: Wheel Hop explained and some cures.



heavymetals
01-26-06, 02:18 PM
I sent a few of you an article on the mechanics of wheel hop and some "cures".
Reed posted it to the FAQ's.

http://www.cadillacfaq.com/faq/answers/wheelhopexplained.html

Kadonny
01-26-06, 03:11 PM
Not a bad read, but this stuff is pretty much common knowlege by now on our cars. Thus the ole debate of what tires to run.

The key is finding a sticky tire for handling while also eliminating the hop.

ace996
01-26-06, 06:53 PM
I have that article too, good read. Only thing is the Vettes don't have our rubber-mounted, two-piece driveshaft and dual-mass flywheel to add to the problem. There is no tire that will give side grip without winding-up the drivetrain with forward grip. Our problem is even more severe, since we have..in effect, a drivetrain that stores energy up until traction breaks.

There's a way to fix it, actually several ways...I posted this before but it may help with the discussion here...
The drivetrain on the V is a fkucing mess. First, there's the dual-mass flywheel. Second, there's rubber mounting of the driveshafts...yes, plural used because there's two..with rubber in the middle. Third, the rubber mounted differential that allows pitching. Fourth, rear-cradle is rubber mounted. Fifth, the rear trailing arms and toe-links are rubber bushed.

Five problems that are not used on modern race-cars. Reason...solid mounting would create plenty of noise as NVH would be quite high. There is a better way, though, a compromise of sorts.

The dual-mass flywheel has springs that absorbs the engine torque, when the springs have ceased to compress...the rubber-mounts of the driveshaft absorb the transferred torque...then the pinion jacks....then the wheels start moving...then the trailing-arms and toe-links get torqued-out of position and then....finally...the tires break traction. This allows the whole freaking driveline to straighten-out and spin the tires while they are off the ground. When the tires come back into contact with the road....the whole freaking event starts over again. This occurs several times until the the vehicle is moving at a rate fast enough to prevent hop...resultant from not enough power to break traction in a continuous sequence.

The only way to completely eliminate the hop would be to make all this absorb/release energy simply be applied correctly via solid mounting...or much stiffer rubber mounting...via poly-urethane. But the flywheel needs to be made solid, as that is a major contributor to the driveline clunk/torque reversal that GM claims as "normal". (I still can't believe that a company can get away with such lies...normal they say...fkucing clowns!!!)

My initial thoughts would be to mount a solid lightweight flywheel, pillow-ball mounted trailing-arms/toe-rods, and a solid interface/mounts of the driveshaft. However, taking away any energy absorbing rubber from one part will simply transmit the torque to the remaining rubber mounts/bushings and would probably lead to their pre-mature demise. That is where the poly-urethane mounts/bushings come into play. They would resist the torque-absorbtion much better but would transmit more NVH than the current pieces.
In the end, I'd still settle with more NVH for a stronger, more efficient driveline/rear-end/cradle. Driveline losses would be less...meaning more power to the ground. And then the only part that would wear-out more would be the tires...the actual parts that are supposed to wear-out, and our differentials would not be treated to jack-hammer power-pulses that certainly are the major contributor to failure.

Oh well...
-ace

Seattle CTS-V
01-26-06, 07:31 PM
Wow, great detail there. I could actually visualize a 3-D journey of "Torque-man" flying around the flywheel, down the driveshaft, and out the differential!

CTSV05
01-27-06, 12:07 AM
Orrrrrrrrr

We can fix the flywheel, install a 1 piece shaft, stabilize the cradle and install an auxillary shock in a different angle on the lower control arms.

CTS-VPaco
01-27-06, 12:20 PM
Or we can close our eyes, click our heels together three times and say, "There's no place like home... There's no place like home..." :cookoo:

CTS-VPaco
01-27-06, 12:21 PM
But seriously, wouldn't it have been nice that the whitecoats got this right so the marketing department didn't have to lie about this shit?

CTSV05
01-27-06, 03:25 PM
"Theres no peeps like marketing liars..............theres no peeps like marketing liars"

obzidian
01-27-06, 03:43 PM
How about a new flywheel, driveshaft, cradle stabi kit, poly/rod-end trailing arms or LCA'z

....and a set of non leveling rear shocks. I just cant remove the idea that the rear shocks are a huge problem...

basically, when you go from a launch, you compress the rear. The leveling shocks are taken below its preset "comfort-zone" and push back up. The rear is unable to maintain is previous angle, causing less weight over the rear wheels. Less weight, less grip potentiality....boom!! wheel hop!!

Gm rules!!!

ace996
01-27-06, 07:42 PM
How about a new flywheel, driveshaft, cradle stabi kit, poly/rod-end trailing arms or LCA'z

....and a set of non leveling rear shocks. I just cant remove the idea that the rear shocks are a huge problem...

basically, when you go from a launch, you compress the rear. The leveling shocks are taken below its preset "comfort-zone" and push back up. The rear is unable to maintain is previous angle, causing less weight over the rear wheels. Less weight, less grip potentiality....boom!! wheel hop!!

Gm rules!!!

I hear you, and sounds reasonable except that the shocks aren't "instant" leveling...they take some driving to "pump-up". Really, the shocks aren't the problem...its all the rubber/squirm.

Good idea, Doug, with the auxiliary shocks....but a custom ladder-bar assembly should work, too, no?

-ace

CTSV05
01-27-06, 10:35 PM
Ace, I think that would be too intrusive. The ladder bar would be a major limiter on our suspensions ability to move and therefore cause some loss in a corner, IMO, anyway.

An aux shock however may add some stiffness to the ride, but would not interfere with our Vs ability to corner.

Lets face it, any 100% complete fix is going to bring some type of comprimise in the Vs ability to be a well rounded performer. It just depends on what you (me) are willing to give away.

I think I will begin looking into doing something with a aux shock setup soon.

Our car is very good now, but not perfect.....yet!! LOL

ace996
01-28-06, 02:02 AM
You're prior exhibitions of technique have shown that your KungFu is indeed quite good, Doug. I'm guessing that it would have the top-mounts angled toward the front of the car and need high-high.speed damping but low-slow.speed damping, to limit forward movement...yes?
-ace

10secvette
01-28-06, 09:51 AM
Orrrrrrrrr

We can fix the flywheel, install a 1 piece shaft, stabilize the cradle and install an auxillary shock in a different angle on the lower control arms.


:yup: :yup: :yup: