JaguarJay

Is it possible to run launch control on the DIYPNP for a '91 MX-5 (yes it is :P)? I want to use the clutch switch and an external switch to turn it on and off. It's connected from 1V on the board to the input 2 input pin, then from output to db15 pin 15, which is connected to a switch, which is connected to db15 pin 14. Pin 14 is connected to the Flex port on the mainboard. Will this work or is the clutch switch on a '91 connected to a different port (say 1L or something).

Aside from that, is it possible to run LC without a vTPS, since the MS wants to set the launch control above a certain TPS%?

Matt Cramer

To make launch control something you can turn off and on without a VTPS, I'd use the switch on your TPS with a 5V pull up. Make it so the switch on is 100% TPS and the switch off is 0%. Solve both problems at once.

Just don't turn it on while cranking or you'll go into flood clear mode.

JaguarJay

That's a nifty idea, I'm definately going to try that next time I pull my MS out of my car. But for now I'm just going to focus on getting it running the way I want it to so that'll be something for another time. Thanks for the tip!

aidandj

iTrader: (5)

An easier way to do it IMO is just to put a switch between the clutch switch and the ECU. Disconnect the clutch switch to turn it off,

That is a fancy way to kill 2 birds with one switch though.

JaguarJay

So if I understand correctly I either need to apply the version Matt gave me, or I can keep it the way I have it now and get a VTPS? In other words, unless you're mocking a 100% TPS signal with a switch, you can't run launch control without an actual VTPS? Either way I'll have to take out the MS again xD

aidandj

iTrader: (5)

What is the TPS value with no VTPS? You might be able to just set the launch TPS% to 0 and see if that works.

JaguarJay

The TPS value sits at 0% at all times. I already put the LC TPS value at 0 but that doesn't seem to work. Is the 1V on the DIYPNP connector board even the clutch switch on a '91 MX-5? :'D
If it is, do I need to run a wire from 1V > DB15 > external switch > DB15 > Input and then another wire from Output > FLX? Or will my current setup be able to handle it? If it wasn't clear already my current setup is 1V > Input and then Output > DB15 > external switch > DB15 > FLX.

deezums

iTrader: (3)

Launch control with no TPS signal is going to suck hard, even if you interrupt the clutch signal.

1V is the clutch switch. Input circuit goes to 1V, output goes to whatever CPU pin you want to use. You can also just hook the switched ground wire (1V) straight to the CPU pin, but that's not proper.

Sounds like you have it wired wrong.

theAnswerIsMiata

I recognize this thread is from 2016, however I found it helpful in my search for answers and thought I would update it with a sound conclusion.
I have a '91 1.6 running on an MSPNP2 v1.3. I have no aftermarket vtps, just the stock sensor.
The procedure for my launch control setup is as follows:
-Wire 12v to a switch, on the other side of that switch wire a wire to pin 2L on your ecu harness. (I just connected it to the existing wire)
-Open your ecu and jumper the the pins that allow for VTPS to work. (This is detailed in the MSPNP2 manual)
-In Tuner studio set the launch control option to LAUNCH, and input on LAUNCH. The MSPNP2 is pre-wired to sue the factory clutch switch, but if you want to use an external you can pull the corresponding jumper as per the manual.
-Follow the procedure for calibrating a VTPS sensor by going to tools, the claibrate TPS then with the car off get current with the switch off, then do get current with the switch flipped on.

-That's it, when you flip your switch the VTPS will reed on your gauge cluster at 99%~ throttle and when you push in your clutch Launch controll will be enabled. when you flip the swithc back off the TPS guage should go back to ~0% throttle.Note, the flaw here is that you probably want to enable flat foot shifting as well other wise when you go to shift into second gear unless you flip that switch back off the car will try and turn launch control back on when you are already way above your hard limit.