A340e 4th solenoid questions

[2jzhilux]

Hi i have an aristo gearbox with 3 shift solenoids and 1 solenoid that controls the line pressure
Now my question is does anyone know what the 4th soleniod expects to see and what inputs control it
I have bought a suprastickv4 and it will only control the 3 shift soleniods but im wonderin g if i could hook up the 4th solenoid to a pwm signal from my haltech or just run 12 volts to it and run it on max line pressure all the time.

[Big rob]

You could PWM the 4th solenoid based off of an input to control line pressure. For example map it against TPS so that at low throttle it is nicer on the shifts andhigh percentages its solid. Should also be good for fuel economy too.

[Mos]

Borrow someone with a scope and take a look at what the factory ECU does with it. I've been meaning to do that for ages, but somehow haven't gotten around to it. I don't think many people have done that so I doubt there'd be much info floating around.

[Kyosho]

It's PWM based.

having it disconnected = max line pressure.

[Big rob]

Sorry 2JZhilux as Kyosho said (I forgot about this) the 4th solenoid bypass's fluid to maintain line pressure not restrict it so if you don't connect it you will see max line pressure.

Rob

[2jzhilux]

Would max line pressure at all times be a bad thing besides driveablility at low speeds

[brett_celicacoupe]

might be extra heat at the least but you probably have a largish cooler anyway?



ooh and youll be fully hektik if your auto chirps 2nd

[Big rob]

2jzhilux I know you have already bought the suprastick but if you reakon you could part with it buy this:
http://www.powertraincontrolsolution...content-4.html

A much better option for later moddel boxes.

[2jzhilux]

might be extra heat at the least but you probably have a largish cooler anyway?



ooh and youll be fully hektik if your auto chirps 2nd

The 3500 high stall should stop the hektikness
I am also hoping for it to smoke the tyres into second anyway

Thanks for the link big rob i may have a look into that

[Kyosho]

It will, to a degree, be better to have high pressure then low pressure.

Low pressure causes the clutchs to slip too much etc. Something that causes the gearboxes to fail when they're being punished.

The high pressure more starts putting stress on other components, tailshaft, diff, axles, etc, due to hard shifts.