[WeekendWarriorz]

Originally Posted by pokeybritches

I would look at pulley sizes on the kits. IIRC they both use Vortech V3 Si units, so the same pulley size should achieve similar results.

The VF bracket is superior. I know of several ESS owners that have had oil filter housings crack, including the previous owner of my car. The VF kit has more belt wrap for less slip. I believe ESS redesigned their bracket a couple years ago, but I haven't really followed.

I haven't heard of either VF or ESS offering alternative software for the Z4M... only the E46 M3.

554 whp sounds like a lot of dyno correction factor or a very generous dyno, since it would mean the engine is operating at close to 200% VE (almost 15 psi of boost with zero supercharger drive losses or ignition retard due to heat). I wouldn't trust a canned tune at those boost levels on an S54, no matter who it's from.

I mean they developed the canned software for the pullies that come with the kit, so it should be possible for them to make software. Either way TTFS can take care of it.

As for the dyno it was at European AutoSource which uses a DynoJet, and their shop is highly used for performance figures. Fuel is undisclosed but the software wasn't changed from the software given. How is the support from G power?