OK

I know that unburnt fuel in a hot decat exhaust = flames

So what circumstances makes this happen? AFAIK it as you get back on the gas after a gearchange whilst flooring it through the gears, also on overrun after accelerating in the same gear.

But how about when flooring it at 2000 rpm in 2nd, waiting for the laggy TD05 to spool up, then as it comes on boost? Due to the decat I get the usual bit of over boost, its at this point I hear a 'pop' as all hell breaks loose. Whether there is a slight hesitation at that point is hard to tell, all I know is that after the pop it pulls well all the way to 7000rpm very well indeed

Any ideas what the pop can be? Flame or otherwise?

Full decat, OE dumpvalve, OE Boost control solonoid, OE Z4map, Optimax + NF etc

Cheers

Justin

 

sounds like you're hitting boost cut, maybe only slightly