86NA7XR

I've seen many video's of people in rx7's that are staging on a track and when they bring their revs up it makes the BIG rotary POP POP POP POP POP. I was just wondering what that was. Is it because they're to rich or lean. Or is it the rev limiter?

PercentSevenC

It's called a two-step rev limiter. It's not just rotaries, piston engines do it, too. Like this Supra, for instance: http://www.youtube.com/watch?v=Aeh4AIaS3dw

86NA7XR

How does a two-step rev limiter work?

rxtasy3

iTrader: (2)

can't be good for any engine to bounce it off the limiter like that.

mikeb89fc

like this??????

http://www.youtube.com/watch?v=tQ9zaqTfNTk

Jimmy2222

iTrader: (3)

I always thought the pops were the way the exhaust pulsated or something (not the limiter bounce ones).

PercentSevenC

It's a button or switch (often a clutch switch) that, when triggered, limits engine speed to a preset level by cutting or severely retarding the ignition. This allows the user to launch at a consistent RPM. It's particularly beneficial for turbocharged cars, as keeping the throttle fully open allows the turbo to build boost prior to launch. It's called a "two-step" because there are two RPM limits: the normal one that prevents excessive engine speed, and one at a lower RPM used for launching. The loud popping is caused by unburnt air and fuel igniting in the exhaust system.

bwaits

iTrader: (12)

As long as it is a ignition cut rather than fuel cut limiter all goes well.

-billy