My 521 dyno data

[Naja]

John -
Looks great.
I have a similar engine that I have only done an engine dyno on, so I'm not sure about the differences in the curves that the drivetrain might generate. My torque curve was quite flat from the initial logging point (2600 rpm) to its peak at 4700 rpm. I have about the same setup as Tom, but I got significantly higher numbers (both hp and fp) - again, I don't have a good feel for a reasonable correction factor between types of dyno tests (except that it could be anywhere from 15 to 100 hp difference).
The people who set up my engine and did the dyno felt that the Torker II manifold was a significant restriction to airflow, and, hence, performance (and I agree). We all felt that if I were able to put a Victor Jr. manifold on the engine, we would have gotten around 700 fp and 600-650 hp.
I have had discussions with others about their injector sizing. I am using 65 lb. injectors and have a 60% Duty Cycle at the maximum performance point. Considering the restricted air flow, I feel that I would have hit the target of 80% Duty Cylce with a Victor manifold, like yours. This raises the question: What size injectors are you using? Tom and Steven (Back In Black) are using 36 lb. I feel that their engines are not realizing their potential because of undersized injectors. I feel that 48 lb. would be about right for our setups. (I'll keep the 65s because I may go to something that will utilize them in a couple of years). With your Victor manifold, I feel that 65 lb. injectors are necessary for you to get the most out of your engine and not run to close to 100% Duty Cycle and fry the injectors.
I would be interested in your comments.
Regards,
Frank Newman