Author Topic: Whats your rear susp/ tire setup for track?  (Read 12054 times)

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Offline Steve Wood

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Re: Whats your rear susp/ tire setup for track?
« Reply #30 on: July 08 2013, 10:16:56 PM »
Hopefully it is not the poly bushings binding up...which holes did you use on the sway bar?  shortest ones?  If so, try the middle ones
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Offline Shimy87

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Re: Whats your rear susp/ tire setup for track?
« Reply #31 on: July 08 2013, 10:54:34 PM »
Middle ones
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Offline Charlief1

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Re: Whats your rear susp/ tire setup for track?
« Reply #32 on: July 09 2013, 12:20:37 AM »
Get rid of the poly bushings. There's supposed to be some flex in the rear suspension and poly bushings don't allow for it. :sw:
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Offline Shimy87

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Re: Whats your rear susp/ tire setup for track?
« Reply #33 on: July 09 2013, 10:32:36 AM »
Get rid of the poly bushings. There's supposed to be some flex in the rear suspension and poly bushings don't allow for it. :sw:

No kidding! it was a bitch to install these in the top arms. I thought these poly bushings were supposed to be the cats ass?
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

Offline Steve Wood

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Re: Whats your rear susp/ tire setup for track?
« Reply #34 on: July 09 2013, 10:58:37 AM »
Cats asses don't work well for rear suspension pieces.  did a vendor tell you that was what you needed?  the rear bars do not rotate on a common center so they tend to bind if the bushings do not allow for some movement.

Then try putting the sway bar links in the shortest holes to increase the load on the tires on side to side movements and see if that helps.

IF not, put the stock lowers back on...do one at a time and it should not be a hard job unless fighting rusted up bolts
Steve Wood

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Offline Steve Wood

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Re: Whats your rear susp/ tire setup for track?
« Reply #35 on: July 09 2013, 11:28:35 AM »
BTW, don't you have those donk like tires on the back?  They might make the problem worse?
Steve Wood

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Offline Charlief1

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Re: Whats your rear susp/ tire setup for track?
« Reply #36 on: July 09 2013, 12:18:32 PM »
Poly bushings are great, if you plan on going to a road course. For a drag strip Steve's right, they cause the rear arms to bind rather than work properly. If you just want to see a simple difference, loosen the bolts that hold the arms in place just enough to let the arms move. It will make some noise but try doing a light launch on the street and you'll see a big difference. :icon_lol:
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Offline PacecarTA

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Re: Whats your rear susp/ tire setup for track?
« Reply #37 on: July 09 2013, 12:52:31 PM »
for a road course that need the rear to articulate  the poly can and does restrict  articulating movement  compared to the softer stock bushings.
for drag strip polys work , they  dont bind for what they need to do  which is travel up and down evenly .  the poly centers are free to rotate where the stock bushings only rotate by twisting the rubber (unless you loosen the bolts)
problem with stock is the amount of compression they just dont cut it when the hp gets higher  ,   i split the poly pop in  bushings in the umi rear lower control arms.   the energy suspsenion bushings are better.

on the rear i now run heim end uppers and lowers (wolfe racecraft) , and wolfe pivot bushings in the rear axle ears
they have no bind and wont compress so i can set my pinion angle close to zero degree and it will not move from there, poly can move as much as 4 degrees and stock bushing more than 6 degrees

for rear sway bar i run the hrpartsnstuff HD rear bar which has heim end links


for the front the stock bushings are serrated and restrict travel since the rubber is bound to the center tube and the outer shell (thats why you have to tighten them when they are at ride height ) , polys dont restrict movement up and down because neither the center tube or the shell are bound to the rubber.
to lessen the stock bushing restriction you can loosen the nuts at end of upper control arm and loosen the bolts on the lowers
« Last Edit: July 09 2013, 01:16:23 PM by PacecarTA »
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Offline Shimy87

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Re: Whats your rear susp/ tire setup for track?
« Reply #38 on: July 09 2013, 02:12:19 PM »
I have the Energy Suspension bushings all the way around on the car. With the bolts tight, the center metal tube locks in but the poly bushing can rotate freely when the arm travels up and down? I can try moving the sway bar to the shortest hole. For tires I have 17 inch wheels but the tires are the same height as stock tires were. I measured at the time so they would be the same but dont remember what the number was now.
87 GN, K&N cold air, gutted cat, TT 5.7 chip, AFPR, 340 Walbro w/ hotwire, 60 LBS injectors, 981 valve springs, 206/206 Cam, RJC Powerplate, LS1 MAF & translator, Vacuum brakes, Hellwig rear sway bar, Energy suspension poly bushings, Razors Alky, Pypes exhaust, 5931 turbo, CK9.5 converter

 

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