learn me on some launch control!
 

i wasnt worried about building boost with the 13g, but with my t3/t4 install almost done, something to build boost is probally a good idea now. but i am a tad confused on the circuit to build.

http://www.msextra.com/manuals/MS_Ex...al.htm#launchC

here is the curcuit, i was plaing on the low input
http://www.msextra.com/manuals/MS_Ex...l.htm#launchin

so i take the clutch switch wire, put a 5v and diode to it, then take that to JS11? but wouldnt that just give JS11 5v all the time? can someone clear that up for me so i dont short my board :) and i know to put a inline toggle so i can turn it on and off without the laptop.

basicly you just are grounding out the JS11 when its activated. You DONT need that circuit, it just helps protect from noise and voltage comming in. it will work fine without it. I bypassed the original clutch loop and then just used the OEM clutch switch connected to ground on one side and js11 on the other..... completing the circuit to ground when the clutch is depressed. Be sure not to EVER send 5 volts on the line, or else you will fry the chip. i had a wiring issue and fried 3 chips.

Essentially you are just switching a ground....thats all. if you choose to make the circuit you need to make the active low input

so i just take the clutch switch wire that went to the stock ecu and take it straight to js11?

You run a jumper from JS11 to one of the input/outputs and then run a wire to that pin on the DB37 and then tap the clutch switch wire at the ECU. You don't need any circuit or anything, the MS just needs to see the clutch ground.

i cant beleive its that simple. thanks guys.

Used it for all my launches at the autocross today. I have it cutting fuel and spark, 5 degrees I believe at 3000 rpm. Works great so have some fun with it.

also... flat shift is the shit if set up well... even on a stock miata

I'd say flat shift would be even better for a Turbo miata, all the better to stay in boost.

i tested mine on jackstands....not as cool. :bang:

I was pondering setting up the launch control / flat shift on the hydra. haven't got to it yet.

Worthless without video!!!!!!

C

sorry for the ignorance, but to make it work all I need is tapping the clutch switch with a 18gauge cable or so and solder and heatshrink it to the js11 on my middle connector on MS PNP?
that would be simple, why didnt I do it before

Not even that. The clutch switch in question (the upper switch, not the one which engages the starter)is already brought to your ECU harness. It's the Brown/White wire at position 1V. Closes to ground when the clutch pedal is moved from the upper stop.

SO you are saying all I need to do is go to Megatune and activate launch control and it'll work?
Wow

After having connected the wire, yes. I was merely pointing out that you need not go all the way back to the clutch pedal itself to find the wire- it's right there waiting for you in the ECU harness.

Yep, 1V on harness, into MS to JS11. turn it on in mega tune, the end.

It if have/had cruise control, you need to remove the neutral switch circuit, as it causes the the signal to ground at the wrong time, ie not in gear.

I just tapped the brown-white clutch wire to JS11. Doesnt work....
I had cruise control maybe that's why, it's removed now. I checked for the neutral switch, according to the Miata manual (page F-141) it's located in the transmission. It has two plugs, if I disconnect these wires, would it work?

NEVER MIND. ACCORDING TO MSPNP MANUAL, TO ACTIVATE LAUNCH CONTROL, SOLDER PINS 12 AND 13 ON THE MIDDLE CONNECTOR TOGETHER.

not quite sure. i didn't play with it, new one doesn't have ;)

the clutch switch breaks the circuit when the clutch is off, however, the neutral switch completes the circuit when in gear :doh:

so no matter what, when in gear, the launch control light should be on...something like that.

but yes. it seems, if you simply disconnect them, it should work.

6-speed + pucked clutch + 80lb.ft buffer between power output and clutch rating = FFS and LC for me. ;)

Ok, I just soldered pins 12 & 13 together and the launch control works.
It doesnt work well though. When I accelerate the rpms go to 2300-2400 the timing drops to 5 degrees and the rpms drop to 1200rpms...wtf??
The settings are:
Start retarding at: 2500rpms
retard to: 5 degrees
Hard cut at" 2700

I tried retarding timing to only 15 degrees and raising the rpms to 3000 retard and 3100 hard cut and it does the same? ANY INPUT

is it doing this when you are driving?

yes but only when I clutch to shift and I accelerate with the clutch on (depressed). It accelerates kinda rough too.
It does it when I try to launch too. And when I'm in neutral and accelerate

when does the green launch control light, light up?

I dont know, I'll check and let you know. tomorrow. I will also datalog it.

alright bitches. got it all wired up and "launch on" comes on when i hit the clutch. but i cant test it untill i get my exhaust gaskets in the mail. can someone post a screen shot of their settings to give me an idea on the retard settings on such?

the launch control light gets red only when I press the clutch.
It works now, I changed the Rev Limiter to cut the fuel instead of spark and it works. I also activated the flat shift, what a great feature, it's fun.
Why do you guys think that the launch control only works with fuel cut? and not spark cut? maybe spark cut is just flooding the engine? is fuel cut harmful to the engine? AFRs go all the way lean, no fuel..

Mine are:

Start retarding at 3000
Retard to 5 degrees
TPS = 30 (I dont think it matters with 1.6)
Hard cut= 3200
Variable= off
Arming flat shift rpm= 4000
retard at= 5800
hard cut= 6000

It works since 5 minutes ago.

thanks man, i will give those a try. hopefully i will have the car running again this weekend

I dont know if I like launch control. It may be good for drag racing but I cant heel toe anymore because it will limit my heel toe to 3200 rpms

um... not if you have it set up correctly.


Oh... nvm, you dont have a variable TPS do you?

EDIT:

Also, learn how to heal tow double clutch. That way you are changing the RPMS while the clutch is out. Its just habit for me now to double clutch at every downshift.

if you are road racing, you don't need launch control....

if you are drag racing, you don't need heel toe....

if you are autoxing... its nice

if you are boosted...flat shift keeps you on boost more...so road racing is back in


if you can set it up right its a nice feature to have, not your every day feature but still usefull none the less.

got the car up and running, boost controll works. havent tried to actually lauch yet because i am scared of my 1.6 open read end. but i just wanted to say that flat shit is cool as hell!

I like launch control when turning from a set of red lights and taking off completely sideways around the turn. :)