Toyota 86 Competition GR Parts - 4th gear + transmission parts

[mav1178]

Toyota Gazoo Racing announced some gear upgrades for their domestic 86 Competition parts.

https://toyotagazooracing.com/jp/gr/grparts/ (you have to click on "86 Race Parts" in the menu in the middle of the page.






It looks like all 4 parts are needed, but it's a strengthened output shaft, counter shaft, and 4th gear? Not sure why 4th gear exactly needs to be replaced, the notes below says that the gear ratio isn't changed.

-alex

[NoHaveMSG]

Originally Posted by mav1178

It looks like all 4 parts are needed, but it's a strengthened output shaft, counter shaft, and 4th gear? Not sure why 4th gear exactly needs to be replaced, the notes below says that the gear ratio isn't changed.

-alex

https://www.jackstransmissions.com/i...483&search=brz

From Jacks Transmissions. Wonder if this is another solution to fix the clip issue.

such as with the 4th gear thrust issues. The 4th gear thrust issue is a major concern for those who are making above stock torque levels. The added torque puts excessive force into the 4th gear clip, causing it to rub against, and chip, the teeth on the shaft. As the gear floats across the countershaft, they become misaligned resulting in a major gear failure.

[mav1178]

Originally Posted by NoHaveMSG

From Jacks Transmissions. Wonder if this is another solution to fix the clip issue.

possible, but this was specifically produced for the competition and endurance cars, which are making slightly more than stock power.

anyhow, worth looking into for some folks out there. obviously Toyota felt it was important enough to produce upgraded parts.

[gpvecchi]

First and second gear are on the same shaft?

[mav1178]

Originally Posted by gpvecchi

First and second gear are on the same shaft?

I don't know, haven't taken apart any ZC6/ZN6 transmissions yet.

[prandelia]

These are the new gear upgrades for the GT86 race series in Japan, and official parts. This is great news.

[Bonburner]

4th gear is known to get destroyed with FI cars.
Mostly (to my understanding) 1-3 are triple cones and much sturdier than the 4-6 which are single cones.

[DarkPira7e]

Can anyone who has shredded transmissions with power (not drivetrain shock) confirm that 4th is the one that goes? It makes sense, since at that speed, it probably experiences the highest load and 5th and 6th are less likely to be run out unless someone is doing a mile sprint or a 140MP+ run.

[prandelia]

Originally Posted by Bonburner

4th gear is known to get destroyed with FI cars.
Mostly (to my understanding) 1-3 are triple cones and much sturdier than the 4-6 which are single cones.

They actually upgraded 6th gear to be a bit beefier in the '17 cars as part of OE upgrades. But it's not just about power, if you are using sticky race tires, then it puts extra load/shock through the entire drive-line assembly as well.

If you are FI or motor swapping, these are also very desirable parts.

[prandelia]

Originally Posted by DarkPira7e

Can anyone who has shredded transmissions with power (not drivetrain shock) confirm that 4th is the one that goes? It makes sense, since at that speed, it probably experiences the highest load and 5th and 6th are less likely to be run out unless someone is doing a mile sprint or a 140MP+ run.

4th gear takes the most beating of the smaller gears, for track-use. That's why they are shredding them in road racing applications with 200whp levels...it's a combination of a little more power, sticky tires, and load on 4th gear, as 3rd and 4th gear are the most used at any race track.

[DarkPira7e]

Originally Posted by prandelia

4th gear takes the most beating of the smaller gears, for track-use. That's why they are shredding them in road racing applications with 200whp levels...it's a combination of a little more power, sticky tires, and load on 4th gear, as 3rd and 4th gear are the most used at any race track.

Makes the most sense. I'm curious more as to how often 2nd or 3rd are sheared during acceleration with drag radials, or if 4th really is the weakest by design all around. This would stop a lot of CD009 conversions if there was a great 4th gear replacement and the gear shearing incidents could be isolated to only 4th 5th and 6th.

TL;DR I want to know if 450wtq with drag radials will break axles before gears if I stay in 1-3.

[churchx]

I might be wrong, but IIRC triple-cone synchros were for just 1&2, not 3rd and above.

[Bonburner]

It's always been 1-3 gears were triple cone.

Even the 2020 brochure states it still: https://www.toyota.com/86/ebrochure/
(Search 'Triple')

I haven't heard too many racing tires having that much grip that it's enough for a NA powered 4th gear to shred, but hypothetically logically possible.

[churchx]

Hmm, indeed, 1-3. Though still i don't see synchros much to do with 4th gear grenading on massively overboosted car, unless one driving such also flat foot shifts. One should use normally clutch during shifts, and once it's in gear, synchros do no other job but spinning together with gears. If engine's power is not applied to them, boost level should play no role on syncros wear, nor those should affect actual gears.
One shouldn't also call our gearboxes weak, as they do their job with reasonable power/torque, even that of boost, fine. One in thousand that boosts much more then that doesn't warranty rest 999 twin owners to have overengineered gearbox cost pushed onto them.