::.. Wheel hop. Hipity hop...

[Qube]

Under dry conditions, I'll get rear wheelspin signalled by very minor chirping. In wet, any launch above mild will induce wonderful chassis-shuddering wheel hop.

My question then is: I take it this is not normal? That is, no matter dry and wet, the power should stay down and wheelspin instead of hop?

By the way, I'm riding 235-45/17 with Vogtland Sports on Bilstein HDs. I'll switch over to the Koni adjustables once the Bilsteins die.

On a side note, I'd guess that hop is better than losing the rear in a spin. Of course, your drivetrain starts to hate you then...


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Wheel Hop:
Definition: An undesirable suspension characteristic in which a wheel (or several) moves up and down so violently that it actually leaves the ground. Wheel hop can be caused by many problems, including excessive unsprung weight, insufficient shock damping, or poor torsional axle control.
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Research:

http://www.bimmer.info/forum/showthread.php?t=23096&highlight=wheel+hop
- Subframe bushes? CV? Guibo?
- ... centre drive shaft bearing. If the rubber around the centre bearing housing has failed, the driveshaft will distort under acceleration and the shaft bangs on the support surround.

http://www.bimmer.info/forum/showthread.php?t=3053&highlight=wheel+hop
- thicker sidewall tire with less pressure such as the stock 15's
- stiffer rear swaybar in a traditional type car
- different compound tires
- shocks may be too stiff along with stiffer springs all contribute to the hop

http://www.cadillacforums.com/forums/open-letters-cadillac-corporate/29613-wheel-hop-how-much-would-you.html
- Wow. Apparently the Cadillac CTS-V has major problems with wheelhop ;)

http://forums.thevboard.com/viewtopic.php?t=4876
- entire suspension (control arm or solid axle) starts oscillating
- RWD, wheel hop is strictly related to tire & suspension design and the surface you are running on

[sKilled]

I would look at your suspension first - would be my first port of call for wheel hop.

[632 Regal]

Stiff springs/shocks can alone cause wheel hop. Any loose bushings will contribute along with a loose anti swaybar. Start by looking for sloppy bushings then to the springs/shocks.

[Alexlind123]

Get an alignment.

[nizmainiac]

the front shocks on mine do it aswell , i've just got to get round to putting my jamex shocks and springs on thats all, mine does it in bends and over large bumps in both wet and dry weather you can feel it more on the n/s/f than the other side, but then again both front shocks are well and truly leaking

[Ross]

My guess is the shocks are too soft or shot.

[Qube]

My guess is the shocks are too soft or shot.

Too soft? I would have thought on the contrary?

[Qube]

Still, it takes me back to the primary point... should there be hop when wet and yet it only chirps when dry?

[Bill R.]

abusing it.. The tire is either drying spots rapidly as its spinning which makes it grab and get traction for a split second. Which makes the rear end squat down, since the bmw's squat as the suspension winds up, then it immediately hits another spot of poor traction ie. more water and starts spinning again.
This violent grabbing and slipping causes the wheel to hop up and down.
and it repeats this cycle as it hops up and down. You don't have enough horsepower for it to hop dry otherwise it would.




Still, it takes me back to the primary point... should there be hop when wet and yet it only chirps when dry?

[Qube]

Grrrr.... not enough horsepower for it to dry hop... grrrr

Okay. Turbo. Spool it up and launch it. Screw the body kit ;)

Thanks Bill R!

EDIT: Granted, I'm not abusing it... really, it's not a hard launch by any accord in the rain but meh :(

[632 Regal]

mine does the same thing in wet conditions, personally dont think the bilsteins are helping much as it would just spin with the stock shocks.

Grrrr.... not enough horsepower for it to dry hop... grrrr

Okay. Turbo. Spool it up and launch it. Screw the body kit ;)

Thanks Bill R!

EDIT: Granted, I'm not abusing it... really, it's not a hard launch by any accord in the rain but meh :(

[Qube]

Thanks Jeff. That's all I needed to know. We need some kind of point system, like Experts-Exchange. Heh.

[632 Regal]

lol, if I got a dollar for each meaningless post...
Thanks Jeff. That's all I needed to know. We need some kind of point system, like Experts-Exchange. Heh.

[Alexlind123]

I dont have wheel hop in the wet, even when there is plenty of wheelspin.

[ILoveMPower]

Don't worry bud, my m30 5-spd does the EXACT same thing, stock suspension on 18" m-pars and michelin pilot sports.

If you drop it in gear at about 4k+ in the rain, it usually just spins tire for a bit and then once it hooks up just a tiny bit of hopping. I have problems with hopping in the dry as well though.

Solution: Call TCD and spend $4k on some forced induction :D

[632 Regal]

stock springs and struts?
I dont have wheel hop in the wet, even when there is plenty of wheelspin.