GR Yaris If u know how hot ur Gr Yaris transfer case can get, u will never drive ur Gr Yaris in same way

[Diyman25]

I never understood why Toyota give green light on this design , or they are pretty comfortable Gr Yaris transfer case strength
Which will run over 170-180c even with GRMN panel install just 2lap of serious track driving from 82/82 (75/140 gear oil ) which is crazy
I have to use gear oil of 75/250 that design for drag car to kind da control temperature around 150c
As u can see gearbox oil in very normal operating temperatures

 

[Diyman25]

I now install transfer case cooler on my Time attack Gr Yaris , hope this can solve
Transfer case overheat problem

 

[TTomas]

If you have Xshift sequential they do make a dry sump conection with the transfer case.

 

[Diyman25]

If you have Xshift sequential they do make a dry sump conection with the transfer case.

From what I gather feedback on the community
Kotouc is better quality box

 

[TTomas]

My friend designed and tested the Xshift and it should be a bit better (gear can not get stuck and have the trans oil conection) but both are superior. They use to be one company Kaps trans here in Czech but split some time ago.

 

[MRA3]

I don’t think the standard gr yaris transfer case had a design brief to be able to cope with serious track work, on 295 semi slick tires with a lot of extra downforce. You should upgrade it to your use case and not blame the OEM, imho.

 

[Ecsrobin]

I don’t think the standard gr yaris transfer case had a design brief to be able to cope with serious track work, on 295 semi slick tires with a lot of extra downforce. You should upgrade it to your use case and not blame the OEM, imho.

This. It’s designed for the road and copes fine in that scenario.

 

[Diyman25]

Even in stander power trim , the transfer case is still very hot , transfer case can go over 150C if use in track condion ( been monitor it since day 1 )

 

[tonic]

Even in stander power trim , the transfer case is still very hot , transfer case can go over 150C if use in track condion ( been monitor it since day 1 )

Do you have photos of the temp sensor installation and plumbing of the cooling lines?

 

[Ecsrobin]

Even in stander power trim , the transfer case is still very hot , transfer case can go over 150C if use in track condion ( been monitor it since day 1 )

Standard power trim with wide slicks or standard power and wheels/tyres?

 

[Diyman25]

Standard power trim with wide slicks or standard power and wheels/tyres?

Bolt on like intake , down pipe and hks power editor
Wide high performance tire

 

[Philevo6]

What is THE best oil and grade for the transfer box?..that will cope better with high track temps?..

 

[Ecsrobin]

Bolt on like intake , down pipe and hks power editor
Wide high performance tire

So not standard.

Toyota will have done a lot of testing and it’s not something people are experiencing in the use that Toyota designed it for so I’d say they’ve done a good job.

As you’re modifying (and I’d say the extreme end of that) you’re finding the limits of the parts, I wonder what the super taikyu or rally2 cars are doing to keep the temps down?

 

[Diyman25]

For people interested on what oil I use
This oil is what I use , it actually reduces temperature to 20c on my case

 

[Diyman25]

So not standard.

Toyota will have done a lot of testing and it’s not something people are experiencing in the use that Toyota designed it for so I’d say they’ve done a good job.

As you’re modifying (and I’d say the extreme end of that) you’re finding the limits of the parts, I wonder what the super taikyu or rally2 cars are doing to keep the temps down?

More like GRMN , so pretty standard
Trust me , this transfer case go very hot in track use , if u did not mentor it please don’t say Is good job
U can check my other thread about the tranmission

 

[SckSqzBngBlo]

Is there a heatshield between the dump pipe off the turbo and the transfer case?

 

[Michael Knight]

Is there a heatshield between the dump pipe off the turbo and the transfer case?

see another thread

 

[azet]

View attachment 33179View attachment 33181
I now install transfer case cooler on my Time attack Gr Yaris , hope this can solve
Transfer case overheat problem

which pump or what solution have you used? have you considered interconnecting the transfer case with transmission, or no need to cool the gearbox additionally?

 

[SckSqzBngBlo]

Transfer case is GL5 fluid, gearbox is GL4 fluid.

 

[MRA3]

So not standard.

Toyota will have done a lot of testing and it’s not something people are experiencing in the use that Toyota designed it for so I’d say they’ve done a good job.

As you’re modifying (and I’d say the extreme end of that) you’re finding the limits of the parts, I wonder what the super taikyu or rally2 cars are doing to keep the temps down?

Exactly, Toyota tested the GR Yaris on several track both in Japan and Europe prior to its release. And they tested at least with stock ps4s tires and cup 2, so I’d say for an occasional track day, the car is fine.

Another thing is this is a dedicated track day that does 90% of its miles on the Ring or another circuit for that matter. Then, you probably need to updgrade a good few things to get proper reliability.