GR Yaris Rear Toe adjustment

[Attey]

I'm looking at adjusting the front and rear toe next week. I will be looking to get +/-1mm toe on the rear.

Looking through previous threads it is not clear if the rear toe is easy to adjust or if you need to change anything on the car to allow the adjustment.

Can you please advise if/what is needed to do adjustment of the rear toe.

Thanks, David

 

[Sly]

@Lauren might know having hers done due to the oversteer she was having

 

[Lauren]

@Lauren might know having hers done due to the oversteer she was having

I've still got the oversteer, though I don't mind that. In answer to the OP's question rear toe is easy enough to adjust. You must have toe in. I tend to run on the minimum toe in spec from factory settings at 0.04. If you want more to in to increase rear stability then you can go up to around 0.12 or so.

Adjusting toe will affect rear camber which is not adjustable as standard. However variations are relatively small, so nothing to really worry about.

 

[Attey]

I've still got the oversteer, though I don't mind that. In answer to the OP's question rear toe is easy enough to adjust. You must have toe in. I tend to run on the minimum toe in spec from factory settings at 0.04. If you want more to in to increase rear stability then you can go up to around 0.12 or so.

Adjusting toe will affect rear camber which is not adjustable as standard. However variations are relatively small, so nothing to really worry about.

Thanks Lauren, I want to try different settings to try to free the back end which is too planted at the factory settings. I have a camber gauge to keep an eye on the effects on the camber, but I wanted to check what the adjustment is for the rear toe before I look at the rear suspension and do the adjustments (hopefully on Tuesday). If I needed shims or similar, I could see about ordering some to ensure I can get started before an Anglesey trackday next weekend.

So any info on what to adjust would help and save me time when I start on it.

 

[Phil1291]

These are eccentric bolts on which you can adjust toe.
No special tools or anything needed for that.

 

[Lauren]

Thanks Lauren, I want to try different settings to try to free the back end which is too planted at the factory settings. I have a camber gauge to keep an eye on the effects on the camber, but I wanted to check what the adjustment is for the rear toe before I look at the rear suspension and do the adjustments (hopefully on Tuesday). If I needed shims or similar, I could see about ordering some to ensure I can get started before an Anglesey trackday next weekend.

So any info on what to adjust would help and save me time when I start on it.

Have you increased camber on the front? I run 2.5 deg negative up front with the OEM crash bolts. Run less toe in on the rear, that will help.

 

[Attey]

These are eccentric bolts on which you can adjust toe.
No special tools or anything needed for that.

View attachment 6704

Thank you Phil,
This is exactly what I wanted to know and I think it would have taken a bit of working out when crawling under the car. I would have been looking to move the other mount rather than the main lower suspension leg, it is now obvious why it will have more effect on the camber.
Am I right to assume the other mounting point is in front of this one, so moving this inboard will give toe out? and hence less negative camber?
David

 

[Attey]

Have you increased camber on the front? I run 2.5 deg negative up front with the OEM crash bolts. Run less toe in on the rear, that will help.

Lauren, I have not yet played with the camber, but was thinking of playing with Toe first then camber.
I normally like a very small amount of toe out at the front for better turn in. I'm used to a rear wheel drive kit car.
I was thinking of very small toe out initially, but note you suggest to keep to toe in. I wish to get the rear to be a bit looser to remove the 4wd understeer. I was planning to try small toe in and out to see what I prefer, but would appreciate any constructive comments on what others have found.

 

[Phil1291]

Thank you Phil,
This is exactly what I wanted to know and I think it would have taken a bit of working out when crawling under the car. I would have been looking to move the other mount rather than the main lower suspension leg, it is now obvious why it will have more effect on the camber.
Am I right to assume the other mounting point is in front of this one, so moving this inboard will give toe out? and hence less negative camber?
David

Yes. Camber can be adjusted with aftermarket Camber Bolts, Whiteline for example.

I drive 1mm toe out plus -2.5 degree camber at the rear per wheel and i love it.
But that‘s with a lowered car and pretty stiff suspension.
Plus it‘s very lively.

On a stock car i would not suggest such an aggressive setup because you gain a lot of camber over suspension travel.

 

[Spirited]

... I wish to get the rear to be a bit looser to remove the 4wd understeer... would appreciate any constructive comments on what others have found.

I'm looking for the same!

 

[Phil1291]

I'm looking for the same!

0.5mm toe out at the rear and 0.1bar more air pressure than in the front tires will fix your problem.

 

[Spirited]

Yes. Camber can be adjusted with aftermarket Camber Bolts, Whiteline for example.

I drive 1mm toe out plus -2.5 degree camber at the rear per wheel and i love it.
But that‘s with a lowered car and pretty stiff suspension.
Plus it‘s very lively.

On a stock car i would not suggest such an aggressive setup because you gain a lot of camber over suspension travel.

I think it's wise that you're making the distinction between stock suspension cars and ones with aftermarket lowered one. It's easy to get excited with geo we read works for racing machines like yours, try to replicate it blindly on our stock suspension and end up with a car that wants to kill you, as you put it.

Your suggestion for the rear combo of tow & tyre pressure settings is invaluable; thank you!

@Heliomalt praised you for the clean suspension setup you did on his car.

So, based on so many GRYs and settings you've worked on so far, would you like to also share your suggestion for the front, for GRYs with a stock suspension? I'm considering to go down the "DNA Racing" top mounts route for some:

• Camber
• Dynamic camber
• Caster

but keep the (long travel) stock suspension.

Also, I assume that any suggestion for the front geo would still work after I follow your advice for the tow out & slightly higher pressure at the rear.

 

[Phil1291]

I think it's wise that you're making the distinction between stock suspension cars and ones with aftermarket lowered one. It's easy to get excited with geo we read works for racing machines like yours, try to replicate it blindly on our stock suspension and end up with a car that wants to kill you, as you put it.

Your suggestion for the rear combo of tow & tyre pressure settings is invaluable; thank you!

@Heliomalt praised you for the clean suspension setup you did on his car.

So, based on so many GRYs and settings you've worked on so far, would you like to also share your suggestion for the front, for GRYs with a stock suspension? I'm considering to go down the "DNA Racing" top mounts route for some:

• Camber
• Dynamic camber
• Caster

but keep the (long travel) stock suspension.

Also, I assume that any suggestion for the front geo would still work after I follow your advice for the tow out & slightly higher pressure at the rear.

I let castor as suggested for stock.

Front camber i have -3,5 degree and also 1.0mm toe out.

I‘d recommend -2.5 to -3.0 camber front and 0.5mm toe out.

Toe in at the front will create a faster/sharper initial response to steering inputs, but can make over corrections difficult.
Toe out responds slower to inputs, but helps to rotate the car.

 

[Spirited]

Front camber i have -3,5 degree...

You're brave!

I‘d recommend -2.5 to -3.0 camber front and 0.5mm toe out.

Much appreciated

Toe in at the front will create a faster/sharper initial response to steering inputs, but can make over corrections difficult.
Toe out responds slower to inputs, but helps to rotate the car.

Thank you for putting these in context. Makes perfect sense, as does toe out at the front with reference to the Ackermann effect.

Hopefully one day I'll get my head around the effects of toe in/out at the rear.

In the meantime, I'll experiment with your suggestion and at some point ideally visit you for a proper setup. It's just that you're three countries away from me

 

[Lauren]

Lauren, I have not yet played with the camber, but was thinking of playing with Toe first then camber.
I normally like a very small amount of toe out at the front for better turn in. I'm used to a rear wheel drive kit car.
I was thinking of very small toe out initially, but note you suggest to keep to toe in. I wish to get the rear to be a bit looser to remove the 4wd understeer. I was planning to try small toe in and out to see what I prefer, but would appreciate any constructive comments on what others have found.

You can run toe out on the front, but obviously not advised on the rear. But by all means try it if you wish. Think you will find toe out at the rear makes it unstable. I have tried this by accident previously and didn't like it.

I run parallel toe on the front. But I know others run toe out. Other than the camber bolts my suspension is stock. The 2.5 degrees negative camber at the front helps with turn in. I do find when sprinting on faster corners on track that the car does oversteer literally every time you come out of the throttle at higher speeds. I don't mind this, but I can understand how it could catch others out. Rotation under trail braking into hairpins is also very good, though again it can be too much at times. Cold rear tyres though I think are more the issue here.

 

[Yaris San]

having a tail happy or 'loose' rear is good fun and superb on track where you can get the rear rotating when cornering allowing you to straighten the wheel much earlier and power out way before the same guy still one and half turns dialled in but....

for a street and B road car what's going to happen when you're hard into a blind corner and suddenly there are two cyclists abreast taking up half of your lane and a vehicle coming the other way

at this point you'll need to violently throw the car into the path of the oncoming vehicle and then throw it violently back to your side hopefully not wiping out the cyclists
is this a good time to have a 'tail happy' set up car ?

 

[swistak]

hard into a blind corner

I don't think that's great B-road etiquette (as a cyclist and a yaris b-road enthusiast)
I agree with the rest of the points you've raised.

 

[Phil1291]

If you drive your car on the absolut limit on a public road where you can‘t see whats ahead of you, in my opinion, you should instantly loose your licence.

If you want to test the limits of yourself and your car, you should attend a trackday.

 

[Yaris San]

im not referring to driving on the vehicles limit, pretty much every single corner on a typical B road is blind, what I'm referring to is the ability to safely but quickly make a course correction mid corner

should also mention what some ppl are referring to is taking a stable vehicle and deliberately making unstable because its more 'fun'

 

[Spirited]

Good food for thought on this thread.

It's worth taking one step at a time with geo changes and experimenting in a safe environment to realise implications and digest trade-offs.

What I've felt in practice is that Toyota (rightly) offered us the car set up to understeer primarily. When, by mistake, I leave the drive mode in Normal, the understeer is beyond joke. However, even in Sport, it's pretty much there, definitely more than I would expect and like from a car with 70% of the power going to the rear.

Especially given the lack of a longer wheelbase that would bring progressiveness and therefore make any antics more predictable and controllable, I'm still grateful for the chance the understeery set up gave me to familiarise myself with the car. 10k miles in, the understeer and the vagueness that comes with it became quite annoying, though.

Morizo's prompt (at around 4:20 of the video below) to put the "final touches" sounds louder and clearer to me as the miles add up. I wouldn't mind a bit of tyre art either, in the right circumstances.