Im not in the market dor upgrades right now, but i will keep this in mind for next year. Ive maxed my budget for automotive right now. But this is a very reasonable fix. Just add oil cooling and a bigger radiator, and coil ivers and this is a solid platform for a variety of automotive events.
@@mmc2k9999 they have not mentioned the rear differential at all in any marketing or release information, so with that I'd assume it suffers from the same problem still.
@PaintflowException software update or just another computer somewhere installed figuring out things. Normal mode adjusts the front/rear torque distribution to 60:40 for everyday driving. Gravel adjusts the distribution to 50:50 to help deliver maximum traction. Track mode adjusts distribution by continuously varying the drive force distribution from front-focused 60:40 to rear-focused 30:70 based on the driver’s input and vehicle status.
the jdm gr yaris has a kit that does exactly what you did, and it requires a pcm recalibration, so if you were to replicate this on a gr corolla aftermarket, then a syvecs controller tune is probably required
I was going to comment the same thing. I wonder if we can find the oem constant velocity part numbers, that would surely be cheaper ex Japan than 2100usd.
@@__dm__ I have tried to find the part number previously to no avail. When the first gen came out it was an option in the RC model which isn’t available outside of Japan.
Quick summary guys: they found the fix to the overheating diff. They blew up the engine! That's right, all you gotta do to stop the diff from overheating is blow up the engine! Can't overheat the diff if the car doesn't drive. That's your pro tip for the day!
you did your research regarding the oil? 7:12 amsoil says following: AMSOIL SEVERE GEAR is compatible with most limited-slip differentials. For applications that require additional limited-slip friction modifier, add AMSOIL Slip Lock.® the clutch pack needs that friction modifier or an oil which already has them in it.
We’ve played around with different fluids in the rear dif and the severe gear did good for the lsd but we started running 75-140 and it seems to be way way better
@@NemtecRacing can you actually confirm, the clutchpack and rear diff housing are interconnected? which means they are sharing the same fluid? I never checked, but there was a common knowledge on the gr yaris forums, that the clutchpack is a sealed unit with a “lifetime” fluid filling…
I've been on the fence about the gr Corolla. For me, i just want a reliable 50/50 split. Correct me if im wrong but in the 30/70 mode with the ring and pinion, is it a true 50/50 with the factory diff controller? Would love a test video, say lift the car in the air and cycle through the modes in first gear idle.
Well i won't say this isnt one solution, but this deletes the car's ability to have any rear bias at all. In fact with that diff ratio you can probably replace the diff clutch system completely with something like a one way clutch (so you can keep your handbrake turns) since there's no speed difference between the wheels anymore. If you still want your rear bias then itll have to be some sort of cooling solution like a diff cooler, which should work now that you've found out how they share diff fluid between the LSD and the clutch
Main issue for heat isnt friction its heat soak from the exhaust and the diff and exhaust are recessed into the floor pan so they dont get airflow over them to cool down even. This means the exhaust is essentially blow torching the diff while you're doing donuts with the high exhaust temps... Seriously next time you get it hot have a feel at the heat radiating to the diff under there.
Our time attack GR Yaris has never over heated the rear diff. We have no wrapping on our exhaust either. We have raced at World Time Attack for 2 years and have the record around Sydney Motorsport Park
This is great work. Im way off on doing any modifications on my GRC until the warranties run out but im excited that this type of experimentation is being done. Having options in the future for reliability and consistency will be great to have. Keep up the work guys
man this looks sick! Forget about the overheating issue, just making the awd more consistent and predictable is a huge plus. I'm gonna have to do this in the future! Think it will increase reliability?
This is how all these new sporty “Rally” awd cars should come factory. 50/50 permanently awd like the Rally2 basically no centre diff, mechanical rear LSD and awd disabled only when handbrake is pulled or speed below 10mph
The actual problem with the "overheating" is the sensor for the rear diff is too close to the exhaust and over time the exhaust heats up that sensor. The diff is actually perfectly fine. Shield the sensor from the heat with some exhaust tape and it's good to go.
Really good content guys. Very keen to get our GR Corolla driveline rock solid for Rallysprint and Timeattack. I definitely think a cooler or larger capacity housing is a good thing but I think a Syvecs AWD controller and the new crown and pinion will be a game changer for sure. Definitely interested in how the clutch pack goes heat wise once the Syvecs is in and you're pushing more power to the rear. Peace. - Ben, Mad Panda Garage Australia
Wow this is huge! Does kind of suck that the rear bias goes away but this is basically how most AWD systems operate to begin with. I wonder if there's a way to change up the modes so you get full FWD mode for max fuel economy :D Or... hear me out, go into FWD mode mid pull so you put down more power once you don't need as much traction!
awesome. I'm gonna have to do this too. Based on the "Stock"-ish mom setup and new 50/50 setup, no AWD controller needed to do basic gymkhana movement?
Interesting, but maybe GR engineers know better and the car just wasn’t intended for donuts. I guess it’s really more of a street car. After all, it is a diff from the RAV4.
Why you just don’t swap the rear friction discs assy with a mechanical center differential like it was done on Subarus that needed to change the viscous center differential?
Seems like it would need some type of Tune for the Awd system. It might be sturdier, but in practice, is it worst on performance in metrics around a course
Knowing how the newer Golf R controls the rear diff, I thought, why not run left and right clutch packs on the front, right off the transmission? That way it would only send power to the front wheels when the rear wheels break traction.
can you elaborate about the "tiny fluid passage" on the left side that shares the diff fluid to the ITCC? were you trolling or is that legit? @ ~3 min mark
@TimLakeNona Can't post links, but check the ITCC threads on the forum. Me and a couple other members out west have been looking through official literature and trying to find/develop more information. We found direct phrases about the T case and how the 2wd mode works with a thermal model. Presented it to 555 last month, and he has now released testing that agrees with the conclusion.
he's right. the 2 do NOT share fluid. only JTEKT knows what fluid is inside the itcc. it's propriety and a completely sealed unit. how can anyone possibly deny this when they've released diagrams of how the system works and a fully written paper lol
While your motor gets "fixed" How do you fix a shattered block, head, cylinder, and piston? There's no way you're rebuilding that thing, has to be an all new engine.
This is exactly what I was wondering all along. I don't want gimmicks, I want reliability and consistency. Kickass content yet again!
Let me know if your interested I can get you in touch
Im not in the market dor upgrades right now, but i will keep this in mind for next year. Ive maxed my budget for automotive right now. But this is a very reasonable fix. Just add oil cooling and a bigger radiator, and coil ivers and this is a solid platform for a variety of automotive events.
@@PaintflowException kinda what GAZOO RACING is doing with the year 2025. Interesting.
@@mmc2k9999 they have not mentioned the rear differential at all in any marketing or release information, so with that I'd assume it suffers from the same problem still.
@PaintflowException software update or just another computer somewhere installed figuring out things. Normal mode adjusts the front/rear torque distribution to 60:40 for everyday driving. Gravel adjusts the distribution to 50:50 to help deliver maximum traction. Track mode adjusts distribution by continuously varying the drive force distribution from front-focused 60:40 to rear-focused 30:70 based on the driver’s input and vehicle status.
the jdm gr yaris has a kit that does exactly what you did, and it requires a pcm recalibration, so if you were to replicate this on a gr corolla aftermarket, then a syvecs controller tune is probably required
I was going to comment the same thing. I wonder if we can find the oem constant velocity part numbers, that would surely be cheaper ex Japan than 2100usd.
@@jasondoulkeridis6202Well, not just the cost, ostensibly it's likely to be warranteeable and better engineered than aftermarket parts
@@__dm__ I have tried to find the part number previously to no avail. When the first gen came out it was an option in the RC model which isn’t available outside of Japan.
Great content always! Hopefully this works on the long run 💪🏼 perfect for the build!
Appreciate the support 🤘🤘
Great to see you back
Hell yeah
Quick summary guys: they found the fix to the overheating diff. They blew up the engine! That's right, all you gotta do to stop the diff from overheating is blow up the engine! Can't overheat the diff if the car doesn't drive. That's your pro tip for the day!
This looks great so far! And 🔥 donuts
Once our race car gets fixed it’s gonna be so wild
you did your research regarding the oil? 7:12 amsoil says following:
AMSOIL SEVERE GEAR is compatible with most limited-slip
differentials. For applications that require additional limited-slip
friction modifier, add AMSOIL Slip Lock.®
the clutch pack needs that friction modifier or an oil which already has them in it.
We’ve played around with different fluids in the rear dif and the severe gear did good for the lsd but we started running 75-140 and it seems to be way way better
@@NemtecRacing can you actually confirm, the clutchpack and rear diff housing are interconnected? which means they are sharing the same fluid? I never checked, but there was a common knowledge on the gr yaris forums, that the clutchpack is a sealed unit with a “lifetime” fluid filling…
@@nesertema4583yeah I was wrong they do not share fluid
@@NemtecRacingso adding a larger coolant capacity doesn’t really help :/
But it looks like you found a good fix, keep us updated on how it goes!
I've been on the fence about the gr Corolla. For me, i just want a reliable 50/50 split. Correct me if im wrong but in the 30/70 mode with the ring and pinion, is it a true 50/50 with the factory diff controller? Would love a test video, say lift the car in the air and cycle through the modes in first gear idle.
Drift = good
Hel rear diff cooler. Sorted without screwing your F:R ratios.
Well i won't say this isnt one solution, but this deletes the car's ability to have any rear bias at all. In fact with that diff ratio you can probably replace the diff clutch system completely with something like a one way clutch (so you can keep your handbrake turns) since there's no speed difference between the wheels anymore. If you still want your rear bias then itll have to be some sort of cooling solution like a diff cooler, which should work now that you've found out how they share diff fluid between the LSD and the clutch
They don't share fluid, he mucked up that point. Which is why no one has been able to make a proper cooler yet.
More!
Main issue for heat isnt friction its heat soak from the exhaust and the diff and exhaust are recessed into the floor pan so they dont get airflow over them to cool down even. This means the exhaust is essentially blow torching the diff while you're doing donuts with the high exhaust temps... Seriously next time you get it hot have a feel at the heat radiating to the diff under there.
Our time attack GR Yaris has never over heated the rear diff. We have no wrapping on our exhaust either. We have raced at World Time Attack for 2 years and have the record around Sydney Motorsport Park
Help your poor mom out and get the AWE Touring exhaust less boomy inside and better tone outside.
As they say, keep it simple, stupid. Yeah magnetic diamond clutches are a marvel of technology but what good does it do if it never works?
I’m shocked how this channel hasn’t blown up yet. Your content is amazing
Appreciate the support my guy!!! Soon lol
Keep watching, it helps them a lot lol
@@NemtecRacing Would love to see some of your rally races uploaded
The eye of the almighty algorithm shall gaze upon it soon
While cool is kinda sad that you have to pay 3k so it can do was supposed to do from factory.
Definitely not awesome…. But focus rs has the same issue…. I just don’t understand why company’s do this
@@NemtecRacing being able to market "up to 70% rear bias"
Does your mother know what you're doing to her car? Mom, I'm taking your car for an oil change....
She “knows” I’m not sure she understands lol
This 😂😂
I have a feeling a LOT of people are going to be interested in this solution.
Well I came for donuts 🍩 my guy didn’t disappoint. Thanks for the good info ❤
Gotta love the 🍩🍩🍩🍩🍩
This is great work. Im way off on doing any modifications on my GRC until the warranties run out but im excited that this type of experimentation is being done. Having options in the future for reliability and consistency will be great to have. Keep up the work guys
Yeah definitely recommend keeping the warranty as long as possible
man this looks sick! Forget about the overheating issue, just making the awd more consistent and predictable is a huge plus. I'm gonna have to do this in the future!
Think it will increase reliability?
I think so. And it will probably stop the wear on the itcc cause I bet those will wear out
Cries in Focus RS
You gotta love mom for owning a GR Corolla!!
What happens when the rear diff starts to overheat? Is there a warning light or something like that?
This is how all these new sporty “Rally” awd cars should come factory. 50/50 permanently awd like the Rally2 basically no centre diff, mechanical rear LSD and awd disabled only when handbrake is pulled or speed below 10mph
I love seeing comments like this. An actual rally fan! I appreciate the support 🤘
The actual problem with the "overheating" is the sensor for the rear diff is too close to the exhaust and over time the exhaust heats up that sensor.
The diff is actually perfectly fine.
Shield the sensor from the heat with some exhaust tape and it's good to go.
great fix! cant wait to start building mine, keep the content rollin always look forward to it! thanks!
Hell yeah thanks for the support
Really good content guys. Very keen to get our GR Corolla driveline rock solid for Rallysprint and Timeattack. I definitely think a cooler or larger capacity housing is a good thing but I think a Syvecs AWD controller and the new crown and pinion will be a game changer for sure. Definitely interested in how the clutch pack goes heat wise once the Syvecs is in and you're pushing more power to the rear. Peace. - Ben, Mad Panda Garage Australia
Lets goooooooooo 🎉🎉🎉🎉🎉🎉
If this works on a road course you've found the winner.
very cool
Love these updates
Learned a lot from this video 👊🏼
You are a god thank you nemtec
Heck yeah
Heck yeah!! Lol
Heard about the next 2025 Gr Corolla will have a fix regarding the rear diferencial. Going OEM would be the way I would go.
This team is doing great work developing these cars for future GR owners to be able to enjoy modding them!
Have you guys wrapped your exhaust pipe near the rear dif? Seems to help a lot
No I’m not a huge fan of exhaust wrap cause we drive in snow and it gets all wet and stuff
Wow this is huge! Does kind of suck that the rear bias goes away but this is basically how most AWD systems operate to begin with. I wonder if there's a way to change up the modes so you get full FWD mode for max fuel economy :D Or... hear me out, go into FWD mode mid pull so you put down more power once you don't need as much traction!
awesome. I'm gonna have to do this too. Based on the "Stock"-ish mom setup and new 50/50 setup, no AWD controller needed to do basic gymkhana movement?
Yooo that’s soo clean bro 👌🏽. Car is a lil beast
Hell yeah dude thanks for watching!!!
So if you change wheel and tire size in the rear that could also help?
That would cause issues
Nice excellent explanation of this mod
Correction: Rear diff and itcc causing the transfer case to overheat. Its a deep issue!
Great video!
Appreciate the support
Have you wrapped the exhaust by the diff yet? Its a common effective fix for the GR Yaris.
Interesting, but maybe GR engineers know better and the car just wasn’t intended for donuts. I guess it’s really more of a street car. After all, it is a diff from the RAV4.
Why you just don’t swap the rear friction discs assy with a mechanical center differential like it was done on Subarus that needed to change the viscous center differential?
Makes me wonder if it's better to get a base non lsd core and do the rear gear and lsd.. 😅 Keep it in 50/50 and mosh
Base non lsd core is extremely rare though :/
@@Pupperino7773 there's a few out there down here.
Seems like it would need some type of Tune for the Awd system. It might be sturdier, but in practice, is it worst on performance in metrics around a course
How the hell is he financing all this?
Me myself and i
Knowing how the newer Golf R controls the rear diff, I thought, why not run left and right clutch packs on the front, right off the transmission? That way it would only send power to the front wheels when the rear wheels break traction.
More parts, more complexity, more weight, more money.
can you elaborate about the "tiny fluid passage" on the left side that shares the diff fluid to the ITCC? were you trolling or is that legit? @ ~3 min mark
They don’t share fluid at all.
I didn't seem to see a single donut
Didn’t watch the end of the video lol
@@NemtecRacing only saw figure eights. 😢
So don’t plan to try the 555 Engineering ITCC case?
We’ve been in talks. I think once we get it in our race car in a month or so we will see if it truly fixes the problem. If not 555 is our next call
@@NemtecRacing555 halted development after finding the shutoff was barely correlated to ITCC temp.
@@zadekharbatwhere did you get the info? I just looked at their website and I saw they don’t sell anything anymore as well.
@TimLakeNona Can't post links, but check the ITCC threads on the forum. Me and a couple other members out west have been looking through official literature and trying to find/develop more information. We found direct phrases about the T case and how the 2wd mode works with a thermal model. Presented it to 555 last month, and he has now released testing that agrees with the conclusion.
Why don’t you just delete the clutch pack entirely? From my understanding, it would now be permanently 70-30 ?
Because the rear wheels would always be spinning faster then the fronts. The car wouldn’t be drivable
@@NemtecRacing from my understanding it’s a 1% speed difference or so, would you really feel it?
the itcc and the rear diff does not share the same fluid. itcc runs a "secret" proprietary fluid that only JTEKT knows
Yeah that’s my bad I made a mistake on that
That wasnt donuts. Good development tho
3:14 the diff fluid is not shared with the clutch pack (ITCC)
you'd know this if you took this apart
Like you and everyone else who keeps echoing this really need to stop. You have 0 knowledge about thermodynamics.
@@apex_gr not sure what thermodynamics has to do with whether or not it is sharing fluid
They have had it apart at least twice now, and he stated that there is a small passage between the two compartments, so how is the fluid not shared?
he's right. the 2 do NOT share fluid. only JTEKT knows what fluid is inside the itcc. it's propriety and a completely sealed unit.
how can anyone possibly deny this when they've released diagrams of how the system works and a fully written paper lol
@@carlstrohm3785 there is no small passage, that’s why. Look at the parts diagram and you’ll see they bolt together in a way that doesn’t share fluid.
While your motor gets "fixed" How do you fix a shattered block, head, cylinder, and piston? There's no way you're rebuilding that thing, has to be an all new engine.
Since the 30/70 is the only mode you spent any time on, can't you just remove the clutch pack and welded it solid?
No because we need a way to disconnect the rear axle. Like when we want to use the handle break the drift
Other comments are right. The ITCC runs a proprietary fluid and is sealed. The differential runs regular gear oil. The two can not share fluid.
Yeah that’s my bad I made a mistake on that
@@NemtecRacing All good, just wanted to make sure you're aware!
fluid is not shared 🤦♂
Yeah that’s my bad I made a mistake on that
The adds are annoying
Yeah idk why UA-cam is just spamming the video….