PorKen

Or, I think I've come up with a use for LH2.2 pin 24.

Stock, pin 24 is an output for an EZ-K ignition brain load signal. EZ-F doesn't use it, as it has it's own MAP sensor. It is unwired at the LH plug, but the code is there, as it would be for a SAAB or Volvo, merrily outputting a 0-200ish Hz frequency.

Deleting the output code doesn't affect fueling, so... I'm thinking about making a LH controlled kickdown relay.


Coding
Autos don't need injector cutoff on decel, so there is a chunk of EPROM codespace available. (~47 bytes, woo-hoo!)

Simplest coding would be a kickdown on WOT, which starts a bit before the pedal hits the floor switch.

The code could allow for a higher shift point (kickdown release) vs. the stock kickdown relay, to go along with a higher rev limit.

There isn't enough room for something as fancy as the GTS dynamic relay programming (it has a PIC processor, AFAIK), and there is no speedo input, so it would be just MAF vs. RPM. Too much load below X-rpm = kickdown. Might need a hysteresis rpm window.


Electronics/wiring
Pin 24 has only a small switching transistor driving it (switched 12V, AFAIK), so the output would have to go through a reed relay, or a power transistor. Could probably put this inside a plain relay with a center 87a (normally closed) terminal, with a wire out the side. This relay would replace the stock kickdown relay.

Replace the foot operated switch with a jumper.

fbarnhill

Hey, you build it and I will be glad to test it. I think it sounds great.

SMTCapeCod

So you say WOT, but then if its MAF v. RPM.... Can a signal be pulled off of the TPS? Is it a potentiometer or just a 'switch' in the true sense?
What about that vacuum signal that goes into the box...is that the EZK box for advance? Maybe that could be t'd off to a MAP sensor? MAPs go negative to read vacuum, right? Just noodling around, far too late....but without octane assist...

PorKen

'85-'86 have EZF ignition. (EZK is '87-up, with knock sensors.) The EZF has the vacuum connection.

The '85-'93 TPS has a switch for idle and WOT. '94-'95 w/dynamic kickdown have a pot and switches. The DK relay kicks down if the pedal is moved quickly if some conditions have been met. (More info - Schocki DK conversion.)

The LH can accept a variable TPS, but it is not programmed for it. (I use this variable input for an user adjustable WOT feature on my chips.)


If the load and rpms are high enough, the LH will go into WOT mode even if the switch is not pressed. It would be easy for me to put the kickdown in as part of the WOT map read.

I might be able to jump in where the acceleration map is read. This might be the ticket as the code has already figured out that you are doing something squirly.

John Speake

Why not use the provided load signal in a modified KD relay ?

Cosmo Kramer

Could an adjustable vacuum switch work for this? I have a pressure switch adjusted to put my LH into open loop at .5 psi to improve my drivability. Maybe a vacuum switch to put it into kickdown at a specified vacuum would work better then the switch on the floor.

PorKen

Because I'm an electronics noob?

Programming is much simpler for me and the circuitry would be quite simple.


Hmmm...I might be able to use/modify a relay for some other function, EG. wiper relay, which would accept a TTL trigger from the LH.


The PIC processor in the GTS relay might be able to be reprogrammed.




That might work. Give it a shot!

Cosmo Kramer

Mine would have to be a pressure switch, it should try hooking it up to the one for my LH that kicks it into open loop at around 1 psi, that is roughly 1/2 throttle on my car at lower rpm. I think putting the bowden cable on an eccentric that pulls it open further at small throttle openings would make the car more lively. The kickdown relay coded on the LH or on a vacuum/pressure switch could make the car drop 2 gears when you only want one, it's like "all or nothing".

Mike Frye

You guys and your silly workarounds to make your car more like a 5-speed.... Sheesh!