exactly so lower compresssion more boost, higher compression less boost. so if you get low compression pistons then you can get a harrop and increase the boost, however if you get higher compression then get a harrop you will have to limit the boost.... so from that i assume if you want more power then lower compression is the way to go... but if you just want to keep the m62 then higher compression is the way to go, correct?
With turbo engines then yes, although your more likely to get lag. However with a SC engine it's a bit more complicated as to get more boost you need to consume more power from the engine. Also SC's, even the TVS, are less efficient than a turbo and arn't really design to create big boost levels. combine that with the cooling and flow restriction of the laminova manifold and you can end up chaseing your tail adding more boost and not making much more power. The advantage of low compression is that it is 'safe' if you don't have full access/ability to map the engine properly.
That exhaust is 
