Has anyone else noticed this?

Lots of the modern era supercars/hypercars/megacars seem to throw out blue flames out of the exhausts under wide open throttle. I certainly don't remember seeing F1 cars do it, and up until now the only flames coming out would be under overrun/antilag or during gearchanges.

So why are they doing it? The Maclaren P1, MP4 and Porsche 918 seem to do it all the time. Is it because the exhausts are much shorter runs that they used to be? I would have thought that any sort of catalytic converter would kill the possibility of flames (certainly modern ones). Also on turbo motors surely the EGTs would be very high and kill turbos pretty quickly. Maybe its just down to valve overlap?

I dunno. Can anyone shed any light on it?

Nobby

i think as with most things there isnt one straight answer

fancy press pics, head/turbo/cat cooling theories, short exhaust runs, valve timing, unburnt fuel all probably have a part to play in various engines.

And the many "bypass at x rpm to make it louder etc" additions to modern cars will also help.