Originally Posted by subarooboy

While most of us know the whole atmo thing is more for the BLING factor, some may argue that recirculating the pressurised air can often raise inlet temps. Eg- the charged hot air fed back into turbine compressor again is going to be warmer than uninterupted cooler air coming straight from air filter etc. Of course, this may not be that significant and so in either case the intercooler may take care of the added temperature... but it is a 'worthy' argument to investigate.

As I mentioned before, having an audible reference point (vented to atmosphere) can often reveal a few things I find useful out on the track.

As far as the negative effects... AGAIN I'll just re-iterate, this has nothing to do with whether a BOV is plumbed back or vented to atmosphere! It is related to your ECU and it's tune. So yes, fitting an atmo to your existing factory ECU setup will increase fueling... but if you had an aftermarket ECU, you can tune to suit open or closed... no need to blame it on the BOV!!!