F-sport rear lower brace on ISF?
09-06-09, 12:22 AM
#16
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But, do you not think the one piece welded design is stiffer.. ??
Wether its installed on IS350 or even an IS-F...
Originally Posted by F-Sport Under Chassis Brace
Increase structural stiffness in the rear suspension mounts under the chassis ahead of the rear wheels with the F-Sport Under Chassis Brace. This helps limit deflection of the rear suspension particularly under cornering loads. It replaces the stamped steel OE brace. The F-Sport Brace is constructed of formed high-strength 19mm diameter x 1.7mm wall steel tubing reinforced with laser cut steel plate that is Tig welded and finished in F-Sport Blue.
Joe Z
Last edited by Joe Z; 09-06-09 at 12:25 AM.
09-06-09, 12:59 AM
#17
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Another thing I just noticed is that the F-Sport Chassis brace is ONLY designed to fit the 2006 to 2008 IS250 & IS350...
Since that part was developed here in the USA where there were NO Underbody Aerodynamic panels in those years..
So basically, this brace will not install correctly on an IS-F or 2009+ ISx50, unless the panels are ditched..
That's also why its no longer listed on Lexus.com accessory page.
On the other hand the TOM's unit was/is built flat with tabs in place to accept the under body panels.
Built to fit ALL IS250, IS350 & IS-F models from 2006 to 2010 (so far)...
Regards,
Joe Z
Since that part was developed here in the USA where there were NO Underbody Aerodynamic panels in those years..
So basically, this brace will not install correctly on an IS-F or 2009+ ISx50, unless the panels are ditched..
That's also why its no longer listed on Lexus.com accessory page.
On the other hand the TOM's unit was/is built flat with tabs in place to accept the under body panels.
Built to fit ALL IS250, IS350 & IS-F models from 2006 to 2010 (so far)...
Regards,
Joe Z
09-06-09, 08:41 AM
#18
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Yeah, but the F-Sport actually does have some triangulation in it. The Tom's piece is no better than stock, it's just heavier. If they ran tubes in an X across the open space it might actually do something, but this brace is just about as worthless as a shock tower bar held together with pivot bolts. See below for how it should have been done. Either of these would have been vastly better than what they did.
Last edited by lobuxracer; 09-06-09 at 09:28 AM.
09-06-09, 08:47 AM
#19
Yeah, but the F-Sport actually does have some triangulation in it. The Tom's piece is no better than stock, it's just heavier. If they ran tubes in an X across the open space it might actually do something, but this brace is just about as worthless as a shock tower bar held together with pivot bolts. See below for how it should have been done. Either of these would have been vastly better than what they did.
As an frame of reference:
Compare a cardboard box's rigidity with the bottom/top open, then compare it closed.
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09-06-09, 02:28 PM
#20
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Yeah, but the F-Sport actually does have some triangulation in it. The Tom's piece is no better than stock, it's just heavier. If they ran tubes in an X across the open space it might actually do something, but this brace is just about as worthless as a shock tower bar held together with pivot bolts. See below for how it should have been done. Either of these would have been vastly better than what they did.
But, the Toms solid 1 piece unit welded in 12 places has to be stiffer than the "flimsy" 2 Oem stamped steel braces and the 1 Oem tubular cross member brace.
Plus, it comes with the stiffer replacement center smaller brace..
Also, available for the F are a few more solid rear braces and the 2 front braces..
I'm NO suspension expert but these parts should be a whole lot stiffer & ridge, when compared to the OEM pieces.
&
Should provide an overall improvement over them as well..
Joe Z
Last edited by Joe Z; 09-06-09 at 02:32 PM.
09-08-09, 10:22 AM
#24
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I'm still not 100% convinced all this bracing is anything more than dead weight. I'd really like to see some quantification, like measured chassis flex. Just because a piece looks bigger and "beefier" than the OEM piece doesn't mean it is necessary or even providing value. Case in point is any shock/strut tower bar using brackets and a beam bolted to the brackets in a pivot design. Those things are really nothing but dead weight because they don't do the thing you want - reduce camber loss on the outside front wheel. They just pivot on the pivot bolt and flex like the hinge they are.
Perfect example of bad:
Perfect example of at least better:
Example of something that might actually do what you want:
It never ceases to amaze me how many people buy stuff like this without really figuring out whether it is needed or not.
09-08-09, 10:44 AM
#25
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I would hope TOM's R&D on the IS-F is legitimate... I would almost bet some of these guys worked on helping develop the IS- F in Japan with Lexus.
While where are on the Topic of Front Shock tower bars....
How do you feel about this one??
- Joe Z
While where are on the Topic of Front Shock tower bars....
How do you feel about this one??
- Joe Z
09-08-09, 11:00 AM
#26
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Case in point - Targa top Supras benefit from a shock tower bar. Hard top Supras do not because the chassis is a whole lot stiffer without the removable panel in the roof. Since the F has a solid roof (for the most part anyway), you're not going to make a SOTP difference.
If the car had struts everything I'm saying would be different, but we don't, so I don't have a lot of concern about front (or rear) flex on the IS chassis with street tires.
09-08-09, 11:18 AM
#27
I got a free brace and wanted to see if I could put it on... for fun. There aren't many budget minded mods available for this car... sucks for a guy that loves to work in the garage.
If it helps, great. If not I'll sell it.
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