Msd and probably Mallory market them. In my drag racing days years ago we used them to leave at a certain rpm for bracket racing. That way with a mobile weather station and everything else being the same (launch rpm) you could dial your car in perfectly if you were lucky and maybe get the win. It just lets you leave at the rpm you choose in an n/a car. We also used throttle stops and delay timers made by Dedenbear and others to help cut that perfect light and time occasionally. Sorry for the long explanation. Good luck!

 

But HOW does it do that. is what he wants to know.

How does the raw fuel load the turbo?

 

raw fuel dumped in the exhaust essentially will raise the EGTs ALOT. and the hotter exhaust gases will make the turbo spool up much quicker due to heating up the exhaust gases which translates to heating up the turbo.

if all it does is shut off cylinders, i understand it. i thought it had something that was boost referenced off the manifold or something because i always saw it referencing to building boost.

i dont plan on ever being turbo'd so i wont need one.


but another question(referencing to zo6ted), wouldnt a trans-brake do the same thing, allowing you to leave at a certain rpm for bracket racing, provided you had the correct TC?

 

according to my resources it can also pull timing.

 

a 2 step is essentially a second rev limiter. It does the same thing your stock rev limiter does just at whatever rpm you set it at. I have the lingenfelter 2-step and love it. I set it to 3200 so that when I am on the transbrake I press the button and put the gas to the floor. The engine revs to 3200 and it cuts ingnition. It is just like bounceing off the rev limiter. I let off the button and thats all she wrote.

 

do you have your transbrake and 2-step wired to the same button or do you hav to hold down 2 separate buttons when taking off?

 

what?! you holdin out on me now? dang.

 

now i see the usefulness of this on a non-turbo setup.

i just about knew i saw that you had a 2-step in one of your build threads and i knew you were procharged so i knew there had to be a reason to use it without a turbo

 

Three things a 2-step does to aid in boost...

Pulls timing. (flip a switch and run less timing, useful in nitrous set-ups too)
Kills spark to cylinders and actively switches "dead cylinders"
allows the throttle blade to go to 100%

Also with a standered trans and a 2-step hooked to a clutch switch the driver can just mash the gas and touch the clutch, the 2-step will cut rpm down to allow for gear change with minimum boost drop.
LPE's unit appears to have a map sensor input, I'm assuming this is to control the amount of boost the 2-step can make..

I plaid with a DIY 2-step with hptuners, (uses factory rev limiter) It worked well allowing my old set-up to build 3 psi of boost in park. But it had a tendency to overshoot, but there are standered trans guys using it to aid in launching...

Also try searching for these terms....
Studderbox
2-step
launch control

 

for those saying its useless on N/A applications, most door slammer drag cars are running them N/A. they call them studder boxes, but its all the same principle, just for a distributor. the easiest way to explain it is that its a controlled misfire, kind of like your upper rev limiter.

on standard cars, it will help give you that perfect launch every time. they are tough to launch and these things help control how you put the power to the ground. wire it into your clutch switch and as soon as you lift your foot, zoom.

i run index. in index your trying to achieve a certain time as exact as you can...if you go faster than that time you lose. thats where auto transmissions benifit. get the same exact launch every time. they are usually used in conjunction with a trans-brake on the same button that way you can pull up to the line, hit your transbrake button and activate your two step and transbrake at the same time. let off the brake and floor the go peddle and as soon as you let off that button your engine is free to rev, and your transmission cuts loose and zoom. if your having problems spinning, you back down the 2 step rpm. if your hooking great you can move it up. its a great tuning tool for index or bracket racing.

turbo guys use them to spool up quicker. the controlled misfire dumps fuel and it burns in the exhaust. im no turbo expert but i think it ends up igniting in the exhaust and spools up the turbos alot quicker.