So I'm looking to upgrade my sway bars. I'm kind of on a budget since I'm in school and spent $5000 this month on mods haha. Anyways, I know the f-sport rear is what I'm getting, but for the front, I researched and it sounds like the front is350 is a larger bar than the 250s. I see them for sale all the time for CHEAP. So if I get a Fsport rear and the is350 front sway bar will that be a decent improvement? My buddy is going to powdercoat them red for me... I hate the color blue

 

The stock sway bars are identical between the 250 and 350.

Likewise the F-sport bar is exactly the same for both cars.

Get both F-sport bars if you are trying to upgrade.

 

As Kurtz just posted the RWD front and rear sways are exactly same for the IS250 and the IS350. There are a few threads about this.

Lou

 

Really? The one thread I found that actually discussed this had said the 350 sway bar was slightly bigger. Must have been a mistake or I misread it. Thanks guys!

 

This is what I read:
https://www.clublexus.com/forums/sus...is250-rwd.html

 

and from threads like that we concluded that either they're different, or Lexus is lying about the stiffness #s on the F-sport bars (because if both stock sets are the same, and both F-sport sets are the same, there can't be a difference in stiffness increase between 250 and 350 like they're suggesting).

Then Lou actually crawled under both cars and measured em. Same size.

 

maybe an is-f rear sway like I did ? it's black. 17mm.
perhaps it's cheaper than the f-sport ?

 

They could be the same size but I wonder with stiffness?! There's nothing in that thread that states they concluded differently.

 

Well I'm getting an Fsport rear for sure. They're cheap. I'm just trying to serif I could save and still improve handling with the 350 front

 

That has aslo been investigated. The PNs are the same. I obtained the PN info first, and when it was challenged I crawled under some IFX50s and made my measurements.

Lou

 

Perfect, that's the info I was looking for. Thanks Lou. Guess I'll just buy the rear and get the Fsport front in the near future.