GR Yaris I Broke my third Transmission at track 。this time GRMN close gear set

How are y'all's transmissions holding on with the Cusco hubs? I'd like to build my engine in the future and I'm trying to manage expectations.

Aside from the clutch and the gearbox how durable is the transfer and the ITCC?
 
I have the Cusco 1-2 and 3-4 hubs and the neat 5-6 hub/synchros, brass shifter fork pads, new bearings and synchros, all much cheaper direct from Japan/Australia - it took months to get all that and a new clutch sorted, and have been dealing with turbo problems since then :rolleyes:

I had an extreme clutch with single mass flywheel, it didn’t last long - I was at about 400bhp, think I worked out that that was bang on the rated torque limit, so no surprise really.

boiNXTdoor said:
Aside from the clutch and the gearbox how durable is the transfer and the ITCC?
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I think fensport broke a transfer case in the early days, but haven’t heard of others. Both can get hot…
 
Transfer is very easy to overheat and break, driving hard on Sport AWD mode.
Especially with Syvecs AWD controller with no built in overheat protection.
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That Crome-Moly synchro ring looks like a great idea.
I have this feeling that Dayman's transmission problems may be linked to his single mass flywheel. :rolleyes:
 
I think synchro hubs are just a matter of time if you go big turbo, standard or single mass flywheel doesn’t seem to be a huge factor from people I’ve spoken to.

Interested to hear more about transfer case problems - for sure they get hot, and plenty of folks go for the gold plated Brena option or other 50:50ish gearing, but I haven’t heard much about people actually breaking the OEM TC?

There is no temp sensor in the transfer case, I think the only sensor is near the rear diff, and the rest is modelled - syvecs AWD controller definitely has overheat protection along the lines of OEM, I have one and have triggered 2WD with it. I added the HEL diff cooler and a transfer case temp sensor (with a view to adding a pump/rad if needed) at the start of the year, but due to issues mentioned above, haven’t had enough track time to have feedback yet…
 
There is a temperature sensor in the ITCC, which Syvecs AWD controller can read and use to trigger overheat protection.
However, it does not estimate the transfer or rear differential temperatures the way the OEM AWD controller does.
This is why Syvecs recently added support for an optional transfer-case temperature sensor and limp map in the latest firmware.
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yan.ko said:
There is a temperature sensor in the ITCC, which Syvecs AWD controller can read and use to trigger overheat protection.
However, it does not estimate the transfer or rear differential temperatures the way the OEM AWD controller does.
This is why Syvecs recently added support for an optional transfer-case temperature sensor and limp map in the latest firmware.
View attachment 38802
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What temp does it go into Limp mode?
 
The latest firmware default vaues are

AwdTemp Limp Limit = 100
AwdTransferTemp Limp Limit = 130

The AWD controller allows you to modify these values freely.
 
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After 100 track day in 5 years , My transfer develop a leak right before the big time attack event , Anorher poor design by Toyota
I change my transfer case oil every time after track day , and even install oil cooler last year
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sixtentouge said:
Makes more torque than a Rally1 car. Running 295/35/18 A050. Over100 track days. Single mass flywheel and twin disc carbon clutch.

Transfer case develops a leak. Blames Toyota :)
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Yeah like u don’t read the thread , whole drivetrain of GR Yaris is borrow from RAV4
This along already proved not a proper setup
 
Also sorry to inform all the thread fellower
Buddy of mine his track only GR Yaris width wide tire and GCG28R and Cusco hub and stock dual mass flywheel broken the transmission too , he probably drove like 100 lap after gcg28R and Cusco hub
I need to get more information on it , to report back what did he broken
 
Some update on my buddy’s car
He damage his transmission from quick shifter loose that cause improper shift motion , so transmission damage might not be weakness of Cusco hub
, he upgrade PPG straight gear this time

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