GR Yaris Geo fast road help and track set up

[micsub]

It's true that Tyre pressures are the first thing to monitor before jumping to set-up considerations.
However, in the first year I had mine, I had come to the false conclusion that these PS4S were no good, tyre walls too soft etc. Even though having played with tyre pressures balance F to R, equal to, more than and even less than constructor's advice, without any really good result.
Then went for a Geo, it was found out of spec, corrected it and found a new car.
But, I had already switched to a new set of wheels 8.5x18" wrapped in 235/45/18 Yoko A052, PRIOR to the alignment... Ofcourse it was a neat overall improvement from the OE.
It was only about 8 months later, when I switched back to the OE wheels and PS4S, that I started appreciating those tyres to their real value.
Then went back for an improved geo setting (-2.2° camber, slight Toe in but close to zero Front, -2° camber and +4' toe in Rear) and the PS4S was still very good.
Recently added some camber F, (-3°), and I do think it's a bit too much. Next will try -2.5° front camber should be the sweet spot with those toe values.
Ofcourse, each one has a different feeling of these things, so there is no "copy-paste" values, just a basis setup according to what you use the car most for, (snow & dirt, tarmac roads, track...) you just have to progressively find the setting where YOU feel comfortable. Only change one parameter at a time and test to feel if any real difference is best.

 

[Michael Knight]

It's true that Tyre pressures are the first thing to monitor before jumping to set-up considerations.
However, in the first year I had mine, I had come to the false conclusion that these PS4S were no good, tyre walls too soft etc. Even though having played with tyre pressures balance F to R, equal to, more than and even less than constructor's advice, without any really good result.
Then went for a Geo, it was found out of spec, corrected it and found a new car.
But, I had already switched to a new set of wheels 8.5x18" wrapped in 235/45/18 Yoko A052, PRIOR to the alignment... Ofcourse it was a neat overall improvement from the OE.
It was only about 8 months later, when I switched back to the OE wheels and PS4S, that I started appreciating those tyres to their real value.
Then went back for an improved geo setting (-2.2° camber, slight Toe in but close to zero Front, -2° camber and +4' toe in Rear) and the PS4S was still very good.
Recently added some camber F, (-3°), and I do think it's a bit too much. Next will try -2.5° front camber should be the sweet spot with those toe values.
Ofcourse, each one has a different feeling of these things, so there is no "copy-paste" values, just a basis setup according to what you use the car most for, (snow & dirt, tarmac roads, track...) you just have to progressively find the setting where YOU feel comfortable. Only change one parameter at a time and test to feel if any real difference is best.

similar thoughts. full track setup with fat semi slicks is bit different to 50/50 road track with "regular" tires.

 

[Spirited]

...
Recently added some camber F, (-3°), and I do think it's a bit too much
...

Which aspect / characteristic left you feeling "too much" with front camber at -3°, @micsub?

 

[Onehp]

Stock BBS forged wheels; so, 225/40 R18 with Continental SportContact7.

Pressures are:

• front 32 psi;
• rear have been anything between 29 & 31 psi with no material difference to that problematic behaviour; or none that I could notice, anyway.

I ask because the "right" amount of toe depends on the flex/slip angle of the tyre.

Since its close to stock, go with recommendations of others, as I didn't have stock setup.

 

[Spirited]

maybe its matter of balance. as a driver I prefer light understeer setup as it easier to build confidence, and in practice that is managed with driving technique using trail in braking etc. maybe you could try adding slightly rear toe to get more stability there.

I'm not certain how rear toe acts in suspension movement but its possible that it adds toe out when suspension extracts ? It could explain your sensation of vagueness there (ie. goes to toe out in certain points).

I wouldn't say that you've gone 'too aggessive' as I am running a very similar set up and find the car to be very well balanced.

@Michael Knight makes a good point in relation to your rear toe and adding a bit more (I run 0.10') will help stabilize the rear.

Are you using adjustable dampers/ride height? If so, then around 10mm positive rake will assist in reducing understeer.

@Spirited you do mean you have toe in now in the rear? Yeah add some more, the rear will communicate better with you then. I would also go neutral toe in front, with that camber that effectively feels like toe in and gives more immediate front axle feedback and you don't need the toe out for turn in grip anyway with that camber.

Is there any point in adding negative camber at the rear instead of or as well as adding toe in there? For example, if from current -2º24' I maxed out the Powerflex bolts there, I would expect anything between -2º35' & -2º45' would add a bit of stability and work better in tandem with the -3º front, as the front-rear difference would be less than half a degree.

On the other hand, I'm thinking that when I drive over a mid-corner pothole, crest or uneven surface, the greater rear camber may mean more chances of instability, as the wheel that maintains traction will push more to the side. So, if, for example, the outer wheel hops slightly over a pothole or crest, it makes sense to me that I will get unwanted oversteer.

While by adding toe in only, there shouldn't be any trade-offs in terms of stability and rear antics.

 

[Michael Knight]

Is there any point in adding negative camber at the rear instead of or as well as adding toe in there? For example, if from current -2º24' I maxed out the Powerflex bolts there, I would expect anything between -2º35' & -2º45' would add a bit of stability and work better in tandem with the -3º front, as the front-rear difference would be less than half a degree.

On the other hand, I'm thinking that when I drive over a mid-corner pothole, crest or uneven surface, the greater rear camber may mean more chances of instability, as the wheel that maintains traction will push more to the side. So, if, for example, the outer wheel hops slightly over a pothole or crest, it makes sense to me that I will get unwanted oversteer.

While by adding toe in only, there shouldn't be any trade-offs in terms of stability and rear antics.

I don't know the effect , haven't tried more than what I currently have (2 degrees and 25 minutes.). but reasoned I'll keep the rear 0.5 less vs front.

 

[Onehp]

Is there any point in adding negative camber at the rear instead of or as well as adding toe in there? For example, if from current -2º24' I maxed out the Powerflex bolts there, I would expect anything between -2º35' & -2º45' would add a bit of stability and work better in tandem with the -3º front, as the front-rear difference would be less than half a degree.

On the other hand, I'm thinking that when I drive over a mid-corner pothole, crest or uneven surface, the greater rear camber may mean more chances of instability, as the wheel that maintains traction will push more to the side. So, if, for example, the outer wheel hops slightly over a pothole or crest, it makes sense to me that I will get unwanted oversteer.

While by adding toe in only, there shouldn't be any trade-offs in terms of stability and rear antics.

Simply put, with toe you more influence the behaviour straight on and in the initial turn-in phase. Camber is more dominant into the curve as you start working up G-forces as it changes the grip level of front vs rear axle and thus the balance there.

The only reason for me to have (had) more camber in front is because when running a constant speed in a turn near the grip limit, I wanted the car the settle in a 4 wheel slide as I go onto throttle, instead of going understeer. Because that is something that is difficult* to drive around. The goal is NOT to take out ALL understeer - understeer in good! Good for stability, good to gauge grip levels on turn in, and good to not spin out as soon as you hit a little lower grip when powering out of a curve. These are situations where you can drive around the understeer. If you get understeer on turn-in, you need more trailbraking and weight transfer in front. When mashing the throttle out of a turn and then turning the wheel more, you will get understeer - you should, as you did weight transfer rear first. If you don't want that, you need to turn first and add throttle later. Only in this latter scenario, if you still get chronic understeer, you maybe want to reduce understeer.

I also remember warning to not to overdo the front camber thing in case of evasive maneuvers - a too oversteered balance can really bite hard. This is a reminder.

In summary - don't think all understeer is bad. Just want to reduce it a little.... it's literally a balance act.


Hope this helps...


*And even here, a small left foot brake dab on the brakes can break the understeer, but it is a little disturbance in the driving flow...

 

[micsub]

Which aspect / characteristic left you feeling "too much" with front camber at -3°, @micsub?

Since I replaced the suspension from OE to TracTive, the camber insert ithough would be the most suitable, in fact gave -3°. And so still am at -3°, and definitely have the feel that she is heavier on the steering, and having that slightly under-steery feel on the wet, obliging to stray longer on the brakes to keep the front wheels loaded. Could be my imagination ?

 

[micsub]

Simply put, with toe you more influence the behaviour straight on and in the initial turn-in phase. Camber is more dominant into the curve as you start working up G-forces as it changes the grip level of front vs rear axle and thus the balance there.

The only reason for me to have (had) more camber in front is because when running a constant speed in a turn near the grip limit, I wanted the car the settle in a 4 wheel slide as I go onto throttle, instead of going understeer. Because that is something that is difficult* to drive around. The goal is NOT to take out ALL understeer - understeer in good! Good for stability, good to gauge grip levels on turn in, and good to not spin out as soon as you hit a little lower grip when powering out of a curve. These are situations where you can drive around the understeer. If you get understeer on turn-in, you need more trailbraking and weight transfer in front. When mashing the throttle out of a turn and then turning the wheel more, you will get understeer - you should, as you did weight transfer rear first. If you don't want that, you need to turn first and add throttle later. Only in this latter scenario, if you still get chronic understeer, you maybe want to reduce understeer.

I also remember warning to not to overdo the front camber thing in case of evasive maneuvers - a too oversteered balance can really bite hard. This is a reminder.

In summary - don't think all understeer is bad. Just want to reduce it a little.... it's literally a balance act.


Hope this helps...


*And even here, a small left foot brake dab on the brakes can break the understeer, but it is a little disturbance in the driving flow...

Fully agree. Which is why I will reduce that -3° camber to something more road-reasonable to around -2.5° max.

 

[Heliomalt]

I've tried a few different settings since I've owned the car, Powerflex camber bolts are fitted at the front and rear and tightened to the prescribed torque, 252Nm at the front and 63NM at the rear.

My first setup was this one::

Front Chamber - 2° 50'
Toe each side 0° 14'

Rear - 2° 30'
Toe each side - 0 ° 2'

The car was very agile around bends, but the tyres were destroyed inside after only 5000km, see picture.

I then bought new tyres, checked the settings, everything was completely out of adjustment, massive differences in camber and toe. Unfortunately, I no longer have the values. Setup adjusted according to tips from the forum, less camber, about 2° and toe almost 0°, original values at the rear.
After a few weeks, I noticed the first signs of uneven wear on the tyres again, checked the settings and found the following values:

Front Chamber left - 2° 29' right - 3° 2'
Toe left 30' right - 25'

Rear left - 2° 2' right - 2° 25'
Toe left - 7' right - 10'

Then I set the original values at the front and rear as an experiment, the tyres last much longer, there is still slightly more wear on the inside, but the handling is terribly boring.
I'm now fitting Yokohama A052 tyres this week and will check the values to be on the safe side and would actually like to adjust the front tyres by 2 to 2.5° camber and 8' toe total, and the rear tyres by the standard Toyota values.

I suspect that the values have been adjusted again this time, but I have no idea why this keeps happening and I also want to prevent the Yokohama from wearing unevenly unnecessarily. Does anyone have any idea what the problem could be and how to prevent it? Would be grateful for any advice.

I don't drive on a racetrack, only on the road, but a lot of bends, mountain roads, mountain passes, just the typical things Switzerland has to offer.

 

[Yaris San]

I've tried a few different settings since I've owned the car, Powerflex camber bolts are fitted at the front and rear and tightened to the prescribed torque, 252Nm at the front and 63NM at the rear.

My first setup was this one::

Front Chamber - 2° 50'
Toe each side 0° 14'

Rear - 2° 30'
Toe each side - 0 ° 2'

The car was very agile around bends, but the tyres were destroyed inside after only 5000km, see picture.

I then bought new tyres, checked the settings, everything was completely out of adjustment, massive differences in camber and toe. Unfortunately, I no longer have the values. Setup adjusted according to tips from the forum, less camber, about 2° and toe almost 0°, original values at the rear.
After a few weeks, I noticed the first signs of uneven wear on the tyres again, checked the settings and found the following values:

Front Chamber left - 2° 29' right - 3° 2'
Toe left 30' right - 25'

Rear left - 2° 2' right - 2° 25'
Toe left - 7' right - 10'

Then I set the original values at the front and rear as an experiment, the tyres last much longer, there is still slightly more wear on the inside, but the handling is terribly boring.
I'm now fitting Yokohama A052 tyres this week and will check the values to be on the safe side and would actually like to adjust the front tyres by 2 to 2.5° camber and 8' toe total, and the rear tyres by the standard Toyota values.

I suspect that the values have been adjusted again this time, but I have no idea why this keeps happening and I also want to prevent the Yokohama from wearing unevenly unnecessarily. Does anyone have any idea what the problem could be and how to prevent it? Would be grateful for any advice.

I don't drive on a racetrack, only on the road, but a lot of bends, mountain roads, mountain passes, just the typical things Switzerland has to offer.

View attachment 35016

Typical lack of front caster, increase the caster to around 7° or more and problem will disappear, not cheap though

 

[Heliomalt]

Thank you for your answer. Maybe, but the problem was too much toe, which Phil set for me at the time. Now with the standard values the tyre looks like this. A little more pressure and the tyre would look different, but it's ok for me. It doesn't matter any more, because firstly I've found a solution, secondly I'm throwing the f***ing Powerflex bolts in the bin and thirdly in future I'll keep my hands off hobby tuners who demand unnecessary money, shine with half-knowledge and afterwards, when it turns out that their work has led to unnecessary additional costs, don't offer a solution, at most want to sell even more, which completely misses the mark for a pure road rider.

If I had gone to someone from the start who really knew about the suspension, settings and intended use of the respective rider, I could have saved myself a lot of time, money and trouble. I don't care about tyre wear, I didn't buy the car to drive it like a family car.

The fact is that 3° camber and more for pure road use with the original suspension is simply rubbish, the fact is also that all the camber bolts don't hold, can break and are only a half-baked solution.



btw. this is the Supersport F1, with standard setup from Toyota. 7000km, front.

 

[Yohz78]

Hey everyone,

I have bought 90105-17013 bolt. I plan to mount them in order to reach - 2.2 ° / -2.3° camber front.

From what I understood, I can have - 2° rear with stock bolts.

That would allow me to have - 2.3° front and -2° rear which seems perfect for me and my "fast road" use. I don't want too agressive camber that would destroy the inner line of my tyres.

However I'm a bit lost when it comes to toe. I am tempted to keep stock toe front/rear as I find the entry balance quite good. Is it a mistake given the camber change ? Should I go for close to neutral front and some toe in rear ? I like a bit of oversteer during entry as I'm used to FWD cars but I don't want the yaris to try to kill me during fast corner entry either.

What would be the recommandation ? Stock suspensions, standard PS4S. Thanks !

 

[GottGry]

The fact is that 3° camber and more for pure road use with the original suspension is simply rubbish, the fact is also that all the camber bolts don't hold, can break and are only a half-baked solution.

View attachment 35099

btw. this is the Supersport F1, with standard setup from Toyota. 7000km, front.

is it worn on the inside or the outside?

 

[Heliomalt]

is it worn on the inside or the outside?

On both sides, as you can see. Air pressure was 2.2 cold, 2.5 to 2.6 bar warm. Which, according to my tyre dealer, is still too low for my driving style and the roads. Rear tyre pressure 2.3 warm indicated in summer. And mind you, this is Toyota's standard setup for Goodyear tyres.

 

[Orion]

sad to hear your struggles, @Heliomalt

My geo is camber: -3°/-2.5° camber (using whiteline KCA417 front and powerflex black rear camber bolts), toe: 0.55mm in/2.2mm in
my guess is your excessive chording/wear on the inside is due to toe out and not camber
the reason I believe that because all my tires last 10-15tkm and they have very linear wear pattern from inside to outside (worn to ~0-2mm inside, 2-3mm outside) and not just in an inner strip

My car is at 76.000km, I had my geo setup at around 13.000km, so 63.000-ish km ago, I have checked several times and my setup is still spot on. I have gone through ~ 3000 track kilometers, 7 sets of front and 1 set of rear brake pads (on factory rotors still), around 5 sets of summer tires (PS4S, Cup2, GYEF1SS, CSC7...)
so I don't exactly baby my car plus I live in the country of potholes, too

 

[Heliomalt]

You have the original Toyota values for the toe at the rear, but much less at the front. The factory specification is 0.08°, which is 1.6 mm.

As I said, I set the Toyota values last time, but I strongly believe that it has been adjusted again and the values are no longer correct.

If the values are correct on Friday, then I'll have it checked, then it would be even crazier if the tyres are more worn on one side. It's much better now, but still slightly more on the inside as already mentioned. According to my tyre dealer, the heavy wear on the outside and inside has to do with insufficient pressure and the speed in bends on narrow roads.

It's starting to drive me a little crazy.

 

[Orion]

2.2bar cold could explain outter wear... I run 2.3-2.5bar front (and 2.2-2.4bar rear) cold, depending on tire
while I had the Goodyear Eagle F1 Supersport, I had quite an even wear (although I used them on a very abrasive track), but I run them at 2.7-2.8bar hot

 

[GottGry]

You have the original Toyota values for the toe at the rear, but much less at the front. The factory specification is 0.08°, which is 1.6 mm.

0.08° is the same as 4,8' (0.08x60/100).
If you look at the chart for 5' (4,8') and 18" it says just 0.6mm, and not 1,6mm.
I have no clue about the factory spec values, but the advice I got was to set front total toe to 0° +-0.10° (maybe just 0.05°).

ps: I have my front toe at dead zero 0.00°/0'/0.0mm so no confusions/conversions when you do the job.

 

[Heliomalt]

Front is 0°08' or 0.14°. In this case, I think I have to correct myself, then the front toe is pretty much what Toyota specifies.

At the front, I followed Toyota's instructions for the toe. Let's see on Friday what the current values are.

The last few days have been nice here in my neighbourhood and I was able to do a few laps with the GR on the road. I can already say, regardless of the suspension settings, that the Yokohama A052 opens a new chapter in terms of grip, no comparison with the Michelin or Goodyear. Where the car used to slide slightly and the tyres used to squeal, now there is just ungodly grip. Unbelievable, confirms once again that the most important tuning on a car is the tyres. A speed in bends that is borderline or let's call it sick on public roads. Summer can come.

Front