Jim, there aint THAT much difference in lag TBH.........0.48 will come on boost about 300rpm sooner maybe if that. I personally FAR preferred a 0.63 on my car as it just kept pulling to the redline.

When's it hitting full boost at the moment BTW? It shouldn't be anywhere near as bad as your making out....maybe it needs setting up properly? It should be at full boost by 3,500rpm for deffo BTW.

Cheers,
Ian