Hi everyone, its been a while. I have an 08 IS 250 with Tein s tech springs and Track Wheels, I was wondering what other upgrades i can do for the car to handle and feel more balanced as i drive and take corners. I will be purchasing the F sport Rear Sway bar soon as it seems to be a must do. Besides coilovers, what other parts can i add to stiffen up the ride, handle, feel more stable and solid?

 

Basically the f sport rear sway is all that you will notice. Unless you really push the car you will not feel the difference between any chassis braces. Do the tires you have have a stiff side wall?

 

Best bang for the buck: F-sport rear sway/chassis brace and sticky summer tires

 

Rear sway will be the most noticeable regardless of being a 250/350.
Front sway will be noticeable on a 250 since the oem sway is much smaller than the OEM 350. The oem 350 to the F-sport front sway is a negligible difference as the diameters are very close.
Sways are all you need until you switch the springs to adjustable coils!

 

Obviously sway bars are a given; chassis stiffening (tower bars, under chassis bracing) to me is the very last thing I'd add because they provide you the least return on investment.

Sticky tires are top on the list, even over sway bars; but pricing is definitely > sway bars.

 

Thanks everyone.
XanderES I kept reading reviews on the sways and there has been much confusion about the front sway bar. But it seems like after all these years we have finally come to a conclusion?
Gville350 so to tighten up chassis you recommend Tower bar and under chassis components. What are the names of all those bars under car that could or should be upgraded. Many people say certain bars and brackets dont do anything. What are your thoughts and whats the name of all these individual parts.

 

I had coil overs, F Sport front and rear seat bars, GT Spec upper tower brace, F Sport rear chassis brace, Tuned Parts rigid bars, Jun TW center tunnel brace, GT Spec 4 point lower brace, Tanabe 2 point lower brace. Like all said its the sways that do the most. The rest are minimal but my ride was TIGHT!

 

Thank you for the detailed description of everything you had. i will be using this as a guide and slowly researching and purchasing these parts. Cant wait to have a more stiffer ride

 

When i install the sway bar. Does anyone recommend upgrading the sway bar endlinks for the sway bar to perform better? I am on Tein S tech springs.

 

I think you misunderstood what Gville was trying to say. He said those would be the last things to be done because they cost so much for their small performance increase.
The front sway bar is only a good upgrade for the 250's.

 

XanderES... No i got him. My first purchase will be the F sport sway bar Front and Rear. I just wanted to know the names of all the other parts that could contribute to a more stiffer ride

 

Do you have supporting data which shows the IS250 front sway bar being thinner in diameter than the IS350?

To my knowledge, it was determined via several members from the CL forums that the front sway bar is the exact same size on the IS250/IS350:

 

No problem. According to the old Fsport site which is no longer available the f-sport bars gave different stiffnesses to the 250 and 350.

This mod says that they're different. As well as a bunch of other people in various threads.
https://www.clublexus.com/forums/2ge...our-is250.html

https://www.clublexus.com/forums/sus...-to-is250.html
This thread is the logical argument between the f sport site being wrong and the bars being the same. My brain hurts from trying to find the answer. Im not so sure anymore. Its way too early for this.

 

Yup, I remember the old F-Sport brochure stiffness comparison debate (6% vs 42%) and the "IS350 front sway to IS250" thread from years ago. Some say the part numbers for the IS250/IS350 front sway bar are the some and others say that the stiffness differs between the two cars based on other factors. Years later and I still don't think we have a conclusive answer!

EDIT: I still have the PDF version of the F-Sport brochure with the revised stiffness % for the IS350 (changed from 6% to 42% for the front).

 

Yes i too have read numerous threads and comments spending hours trying to find out what sizes these 250 and 350 have. I have that same chart REDSPENCER. But yet everyone is still in debate of whether or not they are any different. Then they claimed Lexus and Sewell made a typo because the bars are same part number ect. Still confused. Either way im going to end up getting both F and R.