Definitely do F Sport springs. I'd immediately return the RSR down. WAY too low and you'll screw up your handling and bushings.

 

no, i already have installed the f-sport springs. i returned the rsr, like, a week ago.

my major complaint is that the front isn't nearly as low as the rear and i don't know if there is anything i can do about it.

 

I think the F-sport springs will allow a 1/2" drop, and no, not much you can do.

 

damn, my fronts haven't dropped at all. thanks for replying though!

 

I would disagree with this statement absolutely. The difference between the F Sport springs and RSR Downs is only slight....but the RSR Downs are lower.
If you think the RSR Downs is "WAY too low", then I wonder what you think about the RSR Superdowns...cause they are "WAY lower".
And no...just like the other million members here...the RSR Downs didn't screw up my handling or bushings! What bushings are you even talking about?!?! The car has at least half a dozen bushings at each corner of the vehicle!!
Let's try and keep the responses factual if we can...and not just make up wild conclusions or assumptions.

FYI...with my RSR Downs and 20 inch wheels, my IS corners like it's on rails!!! Just so you know.
Admittedly, if I had to do it again, I would have gone with the same springs, but a 19 inch staggered wheel set.

 

It usually take at least couple of weeks of driving for the springs to settle. Do a quick measurement now and another one in a few weeks and see how much it actually dropped.

 

thanks, i'll definitely do that.

 

Agree 100% about the RSR downs. I've had them on my '15 IS350 AWD for two years and love them. I think they dropped the car more than they claim. Just right for me.

 

maybe i should have kept the rs*r springs and returned the lexus ones rather than doing it the other way around.

 

If you knew who I was or my background, you'd know I know what I'm talking about. Just because you perceive your car as "cornering on rails" doesn't mean you haven't ruined your handling or your bushings. The bushings don't explode overnight, but you'll accelerate wear. Now your RSR downs are the lesser of two evil, I'm quite familiar with the super downs (Hell, I'm familiar with just about everything), but it doesn't mean they're optimal. You start to wade into ridiculous territory with those springs, particularly if you don't completely modify the suspension to compensate for the drastically altered geometery. If you aren't familiar with pre-load or roll-centers, don't ever mention my name again.

 

No, you did the right thing. Anything more than the F-Sport drop (blue springs), and you really risk your stock dampers, bushings, and handling behavior--particularly (for the bushings) if you don't take the proper steps on all rubber to adjust for static height for the extreme stanceboy drop

 

thanks, i needed to hear/read that. the springs are dropping just a smidgeon now that it's been like four or five days since the install. my rears have dropped more than the front, which is concerning.

 

So please enlighten Club Lexus as to who you are and your background. I'd like to think this is a safe environment.
Clearly you don't know who I am or my background either.
And there are many on here that claim to be engineers of some kind...and from the comments they post, it's clear they are great engineers in theory, but not in practical.
And my "corner's on rail" comment was simply to give a visual representation of how the vehicle feels on the road...I could use fancy words like pre-load, roll center, unsprung weight, etc. that not everyone is going to understand completely...and the point of that would be what??
If you have a point to make about the bushings, then at least provide so actual facts that would support it. Anyone can say anything...it would be nice if you explained why so we could all understand.
And if you're a Mechanical Engineer, don't even bother replying to this...we both know that's the easiest engineering degree to get...so don't embarrass yourself.
At the end of the day, I'm not tracking my IS, and I don't think many are...I'm just driving it on the street...and I'm not going to alter the suspension to pull 2 G's on a skid pad just because I install 1 inch lowering springs.

And I think this is one of the few posts where you didn't mention why BMW is better than a Lexus...so thanks for that!

If you'd like to continue this conversation, feel free to PM me before a moderator suggests it.

To the original poster...sorry for hijacking your thread like this man...I have a low tolerance for people coming out of left field with whatever they think might be true just because the wind is blowing in a certain direction that day.
RSR Downs or F Sport springs...they are both great choices for everyday driving.

 

You got pics, my friend?

Interested to see, might go the fsport spring route. Retails for ~$300, I could get my dealer to install for the low.

 

nope, but i guess i could go about taking some.