I found a You Tube video that makes me seriously reconsider using the FIRST TPI efi manifold. One of the things I had been led to believe was this manifold had an extended RPM range and kept on making power at high RPM. Well, I guess compared to the original TPI from the ’80s and ’90s that would be true, but this test showed a power peak well below the calculation crossover at 5252 RPM (HP= Torque in Ft-lbs*RPM/5252, the point where Torque = HP is 5252 RPM) and the BluePrint crate 383 makes more power and continues to breathe through a Chinese dual plane manifold and 750 CFM carburetor. Now granted the FIRST manifold made 44 more Ft-Lbs of torque, the type of head used for the FIRST manifold test was not listed, and the cam was not mentioned, but the BluePrint engine made the same torque (440 Ft-Lbs) with both a flat-tappet and a roller cam and that Chinese dual plane manifold and Holley 750 CFM carburetor. Something else not mentioned was the headers used in the FIRST test, where the BluePrint tests with 13/4” long-tube headers. Now for an engine packing 383 cubes that is a low-end torque header. Note edited 2019/26/1 to correct header tube diameter from 15/8” to the current size after getting better information.
Well, I plan on making a trip to Lowe’s today to get a couple of 5/16” bolts for the roll cage bender, a 5/8” bolt for the exhaust turnout bender, and a can of butane to make the bender work. So I should probably get to bed now.
Witch on a Bicycle 