobile13
Dirt Maniac

Total posts: 108
posted November 26, 2001 01:40 AM
What would be the advantage of soft bushings on top of the rearend? Wouldnt that cause you to lose traction and change pinion angle

hughes
Dirt Maniac

Total posts: 141
posted November 26, 2001 09:05 AM
I helped a guy that had been racing for about 20 years and he took out the bushings and welded washers over the big holes that were the diameter of the bolt. Then strapped them on, with no rubber on any piece of the rear end, period. Then you talk to others who say run'em. I look at classes such as latemodels and imca mods and they don't have any rubber bushings, I just figured if rubber made you faster, latemodels would have rubber.

racer17j
Dirt Forum Champ
Total posts: 1565
posted November 26, 2001 12:35 PM UIN: 54865418
olds i've just seen a few guys talk about that on here they say it makes it wrap like a leaf spring i would imagines that part of the reason you see rear ends with the shocks on the top on mod rear ends myself i don't worry about the little amout of flex you get out of rubber bushings if i was running asphalt i might but as much as a dirt car bounces around i don't see much effect on what it's gonna do. as for the uper classes they all run heim i don't think you could even find any rubber parts for those cars except for maybee on the a frames and on leaf springs

awkwardjeff
Dirt Freak

Total posts: 458
posted November 27, 2001 05:37 PM
Because the late models run them you think it makes you fast? run there carb, or their heads......you will not go anywhere....it a package deal.....they(lates,mods...ect.) don't run the rubber because the have RACE cars not stock cars......The have moved the mounting points of the rear suspension to free up the suspension.......it you run solid bushing in a stock chassis the suspension will have a bind......

In modifieds we had to run stock rear suspension mounts until a few years ago....what everyone did was to put nylon bushings in every where except one bushing...
some guys put the stock rubber in the lower left, other guys ran them in the upper right...........go figure, racers that didn't totally agree.......both ways were fast enough to win........but every car ran one bubber bushing some in the rear and the rest were solid nylon.

Eveyone agreed on the bind issue, just not on where to put the stock rubber.

hughes
Dirt Maniac

Total posts: 141
posted November 27, 2001 06:30 PM
Well, I didn't mean everything litterly, I just use those cars as an example. I theorize things like if leaf spring cars were faster than coil springs, then latemodels would be running leafs. But i'd put that latemodel motor in a stock car, if for no other reason than COOL POINTS. There is just something about the way 700 ponies rap-out that gets MR. Winky excited.

istock59
Dirt Freak

Total posts: 237
posted November 29, 2001 12:45 PM
Urethane in the lowers, stock rubber in the uppers on mine.

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