2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Need a solution to wheelhop!

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Old Mar 29, 2009 | 12:41 AM
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Need a solution to wheelhop!

Ok I cant drop my clutch out above 2800-3k or i get crazy wheel hop. I know i could greatly improve my times if i could launch at 4-5k with no wheel hop. i have 215/45/17s. 150whp. that 60ft is just not acceptable. i had my rear tires deflated to 28psi for this run my other runs were 16.0-16.4. WHAT SHOULD I DO?

60ft- 2.3411
330ft- 6.6930
1/8ET- 10.2368 @ 69.5mph
1/4ET- 15.8309 @ 88.5mph
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Old Mar 29, 2009 | 12:56 AM
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Originally Posted by millertime6009
WHAT SHOULD I DO?
Stiffer shocks, stiffer springs, soild subframe bushings, solid diff bushings, stickier tires.

Any and all of the above will help.
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Old Mar 29, 2009 | 01:46 AM
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anybody have a link to where i can buy polyurethane subframe and diff bushings? as far as shocks/springs im thinking tokico blues and rb springs?
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Old Mar 29, 2009 | 08:53 AM
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i get wheel hop when I launch at 5k.
i think its my camber links though.

http://mmr-direct.com/catalog1/RX7FC/index.htm
MMR sells the polyurethane bushings.
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Old Mar 29, 2009 | 10:44 AM
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There are a number of causes.

It is important to make sure that all you suspension back there is in good shape. A broken front diff mount will cause mass amounts of wheel hop and may not be obvious from under the car if not completely broken.
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Old Mar 29, 2009 | 01:38 PM
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so i should replace the rear differential mounts? and the Rear control arm bushings and rear subframe mounts
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Old Mar 29, 2009 | 05:49 PM
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replace diff mount and all bushings
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Old Mar 29, 2009 | 06:51 PM
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A pinion snubber can also help cure wheel hop.
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Old Mar 29, 2009 | 09:57 PM
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From: on a twisty road somewhere...
its usually the subframe bushings and diff bushings. some MMR subframe spacers and either a pinion snubber or more significant diffy bushings will do the trick.
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Old Mar 30, 2009 | 03:36 AM
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bump!

great info guys keep it comin.

i read somewhere that shocks and/or springs wont solve the problem but only raise the threshold at where wheelhop occurs...same with sticky tires like drag radials
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Old Oct 13, 2009 | 09:02 AM
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Back on top

millertime, have you solved your wheel hop problem? What did you do?
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Old Oct 13, 2009 | 12:01 PM
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get some nice diff mounts (mazdacomp) and a pinion snubber... problem solved.
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Old Oct 13, 2009 | 12:52 PM
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FYI, I replaced all rear bushings (delrin & mazdacomp for the diff) except the subframe bush and still had wheelhop issues. I'm going solid Aliuminum for the subframe bushing now that I realize how critical it is.
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Old Oct 13, 2009 | 01:56 PM
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Solid subframe bushings have a number of significant negatives. I have driven cars with them and would never go that route with my own. There is an incredible amount of noise communicated through the subframe to the inside of the car, and the entire drivetrain feels harsh. For a track only car, it's a good way to go. For a street car, no way.
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Old Dec 4, 2009 | 10:35 AM
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Out of the RX7 world

Well it's been awhile, but I sold my RX7 back in June. I went out and bought a 2000 Audi S4 lowered and chipped it. Thats where I'm at now. The Audi has amazing power, most notably the 382lb-ft crank torque that comes alive at only 1800 RPM. Never the less I was watching Top Gear this morning and I started missing the effortless drifts I could accomplish in my FC without touching the brakes, the uniqueness of getting around in a car that you practically never see around these parts, and the sound of a rotary screaming to 8,000 RPM through that musical instrument called Racing Beat exhaust. I've got the blues, at least until I get another RX7...
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Old Dec 4, 2009 | 10:39 AM
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Did the Audi S4 solve your wheelhop?
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Old Dec 4, 2009 | 12:16 PM
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https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-pinion-snubber-install-867300/

Pinion Snubber DIY.
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Old Dec 7, 2009 | 11:41 AM
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Yes the Audi did solve my wheelhop, 383lb-ft crank torque and can launch it like a motherfooker.
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Old Dec 7, 2009 | 01:23 PM
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Originally Posted by LargeOrangeFont
Stiffer shocks, stiffer springs, soild subframe bushings, solid diff bushings, stickier tires.

Any and all of the above will help.
I know this is an old post, but this advice is slightly backward. Stiffer springs and shocks can actually make a launch much worse at high hp levels. Drag racers usually have a softer rear suspension so that the car squats over the rear wheels helping transfer all of the weight possible to the rear.
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