airborne

I wanted to ask about a different way to stop wheel hop. My car has always had it despite trailing arms/toe links and new suspension. The last mechanical thing to do is new bushings which it probably needs.

Until then though, could raising tire pressure help reduce wheel hop? Has anyone tried it? I run 32 (or 36, forget) psi all around.
Also, as the tires wear down (they're stock sized s-03s) and traction lessens that will help too right?

Whizbang

well your between tire spinning, and actaully having traction and moving...

raising the pressure with make for more spinning.

you could try a better tire compound and wider tires. i put 20mm wider tires on my FC and it helped. (normal 205, but i put on 235) and keep the tire pressure down to 30ish. that might be able to get you to have full traction.

turbodrx7

iTrader: (43)

Get a diff brace. www.kgparts. com carries them and i think rx7store.net has them too. Like $175 bucks and it should help with wheel hop and help save your diff if you do get a little.
-Austin

$_RXHEAVEN_$

with a diff brace or an engine brace dont u just put extra stress on other parts of ur car. this is just what i have heard, not sure if its true. please correct me if im wrong

Nuvolari

iTrader: (4)

What RPM's are you launching at ? I have the KG diff brace and my wheel hop is all but gone.

airborne

Its not even when I'm launching. If I just ease into 1st from a stop and then get on it I'll hot at the top of first and shifting into 2nd. And that was my theory, that higher tire pressure would make it easier to spin tires which is better for the car than hopping. I'll have to give it a try, but of course thats not great for the tires to drive around like that all the time.

yuichiror

iTrader: (1)

Some more info:
https://www.rx7club.com/showthread.p...&highlight=hop

DamonB

Wheel hop is a resonace. Anything that changes resonance of the tire/suspension/drivertrain will change if/when/to what degree wheel hop happens. Different tires, different air pressure, different surfaces, different bushings, different RPM at launch, different use of the clutch during launch, different shocks, different springs etc.

My bushings, arms and toe links are all stock and not in need of replacement. The only non-stock bushings are Mazdaspeed trailing arm bushings. I have no diff brace or engine torque brace. I constantly launch the car as hard as I wish with R compound tires and get no hop; it's all technique. I could easily make the car hop like crazy but if you're attentive you can drive around that problem without sacrificing the launch. It's all in how you use the clutch and throttle and no, I don't slip the clutch much. You have to feel how the car is hooking up and use the throttle and clutch to modulate power and wheelspin vs grip and hop. A few milliseconds difference in how you let the car hookup off the clutch makes a world of difference.

airborne, you didn't mention engine mounts or diff bushings. Are these in need of replacement? The entire drivetrain hangs from those four bushings. If ANY of them are worn you will have problems, no matter what other braces you stick on the car.

airborne

Damon, thanks for the input. I'm not sure what the previous owner replace but i've had the car 5 years and haven't done any bushings. Would you suggest to start with those? I saw the thread on Ray's $300 pillowballs, and was thinking that might be a good coincidence.

DamonB

People always talk about trailing arms and toe links but IMO the engine and diff mounts are the biggest contributors to hop. There's no need to replace anything that isn't worn out, but you'll have to check each item.

How many miles are on your car?

airborne

Absolutely I'd check them first. About 95k on the chassis. My one worry is actually replacing them, plenty of horror stories out there about getting the old ones out.

I was thinking the engine mounts were ok. Watching some cars on the dyno I could really see the engine twist when they pulled, mine had really no movement.

DamonB

I'd say it's a safe bet the toe link bushings and the 6 pillowballs need replacing if their original. Check the diff bushings as well; look for oil coming out of them. If you see any, they're toast.

cloud9

iTrader: (4)

As a general rule how many miles do you supose can be had from the stock bushings before they need replacement?

DamonB

I really can't say. I bought my car with 64K on it and the toe links were already shot. The original pillowballs went shortly thereafter once I started racing it. My car has about 135K on it now and it's on it's third set of pillowballs but my case is extreme I'm sure as I spend a lot of time on race rubber. If there's 75K or so miles on the car I don't think replacing all the rear end stuff would be a waste of money. In many cases you don't realize it needed done until you do it and notice the difference.

Some people call doing 2 or 3 track days a year tracking their car. I do at least that plus 125 or so autox runs each year while also daily driving the car. My car sees lots of use and gets worked hard

KeloidJonesJr.

iTrader: (8)

Sorry for a noob question, but what is a wheel hop? Is it another way of saying popping a wheelie?

DamonB

Another term would be "axle tramp" or "tire shake". When launching hard a resonance gets setup in the rear end and the tires literally try and bounce on the pavement as the car pulls off. In the FD's case the rear diff then tries to beat the crap out of the bottom of the car