Not sure if I understood/interpret your position correctly, do you mean to say the pictorial by writer is correct?

@amduser may be right with his statement and experience above, which I generally concur .....
i.e the pictorial on understeer/oversteer corrections are not correct and indeed terbalik.

Besides in a vehicle turning or cornering scenario, increases in tyre pressure results in higher spring rate (on tyre contribution) that leads to tyre grip reduction.

Decreased tyre pressure correlates with lower (tyre) spring rate that leads to tyre grip increase.

From the viewpoint of vehicle suspension dynamics in a turning/cornering, @amduser's position is still valid imho.

This post has been edited by zeng: Jan 4 2022, 01:17 PM

many not realize. originals article base on racing slick not street tyre.
saja copy paste to post so make us all upside downed

another reason is becos of posche website maa.
everything become correct when u put reverse gear

so zeng ur way is correct. dont hesitate.

regarding over-understeer. play with tyre pressure on avanza quite strong effect. weight reduction also affecting very much

Is it, on an Avanza?
Ok, will give it a try on my Avanza as I can feel some over-steer right now.
Rear tread depth is low though at around 2 -2.5 mm (at about 100-105k kms usage).
Front tread depth now is about 3 -3.5 mm at about 83k kms usage.
Right Front outer edge wear more than inside edge and Left Front like a difference of say 0.5 mm due to previous mis-alignment I think.

This post has been edited by zeng: Jan 5 2022, 09:55 AM

the key is pam front wheel correctly. twist steer at shopping mall simen type car park no squeeze noise = just right.
then increase rear wheeel accordingly.

the difference between front vs back is just 10kpa my final results

My last known or pumped tyre pressures some 2 months ago were:
275 kpa Front

255 kpa Rear.

Any suggested tyre pressure values?

before weight reduction F270 R230 superb grippy easy control

after buang 3rd seat & spare taya, tend to understeer so F260 R270 is perfects.
the rest full ori never align wheel since bought

When you buy and install brand new tyres on your car(s), beware of brand new tyres with Tyre Conicity defects leading to vehicle pull to one side, despite 'perfect' wheel alignment works being done.



Source:
Diagnosing Tire Pull
by www.tirerack.com

This post has been edited by zeng: Jan 7 2022, 01:38 PM

Wow you both really like really hard pressures.

becos van uses tall side profile

Car without installing Rear Shock Absorber set - See how the Rear Suspension behaves!
21 s.
Have a laugh pl...



This post has been edited by zeng: Mar 7 2022, 11:28 AM

Hi sifus. Please help me out here 😞.
I drive a perodua myvi 2nd gen which has torsion beam at rear. Went to do alignment today and mechanic told me my rear toe in totalling both side to 1 degree. He offered 2 solutions.

1. Change the whole rear axle / torsion beam costing around RM650 Inc installation.

2. (For my understanding) Add shims / washer at 1 of the wheel bearing/ nut hole. To compensate the degree.

Note:
Car has not been in an accident , only minor rear bang/light collision middle not side.

Can any sifu give me some opinions, since toe in will degrade tyre faster right.

Huuh...... Rear Total Toes of 1 degree both sides combined.

Mind sharing the print out of the alignment read outs?

That 's going to eat up the rear tyres really really fast right?

How's your tyre life so far?

Do you experience rear axle instability on rough road surface, especially on turns/curves/cornering?

Yes, replacing the whole rear torsion beam is one option technically.

For RM650 it is probably a used second hand from the kedai potong/scrap yards??

If so the replacement might not be accurate also giving you another set of wrong alignment angles??

If it is new torsion beam from Perodua may be worth trying.

Shimming the rear torsion beam is another option which I personally prefer, problem is I have difficulty in finding a competent and reasonably-priced mechanic in Klang valley to do this kind of job on my Avanza.

Let us know if your mechanic is good and competent on shimming rear torsion beam delivering cun cun good alignment reports.

Here is a link on shimming of rear torsion beam axle on a 2012 Hyundai Elantra with reasonably good results.

https://www.hyundai-forums.com/threads/do-i...7/#post-1984049

This post has been edited by zeng: Mar 16 2022, 09:40 PM

dont see the total toe, see the toe at each side instead, for your case added shim or washer seems to be better choice unless your torsion beam damaged badly then only you change

or you can go to another workshop and have it check, if have you have 1 degree toe in you should experience understeer and excessive tyre wear on the outer thread of the tyres, or the rear of your car will push to one side while driving if the toe is imbalance

If you look through the link I provided 2 posts above on shimming of Rear Torsion Beam/Hub, total shim thickness required by @nightlord in order to shrink its Rear Total Toes to factory specifications would be about 0.40 -0.60 mm on one and/or both sides combined.

Unfortunately the shims or washers thickness I found online is in 1 mm, 2 mm and 3 mm size.......
which imo is not quite suitable for such a typical Rear Torsion Beam shimming job.

Is there metal shims in 0.10 mm or 0.20 mm thickness available in the market, online store or retail shops? Mind intro one or two such outlets?

Replacing with a used rear torsion beam might end up with a rear camber/toe also out of factory specs. IDK.

Replacing with a brand new rear torsion beam would be very pricy. Even then the resulting rear camber and toe might look 'bad' or worse still, also out of specs. So it is a big risk too.

@Nightlord, as suggested above by @amduser do you experience 'understeer', excessive tyre wear?

Rear axle push to left and/or right sides when driving over bumps and potholes?

Car drifts or pulls to one side on straight ahead driving when both hands temporarily off the steering wheel?

With a centred steering wheel the car does not travel straight but move to one side?

Turning left steering effort or smoothness is different from turning right as your steer?

This post has been edited by zeng: Mar 19 2022, 09:59 AM

you can find it online, it is called ring shim, 1mm above is common because of household usage generally require those thickness, there are special kind of ring shim that is made from spring steel and is used for absorber valving tuning

here you can see the size they used
https://www.teknikmotorsport.com/ring-shims/
https://restackor.com/sample-apps/stack-tun...ntals/ring-shim

for those uncommon size you might need to go to those suppliers that specialized in selling gasket and seals, they should have those specialized washer, but they might not willing to sell in small quantity though

here is some ultra thin one you can find from lazada
https://www.lazada.com.my/products/100pcs-s...3364916647.html?

Oh no Bro..... never thought about this option of Ring Shim. Thank you.

The search continues ..... with Ring Shims for Avanza Rear Live axle.....

This post has been edited by zeng: Mar 20 2022, 12:07 PM

Hello all sifus. Sorry for late reply.

I do notice excess wear on outer rear tyres. regarding about understeer, I don't notice it. But I do notice just a little bit of body vibration when getting up to highway speeds. But I already changed the tyres that day cause thread is up.

I went to do second alignment scan at another shop and it shows. Toe: RL0°11' RR0°40' I guess thats almost 1° on total right ? Since 60' is 1°

Heading to do 'shimjob' while replying this.

Thanks all sifus