Originally posted by 1BAD80
The manufactures claim are estimates at best. FALSE !
All the math modeling and flow test are done at all the manufactures, more than one way at that.
I guess they should throw away the flow test machines then. Their tested the same way as a head for flow.
I wish I could guess that close.
I made flow tester's for the oval one on the V8 back in the 80s and could measure the size of a BB difference between ports.
Even Flow must be controlled for all the cylinder's, this is the job of the intake.
Don't forget 1Bad, that the intake velocity has a lot to do with the operating range of the intake. A 400 SBC will have a lot higher intake velocity than a 283. The powerband will start lower with the 400.
Another item to address is the stall and gearing. With a performance converter you only need enough bottom end torque to get you into the beginning of your powerband. With lower gears, the engine isn't under as much load, this will affect the bottom end feel of the car.