If you increase the size of a staggered setup, the bigger sway will help with understeer without a doubt. stock, i wouldn't mess with a thing.

 

for reference I read that the stock is 16 and the F sport is 19

 

^^^^But it's not. I've measured them with a caliper and posted the results in various threads here. See my post on the previous page - but I'll post again.

Where did you get your reference?

Lou

 

To add to this, the rear hotchkis is also 19mm. The only bends are on each ends as shown on one end here.

 

Hotchkis made a sway bar for the is250/is350/is f?

Also, will the F-Sport IS250 AWD Front Sway bar (30mm) work on our IS F?

 

I hope they're for the F! I have a set I got from FIGS yet to be installed.

 

With what springs, at what ride height, and with what wheel and tire setup? Without answers to these questions, you could easily do more harm than good.

Suspension, like engine tuning, is getting a bunch of disparate resources to work well TOGETHER. It's a symphony, and if you fail to tune properly, expect nothing more than cacophony.

 

I have anew one in the box in the man cave . I will measure and post tonight.......if Im not busy. Have company from out of town.

 

I installed the F-Sport rear bar on my IS350, and yeah it helped.. but that car had loads of body roll (and still plenty even after the bar). I considered another F-Sport bar on the ISF but the body roll doesn't feel significant enough to warrant the change.

 

measured the F sport sway bar out of the box.

the mounting points are 32" apart, and the widest part of the bar is 34".

 

I am eager to upgrade my ISF front sway bar, @SikkyMFG has been out of stock for a long time with no real real ETA.
I just came across Megan Racing https://meganracing.com/mrs-lx-0391

Anyone put one of these in?
It's 30mm vs Sikky's 28mm and about half the cost.

Any feedback would be great.

 

^^^^Why do you want to change it❓ Have you looked at the chart I posted 10 years ago in post #18❓

Lou

 

yes, of course, love your chart.

I have the same setup as MotoIQ with modified OEM sway bar.
They reported an improvement when upgrading the front bar to Sikky.
Here is the article: https://motoiq.com/sikky-lexus-is-f-swaybars/3/

I upgraded my rear sway bar from modified F-Sport to Sikky and really like the way it feels now in the stiffest setting.





The front needs little help, I can feel it the most, when turning in on long sweeps. I was going to go with Sikky but just discovered Megan offers 30mm unit which the extra thickness would make up for just two adjustable positions.

 

You sure your front springs are stiff enough to start with? I'd make sure there is enough spring before taking away the independence of your suspension with a swaybar. I'd definitely go stiffer spring before stiffer bar no matter what.

 

It may not necessarily be stiffer than Sikky depending on wall thickness.