For those who aren’t top flight rally drivers it makes a good noise, exhaust flames and reduces the life of your exhaust and turbo significantly.
It also tends to melt spark plugs if you’re not very careful with it. I’ve a pal who just blew up his RS4 B5 650+bhp engine all because he missed a gear change whilst he was using the ‘flat shift’ feature….which works like anti-lag. Basically you can keep your foot hard on the accelerator pedal and then change gears as normal…the ECU recognises that you’ve hit the clutch so it kills the spark ignition but keeps fuelling the cylinders. If you don’t get a snappy gear change…there’s a huge amount of unburnt fuel in the system and it can all go horribly wrong.
Anti-lag…well the clue is in the name…it keeps turbo engines from dumping the boost between gear changes. Some like the sound of the piisstt between gear changes (that’s the boost being released) and some just like that continual flow of power between gear changes.
My motorbike can shoot flames a good 5 feet out of the exhaust. But if anyone else does it, they’re dicks
Like Northwind…my mid-life crisis S4 B5 also has anti-lag & flat shift tuned into the ECU so if you give it a bit of stick it makes lots of bangs, pops & flames. If you drive the car normally, it sounds like any other car.
When I’m driving it with all those noises it makes me feel like a real man…everyone else who does it, well they’re just tools.