scottmog

Ok well ive seen quite a few threads about getting 50+ mpg (when u take it slow) and having 130 hp with vtec. And I am getting ready for this now just becuase when gas hikes back up to 4-5k bucks a gallon i wanna be ready on the information side of this. i have quite a few questions so please be patient with me.

As for bar'ing i was thinking that i would need, motor/tranny, wire harness (or is a adapter good enough?), and the correct ecu correct?

1. this is true correct? 50+ mpg 130 hp vtec?
2. Exact D15 model of the vx?
3. what all do i need for bar'ing this into my 90 crx si?

I do use the search function and do reply in other threads but i want my own thread, please dont leave nasty comments.

scottmog

Apon looking around i see that i was given quite abit of mis-information. maybe i heard that a jdm d15b something was the 130 hp 50+ mpg.

VX Hatchback Key Features:
1.5 Liter, 92-hp, 16-Valve VTEC-E Engine, Lightweight 13" Alloy Wheels, P165/70 R13 All-Season Tires, Chin Spoiler, Tachometer, Dual Manual Remote-Operated Mirrors

http://www.gassavers.org/showthread.php?t=834

edit: just adding more hyperlinks for my info collecting thread.

http://forums.vwvortex.com/zerothread?id=3813631

Bob_760

No no no you're thinking of the few 3-Stage VTEC D15B threads that have been floating around lately. The VX (D15Z1 or JDM D15B VTEC-E) will get 65+ mpg when cruising but will only make 92hp peak. The problem with getting a 3-Stage VTEC setup together is you can only use the stock ECU and it's virtually impossible to find a manual trans 3-Stage VTEC ECU (I'm looking).

dan.

It all depends on how you drive,im sure you could make all d15/d16 with stock or more hp get 45+ mpg

even with vtec,just dont go into vtec.
lol

abnaasefmb

Wow finally an interesting tech question, it’s been a long time. The short answer is yes, anything is possible with the right amount of money. To make 135 and get 50+ mpg, you could do a small turbo on a vtec-e engine. The vtec-e came in the vx hatch and the hf models. It uses a low lift on the primary cam lobes to create a swirl effect that promotes better or more complete combustion. It also uses a lean burn system while cruising, where the ecu will run as lean as 19 to 1 air fuel ratios or so I’ve heard, but at the very lest it is much leaner then stoch 14.7 to one. Reason I care is I just picked up a 95 shitbox vx that I’m just using to cruise to work and around town. The engine in it, is in pretty bad shape so I ordered a new (used jdm) b15b for a few hundred bucks to replace it. The plan is similar to yours, get good gas mileage. I don’t really care about power as my ef has that covered. The easy way to do it would be, source a jdm b15b vtec-e, convert your car to obd1 and get a chipped ecu and just tune it to run lean in the driving parts of the maps. Then if you’re looking to up the power, turbo it and add power within the constraints of the d series engine. No reason you would not be able to have 140hp and get 50 mpg. It’s just how cost effective will it be, I don’t know you have to answer that yourself.

scottmog

Thank you all.

Ok then I guess ill get started and at least start looking for a motor.

To the last person, I'm not really looking for a powerhouse. I just love the crx. So 92hp is what I had in my dx (last crx) and that was fine with me. I'm thinking of doing the swap only for mpg. I love the little crx and I'd love to have it get 50+ like a very nice hf but still have all the si things (black interior, ac, my stock dual tip which are so hard to find lol). I've just heard from many people we'll be looking at 4 to 5 bucks a gallon gas by the summer. So I'm just preping the swap for when the time comes. I would double my mpg for 20 less hp anyday.

JesseCRX

What he said.

I made a thread about doing this project and it's been postponed for now.

It took me 8 months to track down the P2J ECU(Manual version)and that's going through a well connected jdm parts supplier.

I have the motor, the ecu...now I need to have a custom wire harness made to make it plug n play. I am not sure if the ecu is OBD2a or b. Anyway, the point is I still have to send both my OBD0 and OBD2(from the D15B)to Rywire. The engine has an EGR valve and a few other sensors that I am unfamiliar with.

You could wire the motor to run like any other SOHC vtec setup, but like you I want the engine running the way it was intended.

Bob_760

Allthough my one of my CRXs has much more power I'm acctually doing a VX swap into the other and the 90hp it has now is still "fun" and so is the 92 Civic VX a friend of mine has.

abnaasefmb

i don't see why you couldn't just use the free version of crome (if they still have it) convert the d15b to obd1 and just tune it your self. i might be wrong though, i've never really looked into it because i have a vx already. good luck and let us know if you have questions we can help with.

dacrxguy

op have you looked into the 96-99 civic hx they are also the high efficiency model the only thing about them is that they are obd2

Bob_760

I'm not sure who you're replying to and since there are two engines being discussed here...
D15B 3-Stage VTEC: There are 2 VTEC solenoids and a 5 wire O2 that you cant just magically plug into any other ECU.
D15Z1: Still has the 5 wire O2, you can't tune a regular ecu to decide to go into lean burn mode when you're cruising.
You could make it run but you'd defeat the purpose since you could never tune it to safely run as lean as stock.

HX D16Y5 = EX D16Y8 with a VTEC-E cam... D15Z1 = a REAL fuel milage built engine

abnaasefmb

Hum I’ve miss the hubris of Honda tech members. I don’t know anything about the 3 stage vtec engine nor did I refer to them. So they have 2 vtakk solenoids, that must make them twice as good. Thanks. I was only talking about the vtec-e engine, the d15z1 and the d15b both of which I have in my garage currently. I fully understand you can’t just magically plug any engine into any ecu and expect magic. However through the wonders of code hacking many have been able to use this thing called a “rom (read only memory) editor” the software to tune ecu’s. the current version of ectune for instance has a load dependant close loop air fuel targeting function, this has already been proven to achieve the stated goals of the op, search on homemade turbo. You would need some software and some hardware, but if you guys are saying the d15z1 ecu is hard to find (and I don’t know, I’ve never tried) then it would be a reasonable solution.
V/R

abnaasefmb

Btw, there is two versions of the d15z1, one is a 5 wire wideband non California, and the other a 4 wire narrowband California model

scott@8pm

If you drive easy in your Si you could get maybe 50. You may not be happy with the swap even with 92HP as it requires tall gear ratios like in the HF CRX or the VX/CX, and still requires easy driving to get the big numbers.

The D15Z1 single stage VTEC-E ECU is readily available since it is USDM. I've been looking into this since I swapped the 70HP HF motor and trans into my CRX DX. 92HP is looking good to me. Here I am on a D15Z1 thread less than 3yrs old. Hello.

You'll need OBD-1 of course and the VX ECU.

Vtec wiring
EGR wiring
SIL wiring (optional)
5 wire "o2" wiring
possibly other wiring (my HF swap required additional feedback to the ECU regarding clutch and A/C)

fuel feed line
EGR control box
oil cooler lines
tall transmission

lighter weight... your VTEC-E engine might come with the lighter brackets. HF and VX/CX had lighter (list unavailable at this time).

I have access to wiring diagrams, but there's a pinout of the OBD-0 to VX ECU on the wub. I'll post a link
http://www.crxmpg.com/
some of it was 404'd last time I visited.

Bob_760

Indeed it is twice as good, at least IMO, D15B power with D15Z1 economy is twice as good.
It's the manual trans 3-stage vtec ecu thats hard to find.
I didn't know they had come that far with chips I figured it'd be harder than that I don't keep up with that stuff. Either way I was mostly referring to the difficulty (supposed impossibility) of getting the 3-stage vtec to run any other way than stock. VX ecus are plentiful so he could just get one of those I just didn't see the point of not just running it's stock ECU.

Also idk about the HF or CX but the VX has aluminum a/c and alternator brackets

sirtef9

iTrader: (4)

hmm ya

Bunger

I have a VX engine in my striped 88 Hf, and it gets 70+ mpg. I don't hypermill or anything really any more, so I've had a few lower 70 tanks, but 70 mpg is better than what prius owners are netting.

sh!ft

HOW THE FACK IS THAT POSSIBLE^^^^

Dark_Teg

Your goal should be cake! I average 36mpg mostly city driving in an 88 CRX Si with a JDM ITR swap.

sde780

WTTTFFFF

I only get 30 mpg in the city, driving like a freaking granny, with a d15b2. 92 hp. How the hell are you guys getting such good gas mileage? I calculate mine accurately, none of that 450 miles a tank = 45 mpg bullcrap