I was running the road course at TWS today and again experienced the dreaded bad rear wheel hop. Before my next run I noticed a bad sound coming from my left rear wheel area. I jacked the car up and took off the wheels and placed it in gear and the wheels and the sound was gone. I put the wheels back on the car and when backing up and going forward the sound returns. The sound is metal on metal and may have broke something in the axle due to the wheel hop is my best guess.

I have SA Konis with the pro-Kit, RT Torque arm and Panhard Rod.

Any ideas on what broke??

Thanks

 

I am guessing you broke an axle from what you are saying here. 10 bolt axles are notoriously weak, and a condition like wheel hop will stress an axle for sure. You'll have to take the axles (both) out for inspection. If that is the case then call Moser Engineering for a set of alloy axles. That's who I called when my Dana 44 axle broke off on my 3rd gen race car. The other axle was cracked and ready to go also! Turns out Dana 44 stock axles are not that great either.

You also need to get rid of the wheel hop condition, that is stressing all your rear end components (rear gears, posi). Not sure which exactly direction to point you in there, a good place to start is to use less grippy brake pads in back, and maybe try out a brake bias to dial more brake up front. SLP sells those now for the fourth gens I think. That is what I did to eliminate wheel hop on my 3rd gen race car.

 

It definately sounds like something inside of the rear end. If you're getting wheel hop under braking you need less grip on the rear pads. If you are getting wheel hop under acceleration, you might need a torque arm, lower control arms, different springs / shocks or who knows what else. Telling us what modifications your car has so far will help to isolate the problem though.

 

Good point SS, did the wheel hop occur under braking (mine did) or acceleration?

 

The wheel hop was happening under hard braking. I was having to move my braking points way back to eliminate the or diminish the wheel hop. I need to correct this as I am losing precious time having to brake so early.

The mods on the car are the C5 brake conversion with Hawk HP+ pads front and rear. I need to go to stock pads in the rear and I like the idea of installing the brake bias to move more of the braking power to the front.

I have also installed and adjustable pahhard rod given the car has been lowered with The Eiback Pro-Kit with Koni SA's. A Random Technology Torque Arm is also installed and I am running 275/40 Kumho V700 all around.

What else besides cahnging to less aggressive pads and moving the brake bias to put more of the stopping power up front can I do to get rid of this wheel hop.

Thanks for the tip on the alloy axles. I think I am going to go this route.

 

HP Plus in the rear would be part of the issue since you only have HP Plus up front. I agree, less grippy rear pads (HPS would be a good choice), *or* stronger front pads to get the bias more frontwards. IMHO

 

Sam,

The car is handling great, I noticed a difference after installing the 35mm front sway bar. Nice crisp turn ins.

I was really surprised in my times. I have been running my M3 at this track for 3 -4 years and my best time on the 2.9 course was 2:03. I was timed yesterday at a 2:03 and this is only my second day on the track with this car. It looks like all the parts you sold me are doing their job. Again, I was pleasantly surprised at how this Camaro was handling.

On my first day out a few months ago I burned up the Power Steering pump, but problem solved with the underdrive pulley and a 24' Perma Cooler installed to keep the Power steering fluid cooler.

I have had the car on the track two days and each day I have had to leave early because of mechanical problems. It is truly fustrating, but I am not giving up on the car after it handled so well earlier in the day. I think I will label it my money pit.

 

Raider, try out the less grippy brake pads first, that is the easiest thing to do. Only make one change at a time, this way you can keep track of the effects. If that does not eliminate the problem then you can do as Sam suggested and try a more aggressive pad up front, see how that does, then plan your next move. I think your answer will be in there. Sweet set-up btw!