Lots of fuel along the zero load sites and no ignition advance is the way it's done, this way as you lift off throttle it cuts all ignition and Unburnt fuel enters the exhaust. Never had anyone request this on a 'proper' car, usually left for the Clio/corsa/imprezza brigade.
I will start working on a real hard cut limiter for the big kids out there.... Lol.. Give me a few weeks to read up on the full NMAX (engine speed) limiter routine... A victims car maybe needed soon to test ;-)
Well this is interesting can't wait for Nick to come up with it!