millertime6009

iTrader: (1)

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

LargeOrangeFont

iTrader: (7)

Stiffer shocks, stiffer springs, soild subframe bushings, solid diff bushings, stickier tires.

Any and all of the above will help.

millertime6009

iTrader: (1)

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?

Black Knight RX7 FC3S

iTrader: (7)

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.

Aaron Cake

iTrader: (1)

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.

millertime6009

iTrader: (1)

so i should replace the rear differential mounts? and the Rear control arm bushings and rear subframe mounts

arghx

iTrader: (3)

replace diff mount and all bushings

YaNi

iTrader: (2)

A pinion snubber can also help cure wheel hop.

S4GXL

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.

millertime6009

iTrader: (1)

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

RXJIM

iTrader: (3)

millertime, have you solved your wheel hop problem? What did you do?

eage8

iTrader: (9)

get some nice diff mounts (mazdacomp) and a pinion snubber... problem solved.

cone_crushr

iTrader: (18)

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.

Aaron Cake

iTrader: (1)

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.

millertime6009

iTrader: (1)

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...

arghx

iTrader: (3)

Did the Audi S4 solve your wheelhop?

Keboh

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-pinion-snubber-install-867300/

Pinion Snubber DIY.

millertime6009

iTrader: (1)

Yes the Audi did solve my wheelhop, 383lb-ft crank torque and can launch it like a motherfooker.

mikeric

iTrader: (20)

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.