hey guys, i currently have a rb30det using a rb25de series 1 head, it's had around $9000.00 worth of tuning in the last month..... after all the effort the car still doesn't idle very well and i've been told by the compression ratio is too high so were un-able to run the boost/power i wanted to achieve... it's got a rubbish ltx12s microtech ecu so thats probably half the trouble, but i'm using a rb30e forged piston so we can only assume it's in the 10:5.1 compression ratio, cold cranking of 180psi per cylinder. i have been told i can remove and lathe down pistons to get them flat topped, or i can have the squash area in the cylinder head machined to drop the compression, we are using a 1.2mm headgasket. i also wanted to know if the rb25de head was able to flow the 500+ rwkw i was after as i already have all the bits in this head like custom manifold and plenum, cams, etc..... thanks matt Some original photos have not been recovered yet.