lobuxracer

iTrader: (2)

The Supra has adjustable everything. The F only has toe on both ends as FIGS posted above. This was one of my biggest disappointments with the 2IS.

rhy

iTrader: (2)

Thanks for the useful information! However, after reading up on suspension adjustments tonight, I'm slightly confused.

The PDF printout from Gran Turismo (https://www.clublexus.com/forums/5601996-post13.html) shows total toe as follows:

** Before:
front: -0.14in (toe out)
rear: -0.11in (toe out)

** After:
front: 0.07in (toe in)
rear: 0.15in (toe in)

But then, several posts throughout this thread mention going from 1/8" toe out to 1/16" toe out. Shouldn't this be 1/16" toe in? Or am I just reading this wrong?

lobuxracer

iTrader: (2)

The front is not toed in. It's still toed out. Rear is always toed in to help the car turn - even live axle rear ends get cut and welded for a small amount of toe in.

From the looks of things, the inside edges will still wear out faster than the rest of the front tires. I've got about 16k on it so far and it would seem zero front toe is the only hope for even tread wear on the front.

The rear was all jacked up when they put it on the rack - it was toed out for sure on the right rear.

rhy

iTrader: (2)

Interesting... the reason for bringing this up is that the PDF shows a positive number for front toe (after adjustment). Wouldn't that be toe-in?

According to the document, front toe went from negative 0.14in (-3.556mm) to positive 0.07in (1.778mm). This makes sense for tire wear on a RWD car. The general recommendation seems to be to run about 1/16" of positive toe-in at the front of a RWD car to minimize tire wear.

Here's an explanation by TireRack:

"A rear-wheel drive vehicle "pushes" the front axle's tires as they roll along the road. Tire rolling resistance causes a little drag resulting in rearward movement of the suspension arms against their bushings. Because of this, most rear-wheel drive vehicles use some positive toe-in to compensate for the movement, enabling the tires to run parallel to each other at speed."

I'm not trying to be stubborn, but would like to understand this better My car has ~1,600 miles and I scheduled an alignment based on information on these forums. The dealer said, "Bring a printout of your desired settings and we'll do it".


Wouldn't that be zero front toe while the car is at speed? Which would mean some positive toe-in while the car is standing still due to suspension play?

*If* Gran Turismo's printout is correct and the front of your car is set for a slight toe-in and there's still inner tire wear, common sense tells me that the suspension compensates more than the current toe-in setting while the car is in motion. So, in order to minimize inner tire wear, it will need a bit more toe-in.

This is assuming that the "Actual" value means "current, after adjustment".


I agree, the right rear is showing negative 0.14in (-3.556mm) of toe-out before the adjustment. But let's focus on total toe.

Your car originally had negative 0.11in (-2.794mm) of toe-out at the rear. That would increase oversteer and make the car twitchy under power.

The shop seems to have corrected rear toe to positive 0.15in (3.81mm). That would reduce oversteer but in my mind, it should cause outside wear of the rear tires. Is that happening?

Again, thanks for any insight on this!

lobuxracer

iTrader: (2)

The Tire Rack would be right if the steering rack were mounted behind the ball joint. It isn't. It's in front, so dynamically, it toes in, not out. There is no "consensus" for what works best. There are ranges of what we know usually works. Toe out in the front helps the car turn. It also wears the inside edges more rapidly as the amount of toe out increases. Your particular driving has more to do with tire wear than anything. Keep in mind, toe is not static, it changes with ride height on each corner (usually called bump steer) and it changes when you apply the brakes and compress the entire front end. If the suspension designer did a good job, the car handles well under these conditions. If the designer did not, the car does not handle well.


Yeah, and I'm not at all confident the number on there is what it is currently running. Even if it corrected the wear issues, I'd still run it where it is because the car still handles well. More toe in will make it even harder to combat the inherent understeer designed into the suspension by Lexus.




No, toe in at the rear is the same as toe in at the front - guaranteed inside edge wear. My Supra ate a set of tires in 6k miles with Toyota's standard 3mm of toe in. When set to 1mm, I had perfectly even wear across the rear tires and got 33k out of the set of Bridgestone S-02s that replaced the short lived Dunlops.

Having one wheel off spec in the rear means the car didn't like left hand turns as well as it liked right hand turns. You can't "focus on total toe" without considering the impact of the individual wheel settings. The car drove very nicely at Carolina Motorsports Park where the majority of the turns are right hand, and the fastest, most important turns are definitely right hand. I've not had it back with the new settings, but I'm pretty sure I'll like it better under heavy braking - this is the one thing I don't particularly like about the F - the rear end wanders under heavy braking. I suspect part of it was a result of the toed out right rear, but some of it is just unavoidable because it's a heavy car.

Honestly, I think you'd be way ahead to take the car to someone who knows what they're doing and have it aligned for your locale and your driving style. This study is a single car and one set of tires. A skilled person should be able to get your car set up right for where you live and drive. This is why I don't mind paying $100 for an alignment knowing all they can adjust is toe. I'll get something likely to work and I'll have the ability to come back and discuss what I liked and didn't like about it with the person doing the alignments. Until I have my own set of alignment tools, I'm pretty stuck depending on others anyway and it would seem you're in a similar situation.

rhy

iTrader: (2)

I took the car in for an alignment yesterday and brought a printout for reference. After having a chat with the service techs, we decided to go with zero toe at the front.

It turns out that the car had quite a bit of toe-in (more than double the spec). No wonder I was starting to see outside tire wear at 1,500 miles. With zero toe at the front, all I can say is WOW! Huge difference. The car feels a lot more lively now, steering is lighter, cornering feels effortless compared to before. And that's just street driving, I can only imagine the difference this will make on the track

The rear has a bit of toe-in but it's well within spec. Time to put some miles and watch for unusual tire wear. Thanks for all the helpful information! Here is my alignment printout.

Bulls23337

iTrader: (2)

Here's my alignment. Took mine in to the dealer and brought Lance's printout. Got it somewhat similar to his. Biggest change for me was rear toe. The PS2s lasted ~15k miles. They were worn on the inside edges to the cord and bald the rest of the tire. The front tires were fine. We'll see how these Hankook Ventus V12s wear with this new alignment setup.

lobuxracer

iTrader: (2)

Time for another update. Track weekend at CMP used up a lot of tire. More than I had hoped for sure. New tires in front are now in order, and more toe in is also in order. I'm going to adjust both sides 1/4 turn in for more toe. No need for any pennies in this photo session. Also note the outside shoulder blocks are pretty well cooked too. This car is very heavy and these narrow tires suffer heavily at speed.

I really need to model the suspension so I can see what it is doing on compression. I think this is the real next step.

Right front shot from front


Right front shot from front close up


Left front shot from rear


Left front shot from rear - cording

spekterg35

Thanks for the info. Are you going with the same tires?

ES3

Noticing inside wear again on my Michelins, which have just about 9k miles of regular driving on them in less than a year's time. Lexus again, says common with this kind of car. Definitely need a non Lexus alignment.

JKweezy

Hey Bulls, looking at your spec sheet, it seems like your front right wheel is toed out, out of the specified range... was this on purpose? it was within range before alignment...

JKweezy

sorry i don't know if this was discussed but lobux's specified range for toe from Gran Turismo is not the specified range found in rhy's and Bulls spec sheet, which are the same...

ERDoc74

After reading this thread, I went to a local auto shop reccomended to me (for having great alignment skills) by a high end aftermarket wheel/etc. store close to me in KC so I could make my front toe be zero to avoid premature tire wear. I looks like my before was pretty close but now it's dead on. But now I'm concerned that my Front Left caster is quite a bit out of spec. Is this something that I should worry about and have the dealership fix by installing available "No 2 arm brackets" that can ajust the caster 0.33 degrees in the correct direction?
Also, I see that my rear camber is barely out of spec but at least equally so... Is this something I should worry about? From reading a thread on another forum, I think I read that camber is not able to be adjusted independently, but can only be adjusted to make the camber numbers equal from side to side by loosening a "cradle"???

lobuxracer

iTrader: (2)

I'd leave the caster alone. Not worth the hassle unless it pulls while trying to go straight.

Evil Teo

iTrader: (13)

since u mention more toe in how much would you set yours to?