Massive improvement to launch control - My DIY mod

Discussion of tuning specific to MAZDASPEED6/MAZDASPEED Atenza/Mazda 6 MPS vehicles
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judderod
Posts: 2
Joined: May 27th, 2016, 5:16 am

Massive improvement to launch control - My DIY mod

Post by judderod »

Launch control hasn't worked very well on my car. I found I could launch the car a lot quicker manually than when I used LC.

The problem was down to the engagement of the clutch switch.

When LC is active (WOT, holding revs, ready to launch), it's waiting for the clutch switch to be triggered so it knows to turn off and allow true WOT. But the switch on the clutch pedal is very high up on the clutch pedal's travel - it engages right at the top of the range.

Letting off the clutch pedal slowly would mean launch control is still holding back power even as the clutch begins to engage, the car start to move, and hence the revs then drop. The problem was the revs would drop out of boost, so by the time LC turned off and full power came, I was out of boost anyway so had to wait for spool up again.

The other way to launch was to let off the clutch pedal more quickly. But this just caused the car to lurch forward, the engine bog and still come out of boost.

So I found a cheap and dirty workaround. I drilled a small pilot hole in the middle of the plastic pad that contacts the clutch pedal pushrod switch, and put a small screw in it. This is so that the clutch pushrod switch starts to get pushed in when the clutch pedal is lower down. I then turned the screw to adjust the height of its head so that LC turned off (and WOT power came on) just after the clutch begins to bite, as the car begins to move forward.

Now I get full power just as the clutch engages and the car beings to move. No lag, no bogging, no lurching. Launch is a lot smoother and much, much quicker.

I can do a write up if anyone else has the same problem.
Elvang
Posts: 3
Joined: April 11th, 2017, 10:52 am

Re: Massive improvement to launch control - My DIY mod

Post by Elvang »

I had the same issure, and ended up with breaking the clutch switch, when installing the screw. I think I will look for a switch with a longer travel.
judderod
Posts: 2
Joined: May 27th, 2016, 5:16 am

Re: Massive improvement to launch control - My DIY mod

Post by judderod »

Ah man sorry to hear that. It should be worth it to get a longer switch but you really need to be able to adjust it so you can fine tune the engagement point to where your clutch bites.

Might also be worth checking if the old switch is push to make or push to break contacts.
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