Wheel Alignments, Why the inner treads vanish...

See also the post here-

http://forum.altezzaclub.org.au/index.php?...topic=2244&st=0

and learn about the important parts of a wheel alignment here-

http://www.familycar.com/alignment.htm#Cam

and Sydney alignments here-

http://z4.invisionfree.com/lexusaltezzaclu...6940&st=0&#last




factory wheel Alignment specs- On 32psi tyre pressures-

Rear Axle:

Camber -0deg 55min +/- 45min
toe in +0deg 11min +/- 11min

Front Axle:

Camber -0deg 30min +/- 45min
Castor +6deg 5min +/- 45min
toe in +0deg 5min +/- 5min

A common problem on Lexus Altezzas is the scrubbing out of the front tyres. This shows as typical toe-out wear, the inner part of the tyre bald and the outer half OK. Not liable to be noticed unless you look at a tyre when the wheels are on full lock. There are a lot of posts about it in the UK Club, where everyone drives a Lexus.

The 3SGE 4cyl has a lighter engine and less weight on the front tyres. The springs are stiffer also, and I think these factors make it less a problem on the RS200s.

When you get an alignment done, watch the servicemen as they set up the front wheels. There is a range of movement allowed for each measurement, and they can take the easy way out and say "its just within the range, I won't adjust it..." However you need to make them adjust the toe in to the maximum "in" allowable, to minimise the toe out scrubbing.

What will happen to your tyres is graphically illustrated here-

http://z4.invisionfree.com/lexusaltezzaclu...&#entry11305223

Thanks Robo!

Camber is also a problem area. At the rear it is adjusted by a cam bolt at the outer end of the lower arm. The cam part is just a washer with a flat side in its inner hole, and this sits on a bolt with a flat side ground along its length. When you loosen the nut and turn the bolt head, it is meant to turn the washer and push the rear wheel in or out, altering the camber.

However, they seize up after a few years, and get hard to move. More importantly, adjusting camber one way lets the car lower itself, so the weight helps. But adjusting camber the other way means that little washer must raise the car against its own weight. The result often is that the bolt rips the guts out of the washer and you never have adjustable camber again!

So before you take the car in for an alignment, loosen the adjusting nut off a little (half a turn) and spray CRC or WD40 into it on both sides. This will help them turn.

Then once again get under the car with the servicemen & watch them do it. They may have to lift the car with a jack (even tho' it is on the hoist) to allow them to change the camber.

I like plenty of camber on the front wheels (to give plenty of bite into a corner) and not so much on the rear. This means running at opposite ends of the allowable factory limits.

With lowered cars this gets even more important, but you will have to wait for our trip to a suspension shop to learn how!!

This arrowed nut is the camber changer at the rear-

Turning it so the bolt is "inwards" will be towards positive camber, and turning it so the bolt is further "outwards" will be more negative camber. Mine is about midway in this photo.



Attached Image

Hi Keith:
Thanks for ur info. I remember you have posted some info in the old website.
My IS 200 has clocked 40,000KM not long ago. and ~ 10,000km since I had the Eibach springs and 4 wheel alignment done.
I am going to have another 4 wheel alignment soon.

Could you let me the figures of your recommanded setting?
e.g. front toe-in (degree), rear camber.....
Can I just tell them what degree I want and get them to align accordingly??

I got the print out report from last time, Will that help?

Thanks
SSML

OK, I've PM'd them to you.

Could you post the figures you have from the last wheel alignment, the 'before' ones when you take it in, and the 'after' figures when they're finished?

That will give us all an idea what has been done, and let us know if you can feel any difference.

ta

keith

Thanks Keith:
Followings are the figures from my last alignment performed 06-Dec-03.
N.B. figure in ( ) = before alignemnt reading
Setback:+0.09 (+0.21)
Front L Toe=+2.5mm(-0.10);Total Toe=+4.70mm(-4.30);Front R Toe=+2.10mm(-4.20mm)
FL Camber=-1.11(-1.14); Cross camber=+0.04; FR Camber=-1.06(-1.01)
FL Caster=+5.33(+5.38);Cross Caster=+0.26; FR Caster=+5.59(+5.90)

S.A.I Left=+14(+14); S.A.I. Right=+12.8(+12.8)

Included Angle Left= +12.9(+12.8); Included Angle Right= +11.7(+11.7)

Toe Out On Turns Left: +17.1(+17.1) ; Right: +17.3(+17.3)

Thrust Angle: -0.00(+0.26) Right??

Rear L toe=+2.50mm(+0.70); Total toe=+5mm(-5);Rear R toe=+2.5mm(-5.7)
RL Camber= -0.67(-0.66); Cross camber=+0.40; RR camber=-1.07(-1.18)

the alignment was done about 2 wks after Eibach springs installed.
The system they used was: 4500 Computer Alignment system.
some of the numbers I dont quite understand what they are for.....e.g. SAI,Included angle, Toe out on turns, thrust Angle.. Also why there is no figure for Rear Caster?

My tyres wear quite evenly, I havnt noticed any inner shoulder rubbing or any particular uneven wears..
I did a lot of highway driving for the first ~35,000km. now, it's ~41,000km.
Eibach springs installed @~31,000KM.

What do think of the figures fro last time, Keith?
SSML

The 'before' figures are really bad, so they must be the result of lowering the car. You can see why you need a wheel align after installing different suspension.-

SAI is steering aixs inclination or similar, I haven't looked it up in years. How much the steering axis (used to be kingpins) slope away from the vertical. You don't have that or castor (or toeout on turns) for the rear because they only apply to wheels that steer.

I don't know what the thrust or included angles are. Someone will come along here who can tell us.

Plenty of camber & castor on the front for turning into corners & good toe in. I'd stick with those reading for the front.

The rear could do with having the camber evened up between the two wheels. That means adjusting the one cam washer that always gives trouble!!

If the readings have stayed the same I don't think you can improve them enough to feel a difference. You'll just have to go down to Sydney for the track school in summer to try them out against the boys down there!!:lol:

thanks

keith

ssml.. please bear in mind that you need to also consider your current tread wear when you readjust your camber/toe. in some cases it is not worth it until you have a new set of tread. its abit hard to explain it by typing out coz there are alot of hand movements/gestures needed when describing what happens

thunderbird2 can confirm this.

Indeed!

I have had a good lesson in suspension in the last few weeks.

Firstly, my current setup is woeful! The lowering Bilstein springs are okay, considering what you pay for, however for proper 'touge style' driving, they CANNOT handle mid corner bumps. Essentially, you can feel the stock shocks are not matched with the springs, and hence the suspension jars and thumps as it comes on to it's stops.
To make matters worse, the installer took it open himself to crank the rear camber on my car beyond -2, AND without adjusting the front! This means the car shifts from side to side in the rear when going over undulations. Not to mention, as my new tuner of choice kindly showed me, the camber is slightly uneven on each side

tsk tsk tsk

THEN - today, I had a run in Andrew's MX5 - a mate of mine who has an awesome MX5 that i am permitted to drive quite frequently. It's been a while between drives, and i had a run in it today - it has been fully adjusted, toe and camber front and rear, to a specific setup. I was lost for superlatives really, had he not told me, i would have been convinced that he had new suspension hardware. Not ONLY was the turn in quicker, and the rear more stable, but the actual steering rack was tighter and sharper and quicker as well?!?!

LESSON: a good suspension set up needs good adjustment, not just good hardware!!

And, despite my current setup, the IS managed to keep up with some far superior car's today, including Andrew's MX5. He had me in the uphill, really tight 1st/2nd gear sections, but otherwise Thunderbird2 managed to hold her own! Damn, if these car's don't have a brilliant chassis or what?!?

Ah! MX5! I think I'll buy one as a fun car!

What figures are you running Matt?? and when do the stiff shocks go in?

I don't have any figures for my current setup - basically, it is stock apart from the silly rear camber, which we measured the other day at -2.6 and -2.3, from memory. The guy used one of those triangluar ones with the digital readout that you place agains the tire to get a reading, so it was not totally accurate?!?

ive done settings for toe in 5mm, 2mm and toe out 2mm, 0mm with various castor and camber sets.. if there is any much interest i will post it out.. as there is a bit of info to type

Bring it!

IS200 is approx 20mm lower front and rear with Eibachs and Koni Yellows (1 turn out F&R) all round.

Alignment specs:

Front
Camber L-1.25 neg R-1.23 neg
Castor L-6.28 R-6.00
Toe-In L-1.8mm R-1.8mm Total 3.6mm

Rear
Camber L-0.1 neg R-0.1 neg
Toe-In L-1.7mm R-1.7mm Total 3.4mm

Turn in and lateral mechanical grip is fantastic. Extremely well balanced. Excellent ride quality.

Noticeable rear bump steer on constant radius corners. Anyone know how to dial this out?

everything kept equal.. see what differences you get when you pull toe out 1mm and 2mm.

Is there any negative effect from altering this standard toe-out to maximum toe-in? I'm guessing it will affect turn-in in some way ...

I assume it lowers turn-in slightly, but whether or not you will feel it is something else.

Either way, you will have to watch the front tyres for wear patterns.

Outside edges feathered inwards, too much toe-in. (or too much track racing!!)

Inside edges feathered outwards, too much toe-out.

I went through a set of rear tyres in 4000kms of 'nice' motorway driving.

When i stand at the side of my car it looks like the rear tyres are not pointing straight ahead bit toed-in quite significantly. I was thinking that this has had the effect of scrubbing the tread off the the middle of the tyres, there is still plenty of tread at the outside edge of the tyre.
The car had an alignment the day after i picked it up so im thinking they may have adjusted something too far??

Im running 17s with TRD Sportivo suspension setup (20mm lower than factory) wouldnt make a huge difference i would have thought, but i know nothing about suspension/alignment.
All i do know is that i want more than 4000kms out of my next set of tyres!

On a positive note, my front tyres wear perfectly evenly and seem to have only lost about 1mm of tread in the time ive had the car.

Any ideas?

Get a wheel alignment, and post the settings that you have. If your inner tread is vanishing, the usual culprits are camber and toe out, or both. I've been playing around various toe and camber settings and I've settled on what I 'think' is a good balance for road driving with occasional track sprints.

Yeah, get a wheel alignment reading and take a photo of the treads, then post them up here.

We will slowly build a good database of what works and what doesn't.

Where abouts are you Nate?

Which way were the treads scuffed? If you ran your hand a across the tyre, were they feathered edges going in (toe-in) or coming out (toe-out)??

You can usually feel which way the treads are feathered when you rub your hand across the tyre. They "grip" your skin going against the feathering.

Not my alignment, but one of my brother's colleagues. Done somewhere in Tauranga with the primary aim of maximising tyre life.

Attached Image

My alignment, checked by the clowns at Beaurepaires after they fitted some new Direzzas...

Curren WTF???

What does an Altezza have in common with a front wheel drive piece of crap like a Curren??

Anyway, I hope you didn't have to pay for that Jase! You don't need toe-out on the front and you could do with more negative camber on the front too!

Why is all the toe-in on one side at the rear??

Dunno what the curren thing is, as you see it was on both those alignments, I forget where the first one is from, but it wasn't Beaurepaires...

Yeah, you look at those numbers and the alignment is clearly a token gesture. I imagine some people are simply overwhelmed by all the numbers and assume they're set correctly. I've got a voucher out of them for another alignment, so I'll try another Beaurepaires store (not Whakatane) and give them specific instructions on what I want.

Got some notes from Tony at wheels-inmotion.co.uk too (LOCUK geometry guru), so I'll see if I can digest those and get someone to follow them.

OK as we all know, the camber and toe on our cars is adjustable. I've been trying some different values to find a good balance, and here's what it's come to.

C=Caster (deg), FC = Front camber (deg), FT = front toe (mm), RC = rear camber (deg), RT = rear toe (mm), PI = Phillip Island circuit, WT = Winton Circuit

Factory recommended: C ~5.77, FC -0.35, RC -0.35, FT 0.4, RT 0.8

PI - C ~ 6.62, FC -1.29, RC -1.56, FT 0.6, RT 0.8 - Understeering, but not a bad balance, front tyres wearing nicely. (Mod + Lowered / Strut brace) - Increased camber and toe for WT
WT - C ~ 6.24, FC -1.88, RC -2.3, FT 0.7, RT 0.6 - Lots of understeer, more due to track layout and dead front tyres. Increased front camber and and toe for PI, added Koni shocks.
PI - C ~ 6.2, FC -2.15, RC -2.3, FT 0.5, RT 1.2 - Slightly unstable in corners, lots of unexpected oversteer, reduce toe.
NOW - C ~ 5.9, FC -1.65, RC -2.2, FT 0.6, RT 0.8

The current setting seems a good balance for my current suspension/tyre setup, very easy to control when sliding around, and quite progressive. Strikes a good match between tyre wear and performance in my opinion. Will be testing it out at PI / Sandown in the not too distant future, and also looking for thicker rear sway.

PS. KPI is about 10.

Wow that's pretty mean camber for driving around on the roads!

I always like lots of camber in the front and no greater in the rear. Having it all in the back invites understeer.

maybe I'll look at

5.9, -1.7, -1.7, 0.6 & 0.8 or thereabouts.

Greeneyes has been lowered 28mm on new Konis, then raised to be about 15mm lower than stock.

The latest wheel alignment from Manukau Toyota was after I raised it, and I said I wanted equal camber front and rear with no chance of the toe-out wear on the front.

Rear axle-

Camber left -1deg09', right -1deg15'

Toein left 1.1mm, right 1.0mm

Front axle-

Camber left -1deg11', right -1deg08'

Toein left 0.5mm, right 0.6mm

This seems to have cleaned out the understeer that arrived when I lowered the car. The run down to Rotorua and back was just marvellous! All the tight twisty back roads where there is no traffic!