Just thought you would all like to know a quick and really effective upgrade to your IS-F, is to replace the stock IS-F rear sway bar, with the F-Sport rear sway bar (PN: PTR02-53080), which was designed for the 250/350. The F-Sport bar is a 19mm bar, versus, the stock IS-F bar is a 16mm bar. The improvement is very noticeable. Cheers!

Sweet info
What is the change vs normal?
Will it make long drives unbearable?

The change has absolutely no impact on ride quality - its purely a handling enhancement, removing some of that push (understeer) and make it a little more neutral. And its a straight R&R install - takes no more than 15-20 minutes. I strongly recommend.

any pics of the setup? Also I assume you bought the whole F Sport set for the RWD IS cars right?

The F-Sport guys have set up 2 part numbers: 1) For the AWD rear bar, and 2) RWD kit (includes a front and rear bar). The AWD rear bar is the same bar in the RWD kit. I got the pics from the installation instructions that were included in the kit. Its a piece of cake and works awesome.

16mm sway bars on an ISF?????? Are you serious. I had 36mm front and 24mm rear( nismo sway bars) on a G35. They definetly need to widen that. I am amazed at how small that seems .Im sure the car handles, but it still seems narrow to me. A G35 doesnt handle better or flatter than an ISF for gods sake. I guess they make for it with really high spring rates

Is it even worth the 3mm if some aftermarket company is going to come out with something more substantial???

Anybody know if this part is in the making???

Yes, its worth it. And its not all about just going bigger....it's about finding the right size, with the right rates. The F-Sport parts are available now. Just picked mine up from Longo Lexus.

Thanks for the tip. I just ordered one.

Are any of the other F-Sport parts like springs or shocks better than the stock IS F ones? Or just the same?

Actually I heard from Sewell Lexus that the AWD rear bar and the RWD rear bar are not the same.

Can you guys who have ordered give us some more feedback when the time comes? Always looking to take a plunge on new things, but I'd like to hear more.

They are 100% the same identical bar. The F-Sport guys didn't want the AWD owners to waste their money on a front bar they wouldn't need, so they just created an individual part number for that rear bar (stand alone).

Glad I could help. Everything else on the F is solid...the rear bar is really the only upgrade. The F-Sport parts are awesome for the 250/350's.

how much are the rear sway bars? Nilepimp any difference in handling?

The bar retails for $225. And yes, it makes a difference in handling. Brings the vehicle more towards neutral and gets rid of some of that "push" (understeer) that is in the F.