GR Yaris Rear Toe adjustment

[Onehp]

Good discussion, still trying to find that golden compromise between less understeer especially on throttle and on limit / evasive manouvre stability.
Understeer can be controlled by using weight transfer through trail braking, lift off or left foot braking, but that isn't the safest driving style either on public roads where slow in, fast out is the secret sause of safe fun.
3 degrees neg camber in front (as I was sceptical to but which I have myself now anyway) is good fun, but it does make the rear lively on the brakes or even on lift-off at higher speeds...

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Note: Expert mode is pretty good in catching unintended oversteer, so definitely on the road I would recommend leaving at least that on....
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Even so, esp has its limits and if I meet a moose or (more applicable to everyone) someone changes lanes on me on the motorway, I am a bit wary if esp + me will be quick enough to catch the rear in an evasive move.

Next step for me is to add a little more neg camber back in the rear, adding on limit stability while hopefully adding (no or less) understeer on throttle...

 

[Onehp]

Especially given the lack of a longer wheelbase that would bring progressiveness and therefore make any antics more predictable and controllable

Thought that too but as rightly pointed out before, the wheelbase at 256cm is actually quite long, longer than a Delta Integrale (248cm) or a 992 (245cm), and much longer than a Sport Quattro (220cm) for example. So that's not it really.

 

[Spirited]

Thought that too but as rightly pointed out before, the wheelbase at 256cm is actually quite long, longer than a Delta Integrale (248cm) or a 992 (245cm), and much longer than a Sport Quattro (220cm) for example. So that's not it really.

By longer wheelbase, I was referring to my other car. Because due to its longer wheelbase it's very tame and manageable, my other car:

Sorry, I just had to . Point taken, though, it's not the shortest wheelbase.

 

[Lauren]

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 ?

The speed at which oversteer happens, you would not realistically get into on the public road unless driving like a loon, which is not something I would do. Plus on track I have everything turned off. I simply gave some feedback about how the car rotates on track. I don't do trail braking and the like on the road, as you have to be absolutely committed which is foolhardy to do.

The car is not 'tail happy'. I would add that I set the car up to my liking, but I have played with geo setups for decades now and this is why I spoke about a more stable setup.

 

[Spirited]

Good discussion, still trying to find that golden compromise between less understeer especially on throttle and on limit / evasive manouvre stability.
...
Next step for me is to add a little more neg camber back in the rear, adding on limit stability while hopefully adding (no or less) understeer on throttle...

Would adding an anti-lift kit to the mix address understeer on throttle?

I believe @MarkoS had one installed (front Whiteline poly bushes), set it up for anti-lift and felt that it eliminated such understeer.

Increased NVH was the only drawback he mentioned.

 

[MarkoS]

Would adding an anti-lift kit to the mix address understeer on throttle?

I believe @MarkoS had one installed (front Whiteline poly bushes), set it up for anti-lift and felt that it eliminated such understeer.

Increased NVH was the only drawback he mentioned.

Confirm, they are a gamechanger for me. Massively reduced understeer while powering out of corners (specially slow tight corners where car would lift the front a lot).

 

[Michael Knight]

Confirm, they are a gamechanger for me. Massively reduced understeer while powering out of corners (specially slow tight corners where car would lift the front a lot).

they were those that required press to be used for install ? would likely be good for track use but not so for the road.

 

[Spirited]

they were those that required press to be used for install ? would likely be good for track use but not so for the road.

Yes, I believe these are the ones, as seen at 1:00 of:

GR Yaris - Heel'n'Toe GR

First post from me since moving over:

www.gr-zoo.com

A couple of questions, please:

• Tell us more, why are they not so good for the road; always good to have the full picture of pros & cons to inform decisions
• Would there be an alternative kit more suited for the road. For example, I see a similar aftermarket solution offered by Powerflex, but while it mentions about making similar caster adjustments possible, not a single word about anti-lift, understeer, etc:

Powerflex - Performance Polyurethane Bushes

www.powerflex.co.uk

 

[Woznaldo]

I run 1mm toe out at the front and 2mm toe out at the rear. I really like the setup but will add I have yet to push the car hard in a high speed environment as I have mainly been doing Hillclimb events. I do prefer the car with a better rotation and I also run DNA top mounts which gives me 7.5 degrees of caster and 3.0 deg of neg camber up front. This has dramatically helped the turn-in.

I have some Wiborg Engineering lower control arms to put in and I'm hoping the roll-centre correction will will add some front end grip. This may need a change on the rear toe but, time will tell.

 

[Orion]

Good discussion, still trying to find that golden compromise between less understeer especially on throttle and on limit / evasive manouvre stability.
Understeer can be controlled by using weight transfer through trail braking, lift off or left foot braking, but that isn't the safest driving style either on public roads where slow in, fast out is the secret sause of safe fun.
3 degrees neg camber in front (as I was sceptical to but which I have myself now anyway) is good fun, but it does make the rear lively on the brakes or even on lift-off at higher speeds...

_______________________________________________________
Note: Expert mode is pretty good in catching unintended oversteer, so definitely on the road I would recommend leaving at least that on....
_______________________________________________________

Even so, esp has its limits and if I meet a moose or (more applicable to everyone) someone changes lanes on me on the motorway, I am a bit wary if esp + me will be quick enough to catch the rear in an evasive move.

Next step for me is to add a little more neg camber back in the rear, adding on limit stability while hopefully adding (no or less) understeer on throttle...

Dear @Onehp ,
just curious after seeing your comment in the Mk2 thread -- that I did not want to pollut -- about your not-so-great experience with front -3deg camber, if you ever tried setting an adequeate rear camber, too?
The reason I am asking is that I did too start with front -2.5 and then -3deg, keeping the back on factory -2, and that indeed felt scary even in ~20degC on anything but a dry road. On track it rotated like a dream, though.
I ended up maxing out rear camber (for me that was -2.75deg, with front still at -3deg) which feels equally planted in any condition and a night and day difference in cornering grip, compared to factory settings.
(I even have 1mm total toe in on front that a lot of people find amusing, but I kept that to counterweight any tramlining or extra inner thread wear)

 

[Onehp]

Dear @Onehp ,
just curious after seeing your comment in the Mk2 thread -- that I did not want to pollut -- about your not-so-great experience with front -3deg camber, if you ever tried setting an adequeate rear camber, too?
The reason I am asking is that I did too start with front -2.5 and then -3deg, keeping the back on factory -2, and that indeed felt scary even in ~20degC on anything but a dry road. On track it rotated like a dream, though.
I ended up maxing out rear camber (for me that was -2.75deg, with front still at -3deg) which feels equally planted in any condition and a night and day difference in cornering grip, compared to factory settings.
(I even have 1mm total toe in on front that a lot of people find amusing, but I kept that to counterweight any tramlining or extra inner thread wear)

For me it's fine stock rear, even wear, in gravel/ice very tail happy but for me that's ok but wouldn't give my car to a beginner driver though....

Edit: do not want to different settings 3x year... Does wear some inner shoulder on commute. Might go back to neg 2,5 front on new gravel tyres coming...

 

[Onehp]

Be aware of risks and set to personal liking....

 

[GRavy_Baby]

Pulling this thread from the dead..
I’m getting my geo setup done as soon as possible. I’ve requested camber bolts to be installed in the rear but have been advised by two separate geo guys that they’re dead against camber bolts in the rear.

I can accept their recommendations & I’m thinking about getting hardrace or Cusco rear arms. If I was to get these rear arms set to 2-2.5 negative camber, would the stock eccentric toe adjustment give enough range to dial in the toe IN?

I’m putting a full stock Circuit Pack suspension setup on my Convenience Pack car as an upgrade. The rear differential is a LSD, front differential is open. I’ve got thoughts on how I go about getting the front camber/caster/toe adjusted but would adjustable top mounts be overkill on stock Circuit Pack suspension?

 

[Euge]

Cusco upper rear arms are what I would go for - They come with two options; one with pillow ball bearing and a version with a rubber bushing. If you are daily driving the car through all types of weather and seasons I would strongly recommend the rubber bushing variant. As pillow balls hate salt and winter and will seize up. Hard race only comes with pillow ball I believe. You will have no problem dialing in the toe on rear as you will be running circuit pack suspension. Not sure on the best route for the front for you as I don't know what sort of geo you are aiming for.

 

[GRavy_Baby]

Cusco upper rear arms are what I would go for - They come with two options; one with pillow ball bearing and a version with a rubber bushing. If you are daily driving the car through all types of weather and seasons I would strongly recommend the rubber bushing variant. As pillow balls hate salt and winter and will seize up. Hard race only comes with pillow ball I believe. You will have no problem dialing in the toe on rear as you will be running circuit pack suspension. Not sure on the best route for the front for you as I don't know what sort of geo you are aiming for.

Thanks @Euge!

Good advice on the rubber vs pillow ball. It’s a shame they don’t make a boot that protects them from debris.

For the fronts, I’m thinking between 2.5 - 3 degrees of negative camber + toe out (as per @Phil1291 ’s recommendation). If caster adjustment is also something the geometry guy would be inclined to tweak, DNA top mounts may be the way?

As I say, I’m wondering if I’m going into the realm of excess seen as this will be mated to OEM CP suspension.

At the same time, I don’t want to destroy tyres too prematurely but find that balance between wear & handling which is acceptable.

 

[Euge]

Thanks @Euge!

Good advice on the rubber vs pillow ball. It’s a shame they don’t make a boot that protects them from debris.

For the fronts, I’m thinking between 2.5 - 3 degrees of negative camber + toe out (as per @Phil1291 ’s recommendation). If caster adjustment is also something the geometry guy would be inclined to tweak, DNA top mounts may be the way?

As I say, I’m wondering if I’m going into the realm of excess seen as this will be mated to OEM CP suspension.

At the same time, I don’t want to destroy tyres too prematurely but find that balance between wear & handling which is acceptable.

Are you using the car on track or mainly b-road blasting/dailying it?

 

[GRavy_Baby]

Are you using the car on track or mainly b-road blasting/dailying it?

I don’t daily it, just use it for blasting down the b-roads in my spare time. I live in the Yorkshire Dales so it’s pretty much a giant playground for a GRY. I will be using the car on track every now and again after this geo setup but it’s main use will be flying through these twisty country lanes.

 

[Phil1291]

Thanks @Euge!

Good advice on the rubber vs pillow ball. It’s a shame they don’t make a boot that protects them from debris.

For the fronts, I’m thinking between 2.5 - 3 degrees of negative camber + toe out (as per @Phil1291 ’s recommendation). If caster adjustment is also something the geometry guy would be inclined to tweak, DNA top mounts may be the way?

As I say, I’m wondering if I’m going into the realm of excess seen as this will be mated to OEM CP suspension.

At the same time, I don’t want to destroy tyres too prematurely but find that balance between wear & handling which is acceptable.

Just to be clear:
I don't necessary recommend that... And we did a lot of client cars with completely different alignments.

Because, this was 4 years ago and we tuned like 150 cars in the meantime, plus had tens of hours on the track with our own and a few different setups, so we gained quite some experience.
That's why now every car gets a different alignment.
Depending on the car, the drivers capabilitys, the drivers preffered driving style, the suspension, the tires, how they use the car for etc.

Because in this car it's far from one setup that works for everything.

 

[GRavy_Baby]

Just to be clear:
I don't necessary recommend that... And we did a lot of client cars with completely different alignments.

Because, this was 4 years ago and we tuned like 150 cars in the meantime, plus had tens of hours on the track with our own and a few different setups, so we gained quite some experience.
That's why now every car gets a different alignment.
Depending on the car, the drivers capabilitys, the drivers preffered driving style, the suspension, the tires, how they use the car for etc.

Because in this car it's far from one setup that works for everything.

I appreciate the reply @Phil1291. Of course the geometry isn’t a one size fits all & has to suit the driver’s capabilities. In your opinion, with stock CP suspension, is it worthwhile fitting the DNA top mounts & camber arms? Over the top?

I’m wanting a fairly aggressive fast road setup with turn in that leans more towards oversteer where the rear of the car more willing to rotate. Nimble on never ending bendy roads with the occasional track day etc..

I guess that the settings you posted a few years back took into consideration that you were on coilovers at the time & that they may not translate to my setup. I’m sure my geo guy will point me in the right direction if I’m armed with some settings in mind.

 

[Michael Knight]

my car is quite ok for road but neutral on track. Although occasionally it breaks into mid corner oversteer if pushed. I'd say on track you can run more aggressive setting whereas on road as its more uneven and surface changes too aggressive can bite you if not aware. just be cautious.