hootie_john

I'm looking at the Pro Kit or comparable 1.5" drop springs. I'll be keeping the stock shocks/struts for the time being (only 24K miles), but will likely get the upgraded strut mounts or camber plates up front (looking at the J&M). My question is concerning the rear setup - upper and lower control arms. I'm wanting to get rid of the wheel hop we all love so much. My question is does lowering take care of it, or should I go ahead and get the replacement upper/lower control arms? I'm guessing go with the standard lowers and an adjustable upper to correct any geometry problems due to lowering? Would I need to relocation brackets for the lowers? Thanks

427Roush

If this is a DIY project, you might as well replace the LCAs along with the UCA.
If a shop mechanic is going to do it you could always have them install the LCAs first, check your wheel hop and see if the UCA is required. The latter should save you some money.

hootie_john

Yeah I plan on doing the install myself. I'll more than likely be putting an adjustable PHB in there while I'm at it. I did read a thread over on S197 about turning the stock front strut mount around to recover some camber (like what is done with the GT500 mounts). I may try this as well if I don't go with the J&M setup.

Norm Peterson

Don't guess ahead of time, drive it and see. If it doesn't hop or doesn't hop unless you're just showing off you really don't need to do anything. Otherwise start at the top of the following list and work your way down until the hop goes away. Stop there because making further changes won't make "no hop" become less.

If it hops, swap just the LCAs alone first.

If it still hops, swap the UCA.

Then relo brackets.

Then firmer engine & transmission mounts.


Norm

CMcNam

This. Mine is lowered 1.5" and had some wheel hop. I installed just the LCAs and relo brackets and it's completely gone, so I'm not going to change anything else back there.

yourmove

While I am a novice - The answers to my questions are intended to be self-informing.

When we lower a car (in the rear) isn't wheel hop just a part of the problems to occur?

I mean without the proper geometry aren't we quietly awaiting a potential failure with regard to the rear end?

Norm Peterson

Wheel hop is a problem at most any ride height. It is slightly affected by ride height, but this is not as simple as lowering = more wheel hop.

Mostly wheel hop is a stored energy thing, and most of that is where the OE bushings distort under the loads from acceleration and spring back toward their original shape when the tires lose traction (spin).

There is some dependence on ride height, because the side view suspension geometry does not remain constant as you either raise or lower the rear suspension. Relo brackets revise the geometry without changing ride height, so you could say that "lowering" and LCA adjustments via relo brackets are two sides of the same coin.

My preference is to sneak up on a solution by attacking the 'stored energy' situation first, meaning upper and lower control arm bushings. But that's not the only reasonable path. Realizing that swapping the UCA is somewhat more difficult, it could be worth a shot to swap the order I listed for the UCA and the relo brackets and do the relo brackets as the second step. IOW, if LCAs plus relo brackets kills the hop, stop there and forget about the UCA and the other stuff.

FWIW, I put a lot more faith in welding the relo brackets on, though I'd be apt to leave any bolts in place as additional security.

FWIW #2, using relo brackets (particularly the lowest holes) and doing a lot of drag racing has resulted in a number of axle tubes spinning in the pumpkins. If this describes the use the car may see, consider some additional method of securing the axle tubes in the diff housing (welding, pinning, etc.).


I don't know what the first point of structural failure might be, but I'd stay out of hop as much as possible while working my way down the list.


Norm

yourmove

I am concerned with the new angle of the drive shaft from rotation of the axle and seal failure.

I know this is more of a wheel hop thread but I was searching for things related to UCAs/LCAs and why they should be considered after lowering.

F1Fan

If you are not going to install good dampers when you do the springs you will be wasting money because you will need to pay for two alignments and two strut R&Rs. This wasted money will pay for a almost half a set of new Koni Sport dampers which are so much better than the stock dampers it is not funny. Do yourself a favor and save your money up until you can install new Koni Sport dampers at the same time as the sport springs. As far as camber plates go the only good race type camber plates are from GC and Vorshlag. The GC design is superior mechanically but require a higher level of maintainence to prevent spring mount noise. The Vorshlag camber plates are quieter but if the spherical bearing fails the car will collapse and the strut will go through the hood. If you want to not ruin your street ride GC street and Steeda HD camber plates are the only high quality isolated camber plates in town.

Reducing the rear ride height on an S197 chassis does not increase wheel hop, it reduces wheel hop due to the loss of mechanical grip caused by the change in the rear axle instant center. To restore rear grip you can install LCA relocation brackets. Wheel hop is caused by the soft bushings winding up and releasing the stored energy in the UCA and LCA bushings. Reduce the windup and storage of said energy and you reduce or eliminate wheel hop. Installing LCAs with firmer bushings can improve wheel hop but the S197's UCA has a much bigger impact on wheel hop due to the 3-link suspension's geometry. The firmer 3-piece poly bushing, relocated UCA mounting point and significantly longer UCA in the Steeda UCA Comp/Street UCA kit kills several birds with one stone, painful as it is to install. For most S197 GTs with only bolt-ons you can use GT500 LCAs with the Steeda Comp/Street UCA kit and eliminate wheel hop and improve rear grip on power while minimizing any increase in cabin NVH.

You should install LCA relocation brackets if you drag race the car. If you track the car and have lowered the rear end to the point that the LCAs do not point down to the rear axle at least 5 degrees you will need the LCA relocation brackets to restore rear grip and reduce rear axle induced understeer.


HTH!

hootie_john

Great discussion/information guys, thanks! As I'm getting older, I'm slowly learning (the expensive way!) that doing things once makes sense. Wait until you can do it right, as mentioned above. It will end up saving you money in the long run.