Wheel Hop
 

Hey guys! I track my car but only for the drag strip, but this last time I went to the track I had some serious wheel hop and I am assuming it is b/c I have all the upgrades on my car now. So it was mentioned to me by a buddy who was talking to a guy that has a 350 and he mentioned that I should look into upgrading my by bushings. Any and all help will be appreciated.

Only had wheel hop once. It was in a 1971 Ford Capri with super thick swaybars and just when I put them in. Never happened again. Maybe the bushings where a little sticky and stuck to the swaybar increasing spring rate. Haven't looked into swaybars for the Z yet but a little graphite in the bushing might do the trick.

There aren't any upgrade kits available from what I've found. What tires are you running? Usually you can get rid of it if you can maximize traction.

Also make sure you pre-load the car when you stage. If there is any slack that can exacerbate any wheel hop issues and the shock to the driveline can result in damage.

I've done some calling around, talked to the guys at Z1 and we went back and forth on a few things but it came down to upgraded bushings. Does anyone know if there are any out yet for our car? I called SPC and they don't have any but they said they will give me a call back once they find something. CZP is doing their research on this as well to help with my situation. Z1 suggested the Kinetix tractions arms or upgrading the toe bolts.

M4a1 Mustang- I have the RE-11s. Would you mind going into detail about pre-loading? I believe you are referring to an auto-x track? I only do dragstrip.

Believe he is talking about riding the brake and gas while staging (as much as brakes will allow) which should eliminate drivetrain slack. Probably pretty tricky in a 6spd. I might be missing the point though.

I'm talking about drag racing. What you want to do is put load on the drivetrain while you are staged so you don't "shock" it when you launch. This is more about keeping stuff from breaking, but as smooth a launch as possible will help with the prevention of wheel hop. It's a little difficult without a line-lock, but I've found the best way to do it is to deep stage and hold the clutch out just to the point where it barely begins to engage.

You just want to avoid rolling up to the staging box and then waiting there. If you've got slack in the drivetrain when you launch, it's going to take up very quickly, shock the rear end, axles, etc, and likely get the rear tires spinning right away. Can kill a launch, or worse it can kill the rear end.

Takes a bit of practice but it should help some. I would send jnaut a PM and see if you could get him to describe to you how he launches his car. He runs RE-11s and has put down the quickest bolt-on 6MT times in the 370 so far.

Matt, you're right. It's easy in most autos (though the 370 won't allow you to have throttle and brake on at the same time unless you pull the ABS fuse) and it's trickier with manuals that don't have some sort of line-lock or staging assist.

I've emailed SPL about the solid diff bushings for the 350Z. The front bushings should fit without a problem but the rear one will take a little bit of elbow grease to get in there since subframe in the 350Z is slightly different. They did mention that they will be releasing a set specific to the 370Z soon.

I do get some wheelhop when launching at the track, it seems to depend on how I modulate the clutch & gas pedal. If you look at my times, I've managed 1.8x and 1.9x 60-ft times at the track consistently. I'm still on the stock RE050 potenzas.

You might want to check your rear diff bushing. Even though our 370Z's are still pretty new, there's still a decent chance that you might have a busted rear diff mount. Nissan decided to fill it with some fluid to soften the ride. If you abuse your car enough, it'll rip open and spill black fluid all over the diff cover.

the diff mount is offset towards the drivers side, you can kinda see the streak of black fluid in this picture:

http://a1.sphotos.ak.fbcdn.net/hphot..._1329813_n.jpg

Hey guys just a heads up. SPL just came out with some solid differential bushings, they will be released on Monday. I have ordered mine already through CZP. Something that some of you might want to consider.

Sweet, good to know. Let us know how they turn out.

The 2003 Mustang Cobras had really bad wheel hop issues with their IRS. Bushings fixed the issue completely.

Good find! Not on the CZP site yet, I assume you just called to place the pre-order?

Ya it is not to be released until Monday. I had been talking to Kyle at CZP about my situation and he got back to me with this great find and I was able to put an order in so that way it will ship on Monday. So I guess I'll have the first set!!:tup:

Do you know how much they will cost?

Give Kyle a call at CZP and he will give you a quote, depending where you are and how fast you want it the price will be under 200.

Hmmm, ok see the two SPL kits on the CZP site, however a bit confused as to the difference between the two kits and if these are the diff mount bushings as the description (Rear knuckle shock mount bushings) means nothing to me lol.

Suspension Parts, Upgrades, and Accessories

OP, have you installed these?

Care to elaborate on how the install went?

try splparts.com

they don't have the 370Z bushings on there yet, i'd shoot them an email or call.

Hoping for an update on this? Has anyone had any luck?

I did not get a chance for install and ended up going back overseas. I am actually about to be home in a couple weeks though and I will do the install then. I will update asap.

Did you install or sell those SPL rear diff bushings? You need to get rid of the rubber OEM rear diff mounts if you want to kill the wheel hop.

No I actually still I have them at the house. I didn't install them b/c they are made of aluminum and I was afraid it would create a rougher ride. I tried to sell them but nobody wanted them. Does someone sell some polyurethane rear diff mounts?

Yes, Whitline does, the KDT911 diff mount kit for the 350 fits the 370 as well.

Ya I already ordered the kit! Still got the other ones sitting at home.

Diff bushings, sub frame collars, diff brace did nothing for my wheel hop. Remedy required replacing factory bushings in knuckles, upper and lower control arms which is an extremely challenging and time consuming DIY project. Required some grinding / angling of hole end with a carbide burr in order to better seat replacements getting started using ball joint press, as Whiteline's are not tapered like factory bushings are. I suspect a significant % of non professionals will require professional assistance with this project so consider carefully before starting.

Did you get any pics of the install? Rusty posted some of his upgrade to solid SPL at all his articulation points, but I've been looking into urethane options like Whiteline and Super Pro.

Spherical vs urethane.
 

By all accounts the spherical are easier to install than the urethane probably due to the all metal ridgidity. The Whiteline's tend to distort / contort and angle themselves under the pressure of the insertion which creates the challenge of the installation. My car will never see the track and I don't drift so using the spherical bushings with their inherent vibration, noise and cost wasn't my first choice. I can now drive the car to it's potential even with the well worn Bridgestones.:rofl2:

IIRC if you throw the bearings in the freezer for a while before installation you should gain some clearance.

Some have used liquid nitrogen on all metal applications and they drop right in! I wish freezing the urethane applications had more effect than it's had in my projects.

On my past projects, getting the old rubber pieces out was way more challenging than installing urethane upgrades. On the Z, did you have to use a press to get them in?

The last thing you want to do is to freeze poly with nitrogen. You'll crack the poly.