GR Yaris Geo fast road help and track set up

[Phil1291]

Hi @Phil1291 ,
Sorry to bother you with a question on an old post, but is -3 / -2 Camber your recommendation with stock suspension or with an aftermarket one? Thanks!

We learned a bit in the past two years.
It really depends on what you‘re driving, how you‘re driving and what you do like.
We set up each car individually.

 

[Michael Knight]

New setup.
Not sure if that toe is good (50%) what it used to be but lets see.
Front camber now -2 3/4 and rear -2 1/2

 

[Michael Knight]

there was somewhere a question regarding stock caster. at least in my car in first setup caster was tad under 5degrees and 30minutes, so now its 0.5 degree more (thanks to the caster bushings that add roughly 0.5 degree, depening of course how they are set up).

Funnily enough, in my first alignment noted that at least toe setup was out on both axles so worth checking up no matter what camber you will do, just to avoid any excessive tire wear.

 

[LittleMav]

there was somewhere a question regarding stock caster. at least in my car in first setup caster was tad under 5degrees and 30minutes, so now its 0.5 degree more (thanks to the caster bushings that add roughly 0.5 degree, depening of course how they are set up).

Can you / someone else tell how much more dynamic camber the 0.5 degrees are giving us in corners? Thanks!

 

[Spirited]

New setup.
Not sure if that toe is good (50%) what it used to be but lets see.
Front camber now -2 3/4 and rear -2 1/2

View attachment 25833

I've had 3 minutes toe out each side at the front for some time now. I went for it as a conservative approach to toe out, mainly to avoid excessive and uneven tyre wear.

While it probably delivered on the tyre wear front, I haven't been particularly impressed with it other than that. None of that darty, pointy, almost over-sensitive feel I was after.

Owners more experienced than me, like @DeanoC and @Yaris San , seem to be going for 4 minutes each side, which I believe was @Phil1291 's recommendation for fast road use. Based on my experience with 3 minutes, I wouldn't expect a noticeable difference if I tried 4.

I really enjoy 6 minutes on a RWD car, but it's a recent setting so will be monitoring tyres closely for wear. So, next steps for me are likely to be to:

• reduce toe out on the RWD (they don't need as much, according to YS Khong) to preserve tyres.
• increase toe out (to probably more than 4 minutes) on the GRY to experience an almost hyperactive, or at least a bit over-keen, front. Should be nice alongside the increased feel I hope to get through the caster kit and as good as it gets for a 4WD, without killing tyres or getting too much feel through eg solid top mounts.
• continue the pursuit of the elusive sweetspot that I thought you had found at 7 minutes.

What are your early insights from switching from 7 to 3?

 

[Spirited]

there was somewhere a question regarding stock caster. at least in my car in first setup caster was tad under 5degrees and 30minutes, so now its 0.5 degree more (thanks to the caster bushings that add roughly 0.5 degree, depening of course how they are set up).
...

I would be interested to know what caster setting Toyota set for the MK2. And the thinking behind it, if it's lower than for the MK1.

 

[Onehp]

Can you / someone else tell how much more dynamic camber the 0.5 degrees are giving us in corners? Thanks!

Will be surprised if someone can give a straight answer. On some alignment machines you can turn the wheel and read out the dynamic camber. It varies with the turning angle obviously.
You can see it as follows, if you were able to turn the front wheels 90 degrees, you will get the full caster increase in dynamic camber here 0,5 degree. So on a typical quarter turn higher speed turn in, we're ballpark 0,1 degree increase in dynamic camber. Not so much considering most can't tell that difference in static camber. Difference does increase in very tight turns where it can make a noticeable difference.
However, talking dynamic, there is also how the alignment changes under load, and here the relative soft stock bushing will move and reduce camber. Stiffer aftermarket bushing(s) will probably make a similar contribiton as the static angle changes, and compound they make it noticeable.
Fun part of this platform is that there are at least 3-4 bushing and similar amount of (fully adjustable) aftermarket lower arms available already, so you can optimise at infinitum if that's your thing....

 

[LittleMav]

Will be surprised if someone can give a straight answer. On some alignment machines you can turn the wheel and read out the dynamic camber. It varies with the turning angle obviously.
You can see it as follows, if you were able to turn the front wheels 90 degrees, you will get the full caster increase in dynamic camber here 0,5 degree. So on a typical quarter turn higher speed turn in, we're ballpark 0,1 degree increase in dynamic camber. Not so much considering most can't tell that difference in static camber. Difference does increase in very tight turns where it can make a noticeable difference.
However, talking dynamic, there is also how the alignment changes under load, and here the relative soft stock bushing will move and reduce camber. Stiffer aftermarket bushing(s) will probably make a similar contribiton as the static angle changes, and compound they make it noticeable.
Fun part of this platform is that there are at least 3-4 bushing and similar amount of (fully adjustable) aftermarket lower arms available already, so you can optimise at infinitum if that's your thing....

Thank you very much again @Onehp for the reply - this puts things into perspective.

 

[Michael Knight]

Will be surprised if someone can give a straight answer. On some alignment machines you can turn the wheel and read out the dynamic camber. It varies with the turning angle obviously.
You can see it as follows, if you were able to turn the front wheels 90 degrees, you will get the full caster increase in dynamic camber here 0,5 degree. So on a typical quarter turn higher speed turn in, we're ballpark 0,1 degree increase in dynamic camber. Not so much considering most can't tell that difference in static camber. Difference does increase in very tight turns where it can make a noticeable difference.
However, talking dynamic, there is also how the alignment changes under load, and here the relative soft stock bushing will move and reduce camber. Stiffer aftermarket bushing(s) will probably make a similar contribiton as the static angle changes, and compound they make it noticeable.
Fun part of this platform is that there are at least 3-4 bushing and similar amount of (fully adjustable) aftermarket lower arms available already, so you can optimise at infinitum if that's your thing....

also putting one variable into play as suspension movement increases/decreases camber too.

 

[Yaris San]

I've had 3 minutes toe out each side at the front for some time now. I went for it as a conservative approach to toe out, mainly to avoid excessive and uneven tyre wear.

While it probably delivered on the tyre wear front, I haven't been particularly impressed with it other than that. None of that darty, pointy, almost over-sensitive feel I was after.

Owners more experienced than me, like @DeanoC and @Yaris San , seem to be going for 4 minutes each side, which I believe was @Phil1291 's recommendation for fast road use. Based on my experience with 3 minutes, I wouldn't expect a noticeable difference if I tried 4.

I really enjoy 6 minutes on a RWD car, but it's a recent setting so will be monitoring tyres closely for wear. So, next steps for me are likely to be to:

• reduce toe out on the RWD (they don't need as much, according to YS Khong) to preserve tyres.
• increase toe out (to probably more than 4 minutes) on the GRY to experience an almost hyperactive, or at least a bit over-keen, front. Should be nice alongside the increased feel I hope to get through the caster kit and as good as it gets for a 4WD, without killing tyres or getting too much feel through eg solid top mounts.
• continue the pursuit of the elusive sweetspot that I thought you had found at 7 minutes.

What are your early insights from switching from 7 to 3?

if you want let me know what you're hoping to achieve regarding your vehicle's handling might be able to help

 

[Spirited]

if you want let me know what you're hoping to achieve regarding your vehicle's handling might be able to help

Hi, thank you! I appreciate the offer and also the approach, as different setups apply to different tastes and requirements, etc.

For context my current setup (& thinking behind it from a year ago) is as per my post.

I never felt the night-and-day difference others have been experiencing, despite setting front negative camber at -2.5 degrees. The car (on top quality tyres swapped around regularly) still understeers (eg on throttle mid-corner) enough to annoy me, albeit nowhere near as much.

So, what I want to achieve for my fast-road use is to:

1. eliminate understeer without compromising on overall grip, ie by improving front-end grip rather than eg reducing the camber or toe-in at the rear (or increasing tyre pressures there) as a workaround.
2. get a bit more feel from the steering, ie a bit more directness, responsiveness and feedback.
3. not get myself or my tyres killed in the process.

My plan to achieve each of these respectively is:

1. increase static and dynamic front camber to cure understeer. Contemplating moving from current -2.5 to anything between -2.75 and -3, while also installing a caster kit for the maximum +0.5 caster it may bring. -2.75 and caster kit was the initial plan, but reading @Onehp 's view that most won't notice such minor camber changes (ie what the caster kit will bring as dynamic camber or even the added 0.25 degree of negative static I was looking to set), I am gradually leaning towards -3, especially for the summer (it may also be that I have entered an unofficial competition with @Michael Knight as to who loves cornering more; while I'm eagerly awaiting his experience of -2.75, watching typically risk-averse @Onehp following a similar path towards -3 over time doesn't help stick to much lower). I appreciate your mention of -1º of dynamic camber through caster kits, which leaves me wondering, just like @LittleMav in his post, how much camber gain to expect through caster kits.
2. improve front-end feel through a caster kit (ie primarily based on its stiffer bushing, perhaps together with any anti-lift properties) and some (more) toe out. Aiming to install a rear trailing arm uniball, also in the hope that it will offer better steering feel, despite fitted at the rear; @Onehp shares this opinion, so ti must be true.
3. more camber alongside more toe-out will undoubtedly increase tyre wear on the inner side of front tyres. So, looking for my sweetspot and thinking that moving from my current -3 minutes to your -4 minutes will probably not make any noticeable difference. In the meantime, installing the rear trailing arm should hopefully reduce the notorious GRY hop there (ie snap oversteer) making the car more predictable at the limit. I think this and having lived with the current more-aggressive-than-stock settings for a year, justifies reducing rear toe-in a bit (perhaps even toying with zero toe or slight toe-out in the future ) and increasing the front-rear camber difference a tiny bit, which should both contribute towards less understeer overall.

 

[Michael Knight]

I've had 3 minutes toe out each side at the front for some time now. I went for it as a conservative approach to toe out, mainly to avoid excessive and uneven tyre wear.

While it probably delivered on the tyre wear front, I haven't been particularly impressed with it other than that. None of that darty, pointy, almost over-sensitive feel I was after.

Owners more experienced than me, like @DeanoC and @Yaris San , seem to be going for 4 minutes each side, which I believe was @Phil1291 's recommendation for fast road use. Based on my experience with 3 minutes, I wouldn't expect a noticeable difference if I tried 4.

I really enjoy 6 minutes on a RWD car, but it's a recent setting so will be monitoring tyres closely for wear. So, next steps for me are likely to be to:

• reduce toe out on the RWD (they don't need as much, according to YS Khong) to preserve tyres.
• increase toe out (to probably more than 4 minutes) on the GRY to experience an almost hyperactive, or at least a bit over-keen, front. Should be nice alongside the increased feel I hope to get through the caster kit and as good as it gets for a 4WD, without killing tyres or getting too much feel through eg solid top mounts.
• continue the pursuit of the elusive sweetspot that I thought you had found at 7 minutes.

What are your early insights from switching from 7 to 3?

as initial feel tend to agree with your opinion with toe out setup, before it felt nicer in steering.
So maybe need to redial it back, but checking the tyre wear first after this summer.

btw stock caster is -6 in GR Yaris. mine was half degree less initially, now back to stock reference more or less.
With camber I'm with -2.75' now front (or tyre shop guys prefer talking here 2 degrees and 45 minutes). Its always a matter of balance. Likely will not be able to dial all understeer off, but don't see that as a big issue. longer corners are though for gr and those just need to be managed somehow through, with patience. elsewhere I think the new setup will be fun.

 

[Yaris San]

Hi, thank you! I appreciate the offer and also the approach, as different setups apply to different tastes and requirements, etc.

For context my current setup (& thinking behind it from a year ago) is as per my post.

I never felt the night-and-day difference others have been experiencing, despite setting front negative camber at -2.5 degrees. The car (on top quality tyres swapped around regularly) still understeers (eg on throttle mid-corner) enough to annoy me, albeit nowhere near as much.

So, what I want to achieve for my fast-road use is to:

1. eliminate understeer without compromising on overall grip, ie by improving front-end grip rather than eg reducing the camber or toe-in at the rear (or increasing tyre pressures there) as a workaround.
2. get a bit more feel from the steering, ie a bit more directness, responsiveness and feedback.
3. not get myself or my tyres killed in the process.

My plan to achieve each of these respectively is:

1. increase static and dynamic front camber to cure understeer. Contemplating moving from current -2.5 to anything between -2.75 and -3, while also installing a caster kit for the maximum +0.5 caster it may bring. -2.75 and caster kit was the initial plan, but reading @Onehp 's view that most won't notice such minor camber changes (ie what the caster kit will bring as dynamic camber or even the added 0.25 degree of negative static I was looking to set), I am gradually leaning towards -3, especially for the summer (it may also be that I have entered an unofficial competition with @Michael Knight as to who loves cornering more; while I'm eagerly awaiting his experience of -2.75, watching typically risk-averse @Onehp following a similar path towards -3 over time doesn't help stick to much lower). I appreciate your mention of -1º of dynamic camber through caster kits, which leaves me wondering, just like @LittleMav in his post, how much camber gain to expect through caster kits.
2. improve front-end feel through a caster kit (ie primarily based on its stiffer bushing, perhaps together with any anti-lift properties) and some (more) toe out. Aiming to install a rear trailing arm uniball, also in the hope that it will offer better steering feel, despite fitted at the rear; @Onehp shares this opinion, so ti must be true.
3. more camber alongside more toe-out will undoubtedly increase tyre wear on the inner side of front tyres. So, looking for my sweetspot and thinking that moving from my current -3 minutes to your -4 minutes will probably not make any noticeable difference. In the meantime, installing the rear trailing arm should hopefully reduce the notorious GRY hop there (ie snap oversteer) making the car more predictable at the limit. I think this and having lived with the current more-aggressive-than-stock settings for a year, justifies reducing rear toe-in a bit (perhaps even toying with zero toe or slight toe-out in the future ) and increasing the front-rear camber difference a tiny bit, which should both contribute towards less understeer overall.

reading through it seems you're probably 85% correct in what you've done and are trying to achieve

heres my take on some thing you possible already know

2.5º of neg static camber is more than enough for a road car especially if you also induce active camber with increased caster, it also places more rubber on the road in straight line braking than say 3° of camber

Camber does not wear the inner edge of tyres, it'll wear one half of tyre tread a bit more than the other half, the inner wear is caused when the unloaded tyre during cornering 'drags' or 'scrabbles' across the tarmac and this is due to insufficient caster, increase the caster angle and the unloaded tyre will stand more upright during cornering

The factory caster on these is around 5.5º and with a rear front arm bush plus an adjustable top mount over 7º can be achieved which will eliminate inner wear and give more active camber

Engine and gearbox stability from factory is relatively poor but means its good for NVH in the cabin, firm up the mounts will give good improvement to vehicle turn in as vehicle and engine are more tie together instead of slight engine movement delay

Regarding toe, typically toe IN promotes understeer but gives good straight line stability, conversely toe OUT kill off understeer but may induce varying degrees of tramlining, same for rear IN more straight line stability and OUT more loose rear during cornering and of course we know its expensive to experiment with different set ups, I run 4mins toe OUT front, 4mins toe IN rear

Corner weighting does wonder for these cars, half a tank of fuel and driver weight in seat plus adjustable drop links is a good move towards a stable car
most important is to disconnect one end of each drop link while setting up ride height and geo as the links play no part in vehicle set up. However its v important to make sure there's absolutely no tension when finally reconnecting the drop links as even a small amount on the sway bars can induce a gentle sway to the car even in straight line

For ref my car is super planted with zero under or oversteer, changes direction like a Lotus, brakes perfectly in straight line and has massive grip in and out of corners which of course make it highly encouraging to drive

 

[LittleMav]

reading through it seems you're probably 85% correct in what you've done and are trying to achieve

heres my take on some thing you possible already know

2.5º of neg static camber is more than enough for a road car especially if you also induce active camber with increased caster, it also places more rubber on the road in straight line braking than say 3° of camber

Camber does not wear the inner edge of tyres, it'll wear one half of tyre tread a bit more than the other half, the inner wear is caused when the unloaded tyre during cornering 'drags' or 'scrabbles' across the tarmac and this is due to insufficient caster, increase the caster angle and the unloaded tyre will stand more upright during cornering

The factory caster on these is around 5.5º and with a rear front arm bush plus an adjustable top mount over 7º can be achieved which will eliminate inner wear and give more active camber

Engine and gearbox stability from factory is relatively poor but means its good for NVH in the cabin, firm up the mounts will give good improvement to vehicle turn in as vehicle and engine are more tie together instead of slight engine movement delay

Regarding toe, typically toe IN promotes understeer but gives good straight line stability, conversely toe OUT kill off understeer but may induce varying degrees of tramlining, same for rear IN more straight line stability and OUT more loose rear during cornering and of course we know its expensive to experiment with different set ups, I run 4mins toe OUT front, 4mins toe IN rear

Corner weighting does wonder for these cars, half a tank of fuel and driver weight in seat plus adjustable drop links is a good move towards a stable car
most important is to disconnect one end of each drop link while setting up ride height and geo as the links play no part in vehicle set up. However its v important to make sure there's absolutely no tension when finally reconnecting the drop links as even a small amount on the sway bars can induce a gentle sway to the car even in straight line

For ref my car is super planted with zero under or oversteer, changes direction like a Lotus, brakes perfectly in straight line and has massive grip in and out of corners which of course make it highly encouraging to drive

This is a good read, thank you @Yaris San. Question: your reference to -2.5 deg. camber is for the front I suppose. What would you say for the rear?

 

[Onehp]

For ref my car is super planted with zero under or oversteer, changes direction like a Lotus, brakes perfectly in straight line and has massive grip in and out of corners which of course make it highly encouraging to drive

Good write up, please also reference what tyres are used. Also suspension is a relevant factor, as it seems you have corner weight possibilities and perhaps spring rates play in. Not entirely convinced inner wear isn't cause by camber (in combo with toe) but the inner scrubbing is definitely also a factor on high camber.

Also a reminder that geo is a personal thing, e.g. for me the above description sounds a bit boring, I want some minor understeer when I want and also some oversteer under power with added lock...

This is a good read, thank you @Yaris San. Question: your reference to -2.5 deg. camber is for the front I suppose. What would you say for the rear?

Guessing -2 rear

 

[GRgrampa]

Good write up, please also reference what tyres are used. Also suspension is a relevant factor, as it seems you have corner weight possibilities and perhaps spring rates play in. Not entirely convinced inner wear isn't cause by camber (in combo with toe) but the inner scrubbing is definitely also a factor on high camber.

Also a reminder that geo is a personal thing, e.g. for me the above description sounds a bit boring, I want some minor understeer when I want and also some oversteer under power with added lock...


Guessing -2 rear

Was thinking much the same.

 

[Michael Knight]

Went on a short drive on smaller roads and front end feels better in corners so happy with camber add. Hope to get the setup tested on track in April.
the toe can be felt only in initial turn so not really a biggie.

 

[Yaris San]

tyre choice i use a combination of the usual suspects depending on availability so Conti Sport Contact 7, F1 Supersports, PS5, some PS4S, they're all very similar some better in wet others better in dry and some handle track temps a little better, but none have any bearing on my geo set up, still end up with same settings. Same with suspension, fitting a better quality shock but with similar rates to factory has no real bearing on geo setting

it not until you start lowering with considerably firmer springs, proper sticky AR1 or Dizzy level of tyre at which point you can go with a more aggressive geo setting like 8mins toe OUT per side and 4º camber to really exploit the massive grip from track tyres and smooth track surface, a car with that set up may not be too forgiving on public roads just the pot holes alone would be major deterrent

 

[Michael Knight]

Very happy with current geo on track. was able to improve 2 seconds with same tyre from last year in similar layout. Cool day '10'C.
Car does not understeer that much and actually started lifting wheel in corners meaning corner speeds were better.
Took few laps to get the confidence to push faster as front end was gripping better.

Used also higher pressure in tires, now around 2.4-2.7bar. felt they worked better aswell, so can recommend 2.4-2.5 for narrow MPSC2.

best lap

 

[Spirited]

Very happy with current geo on track. was able to improve almost 3s with same tyre from last year in similar layout. Cool day '10'C.
Car does not understeer that much and actually started lifting wheel in corners meaning corner speeds were better.
Took few laps to get the confidence to push faster as front end was gripping better.

Used also higher pressure in tires, now around 2.4-2.7bar. felt they worked better aswell, so can recommend 2.4-2.5 for narrow MPSC2.

Wow, -2.75° & toe out at front, together with added dynamic camber and, as you predicted, some understeer is still evident!

There goes my plan for a similar geo setting.

Not keen to start with learning about, paying for and the whole process for corner weighting, adjustable droplinks & top mounts that @Yaris San kindly mentioned.

So, I will probably be entering the -3° territory for front static camber (plus a bit more through the caster kit); another thing I wasn't too keen on for my road use, but probably easier to live with daily than the harshness that solid top mounts innevitably bring.