GR Yaris Handling upgrades

[Rhys_E]

Hi,

I have a GR Yaris Gen 1 that is completely standard.
What handling upgrades would you recommend for making the car handle better on uneven, undulating B roads.
Does the car even need any modifications?

I watched an old YouTube video from Piras Motorsport which recommended changing the front arm lower rear bushing as well as fitting a spherical rear trailing arm bush.
Has anyone tried this? Is it worth doing for fast road use on mostly broken, bumpy tarmac?
Anything else that you’ve done to the car that improves it?

Thanks

Rhys

 

[Onehp]

Hi,

I have a GR Yaris Gen 1 that is completely standard.
What handling upgrades would you recommend for making the car handle better on uneven, undulating B roads.
Does the car even need any modifications?

I watched an old YouTube video from Piras Motorsport which recommended changing the front arm lower rear bushing as well as fitting a spherical rear trailing arm bush.
Has anyone tried this? Is it worth doing for fast road use on mostly broken, bumpy tarmac?
Anything else that you’ve done to the car that improves it?

Thanks

Rhys

Personally I only do handling mods when I myself find the handling limits and want something changed myself. Else you end up doing mods without particular reason, and if you don't have a clear goal end up throwing all kinds of stuff at it and usually make more compromises...

The stock car handles perfectly fine for most drivers. I could dig up vids of stock cars outrunning modded ones, just with proper drivers.

The only mod I personally did was more negative camber because I myself found a bit too much understeer in a slow in, fast out road driving style. And a load of different wheels for different circumstances.

Sperical bushes are nice and give a bit more feel and less slack, but they are also a maintenance nightmare for a car used year round esp. if salted roads happen.

 

[Duke]

wot he said

The only thing I would do first is change the tyres, assuming you're still on the OEM Michelins (or even the Dunlops )

The Pilot Sport 4S is a great tyre but things have moved on in the last few years. I found the Continental SportContact 7 is a real step up and I've only heard good things about the Pirelli PZ5 which might be even better.

More feel, better turn-in, a better platform for assessing where you think you might need to take things.

 

[Rhys_E]

Personally I only do handling mods when I myself find the handling limits and want something changed myself. Else you end up doing mods without particular reason, and if you don't have a clear goal end up throwing all kinds of stuff at it and usually make more compromises...

The stock car handles perfectly fine for most drivers. I could dig up vids of stock cars outrunning modded ones, just with proper drivers.

The only mod I personally did was more negative camber because I myself found a bit too much understeer in a slow in, fast out road driving style. And a load of different wheels for different circumstances.

Sperical bushes are nice and give a bit more feel and less slack, but they are also a maintenance nightmare for a car used year round esp. if salted roads happen.

Thanks for the advice Onehp.

I bought the car back in May where it had only done 6 miles and it’s done around 900 miles now so could do with a proper alignment.

That’s good to know that the car handles so well from factory as I usually end up modifying cars, but want to do the least modifications as possible on the GR Yaris!
I certainly haven’t found the limits of the car during fast road use on Welsh B roads. I find the standard suspension works really well in these conditions.

 

[Rhys_E]

wot he said

The only thing I would do first is change the tyres, assuming you're still on the OEM Michelins (or even the Dunlops )

The Pilot Sport 4S is a great tyre but things have moved on in the last few years. I found the Continental SportContact 7 is a real step up and I've only heard good things about the Pirelli PZ5 which might be even better.

More feel, better turn-in, a better platform for assessing where you think you might need to take things.

Thanks Duke.

The car is still on the Pilot Sport 4s at the moment.
When I need new tyres I’ll look into changing to the Continental Sport Contact 7 or the Pirelli PZ5 which seem to be getting really good reviews.
I don’t mind the Michelins as I find they grip really well, but added stiffer sidewalls and steering feel would help I’m sure.
My Subaru P1 is on Yokohama Advan A052. A fantastic tyre, but I only use the P1 in the dry so no need to worry about wet weather performance!

 

[Rhys_E]

Personally I only do handling mods when I myself find the handling limits and want something changed myself. Else you end up doing mods without particular reason, and if you don't have a clear goal end up throwing all kinds of stuff at it and usually make more compromises...

The stock car handles perfectly fine for most drivers. I could dig up vids of stock cars outrunning modded ones, just with proper drivers.

The only mod I personally did was more negative camber because I myself found a bit too much understeer in a slow in, fast out road driving style. And a load of different wheels for different circumstances.

Sperical bushes are nice and give a bit more feel and less slack, but they are also a maintenance nightmare for a car used year round esp. if salted roads happen.

Also, what alignment is adjustable from factory?

 

[Duke]

If it's any guide, my alignment at about 25k pretty (very?) hard miles was pretty much as it left the factory so I wouldn't worry about 900 miles knocking it too far out of spec.

Apparently every car undergoes a specific alignment check before it leaves the factory to ensure each performs the same, so I imagine yours is pretty much spot-on as far as the OEM settings go.

You're limited in the front camber that can be dialled-in without aftermarket bolts. Toyota do a variety for specific cambers, or you can get Powerflex or similar which are variable.

 

[Duke]

Regarding standard vs changed suspension, I have found that there are very few times the standard suspension gets a little muddled. It really is very good out of the box.

I would be tempted by a set of coilovers, but only if the car doens't lose its playfulness or sense of weight transfer. Making it wooden and skittish might eke out a slightly better laptime, but it would be a worse car on the road.

I definitley wouldn't want to lower it much or at all (even if it makes it look better @Richard Mckay ) because, well, it's rally car and being able to batter across variable terrain without thinking too much about it is kinda its thing. I've driven with some lowered cars and they have to tiptoe over speedbumps etc., by which time a standard car is four corners down the road

 

[Rhys_E]

Regarding standard vs changed suspension, I have found that there are very few times the standard suspension gets a little muddled. It really is very good out of the box.

I would be tempted by a set of coilovers, but only if the car doens't lose its playfulness or sense of weight transfer. Making it wooden and skittish might eke out a slightly better laptime, but it would be a worse car on the road.

I definitley wouldn't want to lower it much or at all (even if it makes it look better @Richard Mckay ) because, well, it's rally car and being able to batter across variable terrain without thinking too much about it is kinda its thing. I've driven with some lowered cars and they have to tiptoe over speedbumps etc., by which time a standard car is four corners down the road

Yes, I definitely wouldn’t want to lower the car as I feel I need the travel on the roads that I drive.
The best suspension set up that I’ve tried is the Bilstein Prodrive WR set up that I have on my P1. It handles everything while remaining quite comfortable.
I did have an M Sport edition fiesta that I fitted some Reiger rally suspension on but found them quite crashy unless you were going flat out!

 

[Onehp]

Thanks Duke.

My Subaru P1 is on Yokohama Advan A052. A fantastic tyre, but I only use the P1 in the dry so no need to worry about wet weather performance!

Actually the A052 is amazing in the wet too, with very high grip and good slip progression - a rare combo. Apart from aquaplaning resistance, obviously, so watch out for puddles...

I did have an M Sport edition fiesta that I fitted some Reiger rally suspension on but found them quite crashy unless you were going flat out!

That sounds amazing actually, no pootling about! Likewise but milder, the GRY is a touch overdampend and flows best when pushing on, and only when going very hard over succesive bumps it can sometimes be overwhelmed. There exists a budget rally suspension for the GRY I was saving up for before I sold mine, search Protlum on the forum here. Reiger and BOS also do gravel and tarmac kits otherwise at quite a cost, those are the only ones I had considered, keeping in mind that servicing must be doable I wasn't in a hurry....

 

[Rhys_E]

Actually the A052 is amazing in the wet too, with very high grip and good slip progression - a rare combo. Apart from aquaplaning resistance, obviously, so watch out for puddles...

That sounds amazing actually, no pootling about! Likewise but milder, the GRY is a touch overdampend and flows best when pushing on, and only when going very hard over succesive bumps it can sometimes be overwhelmed. There exists a budget rally suspension for the GRY I was saving up for before I sold mine, search Protlum on the forum here. Reiger and BOS also do gravel and tarmac kits otherwise at quite a cost, those are the only ones I had considered, keeping in mind that servicing must be doable I wasn't in a hurry....

Yes, I haven't found the limit of the standard suspension on my GR Yaris yet so wouldn't want to change it in a hurry! The gen 2 GR Yaris have stiffer springs so don't think they would work as well on bumpy, broken B roads and might be slightly more biased for track work. I have been looking at some suspension kits from Samsonas, Bigem and Protlum.
The Samsonas have a coilover design rear so not the separate spring and strut combination. I did speak to Piras Motorsport about this and they said that this wouldn't be an issue and wouldn't need strengthening unless you were doing big jumps on gravel. At the moment, I'm just not sure if I'd really benefit from changing the standard suspension as it works well for my use.

As I don't use the car when the road is gritted, do you think it would be worth fitting a rear trailing arm spherical bushing as well as something like a powerflex front lower arm bush kit?

 

[Onehp]

As I don't use the car when the road is gritted, do you think it would be worth fitting a rear trailing arm spherical bushing as well as something like a powerflex front lower arm bush kit?

Sure, I don't think it's game changing but bit more feel is nice to have, from feedback from others and previous experience of doing similar mods and choosing not to do it again. Iirc DNA has a sperical one that is at least a little sealed.

Piras is slightly controversial, he has some good input to the community but sometimes takes his "expertise" beyond where it actually lies... FYI and all IMHO.

 

[Rhys_E]

Sure, I don't think it's game changing but bit more feel is nice to have, from feedback from others and previous experience of doing similar mods and choosing not to do it again. Iirc DNA has a sperical one that is at least a little sealed.

Piras is slightly controversial, he has some good input to the community but sometimes takes his "expertise" beyond where it actually lies... FYI and all IMHO.

I bought this car and promised myself that I wouldn't modify it as I've spent thousands in the past on cars modifying! Some things improve cars but other things can make them worse to drive and when you do a lot of modifying, sometimes it's hard to know what's doing what!

From speaking to you and others on this forum, it seems like the best thing to do would be to leave the car standard as it drives so well as it is for my needs.

Thanks again for your advice!

 

[Ecsrobin]

The gen 2 GR Yaris have stiffer springs so don't think they would work as well on bumpy, broken B roads and might be slightly more biased for track work.

I disagree. My Gen2 is much more compliant over a broken B road than my Gen1 it’s firmer but smoother and on hard compressions where the Gen1 would rebound with quite an unsettling bounce the Gen2 just settles down and carries on. I can definitely carry more pace now on a back road run.

 

[Onehp]

I disagree. My Gen2 is much more compliant over a broken B road than my Gen1 it’s firmer but smoother and on hard compressions where the Gen1 would rebound with quite an unsettling bounce the Gen2 just settles down and carries on. I can definitely carry more pace now on a back road run.

Yeah it's a bit firmer but there is more quality to the damping. In the end, both remain great driver tools with each their nuances, it's easy to be drawn into a modding rabbit hole when one really only needs to make more memorable drives...

 

[Rhys_E]

I disagree. My Gen2 is much more compliant over a broken B road than my Gen1 it’s firmer but smoother and on hard compressions where the Gen1 would rebound with quite an unsettling bounce the Gen2 just settles down and carries on. I can definitely carry more pace now on a back road run.

That's good to know! I was a bit worried that Toyota had stiffened the suspension up too much for slightly more track bias on the Gen 2. Good to know that the Gen 2 GR Yaris has stuck to it's rally roots. I haven't driven a Gen 2 to compare. It would be nice to try one just to see the differences. Both great B road cars undoubtedly.

 

[Rhys_E]

Yeah it's a bit firmer but there is more quality to the damping. In the end, both remain great driver tools with each their nuances, it's easy to be drawn into a modding rabbit hole when one really only needs to make more memorable drives...

I'm definitely guilty of this. Always thinking about how to improve cars without just going out and enjoying the driving experience!

 

[Yohz78]

I'm definitely guilty of this. Always thinking about how to improve cars without just going out and enjoying the driving experience!

My advice would be to do an alignment with more neg camber front (Toyota intermediate camber bolt maxed out give around -2° 25' of camber which is enough on the road), a tiny touch of toe out front and toe in rear and that's all. Put better tyres (I like 235 / 40 more than 225 / 40 but you do you).

If you don't track the car, just keep the money to burn tyres&fuel and enjoy the ride !

 

[Rhys_E]

My advice would be to do an alignment with more neg camber front (Toyota intermediate camber bolt maxed out give around -2° 25' of camber which is enough on the road), a tiny touch of toe out front and toe in rear and that's all. Put better tyres (I like 235 / 40 more than 225 / 40 but you do you).

If you don't track the car, just keep the money to burn tyres&fuel and enjoy the ride !

Thanks for the advice. I'll definitely look to get a camber of around 2 degrees at the front. I actually prefer a toe in up front and back on all of the cars that I've driven. I find that it improves stability and gives more instant steering response and turn in.

Do you happen to have the part number or link to the camber bolts please?

 

[Duke]

Thanks for the advice. I'll definitely look to get a camber of around 2 degrees at the front. I actually prefer a toe in up front and back on all of the cars that I've driven. I find that it improves stability and gives more instant steering response and turn in.

Do you happen to have the part number or link to the camber bolts please?

Part numbers here: https://www.gr-zoo.com/threads/camber-bolts.343/post-2434