Originally Posted by flipm3
My theory is that that the S65B40 and MSS65 DME are just very tricky to consistently dyno. I could almost bet that these cars with similar bolt ons, but different brands, will perform very similar in acceleration despite brands and dyno numbers. Just a theory though...
Looking at every 100% stock E9X M3 on the forums, they can vary as wide as 40+whp. I doubt BMW is that inconsistent
M3 uses the MSS60 DME, M5 is equipped with MSS65.
Final numbers can be attributed to a number of variables, including conditions, fuel, maintenance, etc. We've seen some stock M3s dyno as low in the low 300s, and some as high as 365whp.