RA40

iTrader: (6)

Of course I realize this is not a race car or even a sports car.

This has been beaten well beyond and yet I find the discussion interesting from different aspects. For many of us it is an appearance issue to have the wheels fit in the fender wells a particular way. We see many cars flushed or beyond in the current trends.

I've set ours up conservatively to achieve reasonable handling as far as this barge goes and tire wear for same. The raked front height affects handling and ours is heavy in the front and especially noticeable in tighter corners. On lighter flowing twisties it is passable and no means a P-car. I've measured tire temps so that I have an idea how the tires will wear when I do drive the car harder.

So I've been wanting to do something about the conservative rear +40 offset. On a recent trip, it was tucking rear tire and I measured out ~13-14mm of tire clearance to the untouched inner fender lip. A 15mm adapter with some shaving would be the simple approach. BUT... My wheels are cut differently so there is no hub recess that allows a bolt on adapter and have wheel studs come through. Because of this open wheel design, I have to resort to a spacer over an adapter. Initially I was going to put in a 12mm spacer and be done.

After flipping through countess threads on spacers, studs, I wasn't liking some potential problems we hear about spacers/adapters. We hear about the handling discussions on track width from front to back and I began reading those. The car in OEM setup understeers and having applied minimal changes to the sway bar bushings, ride height it does not under steer as much. So with spacers, I began reading how the rear track width will change handling. Ugh...it is endless. The least of what I want is to add more understeer to the car. Again, this isn't some big mega HP monster where I'm losing traction and needing more rear tire to compensate.

Then I came across this discussion on Rear/Front track width:
http://www.f1technical.net/forum/vie...php?f=6&t=6311

As much as I want to change the wheel appearance in the fenders, I may just leave it. As minimal as the consequences may be, I'm not a Toyota engineer or knowledgeable about handling to think some of these are as easy as it seems. Could be my age too. Ugh...

My rambings.

PureDrifter

iTrader: (10)

mike if you want to keep the balance relatively neutral (or at least, the same as it is now) you could add spacers front and rear, 10mm all around and not exacerbate the understeer you're already feeling. Being a big heavy FR car, too much front rake will cause pushing on corner entry, and if the springs are a little too hard, push through exit is possible as well.

what's your front/rear fitment and suspension setup mate, it's been a long time and i don't remember any more

xinkid

If you get spacers, make sure you get hubcentric spacers.

lower offset (wider stance) causes that end's wheel rate (rate of the springs experienced by the wheel) to decrease, transfering more grip to that end of the car. Wider wheels at the same offset will not have that effect but that means you have to lug around heavier rotating mass, which may actuallly cause the suspension on that end to work less optimally than before, resulting in less grip.

If you're on coilovers, you can change the track width of the rear and compensate by upping the rear spring rate slightly, like 25lb/in or just try out different rates until you find the balance you like. Note though, too lower an offset puts a lot more load on all suspension parts and cause them to wear out more quickly. I prefer wider and lighter if you're going for very low offsets.

p.s. If you change your rear spring rate exactly right to compensate the loss in wheel rate with lower offset wheels, then your ride characteristics and handling should stay the same except your shocks and other parts will work harder.

RA40

iTrader: (6)

Hee-hee, I forget myself at times since it has been on there so long unchanged.

Wheels 18x8" offset either +40 or 45mm.
Suspension Bilsten HD on Eibach Pro Kit.
Tires 245/40

Camber, F -1.5, rear is -1. Give take a small amount, these are the specs I have it adjusted to. I don't have my file on the toe settings or caster angles.

PureDrifter

iTrader: (10)

lol mike with those offsets you could shove 20mm adapters (h&r or eibach please) on all 4 corners and be fine! or 15mm studs+spacers in the front and 20mm adapters in the rear. (front studs are CAKE, rears not so much...).

your front fenders are rolled right? 8j +20 is equivalent to ~9j +33. the rears should fit without any mods, the fronts may need only a mild roll/shave.

awdandrwd

iTrader: (1)

Interesting to hear yours understeers. I haven't noticed this problem with my '94 on stock springs, we'll see what happens when BCs finally show up.

Stan

PureDrifter

iTrader: (10)

all LS' are setup from factory to understeer to some degree. as are pretty much all non-sports cars made in the past 30-40 years.

awdandrwd

iTrader: (1)

Agreed, most cars are set up for understeer because it's safer and forces you to slow down. I know understeer well, I drove a Subaru for a long time. My LS tracks just fine though, it's amazing how fast I can take corners if driven like on the track (hug the inside then track it out while exiting).

Maybe your tires are too wide? I had a wheel experience running 245/45s on a car once, they plowed more than 225/50s that replaced them. Or, maybe the front is too low and you are bottoming out on the bumpstops -- had that happen too.

Stan

RA40

iTrader: (6)

As conservative as it is, the front rubs on aggressive handling and with peeps in the car, it definitely rubs. Tire contacts the black fender well trim piece. I'm ok with the front offset, the rear bugs me.

If I dropped the rear snap ring to the low position I would gain better balance in handling. However, because I do have people in the rear seat and the trunk loaded, it remains comfortable. Compromises in practicality over aesthetics.

5mm seems so mild, I'm better off leaving it as it is.
10mm, better but I know 12mm is a tad better and still does not require bringing out the grinder.
15mm does fine with a few mm shave off the trim.
20mm yup. But the front would look sunk so 5mm up there.
25mm Hee-hee but I should have had a better wheel fitment if I was aiming for that.

The web page I just read lists the front and rear track of the 95-97 LS 400 at 1574.00 mm. Does that seem right?

PureDrifter

iTrader: (10)

lexus lists the width of the car at 72" so unless there's almost a foot in another dimension i'd say that number was off

awdandrwd

iTrader: (1)

If your fronts have adjustible perches as well, I'd raise them up and see if the car plows less. If it does, you are likely on the bumpstops when cornering and no spacers will fix that. To fix that you could use a fancy polyurithane progressive bumpstop -- I ran some on a Miata. Not enough front travel = plowing, even without getting into geometry issues.

Stan

awdandrwd

iTrader: (1)

Have a look here regarding my bumpstop comments. Shaikh at http://fatcatmotorsports.com/ knows what's up and I've spoken about these things to him in person. It isn't LS-specific but same principles apply.

Stan

RA40

iTrader: (6)

Interesting site, thanks. Let me chew on all the info there.

Mugen_1

Been looking at spacers myself; 20mm for rears and 15mm for front. The thing I'm coming across, though, is several have shown they're for a specific center bore size. What's the center bore size of the UCF20?

Edit: Nevermind, it looks like it's 60.1

skperformance

iTrader: (6)

Just to throw some numbers and ideas.
I am running 1 25mm (1 ") spacer on top of my 15mm H&R extended studs and spacers up front .Total 40mm ...
On my rear is it just the 25mm 1" spacer which replaced my project Kics .
I have had the 15mm up front for 7 years and rears 4 years and they have been fine even in NY city roads.