Originally Posted by Maxx2
I have been looking at ALL the available options right now and there are only 2 options for the really big numbers; Dinan and Hartge.
On the F10 550's Dinan are currently at stage 3 and the advertised numbers are north of 500hp now. There are a few guys who will be putting their stage 3 cars on the dyno in the coming days/weeks and I am awaiting those results. If they confirm the "claimed" Dinan numbers then I think this can be put to bed once and for all.
As far as the Hartge is concerned, their tune brings power up to 490hp which is comparable to Dinan. It appears that it is not a "flash" tune and more like a "piggyback". I contacted them directly, but unfortunately they do not offer engine tuning for U.S. cars. I will follow up with them to get more details on why they don't offer anything for U.S. customers.
Could these two companies be inflating their numbers for marketing? Very possible, but don't want to dismiss them so quickly. Until there is proof that these numbers are indeed "inflated" than I will reserve judgement.
Here's something else...l know that Dinan has made a point in the past that they dyno their cars with large fans aimed at the engine, trying to simulate real-world conditions where air enters the engine faster at speed. If they achieved these numbers using this method, and other tuners didn't use this method, then that tells us a lot. Assuming that the tunes are fundamentally very similar, the big difference is...drumroll...air! If all that is true, it would pretty much confirm that the limiting factor on this engine up top is the amount of air it is seeing rather than turbos themselves. If it was the turbos, then the engine would make the same power with and without added airflow.
2015 BMW M4 Alpine white/black
2011 Nissan GTR Red/black - HP Logic tune/midpipe
2013 BMW X5 50i M-sport M-performance Alpine white/black
Gone but not forgotten: '12 X5M, '07 AM SuperVantage, '05 Boxster S, '01 BMW M3,...