FellowTraveler
Well-Known Member
Interesting improvement in total fuel. Frankly that's an ugly fuel curve for a large turbo that lights off at 2000 RPM. (I am talking about the ATT AND the generic HX40II I tried out where both would light up around 2K RPM.) Typical DB2 or not.
Unless you have good new and perhaps better valve springs it's all risk over 3600 RPM.
I wonder how much fuel loss is from the governor starting to shut off the fuel?
I see the Hypermax smoke puff limiter need. Can they curve the fuel better by other means? Aka 6.5 normal fuel till around 2000 RPM and then pour it on till redline and then cut it back for a soft free rev limiter emissions snap test?
IMO, compound turbos would be the ticket for that fuel.