rednari2

iTrader: (1)

I just put a new cam in my car. The car is an 04 GTO and makes about 470 RWHP. This number is before the new cam install. The new cam was installed after the old cam failed (see stuck # 7 lifter in the Gen III internal engine section). Since, the new cam is the same specs as the old one the HP numbers should be the same.

Here's the problem. I am getting wheel hop at high RPMs. This didn't happen before. When I say higher RPMs, I mean when I wind out 1st. The hop starts between 6000 - 6500 RPMs and gets worse if you stay on it. This also never happened before. I have no wheel hop coming out of the hole, and because of the wheel hop, I haven't power shifted the car into 2nd. So, I do not known if it will continue in that gear or stop.

This one has me scratching my head. Wheel hop out of the hole I get. But, I never had a car that digs well and starts to hop at the shift point to 2nd. Suggestions please.

gesto

What is your suspension set up?

rednari2

iTrader: (1)

I have B&G dropped springs: 1 1/4" fronts and 1 " rears; Koni yellows single adjustables, Hotchkiss sways and BFG KDW IIs. The car also has Pro sport poly bushings in the body to control arm connections and lower control arm bushings. DS is a single piece 3.5 AL with 1350 spicer joints.

JD_AMG

So no wheel hop until you get to around 6000rpms? You sure its wheel hop and not something else? Are you getting traction in the lower RPMs or is the car spinning in the low RPMs and trying to get traction by the top of 1st which is why its hopping?

rednari2

iTrader: (1)

Its wheel hop. I am getting traction all through 1st until I get to the top where it starts hopping. Then I let off and shift to second, and its OK. I am going to check tire pressure and try again tomorrow. Its weird. I worked out the set up years ago to where I had no wheel hop from a stop or at any speed and now this??

I am going to try tweaking the sway bar and the right rear shock to stiffen rebound.

gesto

Do you have the rear LCA's in the stock location?

rednari2

iTrader: (1)

Yes. The GTO uses a trailing arm that is fixed to the body and that the springs ride on. The upper spring mounts are part of the chassis. The trailing arm attaches to the body at two points and each point has two bushings. There are no OE adjustments, but some people have tweaked the arm over the years. My arm is OE and in the OE position. The original rubber bushings were replaced years ago with polys.

I am starting to suspect the tires since they are four seasons old, but I thought it was strange that the hop occurred after the cam change.

gesto

Sorry, wrong car. My LCA question would not apply to the GTO. The worst part is I have a GTO and should have caught that . Old tires could be the culprit. If they aren't you might consider anti-wheel hop axles. I have stock suspension and a single anti-hop axle fixed my wheelhop.

rednari2

iTrader: (1)

Ok. Does the oversized anti-hop axle go on the right side? I am also considering drag bags. What pressure are the bags set at?

gesto

I have a Gforce Level I anti-hop axle on the passenger side and stock on the driver side. I also have drag bags in stock springs. At the drag strip I run 20 - 25 psi in the bags but it's not enough to stop severe squat in the stock suspension. There's no wheel hop though. With your springs and shocks, I'd guess you won't need so much psi in the bags.

I had wheel hop on 100% stock suspension and drag tires. I added the drag bags and they helped some. I added the axle when the wheel hop persisted and it stopped the wheel hop.

rednari2

iTrader: (1)

OK, good to know the axle works.