i am going from 3.42s to 3.73s. can anybody give an estimated guess what kind of gain i should see. for example if some one gets a torque converter somebody might say he should shave at least 1/2 a sec. i am guessing with all variables constant i should expect at least .2 of a sec shavings. is this wrong?

 

dayamn, i cant believe nobody here has at least a guess. it would be nice to hear from somebody with proof, but i would have settled for a guess.

 

For what it's worth, I picked up .2 going from 3:23 -->3:73. I suspect it would be similar from 3:42.

 

well, like you said the key is all other things equal.....it greatly depends on variations in your setup. In my case, simply going from a 3.73 to a 4.10 will most likely yield almost a second lower et. this is because the 3.73's drop the motor 400 rpm below the power band on every shift, and the 4.10s will move all the shift points up the track, allowing me to cross the traps hard into 4th (as opposed to wound out in 3rd) the cam makes power from about 4400-7000.

my brothers 86 z has a mildy built 355 and had 2.90's in it i believe (they were disgusting) the poor kids first outing at the track he pulled 16's. after swapping in a rare 9-bolt with some 3.23's in it (im sure experience aided this as well) the car dropped into the high 14's!!! almost 2 seconds.

then there are some people who barely notice the difference, but if your setup lends its self to a particular gear ratio, then it can make a big difference