Originally posted by chris718
the 700r4 will take just as much punishment as the 2004r when built with the right components.the main differences are in the mechanical design and principles of operation between the 2.the 2004r uses 3 sets of planetaries to achieve 4 forward speeds and one reverse.the 700r4 uses 2 sets of planetaries to achieve 4 forward speeds and one reverse.the held and driven members to provide these ratios is reversed in first gear in the 700r4.the sun gear is the input member which defies most all other of gm previous designs.if the 700r4 used the ring gear of the front planet as input however the ratio would be similar to the typical 3 speed or 2004r.overdrive in the 700r4 generates more heat because the rear sun gear is held and the output ring gear turns at a higher speed.although both units use a band to stop the rear sun gear for 2nd gear the 700r4 has a larger band and drum and as such provides much more clamping force.the 700r4 is less sensitive to suttle accumulation changes which imo allows easier calibration of the 1/2 shift.the valve bodies function very similar and use just about all the same valves in the control body.the 2004r however uses a flyball style governor verses the design of the 700r4.tuning of the governor is much easier with the 700r4.the governor circuit in a 2004r is charged and bled off depending on output speed and the 700r4 is horseshoed back into the governor upshift circuit after regulation.the direct clutch capacity with stock thickness steels is more than double when using my methods.the lubrication system in the 2004r beats out the 700r4 and as such the 2004r has less lube circuit associated failures.heavy cars with numerically lower final drives will out accelerate a similary outfitted car with a 2004r.however the engine rpm obtained during a ratio change may hurt accelleration with the 700r4 if the vehicle has a camshaft with a wide lca ,ie a cam that produces poor intake manifold vaccum during all throttle angles before maximum cylinder filling occurs.turbo and supercharging will not be greatly affected by this because of the positive intake manifold pressure.in mechanical theory and certainly in the real world under certain condition closer ratios provide maximum accelleration,.this is however providing the car does have the correct starting line ratio.they both are very unique in their own ways and both have their place in the performance aftermarket.i have used 700r4s in turbo buicks with great success and 2004rs in non turbo applications with the same results.i base selection on final drive ,vehicle weight ,intended use,induction ,and camshaft type.and although this may not make sense to some ,here it is .when alexander the great was faced with the gordion knot,which the scholars said would be undone by the greatest conquerer the world as ever seen ,he said what cant be untied can be cut and he cut it.
