VX engine swap on to Coupe
 

I can't find a clean VX. The only clean one I found was the white one in LA for $5k, see my previous post.

I like the VX hatchback, but I like the coupe more.

I figure Coupes are everwhere for $2k and DX Coupe curb weight is 2231 vs VX at 2094.
That's only 137 lb difference in curb weight. the DX engine is heavier the VX right? how many lbs each? (there may be less difference with VX engine in donor DX Coupe)

I'm thinking if I have my little boy in the car seat in the back (center), a coupe might also offer better protection than VX HB.

Has anyone successfully swap a VX D15Z1 engine into a 92-95 Coupe?
What are the results? Please share your experience and knowledge.

I've search and couldn't find any info in these forums, just VX swap in CRX HF.

Specific questions:

I've read that the CX to VX swap is a simple engine swap and bolt up mechanically speaking. Is the true for all civics? Would all VX engines bolt up the same as any EX, LX, DX, donor drivetrain and chassis mount points, exhaust, etc?

Would I need new tranny or re-gear? (Yes I would have picked a 5 speed donor DX coupe)

Electrically, ECU VTEC unit-wise, what does it take?
(I never really played with 4-cyl Japanese cars in my car wrenching teenage years, as you can tell)

Would a reputable JDM engine swap shop know how to make this VX swap work and warranty the work? Will it pass smog?

Thanks for your advice, cheers!

Swapping a VX motor into ANY other 1992-1995 Civic (whether hatch, coupe, sedan, or Del Sol) is, for the most part, quite easy. The motor drops right in. And the ECU will plug right in. Pretty much all you REALLY have to worry about is running a few extra wires for the five wire oxygen sensor, EGR valve, and VTEC (if the car is not so equipped). If you get a complete, uncut engine harness with the D15Z1, all you have to do is add wires from the ECU plugs to the plugs under the dash (although 1992-1993cars are supposedly prewired for VTEC). Otherwise, you will have to modify the stock harness. But apart from wiring, it is (for the most part) pretty much the same as a stock engine replacement.

You CAN use your stock transmission. BUT, fuel economy will not be as good as with the VX transmission. The engine will probably not be able to run out of VTEC and in lean burn mode if you use gearing THAT short. So it is best to run a CX/VX transmission. But no changes have to be made when swapping over to a VX/CX transmission.

As for having a shop do this swap, it is impossible to tell you what kind of work any given shop would do here. ANYONE who is competent when it comes to engine swaps should be able to get the job done. But when it comes to warranties on the work, every shop will be different here.

Is the CX and VX trans the same? Identical in all gear ratio/final drive?
I thought I read somewhere CX and VX had different ratio?

Thanks for the info on VX drop in to any 5th gen Civic.

As far as I know, they are the same transmissions.

B15Z1? or a D15Z1?

Results from my work = :D
https://www.gassavers.org/garage/view/1467
-Lifetime Fuel Economy: 38.74 MPG(US)
-90 Day Running Average: 39.31 MPG(US)
-1995 EX @ 2250 (2312# actual) pounds (no driver/0.5 tank of gas)

I just installed a "China 4-2-1 header" and hope to dyno the car soon to adjust the fuel/ignition maps for even greater FE.

The motor bolted in without issues. The prior owner installed a Prelude motor so there was some work reversing that stuff. :rolleyes:

The exhaust is the full EX version (cat under the subframe not on the block).

I was using a EX/SI tranny but just swapped it out (last night) for a low mileage CX/VX unit due to excessive bearing/gear noise. Once I rebuild the EX/SI unit it will be put back in because I like the gearing 'much' better than the CX/VX tranny. :p

VTEC wise since the car had a D16Z1 from the factory, the wires ready to go for the chipped P-28 ECU that I am currently running (4 wire o2 sensor).

Experience and Knowledge = I am trying to create a 'build post' with pictures to share. I am not sure when I will finish it. :(

I meant the D15Z1. What is the B15Z1? Does it exist?
My typo error- sorry for the confusion. I'm a noob. :D

Your numbers are impressive. Would you get better or worse FE if you used the CX/VX gearbox? Are 45-50mpg possible with coupe and VX motor/trans?

Did you lighten your EX? (2250# is 193 less than spec.)

I didn't think about using a EX due to weight but if you get 2250 for EX coupe, with little/no mod for lightening, EX chassis is a good choice for all the goodies. Do the DX coupes have different exhaust than EX?

Did you do the swap yourself? Want to do mine?!

Look forward to your build post!

I am not sure if there are differences in the muffler or catback tubing. BUT, the EX uses a cast 4-2-1 manifold, while the DX/LX uses a cast shorty 4-1 manifold. However, unlike the stock VX and CX, the DX/LX and EX all use the better, underbody cat design.

Fixed.

D: engine family. AFAIK, all '88+ single cam D-series blocks share the same bolt patterns, so transmissions, cylinder heads and mounts (among other things) can be swapped around.

15 / 16: The engine's displacement in deciliters. 15 = 1.5 liters, 16 = 1.6 liters.

A#, B#, Y#, Z#: The specific engine variant. Z1 = OBD-1 ('92-95) VTEC-E, Z6 = OBD-1 performance VTEC

Vx Swap
 

Its not that hard to do. Im selling mine if anyone wants one $3500 obo
https://ecomodder.com/forum/showthrea...html#post69424

oppz
Z1/Z6 = vtakkk :D

I am not sure about the FE change... we shall see (just bolted a CX tranny up... but installed a header at the same time so I won't be sure which items gives what FE gain). :thumbdown:

My goal is 50mpg on the highway (with a 4 wire 02). Once I finish installing all of my planned mods I will pull the wipers (and pass. side mirror) off and take a nice long trip and see what I can get out of her.

My EX does not have passenger side air bag (or any of the yellow wires or control unit), the trunk is gutted, and there were no a/c parts when I had it corner weighted. I hope to check the corner weight once I finish the a/c install. It will be a 'full wet' weight check with a full tank of gas and trunk parts.

I will try to post up my corner weight numbers this evening when I get home.

I did not plan on using a EX... (did not want a theft magnet hatch) but the price was right for the shell ($1500) and my brother had a spare Z1 swap that needed a home. :D
It had been sitting upside down behind his shop for over a year... :(

The creature comforts (p/s, a/c, pdl, pw, roof, mirrors) made the transition from my 945T Volvo a little bit eaiser. ;)
Now if I could just install some heated leather seats....

I am not sure of the DX/EX exhaust bits...

My brother and I did the swap over the course of a few weeks (working at night). Do it again? I don't think my wife would let me :eek:

Why didn't you go 5 wire on the O2? I read somewhere 4 wire can convert to 5 wire easily right? Why have a CA car when you don't have to? Are there benefits to 4 wire?

What do you mean by corner weight? Are you weighing each corner (wheel) separately on one scale?

Because 4 wires are cheaper than 5. :D

I have a P07 ECU... but with the chippable P28 that I am using, the fuel and ignition maps can be 'adjusted' to suit my needs (along with other items that are adjusted).

If I can get 90%-95% of the FE that a 5 wire system gets without having to worry about keeping the car in lean burn mode... I am all for it.

Corner weight = putting a scale under each wheel and adjusting the coil over suspension to make sure that all four corners of the car exerts the same force on the ground.
https://www.ground-control.com/gctalk4.htm

Corner weight numbers:

729 | 671
---------
475 | 437

X-Weights:
1166/1146

Total:
2312 pounds (I was incorrect)