Automatic Transmission (AT) Information and Upgrade Thread

[wlfpck]

Generic Automatic Transmission Build
To start off, I want to say that as of this time, I do not own a FR-S/BRZ. I am simply speaking from my own knowledge and also my own research.
For those of you that are going to say an automatic is stupid and pointless, or point out any other things in that nature... Congratulations. It’s not your money that others are spending so why do you care? If someone wanted to eat a $100 bill every day for breakfast, it makes no impact to you as it is their money. Please keep it civil. People have clearly made the choice to purchase an automatic transmission.
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Also keep in mind… As of right now (10/2/12), there is no source that gives the capacity for the transmission in the FR-S/BRZ. I don’t think anyone has pushed the torque numbers to the point the transmission has failed.
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I will update this as more information becomes available if there is a positive feedback. If not, then I'll just let this thread sink into the depths of the internet.
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The Automatic Transmission (AT) Code is: TX6A8GD90A. (Thank you to kwood9000)

The Transmission is an A960E transmission from Toyota/Lexus (Aisin makes the transmission though).

https://www.automaticchoice.com/uplo...e/aw_a960e.pdf

http://www.sonnax.com/units/444-A960E-F-TB-65SN-

This A960E is the equivalent to the Aisin TB-65SN.

Using the following website... Aisin has released "specs" for the transmission. (under FR Series, under 6 speed, it is the one with the lowest torque capacity).

http://www.aisin-aw.co.jp/en/product...etrain/lineup/

This shows that it falls around the 300 Nm of torque which I believe is around 260 lbs ft of torque.

Additional notes: If this is correct that it is the Aisin TB-65SN, that means that this transmission is the same one as the one found in the NC Miatas.

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I. Understanding how Automatic Transmissions Work
The point of this guide is to share and discuss what is needed to build an automatic transmission. To start… we need to understand how an automatic transmission works...
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Automatic Transmission:
http://auto.howstuffworks.com/automa...ansmission.htm
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Torque Converter:
http://auto.howstuffworks.com/auto-p...-converter.htm
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The reason for the two links above is that it provides a great resource to understanding the key differences between the automatic transmission and a manual in a mechanical standpoint outside the fact of “there’s only two pedals for an automatic”. Keep in mind that the automatic in the FR-S/BRZ is a traditional automatic and not a DCT (Dual Clutch Transmission). They are VERY different things.
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Now for the generic automatic transmission (AT) build…
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II. Transmission Cooler
Once you have understood how an AT operates (see links above), it is necessary to understand how important the fluid is within an AT. Heat is the killer.
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As you create more power, you generate more heat. More Heat = Bad. The best way to compensate for the increase in heat is to add a better cooling system. This keeps the transmission fluid within the acceptable temperature range which makes for a happy transmission. I personally have a transmission oil cooler from B&M. They sell a variety of coolers. Think of these things as a small radiator purely for your transmission. B&M also sells ones with an electric fan and a temperature switch on it to ensure that cooling is adequate. Other companies make these as well. However, B&M has a high viscosity bypass. This means that if the fluid is cold (outside the operating temperature), it will bypass the cooler until it reaches the right temperature.
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http://bmracing.com/?page_id=1046
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III. Clutch Pack/Friction Plates
If we took a look at the how stuff works site above, you will note that the friction plates are an essential part of the automatic transmission. This is a company that offers aftermarket plates that are able ot withstand the higher heat and torque. They also help to decrease shift times.
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http://www.raybestospowertrain.com/
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IV. Torque Converter
The benefits of the automatic transmission is the ability of the transmission to undergo torque multiplication. This occurs when there is a difference in the speed of the turbine and the impeller. The greater this difference in speed, the greater the torque multiplication.

How does the torque multiplication apply? Well assuming that at a given time, the torque multiplication is 2:1 at a 2500 stall speed, this means that if the engine makes 300 lb-ft of torque; this means that there is 600 lb-ft of torque to the input shaft of the transmission. Unfortunately, this does not last very long. From the initial launch, the difference in speed is the greatest, then as everything is brought up to speed, the torque multiplication drops and approaches 1:1.

However, the transmission never reaches 1:1 until the torque converter locks up. This is due to the fluid coupling that is discussed in the "How Stuff Works" article that is above. Because it is a fuild coupling and not a mechanical coupling, there is slip (loss in the energy transfer). Usually the slip is around 3 - 5 % but as high as 8% slip can be found in some automobiles. In order to achieve the 1:1 ratio, the lock-up torque converter is used. The lock-up torque converter mechanically couples the turbine and impeller when the requirements are met. This creates a no slip, no power loss scenario.
http://www.carcraft.com/techarticles...s/viewall.html
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V. Valve Body/Shift Kits
The valve body is essentially the brains behind the transmission. If we looked at the first couple links that show the importance of the Valve Body, we will understand that this is what causes the transmission to shift. On a generic level... the valve body can be "beefed" up to handle the additional energy. At the same time, you will find that many shift kits available on the market right now (350z for example) has a solenoid upgrade kit. Which creates faster shifts.
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VI. Shift Points
While the argument, years ago, was that it’s pointless to modify automatics because you can’t choose the shift points. That is no longer the case. Given the current state of the FR-S/BRZ, you are able to choose the shift points and this is not really a valid argument.
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VII. Good Shops
Due to the fact that the FR-S/BRZ is so new, I am not quite sure as to whether or not there are available parts (outside the universal parts such as oil cooler). However, these are two shops that are very well known for their work in automatic transmissions.
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Levelten
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IPT
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SSP - Upgrade Parts.
http://www.sspperformance.com/brz-fr...on-cooler.html
http://www.ft86club.com/forums/showthread.php?t=13333
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Boost Logic (They build automatic supra transmissions. Not sure if they’ll be interested in the FR-S/BRZ)
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VIII. High Power Automatic Transmission Builds
P&L Motoring
http://www.ft86club.com/forums/showthread.php?t=15483
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IX. Additional Resources found on FT86 club:
SSP Performance develops parts for the automatic transmission.
http://www.sspperformance.com/brz-fr...on-cooler.html
http://www.ft86club.com/forums/showthread.php?t=51851
http://www.ft86club.com/forums/showthread.php?t=13333

Final Drive Modification:
http://www.ft86club.com/forums/showt...=27647&page=11

Acceleration Comparison (MT vs AT)
http://www.ft86club.com/forums/showt...296#post616296

Moto-P's Thread about Manual vs. Automatic
http://www.ft86club.com/forums/showt...ight=Automatic
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Switching the shifter to do the opposite
http://www.ft86club.com/forums/showt...ight=Automatic
http://www.ft86club.com/forums/showthread.php?t=17018
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Threads about Getting a Manual or Auto
http://www.ft86club.com/forums/showt...ight=Automatic
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Engine Codes and Transmission Codes
http://www.clublexus.com/forums/car-...n-frs-152.html

[Lonewolf]

SSP is in fact interested and still looking for an AT car to make some goodies....

[Captain Insano]

Perfect. I was thinking about making a more generic thread to ask about AT options. You have done a much better/thorough job than I would have. Thanks for starting the thread!

[Jimbo]

Yeah, it's frustrating because someone at Toyota must know exactly how much the auto tranny can handle safely.

-Jim

[stealth1]

Has anyone put a lower gearing ring and pinion in an auto yet? That might wake it up.

[Captain Insano]

Was thinking some of the same things. If the two things keeping the AT from launching as well as the MT are:
--torque converter (biggest factor)
--gear ratios (slight factor)

It seems like somebody could change the final drive ratio and make the AT gears same or even more aggressive than the MT gears.

[wlfpck]

Thanks for the positive feedback. It really is good.

As for the torque converter and such...

I'm assuming that a high stall and early lock up would help it launch better. The thing about the auto transmission is that it is all about the fluid coupling. The transmission and the engine are never fully connected till the point of the torque converter lock up. (discussed in the how stuff works site).

Now assuming that you can make it so that the torque converter locks up earlier... this means that it locks up at a lower RPM which means you get better power transfer from the engine to the wheels.

As for the gear ratio... that's going to be more difficult to do considering that the automatic is very different than the manual.

Though, I will say one thing... On the scion tC first gens... people have been swapping over the 5 speed found in the camary as it provides taller gearing. People do this when they turbo the car. Just some food for thought.

[serialk11r]

Originally Posted by wlfpck

Now assuming that you can make it so that the torque converter locks up earlier... this means that it locks up at a lower RPM which means you get better power transfer from the engine to the wheels.

I thought the torque converter never locks in 1st? The lockup clutch is still there of course, so in theory it's possible to get lockup in 1st.

For drag racing an AT could work extremely well if it had a high stall and engaged the lockup clutch (slipping a little bringing engine rpm down to transmission rpm while transferring a bit of the engine's momentum) as the tires stopped spinning, but the clutch should probably be beefed up a little to take that kind of abuse.

[wlfpck]

Not really sure. This is one of those things that I have not done the research on. Therefore, I did not post anything about torque converters. :P

[wlfpck]

Originally Posted by Lonewolf

SSP is in fact interested and still looking for an AT car to make some goodies....

Someone needs to let them do some R&D. They do some SICK work. like all their clutch kits for the DCTs are just absolutely brilliantly made.

[MmmHamSandwich]

This should be an interesting thread. I personally am not terribly concerned with making the AT "launchable" and I think the stock shifts are already plenty fast but I suspect I will want more power in the future, nothing crazy, but I certainly would like to make sure the transmission will handle it.

Maybe a good start would be to do some research on the torque converter in the IS250 to find out if it is the same unit. Our transmission borrows many parts from that car. There is a good chance our torque converter is out there somewhere in another model. If so that might give us some insight in to what it handles from the factory and possibly how much power tuners are running through it.

Regarding torque converter lockup, Moto-P was unable to provide me with any technical information, but he claimed it locks up almost directly after shifting in all gears except 1st where supposedly it doesn't lock up. Would love concrete information on this. Not sure if this is something that can be monitored via the on board computer by us peasants. I assume the manufacturer can.

[madfast]

dont forget when the TC "slips" it is multiplying torque at the same time. perhaps we should not lockup in 1st gear even if we could reprogram it to do so.

[zoomzoomers]

Anyone know if the IS250 or 350 has launch control? That would be a start.

[wlfpck]

I do not believe that the IS series has launch control (with the exception of the IS-F). I know that the LFA has launch control.

It would be interesting to see if launch control gets developed. If I am not mistaken, launch control is purely an electronic factor. The programming just needs to be created.