MCL

Is anybody running 8" wide wheels on the back on their SC. I really don't want to go with to different sizes because I still want to be able to rotate my wheels because I put a lot of miles on my SC. The wheels that I want only come in 8's, and I know that would be fine on the front but how bad will it sit in the fender on the rear (I don't want to run spacers). If anybody has any pictures could you please post them. Thanks for any help.

MCL

London Bill

MCL;

It depends on what offset the new 8" wheels have, if they are stock +50mm offset they tend to sit well inside the arch, +35mm will bring them out a bit. See my site (below) on suspension/steering about wheel offsets and handling/ride issues.

Lex Luthor

Bill, I wouldn't recommend that much change in offset. A +38 will basically set the wheel flush with the fender, but you'll start to have some changes in the way the car tracks, a +35 will be even worse, I wouldn't dip below the 40's, SC300T can confirm this for you. By the way MCL, an SC3 has 6.5" wide wheels and an SC4 has 7" side wheels, so you'll still be wider than oe, but these cars look much better with staggered rolling stock.
- Jon

SoCalSC4

I dunno, guys- I put 19x9 +37 and 19x10 +37 on my brother's '94 GS3 and found NO adverse steering/tracking effects whatsoever.

I make similar offset changes on Porsche Turbos, Ferrari F360s, Vipers, etc. all day long, and have NEVER had a complaint. I've driven many of these cars myself (stock and modified), and they work great... What tires are you running? Over/under inflated? Bad suspension bushings? Alignment? What's going on? Scrub Radius can be an issue, but generally (on street driven cars anyway) these changes don't create problems.

howiedoit

iTrader: (9)

i've got 18x8 +37 and 18x9 +38, and no complaints from me...

MCL

Thanks for all the help guys.

MCL

London Bill

Lex Luther;

I am not advocating the use of +35mm Offset wheels, indeed far from it, had anyone as I advised, checked the article on SoarerTT about Offset's they would get the following advice;

"Wheels & Offsets:

The Soarer is specified with +50mm (positive) Offset front & rear with standard sized rims (15"x7" / 16" x 8"). It is difficult to obtain these offsets from the European after market wheel manufacturers and many will say that using +40mm 0r +35mm will fit and make no difference to the steering - they are lying.

The front track is affected by fitting wheels with less offset, for example if you fit wheels with +35mm offset you are adding 30mm to the front track width (15mm per side), this has a big effect on the front steering geometry as it alters the Scrub Radius. This effects the steering "feedback" making the steering wheel more lively as any forces applied to the road wheel are exaggerated by the increased offset, this can make the steering feel less stable and more prone to "tramlining" (the tendency for the front wheels to follow any undulations in road surface, straight line braking can also be affected causing the car to "pull", the greater the difference from standard the more this will effect the handling.

Some may prefer the more positive feedback and quicker "turn-in" that the wider track will provide when using less wheel offset, generally you should keep as near as possible to the +50mm Offset on the front wheels to retain the inherent good handling characteristics of the Soarer."

London Bill

SoCalSC4;

please see above post, I have TSW Hockenhein rims with +35mm Offset all round, now I cannot accurately assess the effect this has on my steering as it also has Bilstein gas struts and lowered springs fitted so it is far from stock, but I do have excessive steering kickback, tramlining and it "pulls" or "wanders" under low speed braking. Using Pirellis or Dunlops made little difference, the tyre pressures used are 34PSI F&R but we experimented from 30/36PSI on the fronts.

This could be an accumulative effect of the suspension mods but one of the LSOC members (Mongoose) had similar steering issues which he chased for months before finding out that he was following "none standard" geometry settings, part of his rectification procedure was to put the whole thing back to standard, both geometry settings & factory rims.

Happy with regaining the stock ride as the steering was/is absolutely perfect he re-fitted his TSW rims with +35mm offset, there was a noticable difference in the handling characteristics not as pronounced as when it was running with excessive front camber, Mongoose spent six long months getting this right and tried many variations, the conclusion is that on a stock SC stick with the factory geometry settings and as close to possible the +50mm Offset specificaly on the front axle, the rears are far more tollerant to changes in the offset.

I believe that the SC steering/suspension was designed to perfection for a luxury tourer (not for a sports car), this set-up is hard to better without spoiling one or more aspect of the stock ride/handling (there seems to be a fair number of people here who are now unhappy with the ride after making suspension mods). While some drivers (me included), will prefer the more responsive steering & greater feedback from the increased scrub radius or wider track, at the same time we are less critical or more tolerant about the downside, if you want to throw a car around road bends at high G's then my set-up is perfect, at typical motorway speeds of 75/85mph it is a real b1tch, hard to keep online, needs constant little corrections and gets very tiring.

DIrEctQL

I have 9.5" wide rims that sit very well in the rear. Now, let's discuss rotating tires. Fact or fiction? It will keep you away from a tire store for a while, but still, it doesn't help you make the tires last. Keep in mind, when you replace roated tires, you replace all of them. When you replace tires, you replace either rear tires or the front tires.

London Bill

There is a good reason to rotate the tyres on your stock, every day POS car, you will even out any side/side or front/rear tyre wear pattern, in theory they will all wearout on the same day and you can replace all four at the local tyre store for cheapo money.

Now consider your Soarer or SC, if you are at all concerned about handling this 150+mph car you will fit decent tyres, most of these are rotational (only designed to go round in one direction) so Rotating the wheels is not possible in the normal manner.

Each tyre will wear to the front or rear geometry, swapping them front/rear (same side) would not be recommended as the tyres will now be "set" and you will actually degrade the handling.

If you have performance tyres like SO3's would you really want to replace all four on the same day (that's a lot of money in the UK, about £1100 GBP).

It is quite normal to fit wider rims/tyres on the rear, more rubber on the road, more grip, less wheelspin & looks ******* brilliant.

Lex Luthor

Bill, I agree with every single word of that, i've also seen the difference the altered track width makes to the SC, you described the condition exactly, but i've met plenty of guys who swear they've done it to a Ferrari, Porsche, whatever and it's fine, they can keep making that mistake, but the math doesn't lie, no need to prove this, anyone with a basic understanding of geometry will agree. For the record, I just had my SC aligned by Champion, they do Ferrari, Lambo, Porsche, Aston, Bentley turbo all day long, we discussed this scenario re: wheel offsets and they completely agree. But hey, if you guys wanna find out by trial and error, go nuts....
- Jon

SCV8

17x8,9.5/245/45,265/40;works great for me,with Stock Supra TT springs/shocks that is,the stock stuff would allow the car to wallow around all over the place,not helping the tramlining situation at all even with the stock wheels/tires.
Overall it's WAY better now,balanced mods are the only way to go.

London Bill

I originally thought that all Supra suspension kit would be applicable to the Soarer/SC, I am informed (reliably, perhaps) that the different spring rates and kerb weights make the Supra springs unsuitable for use on the SC without ruining the ride quality. Coilovers - most types have single rate springs (not progressive rate like the standard springs), this will really affect the ride.

Drive a Supra and compare the ride quality with a standard SC, they are like chalk & cheese, yes the SC needs some help in this department but just bolting on Supra kit is detracting from why most of us bought into Lexus in the first place, any modifications from the standard spec need to be thought out carefully. I can testify to this as my suspension mods have turned the ride into a bag of sh1te, when I can obtain lowered springs that retain some of the Lexus ride quality I will swap-out my Bilstein struts.

If you are going to have rock hard, crashing, noisy suspension, you have to ask yourself why didnt I just buy a Supra in the first place!

SC300T

Just get a turbo... Then you can wear the rears as quickly as the fronts! :eek:

SoCalSC4

Lex: So, the Techs at Champion are Mechanical Engineers? Wow!

Perhaps I prefer a car with "lively" steering feel, but I've driven hundreds of cars equipped with wheels made by the company I work for: I have never felt that any of the cars were darty or unstable. This includes F360, F550, F355, Viper, Diablo, Aston Martin Vantage, Porsche 996TT, Corvette C5 (we change the offset on these SIGNIFICANTLY) etc.

Perhaps this is because our wheels are very light. If you've experienced this with a heavier cast wheel, the effect will surely be exaggerated- as speed builds, so does rotational inertia. With a heavy wheel, the effect will grow according to speed. Ever try it with a lightweight performance wheel? I'd be interested to do an instrumented and subjective comparison with one test car and several different wheel set-ups (diameter, offset, tire type).

For all of the 'doubters,' please stay stock... I really don't give a ***** !