GR Yaris Milan's GR Yaris Track build

[MilanGRY]

Hello everyone !

I am Milan, 24 years old and have bought myself a GR Yaris back in October 2022.
Also, I started racing in 2022, quite succesfully getting multiple wins and pole positons in TCR driving a Renault Mégane RS.

I've bought the GR Yaris mainly to drive a few trackdays just for fun and keeping me in shape.

The first thing I did was getting it on the dyno from my dads workshop to get a baseline.
I measured it at 265 hp and 390Nm at the crank.

I then decided to put a half cage and bucket seats on it, so I ordered the half cage from AST from Spain, welded the base plates on the car and painted the cage in white.
For the seats I got the Recaro Pole Position FIA in Velour red as I am huge Honda fan and owner of an S2000, I wanted to go to a little bit of a retro style like a Civic EK9 or a NSX-R with the white and red combo.

Right after I started modifying the suspension with Öhlins R&T coilovers, DNA topmounts, H&R adjustable swaybars and rear adjustable camber arm bolts.
I quickly noticed that with the Öhlins coilovers, the car was sitting way too high for my liking.
So I ordered shorter springs with a different spring rate at the rear and helper springs to keep the preload when lowering further.
I have drawn and 3d printed the helper spring seats and with that setup I got almost perfect fitment.
The rear has a slight rake and I can't go any lower as I only have 2.5cm of compression left on the rear dampers, if I go lower I will hit the bumpstop.

Also I have put new wheels, a very rare set of Rays G07WT in 17x9 +30 with 8mm spacers at the front on Yokohama A052 255/40 R17.

And after that it was time to fit the HJS Downpipe, Whifbitz full titanium exhaust and the Eventuri airbox with the Do88 Turbo inlet.

Then I fitted the Lamspeed oil baffle kit, removed the brake shield and mounted the OEM brake ducts from the Audi RS3.
Also I have drawn a fire extinguisher bracket on Fusion360 and got it laser cut and bend to fit under the passenger seat.

Part 2 coming right up !

 

[MilanGRY]

After that I got a Aim Solo2 Laptimer and did a really clean job of fitting it. It sits under the headunit and not a single wire is visible since I tucked everything neatly behind the dashboard. It starts up automatically when ignition is on and turns itself off after 2mins when no track is near range.
The bracket for the laptimer I did draw and 3d printed it and its bolted down on the panel tray.

I've put a set of braided brake lines and Motion Control 2-piece brake discs with PBS pads and then it was finally time for my first Trackday in the GR Yaris.

I've went to Anneau du Rhin on the 13th March this year on the 3.0km variant and I was seriously impressed by the pace with the car.
The balance is so good its very agile on the high speed section and you can drive very tight lines on the exit of the corners.
Sadly there was way too much traffic in the morning and in the afternoon the tyres were completely shot, but I did manage to drive a 1:22,35, which is almost as fast as a 718 Cayman GTS 4.0 tested by Sport Auto Magazine, very impressive for the GR Yaris with stock ECU and and even with stock suspension arms.

And here is the POV Onboard lap :



This week my wheels finally arrived that I have been waiting for so long.

Desmond Regamaster Evo2 18x9.5 +45
Michelin PS5 265/35 R18

This is everything so far I did to the car since October 2022, there are definitely some details I missed but these are all the major things.
I am currently in the process of restoring my Honda S2000, which hopefully will be ready in the summer, after that the goal is to put Kelford cams and a intercooler on the Yaris and do a Ecutek tune.

 

[Onehp]

Very nice build and nice selection of parts.

One thing though, this ain't a touring car so why go so low, should compensate geometry then if it's to be proper track worthy. But I suppose these are perhaps coming, then my comment is less valid (but still would want more bump travel on bumpy/curbs tracks...)

 

[LittleMav]

Willkommen im Zoo!

 

[MilanGRY]

Very nice build and nice selection of parts.

One thing though, this ain't a touring car so why go so low, should compensate geometry then if it's to be proper track worthy. But I suppose these are perhaps coming, then my comment is less valid (but still would want more bump travel on bumpy/curbs tracks...)

Thanks a lot and your point is completely valid.

Obviously the lower you go the better is the center of gravity and the less drag the car produces.
And as for my application the damper travel is enough, I did test this thoroughly on the street and on the track. For others it might be a problem it always depends where you are driving.
But my plan is to get the complete Verkline kit for full adjustability.
Even in stock height the GR Yaris suffers from a way too high roll center for track driving the difference is really not that big with my ride height.

 

[SuperHoon]

the lap timer mount is very neat, i think i'd like to mount my Garmin Catalyst in a similar location.

 

[Michael Knight]

nice build - welcome!
interested with those RS3 brake ducts - what P/N fits? I just got a damage to driver side aftermarket brake duct so maybe need to swap for something more robust.

 

[Sekred]

So can we have another dyno run with the Mods installed please.

 

[MilanGRY]

nice build - welcome!
interested with those RS3 brake ducts - what P/N fits? I just got a damage to driver side aftermarket brake duct so maybe need to swap for something more robust.

Thank you ! The part numbers are 8V0 407 811 and 8V0 407 812.
They need a bit of trimming to make them fit but nothing too major and so far have been holding well.

So can we have another dyno run with the Mods installed please.

Yes I will definitely do another dyno test with the current mods, we're currently moving to a new workshop hopefully in about a month the dyno will be working again !
But from what I can tell the car did pick up power and what surprised me the most how much more responsive the engine got.

 

[Michael Knight]

Thank you ! The part numbers are 8V0 407 811 and 8V0 407 812.
They need a bit of trimming to make them fit but nothing too major and so far have been holding well.



Yes I will definitely do another dyno test with the current mods, we're currently moving to a new workshop hopefully in about a month the dyno will be working again !
But from what I can tell the car did pick up power and what surprised me the most how much more responsive the engine got.

thanks - ordered a kit!

 

[xpertleader]

Hey @MilanGRY really awesome looking car - congratulations. I spotted the mounting for the Aim Solo 2 DL - I actually ended up going the 3D printed route with mine so I can keep the shelf space for my phone.

I'm interested to hear how you've got on with your Aim Solo? I have mine connected via the OBDII port using the standard OBD/CAN protocol but I'm currently only able to read Engine RPM. I've been in contact with Aim Solo trying to find solutions to getting more critical data (e.g. throttle, brake, steering, etc) but it seems they don't think it's possible without splicing into the loom and running a custom protocol. I've debated trying the GR86 protocol or perhaps another Toyota model. I was wondering if you've had more success getting it to work?

 

[LittleMav]

I am currently in the process of restoring my Honda S2000, which hopefully will be ready in the summer, after that the goal is to put Kelford cams and a intercooler on the Yaris and do a Ecutek tune.

Hello @MilanGRY - Out of curiosity - have you been able to go down the Kelford Cam & Ecutek route yet?

 

[MilanGRY]

Hey @MilanGRY really awesome looking car - congratulations. I spotted the mounting for the Aim Solo 2 DL - I actually ended up going the 3D printed route with mine so I can keep the shelf space for my phone.

View attachment 32559

I'm interested to hear how you've got on with your Aim Solo? I have mine connected via the OBDII port using the standard OBD/CAN protocol but I'm currently only able to read Engine RPM. I've been in contact with Aim Solo trying to find solutions to getting more critical data (e.g. throttle, brake, steering, etc) but it seems they don't think it's possible without splicing into the loom and running a custom protocol. I've debated trying the GR86 protocol or perhaps another Toyota model. I was wondering if you've had more success getting it to work?

Thanks a lot ! Yes currently I am only using the Solo 2 as a lap timer, because Aim doesn't support the GRY Ecu but I've thought about connecting it to the Can Bus and write a Programm with the current known Can Bus adresses (Oil Pressure, Oil temp, Tyre temp etc.)

Hello @MilanGRY - Out of curiosity - have you been able to go down the Kelford Cam & Ecutek route yet?

Hello Mav, sadly not yet I was busy finishing the restoration of my S2000. But I've been debating to put a Syvecs ECU in the car as Ecutek doens't seem to be fully flashed out yet in terms of all the functions.

In the next couple of weeks I will probably make an update as I am currently preparing some cooling mods for the car.

 

[MilanGRY]

Well, its been a few months since I made a update about my build.

I've been busy with a lot of different stuff including finishing the restoration of my Honda S2000.
But I was enjoying some miles in my Yaris the last few months :

But now its time to get serious again.
The first thing I have on my list is to improve the cooling.
Now personally I'm not a huge fan of the traditional air to air oil coolers due to the added risk of damage (stone hitting the cooler for example), the pressure loss and a few other factors.

This is why I'll be doing water cooled oil cooler.
The Gen2 GR Yaris has got an auxiliary radiator. The only thing it does is adding coolant capacity to the system.
My plan is to use a auxiliary radiator, which is dedicated to an additional heat exchanger which then cools the oil.
The oil temperature will be controlled with a thermostat to not overcool it.
I think this is the best solution, because water cooling is more efficient, the pressure loss will be lower as I will be placing the heat exchanger directly beneath the Oil filter housing and there is not much risk in case of damage.
Keep in mind I'm doing all this by myself and this is all in development phase and there will be lots of testing to make it all work.

So for this project alone I have gotten myself a 3D Scanner, new Laptop and a lot of parts.

I started by scanning the front bumper section and removing the bumper and scanning everything behind it to get as much data as possible :

As for the auxiliary radiator i initially planned to use the one from the VW Golf 8 R, so I've measured all the dimensions and made a template in CAD to use for mockup.
I've aligned all the 3D Scans I made and placed the radiator in there to find a good position.

But quickly I found out there is very little space to fit the radiator behind the foglight cover, which is my preferred spot for it.
Its not impossible to make it work, but I've ordered a Gen2 auxiliary radiator to compare it as that one might be more suited because its a little narrower and thicker.
As you can already see in the photo above I'll be using the Gen2 Air duct exit on my Gen1 Bumper because it redirects the air outside the wheelwell to not increase lift.

And for the Air inlet I'll be making a custom cover with an upper and lower inlet to maximize the cooling area.
Below you'll see the first version, some slight improvements will still be made.

Thats so far the update as of today.
For the heat exchanger my plan is to use a Laminova cooler.
I am still debating if I should connect 2 Laminova coolers on this radiator to also cool the transfer case or make a seperate radiator for it on the other side.

 

[GReeni]

Nice thread, great looking car.

 

[LittleMav]

Keep the updates comming Milan…

 

[aitormartin]

Well, its been a few months since I made a update about my build.

I've been busy with a lot of different stuff including finishing the restoration of my Honda S2000.
But I was enjoying some miles in my Yaris the last few months :
View attachment 36672

But now its time to get serious again.
The first thing I have on my list is to improve the cooling.
Now personally I'm not a huge fan of the traditional air to air oil coolers due to the added risk of damage (stone hitting the cooler for example), the pressure loss and a few other factors.

This is why I'll be doing water cooled oil cooler.
The Gen2 GR Yaris has got an auxiliary radiator. The only thing it does is adding coolant capacity to the system.
My plan is to use a auxiliary radiator, which is dedicated to an additional heat exchanger which then cools the oil.
The oil temperature will be controlled with a thermostat to not overcool it.
I think this is the best solution, because water cooling is more efficient, the pressure loss will be lower as I will be placing the heat exchanger directly beneath the Oil filter housing and there is not much risk in case of damage.
Keep in mind I'm doing all this by myself and this is all in development phase and there will be lots of testing to make it all work.

So for this project alone I have gotten myself a 3D Scanner, new Laptop and a lot of parts.

I started by scanning the front bumper section and removing the bumper and scanning everything behind it to get as much data as possible :
View attachment 36674
View attachment 36675

As for the auxiliary radiator i initially planned to use the one from the VW Golf 8 R, so I've measured all the dimensions and made a template in CAD to use for mockup.
I've aligned all the 3D Scans I made and placed the radiator in there to find a good position.
View attachment 36677
View attachment 36679

But quickly I found out there is very little space to fit the radiator behind the foglight cover, which is my preferred spot for it.
Its not impossible to make it work, but I've ordered a Gen2 auxiliary radiator to compare it as that one might be more suited because its a little narrower and thicker.
As you can already see in the photo above I'll be using the Gen2 Air duct exit on my Gen1 Bumper because it redirects the air outside the wheelwell to not increase lift.

And for the Air inlet I'll be making a custom cover with an upper and lower inlet to maximize the cooling area.
Below you'll see the first version, some slight improvements will still be made.
View attachment 36681


Thats so far the update as of today.
For the heat exchanger my plan is to use a Laminova cooler.
I am still debating if I should connect 2 Laminova coolers on this radiator to also cool the transfer case or make a seperate radiator for it on the other side.

Very interesting! What 3D scanner did you get?

 

[MilanGRY]

Nice thread, great looking car.

Thanks a lot I appreciate it !

Keep the updates comming Milan…

For sure I have definitely some more interesting stuff coming.

Very interesting! What 3D scanner did you get?

I got the Einstar Vega, its my first 3D scanner so I can't compare it against others but so far it does the job really good.

 

[MilanGRY]

Time for a little update.

While I have been waiting for the Gen2 Aux Radiator to arrive, I started working on the intercooler setup.
I have gotten the PWR Intercooler from Australia, mainly because its not too big unlike most aftermarket intercoolers and its fairly light as well.
Now with basically every intercooler upgrade you have to get rid of the ducting.
I decided to design a completely new ducting which also seals off the front end completely to force more air to the intercooler and radiator and reduce drag unlike the OEM setup which has inlets on both sides.

I started by scanning the complete front bumper and everything behind it.

I made a rough first prototype and 3D printed in bright green to check how the geometry lines up and how it fits :

The first prototype came out really nice but in reality it took me a further 12 revisions until I was fully satisfied with the ducting.
I literally spent my whole 2 weeks of holiday working on this part alone.
On the right side the duct bolted straight up to the existing threads of the OEM duct. I just added 2 additional bolts on the side of the grill for extra rigidity.
On the left side there were no threads so I made special inserts with threads that are glued on the inside of the grill.

Anyways here is the design of the final version of the duct :

It was very time consuming to make the duct as rigid as possible to keep it from flexing and cracking which is why it has the hexagon backing and additional ridges.
I've 3D printed both sides out of ASA and mounted it to the car :

The final parts will probably printed out of a industrial 3D printer, I will do one and compare it with the current ones.
Also I will paint the intercooler to get rid of the stencil to have a nice clean OEM look.
I'm very proud how it turned out but the focus will now get back on making the Auxiliary radiator.

Stay tuned!

 

[Juri-GR4]

Dedication and focus. Do you know how much the PWR intercoolers weighs?