[sledg77]

I've been playing with my Z4 the last couple years to extract more HP. My journey started by installing an ESS Vortec S/C kit and has since advanced to installing a smaller blower pulley than ESS supplies, adding a methanol-injection kit, a new tune to take advantage of the smaller pulley and meth, and installing the xHP TCU tune to enable true manual shifting of the Steptronic. I'm thrilled with the results - 339 HP, 278 lbs torque @ 6600-6700 rpm at the rear wheels (blue lines). The torque curve is nice and flat and I'd be pulling more power but the injectors that came with the ESS kit are maxing out at 6700 rpm. Just wanted to share what the N52 is capable of without crazy mods. The stock motor before any mods was putting out 208 HP/192 torque.

Still running stock exhaust as well. If I went the next mile and installed larger injectors and custom exhaust, I believe I'd be approaching 400 WHP.