DISCLAIMER - I have not tried any of the following, I do not know if it works, if it is dangerous, or if it will negatively affect your handling or suspension. I simply thought it might be an affordable, reversible, easy way to lower the front of our cars, especially us AWD owners with the additional front ride height. TRY AT YOUR OWN RISK.

I was looking around at roll center adjusters after lowering the front of my car. T-Demand has them for $240.00 and Megan Racing has them for $83.00.

Based on the design of the roll center adjusters, it appears that they are just spacer blocks installed between the steering arm and the front upright. Installing these would actually raise the front hub up in relation to the lower control arm, or, viewed another way, lower the body of the car in relation to the position of the wheel, without having to install springs, worry about ride comfort or additional shock wear, or alter their car in a significant way.

This is a view of the front suspension. The green arrows are pointing at the steering arm, which is what attaches the front upright to the lower control arm and the tie rod.



This is a picture of the Megan Racing Roll Center Adjusters installed on a 4GS. You can see that they are just a spacer blocks with a longer bolt. By extending the length between the lower control arm and the wheel hub, this should also lower the front of the car by the same amount. For additional safety, I would probably replace those provided bolts with ARP hardened bolts, as those two bolts bear the entire weight of that corner of the car.



This is simply a thought experiment for me. I have already installed RSR front springs, and plan to install the rears shortly. If anyone else has an opinion/analysis/experience with what I've laid out above, I'd love to hear from them.

 

I have them and it lowered the car slightly and supposed to correct suspension geometry. Had to increase PSI in the front as the original ride height would have caused it to rub. I believe it is also the reason for allowing me to run GSF front brake rotors with my 19 F Sport wheels and have clearance.

 

The roll center adjusters increase the distance from the control arm to the hub, but the whole assembly is behind the rotor, so it shouldn't have any effect on rotor clearance.

Your factory F-Sport Wheels clear your front GS-F calipers without spacers?

 

RCA's are meant to correct the geometry of the suspension when lowering a vehicle. I've had them on all my previous cars that I've dropped. I have yet to install them on my current vehicle lowered on RSR Coilovers (waiting for LCA bushings). Once you do this on your vehicle you will need to do an alignment.

Can you use it for a mild drop, sure. Just don't expect much from it.

 

Does it drop 30mm if you are using the 30mm spacer?
FYI I have Swift springs and GS F front brakes on my 2013 GS350 RWD. I would like top see another 10mm drop in the front actually.
Assuming these will do the job as well? https://autosportsengineering.com/pr...s-gs300-98-05/

 

GrandSedanFan, on the 4GS, can the RCA be installed without lowering springs? Would doing so adversely impact the geometry of a the front end?

This should give a 30mm reduction in body height of the front end?