ancdmd

If the stock wheels have an offset of 43mm, then that (34mm) is a variance of 9mm, or almost a full centimeter. While this may not seem like much, Lexuses (and most cars today) are finely tuned automobiles with tight tolerances and precision-designed suspension geometries where the wheel specs (which includes the offset) are an integral part of the entire suspension system. The LS430 is incredibly smooth because of the design of the entire suspension system; slightly altering the geometry of certain suspension components (including the wheels) can make a drastic difference, even if its only a "minimal" change.

I wish it didn't make that big of a difference, then the options for custom wheels would be huge (as they often appear to the uninformed wheel shopper); as long as the wheels look good, don't rub anywhere and bolt right on, then they would "fit". Just isn't like that though.

D2-AUTOSPORT

That is not what he said

So with that small of a variance that would not be cause of the kickback, I have personally done setups more aggressive than that and had no kickback issues. As I said before the offset on alot of these wheels is not the problem, its the other specs and the use of spacers and such that cause kickback. Also the stock offset and the offset of a aftermarket are not directly comparable since the wheels are not the same width

ancdmd

He said he had kickback with the +34's, and none noticeable with the +38's. The +38's are 5mm different than stock, the +34's are 9mm different than stock. The difference between 5mm and 9mm is an 80% jump, which can make a noticeable difference. I'd be inclined to say that there's a window of around 5mm from stock offset before you can start to perceive kickback in the steering wheel. Also, I know his experience fairly well, because he is my brother.

What other "specs" cause kickback? Sure, spacers can cause kickback, because they effectively change the offset. He had 3mm spacers on those +34's for a day when he first got them, and the kickback was horrendous. Removal of the spacers made it better, but it was still noticeable. Jumping up to the +38's decreased it to a tolerable and nearly imperceptable level. He even had some suspension components wear out in the front due to the those +34 wheels, although I can't remember which components they were, I'm sure he'll chime in with the details.

Vibration can be caused by a lack of hub-centric rings or simple out-of-balance of the wheel/tire combo. Either of these traits would cause a sensation in the steering wheel, but it would be a vibration sensation and not a kickback sensation.

I beg to differ about the width of wheels. Increasing the width has no effect on the kickback, since the extra drag force expressed by the width increase is distrubuted evenly on both sides of the wheel. Changing from a 7.5" width to a 9.5" will add 1 inch width to both sides of the wheel. Assuming the offset stays the same, there will be no increase in kickback to the steering. It comes down to a matter of simple physics.

D2-AUTOSPORT

Ok, you missed my point again, but its ok. Carry on with your discussion gentlemen and have a good one!

pvo

iTrader: (2)

Thanks for explanations guys.

I'm running +35 in front and don't have any "steering kickback" but my wheels are only 19 inch though.

jpcdmd

Scrub radius is the distance from the point where the steering axis meets the ground, to the center of the contact patch of the tire. Zero scrub radius is desirable. Increasing the scrub radius will result in more kickback through the steering wheel when you hit bumps and increased steering effort.

Offset has nothing to do with wheel width, only if we're trying to achieve optimal cosmetics by making the wheel "flush" with the fender.

Changing the width of the wheel, but keeping the offset the same, has no effect on scrub radius. Changing the offset to accomodate for a wheel that is too wide to fit in the space provided in the wheel well WILL change the scrub radius, and affect the steering feel. The steering will feel heavier the more the offset number is lowered.

Those hoopty lowered Sentras and Crown Vics with the 13" gold Dayton wires sticking way outside the fender - you can bet those drivers have a death grip on the steering wheel and go through a new set of suspension bushings every week.

this explains it all:

http://dsm.aenewton.com/wheel_offset.htm


I just simply wanted to know of other LS430 owners' experiences with how noticeable the steering change was with aftermarket wheels of varying offsets.

jpcdmd

here's another good explanation of scrub radius and how it affects steering, from a Fiero forum:

http://www.realfierotech.com/phpBB/viewtopic.php?t=82

mikepae

iTrader: (1)

nope, none.

ancdmd

OK I've relegated myself to going with the MRR HR2 or the EXE Konvex wheels, and accepting whatever happens as far as changes in steering feel. Now I'm just having trouble deciding which wheels to go with, they both look so good!

devonrh

How did you manually adjust air suspension without datasystems?

mikepae

iTrader: (1)

with a 10mm wrench on my hands and knees. searchhhhh... there should be a thread about it on here somewhere