nathanr

I’ve looked all over the internet but can’t seem to find an answer... What exactly is the difference between the two transmissions? I have a couple buddies that have ISFs(AA80E) and they seem to shift way faster than my 3is is300(AA81E). Is it just different tuning? or a different way the transmission is built...? plz help!

m0chafrap

From what I've read, the AA81E is essentially the same unit with less aggressive programming & G Force sensors that the transmission uses to hold gears in certain driving conditions (hard cornering, etc.). If I'm not mistaken, all of the forward gear ratios are also the exact same as the ISF.

Lexus marketed the fact that it's the same transmission as the ISF as a selling point back in the day for the IS: https://web.archive.org/web/20140707...ls/IS/features

nathanr

thanks for the input. that’s exactly what i was hoping to hear. does that mean that technically, these could be tuned to act like an ISF’s gearbox acts?

DRIFTOPHER

@RRRacing Is there any possibility of gettin our AA81E to be bad *** like the AA80E ?? I would buy this before the engine tune upgrade. Any info would be appreciated.

nathanr

Im not sure what RRRacing has to say, but I reached out to OVTuning and they said that their software allows you to change the shift speeds, up and down, as well as the shift torque (how quickly the shift happens). I ordered the tuning software from them today and hopefully it gets here some time this week. Ill keep you updated on how it works. Not sure if I'm going to have to take it to an actual tuner or not yet.

RRRacing

iTrader: (1)

This is unsubstantiated BS from that tuner. There are MAJOR internal differences between the 2 transmissions. The biggest difference is the number of clutches per gear giving the ISF/RCF tranny significantly higher torque capacity.

Rather than BSing customers, we actually put out time/money/efforts into development and testing. Recently we managed to install the ISF tranny into our supercharged IS350. There are some issues we need to sort out, but I can say that even on stock is350 programming it shifts way more aggressively than stock is350 8sp.... the is350 tranny cannot hold our current 460whp, whereas with the ISF tranny it’s not even breaking a sweat, the difference is HUGE.

Rafi

nathanr

Interesting... Thats disappointing, for the car and for OVTune. I had a pretty thorough conversation with OVTune and they assured me that this would be possible. Lexus even advertised this transmission as being the same one out of the ISF...

DRIFTOPHER

Yeah man, big time bummer. I was hoping the major difference was gearing and the programming.
well, anyway PLEASE let me know how the OVtune goes. Very excited to hear about the results.

DRIFTOPHER

@RRRacing

I sincerely appreciate the information. May I ask, does the AA80E bolt directly up to the IS350 or was there an adapter you had to fabricate?
And what is sport direct shift?

Thanks in advance !

RRRacing

iTrader: (1)

unfortunately, it doesn’t mate up well at all so we made an adapter and other mods are required as well. But We are working hard on finalizing the swap!

Rafi

DRIFTOPHER

Hey, how did the OVTuning software thingy stuff go?

Cyclesadri

Did the transmission swap ever work out? I have an AWD IS 350 and i would like to buy the adapter you made to mate a ISF transmission if possible.

flipside909

AA80E is the 8 AT with lockup torque converter designed for the V8 powered cars (IS F, RC F, GS F, LS 460 SPORT/F SPORT and upcoming IS 500 F SPORT Performance). AA81E is the 8AT for the IS 350, IS 300, GS, RC and etc.

celsior11

Would there not be more sense in a workover for a valvebody for these or higher line pressures in tune to pull some more power, hell even an external oil cooler for slightly more capacity and keep the fluid cool.
Surely it wouldn't take a great deal of effort to make up an adapter in place of the standard cooler with two hose ends in and out to run an external cooler.

Does anybody do a valvebody upgrade for V8 cars ?

Seems alot of effort to make bellhousing adapters, new torque converters etc.

hkhan34

So the isf transmission is the same as the rcf one right so lets say you took an rc350 and swapped it with an rcf motor (by the way what would you have to do to get the engine in there) would the rcf/isf transmission bolt up to the rcf motor in the rc350?