I think the R8 intake makes a big change from the SS/Redline one. Test drove both and much more of an intake note in my HSV. One of the main reasons for buying it over an SS.
I'm still in two minds over an aftermarket intake. Can't decide between:
- keeping current - cheaper, easier, like the sound
- OTR - local, harder to clean filter
- rotofab - looks great, easy to clean, overseas so less support
I think you would struggle to get any significant gains from non standard airbox/CAI.
VF intake, especially on your R8 is not restrictive.
I will soon have my car tuned with R8 intake and then see how that compares with VCM otr tuned LS3s.
I doubt that there is any significant improvement worth the hassle...
In the end VCM would have cost me less than all this hassle but stock look, no leaning of radiator and easy of filter change/cleaning led me to where I am now...
HSV would have not bothered with all this if stock SS airbox intake was working for them.
I believe in early hsv ls3 days they even marketed an option 'sv' that was bump to 340kw by using this setup. They went from 307 to 340kw by playing with air intake and exhaust...