Civic VX engine D15Z1 with an automatic transmission swap?

[MCAT]

Hello all,

I have been reading along and researching this site for a few months now and finally decided to register. Thanks to you all for all the very useful info!!


Now on to my question is:

I have an all stock 92 Civic DX Hatchback with a D15B7 engine with an auto tranny (with AC & PS). I am getting decent MPG for an automatic (29-33mpg mixed city/hwy with AC & PS on) and I was seriously thinking about swapping out my stock D15B7 for a D15Z1 engine from a VX to get even better gas mileage.

With my current job, I drive 4500 miles a month easily, so the more MPG the better! With all the traffic I go through, I refuse to drive a manual transmission (call me lazy).

Now would the D15B7's auto tranny mount to the D15Z1 engine? What ECU would I need install in the car to get better MPG? The stock one that I have in my car now? Or an ECU from a VX model? (sorry I dont now the exact ECU numbers) And what kind of complications should be expected? Also, any idea on what MPG would I get with the D15Z1 engine if it were installed and tuned correctly?

Beside the hybrids, I would like to get at least 40 mpg with an automatic transmission with your normal & rush hour, city/hwy type of driving. Im too busy with work and all to be thinking about FE driving habits.

Thanks in advance!

[beb]

While the D15B7's tranny will probably bolt right up to the D15Z1 without the least difficulty, getting it all to work together might not be practical short of a custom ECU. All USDM P07 ECUs are for manual transmissions.

There might be a way to put a lean-burning D16Y5 and automatic in an EG hatchback. The HX had an automatic transmission option, but it was a CVT and has a bad reputation for premature mechanical failures. I have no idea if an HX automatic ECU (P2N) would work with a non-CVT EK automatic transmission, but if it did, that might be the best swap option even though it would mean converting your EG to OBDII.

Now that the technical part is over, it's time for my opinion:
Unless there's some underlying medical issue to prevent it, driving a manual eventually becomes so 2nd nature that overall effort that would go into using a manual is miniscule compared to what would be required to swap a D15Z1 and automatic into a EG hb - plus there's the vastly better gas mileage with a 5-spd compared to an auto.

[78si]

Its possible. They came with autos in Japan, its going to be tough to find a p07 auto ECU. I can get you a vx auto tranny, and I'll see if I can find a ECU.

[Loserkidwac]

Physically yes it will bolt up....

But as said before at least all US VX's were manual...maybe Canda or the VEI in other countries came with an auto...but I doubt it...

The ECU and the transmission play a big roll in why the VX gets the MPG it is capable of...you would need to have a custom ECU in order for this to produce the numbers you want, I don't believe any one has cracked the VX P07 ECU code...plus the VX uses some of the same ECU pins that the auto ECUs use so I doubt you would be able to make this work as a simple swap...

I think you would be better off as beb said and look for an auto HX swap and converting to OBD2...which is probably gonna be a decent amount of wiring...you could get a custom engine harness from a company like re-wire just tell them what motor trans and chassis and they should be able to make it f you don't want to do it yourself but you'll pay $$$ for it...but if you are serious about a motor swap and not converting to manual I'd look down the HX and auto route...I converted my auto Del sol to a VX manual and it is a fair amount of work for a novice(if this is your first motor swap I'd suggest getting someone with experience to help or having a shop do it...


Good luck, let us know what you decide...Matt

[78si]

Its a simple swap if he can find a JDM p07 and auto tranny. It would be plug and play, all he would need to wire is the vtec,egr, egr box, and the 5 wire 02. Why would anyone wanna swap to obd2.. Thats insane.

[onefastcar]

I have one i will sell it for 200

[mrmad]

Originally Posted by 78si

Its a simple swap if he can find a JDM p07 and auto tranny. It would be plug and play, all he would need to wire is the vtec,egr, egr box, and the 5 wire 02. Why would anyone wanna swap to obd2.. Thats insane.

I won't argue with 78si here, he seems to know more about Honda swaps then most people. The problem you will have here is that you'll never get a JDM ECU to pass smog in CA.

[78si]

Originally Posted by mrmad

I won't argue with 78si here, he seems to know more about Honda swaps then most people. The problem you will have here is that you'll never get a JDM ECU to pass smog in CA.

I always forget that you have to smog test in CA.. We don't have to do that yet. (Calgary Alberta, Canada)

[MCAT]

Originally Posted by mrmad

I won't argue with 78si here, he seems to know more about Honda swaps then most people. The problem you will have here is that you'll never get a JDM ECU to pass smog in CA.

With that JDM ECU and engine swap, can I just get it Ref'd by the CA Bereau of Automotive Repair to pass smog?

[suspendedhatch]

Besides the auto ECU you'll also need the auto tranny controller that resides under the driver's side dash.

Wiring up the EGR, 5 wire O2, VTEC, and tranny solenoids (yes, the OBD1 auto tranny's are partially electronically controlled) is comparable to converting to OBD2. But due to the complications and lack of info of an OBD2 auto tranny swap into an OBD1 chassis, no one who knows what they're talking about would recommend you attempt it.

I personally prefer auto tranny's but I switched to manual (actually sold my old hatch and bought another) because they get better mpg, they put more power to the ground, and because they are far simpler to swap and interchange parts with.