Hello guys

I just installed 20mm spacers yesterday on stock 18inch factory wheels and got my alignment checked but for some reason my car is rubbing on dips mostly rear tires and the fronts are rubbing on turns any solutions for that issue as some fender paint peeled off fyi I am running Michelin cross climate 2

thank you

 

Spacers put more load on the dampers the way they are setup on modern Lexus sedans/coupes (divorced outboard shocks and inboard springs). I find the IS350 F-Sport (mine is a 2019) to be a bit under-damped even in SPORT+ mode with AVS in full stiff. Meaning, there is a pretty long compression stroke before the rebound reverses it going over bumps and expansion joints. I primarily use SPORT+. Throw 20 mm spacers in the mix and you will have rubbing of the tire against the fender liner. I would recommend switching to 15 mm on the front and 12 mm on the rear (since we have staggered setup of 8.5 inches in the rear and 8 inches in the front). I am sure you would not have any rubbing.

 

so to my understanding of what you said rsr down lowering springs would be able to fix the issue as they are stiffer and would have less of a rebound?

 

I am not too sure what the spring rates for the RSR super down are for the IS350 F-Sport. I am kind of new to the IS world. With lowering springs, you would have less gap between the fender liner and the tire so you will have smaller margin. I would say this, in the RCF world many blew their shocks with RSR super down springs and I believe it might have something to do with their spring rates as they target more aggressive drops to give the slammed look. You might want to be cautious with lowering springs as AVS dampers are quite expensive to replace. If swift springs are made for the IS350 F-Sport, I would recommend those. They have a milder drop of around 1 - 1.25 inches, but their spring rates are known to really work well with the RCF dampers so I think same might be the case for the IS350 dampers. Never heard of anyone blowing their shocks with Swift springs.

That is why, you will need significantly stiffer spring rates to compensate for that and swift springs might be a better choice (if they are made for the IS350). There is no guarantee it will not still rub. I would still stick with my recommendation of just going with a milder setup with 12 mm in the back and 15 mm in the front. It will work much better with or without lowering springs.