Stock c4 trans, with B&M shifter. I usually start in 1st, and hit 4500 rpms before shifting each gear. Tried today with it in "D" or "3" on my shifter. Just to let the trans do what it thought it should do. Well, 1st held until 5000, then hit 2nd for half a second or so, then jumped to 3rd with low rpms. Lost 3.5mph and .4 seconds on 1/8 mile track. What does a shift kit do, and how will it help me with this? Is this a normal shift pattern for taking off with WOT (with a spool so very little peeling out, if any).
when all is right, shifts should both be at about the same rpm, & with a shift kit should be slightly elevated above stock shift points. GENERALLY the stock shift points are near the stock hp rating rpm or under it. if you get or have an adjustable modulator you can tailor these points to some extent. unhook the vac line at the modu & look inside for a small screwdriver slot. i think clockwise raises shift points slightly. if you get a rev manual valve body, shift points become fully adjustable; & manual. means you must shift every gear changes. at this point you probably dont need a r/m valve body, & it could slow you up slightly because these use much higher line pressures to lock the clutch packs faster & harder. to generate more line pressure requires a few horsepower. on a 350 hp car, you dont mind using 5 hp to make the trans lock up properly. at 200 hp, it hurts your et & its not needed to keep the trans from slipping. also, many r/m vb's have no band apply in 1st gear. that means if you accel in 1st gear & suddenly let off the gas, you will coast as if in neutral. if you reapply gas then the internals freewheel up to the apply rpm & break the rear tires loose when it shocks the drivetrain. sounds cool, but shouldnt do this. this means maybe 4000 rpm times 1st gear ratio (2.46) is about 10,000 rpm. this may result in a large bang if the drum disintegrates, and small holes appearing in the floor and your leg. yes i have one in my car, but i know what not to do with it, & plan to need it in the future. yes there is no comparison between the shift kit shifts & the r/m shifts. i started with a stall 11" converter, basically a reworked oem piece. about 5 weekends later i shifter into 3rd & buzzed the motor when something broke. took everything out & checked the trans. nothing wrong. cut the converter open. i had shattered the oem turbine hub ( what the input shaft engages). went to a 10" with better internals in it. please keep in mind that as you make the car better, you stress the parts more & things may break.
