hello guys i have a dohc zc in my crx and it has the zc tranny and well im getting sick of the slow zc tranny. i am trying to look to see what the best tranny would be for it and have spent like 25 mins trying the search, so i have resorted to asking for help/ advice. any one have any opinions on trannys?

 

doesnt the usdm d16a6 short geared tranny bolt right up?

 

Si trans with Si axles.

 

Are you sure you have a ZC tranny? Because the ZC's had the shortest gears of any other D series....the next runner up would be a Si tranny. I have one with my DOHC ZC and it really nice.

 

You don't have to buy Si axles....not sure even if the axles are even priced differently but Si and DX axles are the same. The only one you'd have to swap anything is the HF, you'd have to swap the hubs or switch out the inner axle with a Si or DX.

 

ok guys, thanks i will look to see what i can find

 

actually if he has a true DOHC zc transmission he will need to swap axles, at least the usdm drivers side axle. the DOHC zc transmission uses an intermediate shaft like b series transmissions and the drivers axle (or passenger if rhd) is different.

 

x2! get an si trans and drivers si axle just to be safe!

 

Get the SI trans for sure. Especially if you're thinking of the swap

 

I'm surprised no one has mentioned using the ZC gearing with Si final drive yet.

 

this would make the ultimate na trans, but i didn't seem to think it'd be worth bringing up since the o/p doesn't even know what axles to get.

swapping the si fd into the zc trans would make it wicked quick, the zc has super close gear ratios from what i remember, but then honda slowed it down with a 3.888 final drive

http://tjshondas.20m.com/l3.htm

if the info in that thread is correct (I believe it is) you'll also need to replace your passenger side axle.

edit: o/p i should add that if you have the SOHC zc trans then it's the same as an si transmission, so if that's still slow for you then perhaps you need a bigger motor or boost?

 

swapping the fd would be great but they aren't the easiest to come by lol

 

If you go with Si trans, you need both the driver and passenger side axle.
The DOHC trans uses B-series integra axles (as well as the ZC intermediate shaft) which are nothing like the DX/LX/Si axle for how they install into the tranny.

 

If he has a real zc tranny (which I kinda doubt) that would be the best and I'd leave that. If not Si is pretty short but I'd rather have an Si 1-4 and a Dx 5th for highway. It's all about what you want. Just don't go with Hf even if you want MPG's Dx is just fine.

 

Slow ZC tranny? Are you serious. The ZC tranny is geared short as **** man. I doubt you have the orig tranny with that motor.

 

STOCK DOHC ZC is a slower trans except for 4th and 5th.
Notice the higher speed for all the gears except those two.

MAX speeds at 8500 RPM for stock Si trans
42.25
72.5
109.07
146.55
178.11

ZC:
46.28
77.37
111.75
145.61
171.32

Now the hybrid build is freaking fast shifting.
Hybrid using Si final drive with all ZC gearing:

42.25
70.64
102.02
132.93
156.4

On the freeway, just add about 500RPM to maintain normal posted speeds on the hybrid trans if you keep the ZC 5th.
... but who really drives the speed limit?

At 5000 RPM the hybrid trans does 78.2 MPH.
It's really hard to go 80MPH on the freeway for long periods of time. Dipping in and out of vtec.

Change out 5th in the hybrid tranny with the Si 5th and you get your normal cruising RPM back - 3750RPM for that same 78MPH

 

This is a very informative thread, thanks guys!

 

si and dx/lx/ex have same 1-5 and reverse, just different final drives. crx hf and the civic std have both a different gear set, and a different 2-5, but the same 1st and reverse (although the std trans only has 4 speeds not 5, 1-4 is the same as the hf). and to be honest my old transmission was an hf case with si internals with the hf 5th, i BARELY noticed a gain in mpgs with the hf 5th, just engine was a tiny bit quieter, however i had to down shift every time i wanted to accelerate, and had to be on the gas more to stay going at a constant rate

 

If you truly do have a DOHC ZC tranny the best way to tell is if it has a half shaft.....If you really do have one and dont want it, I'd buy that jank off of you. I've been looking for one for over a year now.