7.3l turbo on ford 390

[conn278]

My plans are to go with twin 7.3l turbos. I was told that the 7.3l turbos put out 20 pounds stock and most import turbos boost at 15 pounds stock. I am new to the whole big block thing. Fill me in on the rpm's. Lower is better?

[bmxmon]

Originally Posted by conn278

My plans are to go with twin 7.3l turbos. I was told that the 7.3l turbos put out 20 pounds stock and most import turbos boost at 15 pounds stock. I am new to the whole big block thing. Fill me in on the rpm's. Lower is better?

There is alot more to turbos than just the boost. Im pretty uneducated on them myself, so its really not best for me to be saying much. From what I know you can have high boost but not much actual airflow. My advice would be to spend at least several days on the turboforums, there is alot of information there. Its alot more complex than it appears.
As far as the rpms go, it depends on how the motor is built. The turbos will also factor into it. 9k is extemely fast for a big block to be spinning, I dont think it would last too long at that speed. Big blocks are great for torque, I would play that up. For instance you could build it with a mild cam that would make alot of power down low, then build the turbo system to build the boost later with more airflow for more power up top. Personally I wouldnt go over 6k rpms. Im sure others will chime in who have built BBF's and let you know a little more about their rpm capabilities.

[conn278]

I hope more people chime in and fill me in on BBF. I have no knowledge of ford big blocks.

[Dark_5.0]

Engine RPM and turbo RPM have nothing to do with each other.

Carb'd or fuel injected?
Compression ratio?
Goals for the car?
Budget?
Describe your engine specs as accurately as possible cause a 9000 rpm big block is a hell of an accomplishment all on its own.