I seem to have started a discussion on Facebook about removing the boost return on a G40, it's quite interesting. I'd be interested to hear your thoughts on it.
My understanding has always been that the boost return doesn't do much more than simply return oil vapours back to the charger for lubrication purposes, and that the benefits of a twin inlet are minimal. So don't bother, basically. I've never had the boost return pipework on my car - the crankcase breather is rotated around towards the passenger side and the inlet is blocked off. I've had it like this for eight and a half years, and I've never had any problems. I'm running a stock airbox, single inlet, with the crankcase breather routed to a catch tank.
The German G40 owners on Facebook reckon it's a bad idea, only suited to those who want to get the noise. I've talked them out of the need to have the vapours diverted back to the charger, but their version of things is that it's better to have the boost return because it's directing boost back into the charger so you get full beans more quickly than you would without it. Is this true?
I only ask because the discussion is timely. I found my boost return pipes in the garage the other week and I've been umming and ahhing about putting them back on, but still routing the breather to a catch can, to see what it's like not having the part-throttle hiss. But, as they've been in a dusty box for ages, I'll have to get all fussy about cleaning them (and the pipe through the rocker cover) before they go anywhere near the charger.
Interested to hear the arguments for and against...