yeller_xtc

iTrader: (7)

ive noticed after my a4 3.42 gear swap my car like to hop with the t/c off? what needs to be replaced?

tpunk

iTrader: (8)

It's hard to say for sure. Typically the "fix" is to get new shocks and LCA's/new LCA bushings. If you get aftermarket LCA's I suggest the J&M 3peice poly (standard poly binds). If you just replace the bushings in the stockers get the moog solid rubber bushings. Shocks are dependent on what else you have/plan on doing so we would need that info. A call to one of the sponsors like Strano is always a good idea too so you can talk through the issue.

BMR Tech2

iTrader: (5)

Hello, if you don't have any mods done to the rear suspension a set of lower control arms and relocation brackets will stop the wheel hop. Our lca's are available in either non adjustable or adjustable versions and feature a high durometer urethane bushings. They are also available in poly/rod combo or an on car adjustable race version with QA1 rod ends. The relocation brackets aka anti wheelhop brackets change the angle of the lca's and allow you to move the instant center of your car. The are available in weld on or bolt on versions. Both are laser cut from 3/16" cold formed steel. The bolt on version will work with the factory rear,weld ons with aftermarket. These two items will stop the hop. If you have any questions please give me a call. We will be in the office today until 6pm est.

http://www.bmrfabrication.com/F4.htm

OEM_TA

I have fought that battle myself.
The items that will address the hop are as follows.
Shocks
Lower control arms.
J&M with the poly ball joint are very good to cut down on binding without going to rod end types.
Relocation brackets.
My problem started after replacing stock torque arm and lower control arms.
Added the relocation brackets. Started with 2" drop, then went to 3" drop.
These reduced the hop but the shocks were what finally fixed it.

SteveC

YOU DO NOT NEED TO REPLACE YOUR SHOCK ABSORBERS, if the stock ones are in working order.

You need aftermarket LCA's (boxed), and a Torque Arm, BMR manufactures both units, they are killer.

After installing these units, your vehicle will go from Fafegnugen to Fukenmovin.

SteveC

tpunk

iTrader: (8)

I gotta dissagree with you. The torque arm is NOT needed to get rid of most wheel hop. In fact LCA's tend to be less needed than shocks. The problem is the valving on the stock shocks and the fact that at about 50K miles they are dead. Here is a good way to think about it. If you do shocks first you are fixing the main problem. If you then follow that up with LCA's you are getting rid of another problem point. The reason stock LCA's cause problems is the bushings allow for too much movement. They are not a solid bushing so going solid one will keep things in line much better. Boxed LCA's are not needed in most cases, they are really meant for drag racing. Instead for a street car I recommend the J&M's I told you about earlier, or BMR offers their arms with rubber bushings which won't bind. Bind will cause the car to act like it has a larger rear sway bar thus causing more oversteer. The torque arm is really just getting rid of a little extra flex which contributes to wheel hop in a less extreme way (TA's do more but this is really what helps reduce wheel hop). Changing out the LCA's and TA before the shocks will tend to help reduce wheel hop by a decent amount but it has been my experience that it is really only bandaiding the main issue which is shocks. LCA brackets will help you dial the car in so it can launch how you want or adjust the suspension geometry after a drop.

c5z28

iTrader: (11)

I am actually looking to get 3.42's like the op. Would some koni's in the rear help with wheel hop? I have someone trying to sell only rear's. I figured a torque arm and some lca bushings would help finish it up nicely.

BMR Tech2

iTrader: (5)

Relocation brackets and lower control arms will fix your problem.

Sam Strano

iTrader: (41)

That's simply not true on a number of fronts.


The axle is unsprung weight. Compression damping in the shocks is what damps unsprung weight. Hop stems from a shaking movement, and shocks can most certainly help it, and sometimes cure it.

So can LCA's, or brackets, or TA's.... Sometimes just one of the above stops the hopping, sometimes you need a combination of the parts. And there have been times folks had all the "required" suspension hard parts and the hop didn't stop until shocks were added.

I'm sick and tired of these absolute statements because there can be a number or factors involved. Maybe those parts cured *your* car, but that doesn't mean they will cure every car. Hell, it's not unknown for a change in tires to start or stop a hop....

I have LCA's, and brackets, and TA's and all the same stuff everyone else sells. It that's what we ultimately decide on upon speaking by phone, great. But I will not just blindly state "you need X, Y, Z", and even if I could there are various types of all the compents, more than one style LCA, there are bolt and weld-in brackets, there are long and short TA's with a variety of mounting options.

My job is to help diagnose and fix the issue, I can't do that without talking to the patient, so to speak.