reza

Dang it. Now I have wheel hop. I never had a wheel hop before replacing the bushings, toe links, and the diff mounts. Also no wheel hop with Victoracer or Hossiers....How do I get rid of it? I thought my mods will help prevent that, now instead of preventing, I have it.

Why do I have "wheel hop" after I install the following:
- replaced 6 pillow ball bushings
- replaced toe links with Rotary Extreme toe links
- JimLab's Diff Bushings.

Mods related to questions.
- JIC Magic FLTA2 set at 2/16 all around.
- Rotormotorsports motormounts.
- 9.5# flywheel
- 6-puck ACT clutch.(maybe I should slip the clutch more?)

I tried to launch at 3000rpm, 4000rpm, 5000rpm all resulted in wheel hop.

Oh yea, I think I am making hp close to stock. No engine mods, other than radiator, k&n filter, downpipe, hf cat, manual boost controller set at 10psi, and emission simplification.

DamonB

Typically once someone does the work you have their hop goes away.

Wheel hop is really a resonance in the suspension that causes the wheels to vibrate at the road surface. Any number of things contribute to it; anything in the rear that can be excited to vibrate may cause it. That said, since the Victoracers and Hoosiers are fine you may just be unlucky enough to have your street tires naturally resonate at the suspension frequency. Getting the stars this far into alignment to cause your problem is pretty hard to do I would try adding a couple pounds of rear tire pressure. I bet slight pressure adjustments will be enough to get rid of it since you have already replaced everything else.

I run stock horsepower and stock bushings in the rear end. I launch on race tires from about 2500 and then get hard on the gas as the clutch begins to hook up. I use the clutch to modulate wheelspin off the line and then let it out completely to let the car hook up. Once it hooks up I'm just over 4,000 and pulling hard. It takes a fine foot to not bake the clutch or the tires, but done correctly there is little wear done to either. I replaced my clutch disc at engine rebuild time just because I was in there, but the old disc was only worn about 25% and it easily had a couple hundred launches on it

SleepR1

Rx7 Store Diff Brace and Engine Torque Brace. Say goodbye to wheel hop. Drive line is SOLID. Shifts are crisp.

reza

I think the engine torque brace is not needed when you have urethane engine mount.
They same thing goes for the diff brace vs the jimlab bushing?

My rear pressure drop to about 30psi cold. That means after going around, I will have about 32psi.

I have Kumho MX right now. Its almost full thread at this point. Maybe the thread on the Kumho MX promotes that, while hossiers/victoracer are smooth..thus no hopping.

gambone

iTrader: (3)

The rule for rear wheel drive is soft shocks , but then there is a lack of info as to what the road condetion is , the speed , tire balance. 99E through Jefferson Or is realy and when when I get to the inter state I80 one can most clearly feel the deffrents. I have a RX4 which to have a set of BMW insets in the front and OEM shocks in the rear and one day I was following a farm tarctor home at 15mph and thought I had a problem. Then realized it was the speed ,at 55 or better on 99E there was no problem , Look for all that you can find as to what is going on and this lead to a good anserw.Yep I know my spelling suchs at times

doncojones

I would try and play with the balance of shock damping from front to rear. Say for example, put the fronts on 3 and the rears on 1. The FD kind of likes it when the suspension lets it squat down on its rear tires under acceleration.

apexkw

i have a rx7 store diff brace for sale if you want it. $100+ shipping

DamonB

Axle hop has nothing to do with front/rear balance; it strictly involves the resonance frequency of the components of the driven wheels. Axle hop is an oscillation that is just the same as an undamped spring that continues bouncing. To get rid of hop you have to somehow cancel that oscillation.

reza

Suspension setting is 2 of 16 possible, so its soft all the way around. For autocross, I uses 14 of 16 front and 8 of 16 rear. But I never tried it with street tire in the dry yet. Last time was in the wet, thus no hopping, just spinning around.

Road condition is newly surfaced road in front of my house, so no rough surface at all.
I am suspecting the tires at this time. It was cold that night about 40 degrees. But I have been running around, so the pressure is higher than the 29psi cold, that I test before leaving the house.

1984special

Your shocks are not blown?

reza

I hope not. I got them less than a year ago.
And I can still adjust it stiffer, A blown shock is really soft right?

hardbodeez

iTrader: (4)

I don't know if I read this wrong, but you still have the same stock trailing arms? That is a huge problem right thurr.

reza

Heheeh...yea I pass on the trailing arms at this time. But why do I get this wheel hop now, not before?

DamonB

Because the hop is created by a resonance in the system and that resonance frequency changes as you change or alter components in it. Have you tried just changing the tire pressure yet?

moehler

iTrader: (12)

couldn't agree more. I had wheelhop, added the Diff Brace (rxrotary2_7's brace) and already had the torque brace and have no wheelhop! The whole drive line is solid as a rock.