A340E lockup activation strategy

[1JZ-Rolla]

Only just came across this thread mos, great idea to develop something like this!

My 1JZ A3040Le is manually shifted mechanically (no paddles etc) via a ratchet shifter, and MV Automatics "shift control" box, which simply tells which shift solenoids to operate for the gear selected on the stick.

At the drags, I run 1st & 2nd with no lockup, then lock the converter via a direct 12v switch shortly after shifting to 3rd gear, and finish the run with a few revs to spare (no overdrive used).

Mike at MV advised that lockup with WOT in 3rd gear is absolutely fine, recommending this in preference to shifting to overdrive on the straight at Wakefield Park even, as he was not confident in overdrive's ability to hold power for any extended period.

On the street, from my experience I can't see much benefit in locking the converter in 1st or 2nd gears, but definitely useful in 3rd and 4th. The point at which you choose to have the lockup cut in will depend on the weight of the car, torque converter stall speed, and the response of the turbos used (if a boosted motor) to find the most efficient transition point, so being user configurable (by road speed I guess) would be ideal.

The difference in drive to the wheels is significant between converter locked and unlocked, however my converter is modified for 2800rpm stall, and friction surface upgraded on the lockup clutch (you'd expect a standard converter to be more efficient, and therefore less losses):



131OWN: with the programmed release of the lockup clutch when shifting gears in your shift box design, is this only functional when shifting via paddles, or also when using the mechanical shifter itself, and how does it know that you are about to shift a gear?

Cheers
Phil

[shrekvk]

Does anybody know what pressure the A340LE in a JZS147 aristo operates at?

My auto is flaring quite bad. I put a large Davies, Craig cooler on and today gave it a flush and DEX-III but it still has the same problem.

My next thought is a pressure drop due to the new cooler. Next thought is the clutch bands.

Final thoughts are the exhaust leaks that the car has adn now the computer is reading fluctuating inputs and car does run as nice

[Dieseltrain]

Does it have a shift kit ? If not, then use Toyota type 4 fluid in it . I know guys with Soarers who have tried normal Dex 3 only to have issues until they switch back to type 4 and then its fine again .

Or was the problem there to begin with ?

I doubt the cooler would be causing a flow restriction, unless you downsized the line sizing ?

[Z2TT]

From what I have heard the Boxes that come originally mates to a V8 dont run well with DEX 3, but its fine for the other boxes.

[JustenGT8]

How's the controller going Mos?

[Dieseltrain]

Fair few guys with Jzz30's have had issues running Dex 3 with stock boxes as well as the V8's, and once they have reflushed with Toyota Type 4 fluid have been fine . IM only going from posts in the soarer forums over the last 3-4 yrs .

[shrekvk]

It is not shift kitted and the hose sizes are still the same. I picked the car up, drove it back to my home town (12 hour drive) and all was perfect.

Got home. That night a heater hose let go and I imagine the trans fluid got burnt due to the raised temps of the radiator (as it is 'cooled' at the bottom of radiator).

The next day I fixed heater hose, put a larger trans cooler on (everybody on www.jzs147.com use the same tranny cooler) and ever since I have had bad flaring. I flushed the tranny yesterday and replaced with DEX III.

Could it be that the owner before me had Toyota type - IV, and I have put DEXIII in and it does not like it?

On my trans dipstick it says T-II which I assumed was supurseeded by DEX-III. Everyone on the aristo forum says to use DEXIII in aristos up until around 95, then use toyota type IV after that. I think I may try another flush and use toyota Type - IV

[Sciflyer]

Dont go by what it says on the dipstick. For some reason even autos that need Toyota type IV will just say Dex II or III on the stick. I would also double-check your fluid levels (and only when warm) as its easy to over/under fill

Mos what a340 are you referring to as the valve body in the a340e found behind 1uz, 1jz, and 2jz are all different. They have between 3 and 5 solenoids depending what model you talking about, there are 2 solenoids that do determine what gear you are in and there is a lockup solenoid, but that is where the similarities end, for example on a340e found behind 2jzgte there are 2 other solenoids, these are used to control line pressure and accumulator pressure.

With regards to the converter lockup, 1uz a340e can only engage converter lockup 3rd and 4th gear, when a 1jzgte a340e can engage converter lockup in 2nd, 3rd, and 4th.

Small note: The Soarer 1UZ box is actually an A341LE and will only lockup in 3rd and 4th

[shrekvk]

They are spot on. It had 15 litres professionally flushed through it, then levels checked while hot. Then let to cool and levels checked again.

Might enquire as to how much the genuine toyota type IV is to fill mine

[Big rob]

Dont know if anyone has seen it before but:

http://www.powertraincontrolsolution...anscontrol.php

[Z2TT]

There was a Toyota Technical Service bulletin on which fluids to use where T-II is recommended.

http://www.toyota-club.net/files/06-07-10/tc003_99.pdf

From that TSB if the specified ATF is Type T, use Type T-IV and Not Dexron.
If Specified ATF is Dexron, then use Dexron and not Type T-IV.

It would make sense though to use Dexron if the Dipstick says Dexron as long as it's the original dipstick from that car.

[Supra967]

Pretty handy unit here:

http://www.latentsolutions.com/suprastickuv.html

But only controls the early supra 2 solenoid auto. Doesn't control the line pressure solenoid.

[ZZT231]

Dont know if anyone has seen it before but:

http://www.powertraincontrolsolution...anscontrol.php

That's what I'm running in my car... It's easy to hook up and fully programable. I know people that were running the SupraStick and have gone across to the PCS TCU as it's a better unit and more programable and one of them is running an Aristo valvebody in his A34x gearbox (ex 7MGTE) fully controlled by the PCS and he said it runs great.

The A34x I'm running is with the kick down cable has 2 shift solenoids.

The torque lock up strategy I'm running is engage after 50kph and/or 3rd gear and above. From 3rd into 4th I've said to disengage during change and engage again. I still have to fine tune the TCU (waiting for more fine weather). I've also chosen if I'm going to kick down a gear the torque converter disengages then reengages too.

Beauty about the transmission computer is that you can tell what shift points you want vs throttle position/road speed.

Cheers.

[TheStitt]

is that $750 AU or US??


How does it go manually shifting???

[Sciflyer]

There was a Toyota Technical Service bulletin on which fluids to use where T-II is recommended.

http://www.toyota-club.net/files/06-07-10/tc003_99.pdf

From that TSB if the specified ATF is Type T, use Type T-IV and Not Dexron.
If Specified ATF is Dexron, then use Dexron and not Type T-IV.

It would make sense though to use Dexron if the Dipstick says Dexron as long as it's the original dipstick from that car.

Sorry i confused T-II for Dex II

The UZ dipsticks say T-II therefore as above they should not use Dexron