I'm tryin to figure out if it is neccessary to get a d16a6 tranny. I plan on gettin a d16a6 swap with headpackage from exospeed in about 3 months. When I look at the specs for both trannies, they are the same except for the final drive.

What exactly does the final drive do, and how much of an acceleration difference will there be if I used the si trans?

Usually when I'm racing I don't go into 5th.

is it possible to get a d16a6 performance clutch to fit the dx tranny? I heard that all 89-91 trannies have 20 splines but the 88's have 21. Is this true? If not, who makes a performance clutch for the dx tranny

I want to keep the dx tranny becuase it doesn't grind, but how much will it hurt acceleration?

I have an 89 hatch dx

 

u basically have all the right info
the SI final drive its 4.25 and the DX its 3.88
it does hurt aceleration.. i have a Si wich i broke and its on rebuild process and right now i got the DX installed.......
the aceleration tis just quicker,,,, it feels lighter on the car......
the gears are the same, but as u can see the final drive does make a difference.... IMO it just takes off the 1/4 about .2 of a sec....
if u compare a Si and a 4 speed, u shave a full second that way... i did when i raced on the track....
about the spindles u got it all correct... yes u can fit a 89-91 clutch into ur tranny as long as its not a 88