Here's a test from European Car Magazine on an S54 M3 on replacing all fluids and spark plugs with dyno, Evolve tune with dyno, and GruppeM intake with dyno. Also interesting that the two cars they dyno'd had such a difference in dyno numbers (on same dyno)
http://www.europeancarweb.com/tech/e..._m3/index.html
I am only posting relevant info, I didn't have anything to do with this test or the data in it.