Launch / 2 Step / 3 Step / T-Brake - MegaSquirt MS3-PRO User Manual

7.8 Advanced Engine 7 ADDITIONAL ITEMS: BEYOND BASIC FUEL AND IGNITION CONTROL
set to take more action the longer the traction control is active. The slip number is different based on
the method used.
• For VSS% slip, it is the percent by which the driving wheel speed exceeds the non-driven wheel
speed.
• For perfect run, it is the percentage difference in acceleration or time vs the target.
• For switched mode, off is 0% slip and on is 100% slip.
With on/off nitrous cut, we recommend setting the nitrous cut at 0 for leaving the nitrous off, and 100%
to cut off the nitrous.

7.8.11 Launch / 2 step / 3 step / T-Brake

The MS3-Pro launch control system is a 2-step limiter, typically used in drag racing applications for
consistent hard launches and/or to build boost with a turbocharged engine. The flat shift settings
allow full throttle shifts on a clutched vehicle. A switch on the clutch triggers the flat-shift rev limiting
(for bikes, see also the sequential shift cut, which may be more suitable.) It is important to install the
clutch switch with adjustability, as the exact height has an effect on how well flat-shifting works. Flat
shift is unlikely to be useful when running an automatic transmission. The 3-step is typically used as
a burnout limiter and will often be linked to a line-lock.
A typical drag racing scenario would go like this: You pull forward into the burnout box, stand on
the brakes and flick on the line-lock. This also enables the 3-step. You now do your burnout and the
3-step limits are applied. After your burnout, you pull into stage, depress the clutch (activating the
launch switch) and then push the throttle to the floor. The launch settings will hold the engine close to
your chosen rpm. When you change gear, keep the throttle planted, and only use the clutch. Now the
flat shift settings come into play, and the revs will be limited to those settings. After changing gear and
lifting your foot off the clutch, the limiter is disabled. Be sure to also set the normal rev limiter should
you miss shift.
7.8.11.1 Basic launch control / flat shift settings
• Launch control option
DIYAutoTune.com MS3-Pro manual version 1.036, firmware 1.3.4, 6/10/2015 Page 231