Newbie Line pressure and TCC help please
Hello, I'm new to this forum and have enlisted myself on it from having a read through a load of the existing threads on auto gearboxes.
A little intro to why I'm here:
I'm really into Miatas and especially boosted Miatas, I've boosted a few now and want a new challenge; which is creating an alternate gearbox option for the limited few there are available.
The standard routes are: 6 speed miata (350-400nm limits) RX7 turbo2 (400-500nm limits) or ZF Manual gearbox. I fancy something new and potentially auto so the 8HP fits the bill
What peaked my interest is the ZF 8 speed box is that, where I am in the world (UK) the box can be had for about ?250 or $300.
I want to make a (crude to begin with) standalone TCU to run a 8HP70 gearbox outside of the donor vehicle. I'm happy with the programming and circuitry required to run the gearbox itself but know very little about how automatic gearboxes work.
I have looked at the valve body inside the 8HP box have found a load of info on which solenoid operates which gearset brake and clutch. I fancy building something that will shift it using an arduino or similar coupled to some power transistors which will remove the original TCU.
What I've found out so far is that the Torque converter clutch (TCC) needs variable input (PWM) but want to know the principle behind how much lockup it needs and when. I understand it's to get the car rolling like your conventional manual but am unsure what it should behave like when cruising, wide open throttle and shifting.
Another area I need help with is the Line pressure control, I'm aware it's dependent on torque and varies too but unaware of its relation to cruise/WOT and shifting.
If anyone knows of any good sources to read up on, could they please send me the link or paste it into the replies.
I'm only after the crude principal, not actual values etc.
Any help is appreciated, Many thanks
