Variable Launch control
 

Surprised my searches didn't come up with anything on this topic, seems like a neat feature. I'm using an MS3 Basic on my 93, and am trying to get variable LC to work. My understanding is it functions much like a TPS. ie: requires 5v ref, ground, and a single wire going into a spare analog (0-5v) input. Set the variable launch to 0v=min rpm, 5v=max (using 1500rpm/3300rpm currently). I've programed everything for Spare ADC (ADC13), and if I set a generic sensor input to ADC13, I can set that gauge to read 0v=1500, 5v=3300.

Questions:

1. Is there a launch RPM gauge on TS, or is my generic sensor input gauge the way to display it?
2. In the past I've had issues getting LC to work at all (variable or not), does it only work with the engine running? Cause currently I can't even get my "launch on" indicator to change.

Thanks y'all, and happy boxing day.

1. You're generic sensor input is the way to do it. Thats how I view my variable boost control pot

2. I believe you are correct about the engine running. You just need to ground the launch input. I think the clutch switch has some other sort of connection to the neutral switch though. Not 100% sure.

Ok how about wattage and resistance? I'm looking at the local frys (wilsonville OR) and they have a lot of 2 watt potentiometers in varying resistances, what would work best in my setup? Do I actually get to use I=v/r for this?

lets see if this link works.

Fry's Electronics |

Current/wattage doesn't really matter. That's crazy expensive for a pot. Get something like this.

http://m.ebay.com/itm/371796521152

Maybe I'm just slow this morning, help me understand what you're doing here:
You want a little rotary knob wired up with which you can basically raise/lower LC delta rpm on the fly right? Pretty neat idea

Yes. It's been in the firmware forever. I tried it a bit on my old setup but found variable boost control to be better for me. New setup has multiple knobs.

https://cimg7.ibsrv.net/gimg/www.mia...9d6428de3c.jpg

Just one of those things I want to tinker with. Busy job and current 10.5 month old means a total of .25 (one session) track days last year, this year isn't looking much different. So I might as well play with MS.

my friends launch control on his VVT swap and fresh 225 RS3s was useless at any RPMs, so that's certainly not the point either. Documentation on this nifty feature was near non existent too.

I was gonna say: this would be invaluable on some of the AWD cars I tinker with.
But a Miata? Mehh
But yeah definitely a really cool thing to mess with. Though the boost/timing increase/decrease on launch feature that aidan and I messed with was 100x more beneficial for actually getting these things to hook up, as he already mentioned.

Aidan - when you say it's been in the firmware, does that include the ability to actually adjust real time in the middle of doing it? Like as it's bouncing around, you can raise/lower without letting off the gas? I don't think I've ever even seen that before.

They work in real time. I even modded the code for a customer that wanted to play with the LC boost target in realtime as well:
https://cimg6.ibsrv.net/gimg/www.mia...7b1a540033.png

WHOA! that's awesome hahaha

I dont think you will get a miata to hook on UHP tires by just dumping the clutch. You need to slip it (which the clutch does not like lol), its helpful for holding the rpm at a set point though before you do that.

Picked up these instead. $6.19 on Prime. $.40 more for knobs and 5 less. But what do I need with 10 potentiometers.

https://www.amazon.com/gp/product/B0...=ATVPDKIKX0DER

Sweet. Post vids once installed

individual launch control per cylinder time :D

I already got it to work, kinda. Ground the input and it has the 1500rpm launch, touch it to the 5v wire and it has 2500. I'll turn that up once the potentiometer is in, no need for a 5k rev limit while parked in my garage.

Vids of spark cut launch in your 1 car garage please.

This is actually really useful, I find by letting launch control handle the perfect rpm I can concentrate on feathering the clutch just right. It's been the deciding factor between a top 5 finish and wining the whole event at my local auto x.

If you spent any kind of time at a drag strip you'll quickly learn the difference between a 2.1 60ft time and a 1.9 second is almost inpercievable from the driver's seat but we all know .2 tenths can make all the difference at an auto x.

With that said I just change the RPM with a laptop between runs.

No video of it running yet, baby is sleeping. But it is working. First pot didn't work, 3 solders and 3 crimps later and the 2nd pot works great:


WHERE THE f*&K is the youtube button?!?