[dexx]

Originally Posted by Singletrack

LOL. Show me the logs that show detonation with an aftermarket exhaust like you would experience with 87 octane fuel. You are seriously saying, without any evidence to back it up, that putting an aftermarket exhaust on an M3 is a similar problem for the ECU to deal with as having 87 octane which will cause the M3 to detonate horribly (I imagine) at WOT. The physics are not at ALL the same.

Don't ask me to prove 1+1=2. At some point you understand the basics, or you don't. How about you show me datalogs of a S65 running properly unmodified, and one running with various exhaust changes? Who has provided _proof_ that this works optimally (for sure not) and secondly safely? More power doesn't mean safer. Attach a link to the S65 datalogs.

You are comparing running a fuel outside of the manuf specs in the engine. The car will perform horribly, the engine will suffer some level of damage, and will dyno way down on power. Tell me how the "physics are the same" between that and the ECU adjusting fuel and timing, and probably some other things, for an exhaust that will improve the VE of the engine and result in more HP on the dyno? Makes no sense.

Explain this to me, how do people make more power on the dyno with constant detonation and timing being pulled? Why do tuners, who run the stock car on the dyno for a baseline, NEVER report what you are talking about? Seems like it would be an awesome way to sell their software. How can BMW sell their own exhaust which has been shown to make power on the dyno? Your argument makes no sense.

Also, "adjustments to the base map" are always needed regardless of aftermarket parts. That's why they call it a base map. If everything worked the same on every car in every environment, they would just call it "the map". By your logic - you better not change your fuel quality, drive at different altitudes, or in different ambient temperatures in your car.

Seriously, learn what ignition timing means first. Then what factors influence the optimal timing point(s), and the consequences of being wrong in either direction, and then the effect of octane on being able to reach that point. You can find books at the library about this. There will be potentially a lot of advanced math involved as well. Once you're done with that find a book in engineering principles - manufacturing tolerances and safety margins.