Which tranny for my vx swap

We may earn a small commission from affiliate links and paid advertisements. Terms

H

hunterhound

New Member
I am placing a d15z1 in my 89 dx. I was pondering changing the dx tranny for the cx/vx that actually belongs to this engine, but they hard to come by for a decent price. I have access to a crx hf tranny, i do not know which one it is though. Would my dx tranny run the rpm's too high if I just kept it, and also, would the hf gears be a bit too long and make my pickup speed suffer greatly? While I'm asking questions, will the hf tranny fit the z1 and my hatch with my current mounts?
 
Keep in mind that they switched to hydraulic transmissions for the Civics in 92, so unless you want to do an expensive conversion, you're limited to 91 or older transmissions anyway...
 
The hf trans is simmilar to the cx/vx trans' in that they are geared purely for mileage rather than performance. Being a cable trans it will bolt right up. I know that the dx trannies are only 4 speed, which I would avoid.
 
99sidude said:
Well then if you owned one then you would know better than me. I guess I thought that the dx was the lowest model.
Click to expand...

Nope, the STD is the bottom of the barrel for Civic models. STDs should be avoided at all costs... :D
 
I love my Std. :) Then again, it has a swapped motor and transmission.
 
are u going for fuel efficiency ? just bolt up the HF then. make sure ur clutch/flywheel match the tranny tho.
 
For the non-8v motors, letting the engine rev can net higher MPG. I got 57mpg on the highway, sitting at 4000rpm at 70mph on a D15B-VTEC with DOHC ZC transmission(4.25 Si FD).

For the 8v and VTEC-E engines, it's good to keep the revs a little lower. A good compromise is the to get a DX transmission and just use the HF final drive along with the HF 5th gear.
 
57 MPG.....Wow. Ok now the dumb questions. I've got a Z1 block with everything else (head, i/e and tranny) from my Z6. How do I get even close to that??? I just ran my first tank thru on this set up and got 35MPG doing 50 to 65 on mostly curving rolling hills. I'm really jealous!
 
Well, my setup is pretty close to a "Z6"; but with the Z1 block I'm pretty sure you're losing some power/efficiency from that dished piston. The Z1 head has a smaller combustion chamber to make up for that; so I'd look into changing the piston for P08 or PMS ones.

Also, how you drive makes the biggest difference. Avoid having to give it large amounts of throttle during cruising, don't worry too much about RPM as load makes more of a difference. This means that if you have to give it more gas in order to cruise in the next gear...then just stay in your current gear....especially with hills.
 
OK, I know P08 is Z6. But I've learned over the years to stay away from PMS but now we're talking about pistons, so what is a PMS piston??
 
You must log in or register to reply here.
Back
Top