Nistune Feature, Part 3 – Launch Control

One of the new features introduced in the Nistune ROM Feature Pack is launch control. This works by temporarily modifying the stock rev limiter (fuel cut), and also imposes a temporary ignition retard. Retarding the ignition timing makes EGTs skyrocket, which produces more heat energy through the exhaust manifold, helping to spool the turbo up. Of course, it does need to be done with caution because it raises the EGTs.

There is a common misconception regarding fuel-cut vs spark-cut type launch control systems. Some erroneously feel that spark cut is safer, because cutting fuel will make you run lean. In reality, a fuel cut is just that: a cut. It doesn’t just reduce how much fuel is injected, it completely stops injecting fuel outright. So it doesn’t create a lean air-fuel mixture, there’s just no fuel at all, just air and spark, so there’s zero combustion.

Comparatively, a spark cut still injects fuel, compresses it, then sends it through the hot exhaust system where it can (and will) combust. This can be extremely dangerous and cause damage to the turbochargers and exhaust manifolds, but of course it does give you that cool popping/backfire everyone loves. For this reason, fuel cut is definitely the safer, cleaner alternative, and this is why OEMs use a fuel cut for their factory rev limiters and launch control systems.

Anyway, Nistune’s launch control system can be triggered in one of two ways: speed-based, or toggle-based. In speed-based, nothing physical has to be done or installed, launch control turns on automatically at 0mph. You can still drive the car normally; if you don’t want to launch hard, just take off like you normally would. You can define when it turns off (speed based), so you just have to make sure your shut-off speed comes on before your launch control rev limit would in first gear through normal driving.

The second way is through a toggle-switch. There’s a signal sent to the ECU for when the power steering pressure is raised beyond a certain point, and it just tells the ECU to raise the idle slightly (through the FICD). However, it practically never comes on while the car is stopped/idling, and the launch control can only be enabled when you’re not moving. So the LC trigger button just piggy-backs on this; you don’t need to disable the signal from the power steering pressure sensor as they won’t conflict with each other since they’re used at different times.

I decided to install a dedicated launch control button in my car. I chose a small space to the left of my steering column, as the previous owner had already put a small hole here.

The previous owner had already drilled a small hole in this spot for unknown reasons.

…So it didn’t bother me too much to drill this hole out bigger.

Part of why I like this car is because it reminds me of the 90s, especially the sort of golden 16-bit era of video games, which were a big part of growing up for me. So, I figured, what’s more appropriate than a period-correct arcade button?

Then I just had to make a quick and simple two-wire harness for it.

And finally put it all back together:

A quick splice into the wiring harness and a checkbox in Nistune is all it took to get setup and running. Pressing the button at a stop enables launch control, and the check engine light flashes rapidly to show this.