FR-S Gear Ratio Comparison

[SpeedR]

FR-S Gear Ratio Comparison
____AT ___MT __# differenc _% difference
1 _3.626 __3.538 __0.088 ____2%
2 _2.188 __2.06 ___0.128 ____6%
3 _1.541 __1.404 __0.137 ____10%
4 _1.213 __1 ______0.213 ____21%
5 _1 ______0.713 __0.287 ____40%
6 _0.767 __0.582 __0.185 ____32%
R _3.437 __3.168 __0.269 ____8%

Did they make the AT ratios higher so it would not be significantly faster than the MT cars?

[Ranatsu]

Originally Posted by SpeedR

FR-S Gear Ratio Comparison
____AT ___MT __# differenc _% difference
1 _3.626 __3.538 __0.088 ____2%
2 _2.188 __2.06 ___0.128 ____6%
3 _1.541 __1.404 __0.137 ____10%
4 _1.213 __1 ______0.213 ____21%
5 _1 ______0.713 __0.287 ____40%
6 _0.767 __0.582 __0.185 ____32%
R _3.437 __3.168 __0.269 ____8%

Did they make the AT ratios higher so it would not be significantly faster than the MT cars?

pretty sure the final drive on the auto is much longer than the MT.

[cossey]

Final drives are the same.

I think it has been mentioned here that all Toyota AT have 4th as 1:1 and all manuals have 5th as 1:1 so the auto will be much longer geared unless they shorten the final drive.

as the manual runs a 4.1:1 final drive then it would be difficult for the auto to be much shorter.

the long gearing of the auto is one of the main reasons (along with the less than sonorous engine) that the BRZ got such a savaging by EVO.

[SVTSHC]

After seeing those ratio's I understood why the AT got better fuel mileage than the MT. It's weird seeing a six speed with only one overdriven gear though. Usually the 1 to 1 hits in fourth, and fifth/sixth are overdriven.

[the_3d_man]

I think you got it backwards... but yeah... it's a bit dissapointing that the gears are so much taller on the autos.

[Saibot]

you got your mt and at mixed up.

they made closer gear ratios on mt on purpose for faster acceleraton iirc..

most mts have closer gears than their ats though.

[carbonBLUE]

yeah the auto would be much faster than the manual is they had the same ratios, you just cant beat the autos lightning fast shift times

[Saibot]

Here's a question: I want to do a 6th gear swap. Would other cars with AZ6 trannys qualify as donors (ie S2K or miata)?? Or is there some minor difference tht would prevent it from happening?

[carbonBLUE]

Originally Posted by Saibot

Here's a question: I want to do a 6th gear swap. Would other cars with AZ6 trannys qualify as donors (ie S2K or miata)?? Or is there some minor difference tht would prevent it from happening?

yes, in theory the AZ6 transmissions can exchange parts

the parts are different but the parts should align just the same...

i personally want shorter gear ratios in the auto, but at the same time i dont, i will be going supercharged and the longer ratios would be fine, i dont want to be shifting too much

[serialk11r]

Originally Posted by Saibot

Here's a question: I want to do a 6th gear swap. Would other cars with AZ6 trannys qualify as donors (ie S2K or miata)?? Or is there some minor difference tht would prevent it from happening?

The problem is no other AZ6s have 6th gears that are any shorter...the S2000 has 0.762 instead of 0.767, that's hardly worth the swap. Dropping the 6th gear about 15% would be a nice compromise between power for hills and higher speeds and fuel economy I think.

If you're hardcore about saving gas, you can pulse and glide it, but it's obviously 10 times easier to just have a longer gear.

Maybe in a future model...

[AJ PwR]

Originally Posted by SpeedR

FR-S Gear Ratio Comparison
____AT ___MT __# differenc _% difference
1 _3.626 __3.538 __0.088 ____2%
2 _2.188 __2.06 ___0.128 ____6%
3 _1.541 __1.404 __0.137 ____10%
4 _1.213 __1 ______0.213 ____21%
5 _1 ______0.713 __0.287 ____40%
6 _0.767 __0.582 __0.185 ____32%
R _3.437 __3.168 __0.269 ____8%

Did they make the AT ratios higher so it would not be significantly faster than the MT cars?

IMO, cars with AT are normally heavier and have more drivetrain loss than MT so with higher ratios, it will compensate the difference but I don`t think the AT can be any quicker than the MT.

[matt30]

Originally Posted by AJ PwR

IMO, cars with AT are normally heavier and have more drivetrain loss than MT so with higher ratios, it will compensate the difference but I don`t think the AT can be any quicker than the MT.

The OP reversed the labels.

[Jeff Lange]

Originally Posted by SVTSHC

After seeing those ratio's I understood why the AT got better fuel mileage than the MT. It's weird seeing a six speed with only one overdriven gear though. Usually the 1 to 1 hits in fourth, and fifth/sixth are overdriven.

Quite a few 6-speeds have 5th 1:1, though often times they will have a much taller final drive to make use of it, like the V160 in the Supra, which had a 1:1 5th, but used a 3.13:1 or 3.27:1 final drive.

With the 4.1 final drive and the ratios the way they are in the TL70 (6MT), it will be a very close ratio overall setup.

That's what you really need to be comparing when you're looking at other models, overall ratio. Just looking at the transmission doesn't tell you much, you need to include final drive. Obviously on the Zx6 they're all 4.1 in North America, so there's no need there, I'm just saying.

Jeff

[3MI Racing]

See post 31 for an updated graph!!