I am having a 700R4 built fro my stock 425, dual quad '64 Electra convertible. My question is: What wide open throttle shift point would I like to have? The only mod I have is electronic ignition and intake blocking plates. What will these engines handle for rpm?
They don't do much past 5500 rpm in stock form, even modified its hard to get them to do much past that. I'd say a shift point around 5000 rpm, maybe 5200 rpm...
I wouldn't go anything over 5000rpms with a stock motor. I shift at 4700-4800 and the only thing I haven't touched is the heads.
The whole idea of arriving at wide open throttle shift points is to gain the best acceleration, right? That being said, there's no recipe. Your car, it's weight, gearing, engine, trans, etc. is all unique. To figure out ideal shift rpm means some 1/8 or 1/4 mile experimentation shifting it manually. Make note of what works best for elapsed time when you shift at different rpm. Once you get the best elapsed time, use that data to tailor the governor to do it for you automatically. If holding the trans in first gear it shifts to second automatically below an ideal rpm, then some other work will have to be done. I don't know if that's a 700R4 trait or not. In short, if you don't know how the car performs at various shift rpm, you can't know what to do to your transmission's automatic shift points. Devon
Larry, Buick state that their nailheads produced maximum torque at 2800 rpms. In stock form that would be 445 lb. ft. for a 401, and 465 lb. ft. for a 425. No difference in torque between a single four barrel and a dual four barrel, although Buick rated the 401 at 325 hp, the single four barrel 425 at 340 hp, and the dual four barrel 425 at 360 hp.
Go with what Dev. says.... and work toward getting the governor to shift it for you ... that way you can just stomp and steer , the trans will do the rest,,, and,,,, I might add , way more consistant than you can shifting manually.....
