1997 Civic CX to HX engine/VX trans swap! 63 MPG @ 62 MPH

[Baltothewolf]

Originally Posted by Ecky

It's definitely true that smog levels have decreased drastically since emissions laws have tightened.

Agreed. F150 with no cats or anything rolled passed me yesterday and I thought I was gonna pass out. Lol.

[jcp123]

*shrugs* I started doing this as a way to save $$. I then realized the savings weren't huge, but by then it caught on as a hobby. I highly doubt I'll ever be very environmentally conscious, so if what I do helps, that's great, and if not, no big deal.

[vrmouseyd15b]

Originally Posted by Baltothewolf

Now this interests me, one can add a L/B indicator by simply adding an ECU that supports it?

Maybe. I was thinking about using this same ecu to run my d15z1, but it doesn't have 2 vtec solenoids, or 3 wire idle air valve ( that would mean check engine light - NO LEAN BURN)

but my simple work around would be to have another vtec solenoid next to my 3 wire idle air valve next to my ecu

and of course, the "Happy light". My buddies all think it's hilarious, and they are stunned with my mileage (I'm still trying to break 50)

but that's all you would really have to mod, as far as I know (NOT VERY FAR) but seriously, this ecu (37820 p2j-j62) is only like $39 on eBay, but it's for the cvt tranny, dual vtec jdm d15b. That's why I wire the 3 wire Iacv at the ecu. The manual intake manifold doesn't like the automatic throttle body that the 3 wire iac bolts on to(manual intake mani is probably from a d16y8 motor, not sure though) so I adjust timing at the dizzy as weather gets hotter or colder.

My minion is a dual vtec d15b now, so I'm not faking the ecu there yet. I guess that would be the big difference with this ecu - I don't know what would happen if you actually ran the motor into wild cam rpm range (full 16v operation-mine usually hits at about 5200 rpm's, and it does hit hard! )

The second vtec solenoid would only be needed for the initial key-on start up test. The ecu has to see both vtec solenoids or you get a check engine light. The ecu has to see the 3 wire iac or you get a check engine light. Check engine light = no lean burn.

From that point forward, the wiring is all stock in my lx civic (except for the manual conversion Park interlock and reverse lights) - EVEN THE 4 WIRE OXYGEN SENSOR! (Not sure if you need the second o2 sensor, but it's wired in and I don't have a cat). No check engine lights, yes lean burn!

EDIT:
only downside to this setup is that I lost my obd2 communication at the plug to the ecu. From what I've read, it's because the ecu is " JOBD protocol ". I tried buying a second obd2 bluetooth that is supposed to read JOBD and the euro stuff as well, but it won't communicate to the ecu either. I'm stuck with the paper clip trick to pull codes for now. ..

[California98Civic]

Originally Posted by hackish

Theorizing is fine but just because you think really hard about it doesn't make it correct. Take for example the idea of blocking your grille to help the car heat up faster. In theory this sounds like a great idea - after all the rad cools the engine right?

You didn't understand the point I made. I didn't mention the radiator or the coolant. I was describing warming the engine long enough to know the CAT is lit. The CAT is the only specific component I mentioned. So I'll just say this and leave the discussion alone because it's becoming a thread jack; there is already a thread ("the dirty cost of one man's hypermiling") where a lot of this has been played-out. I can get the CAT lit-up fairly quickly with a combination of light load steady cruising, P&G, and neutral coasting at the start of my trips. My grill blocking then helps keep the CAT hotter as the car coasts engine off (the CAT is right behind the grill openings on these Civics). Because of the blocking, my CAT is not constantly blasted by cold air. So I find it hard to believe that in a few seconds of engine off time, sitting in an engine bay with relatively little circulating air, that a lit CAT drops several hundred degrees and goes out. I don't see any evidence in your argument to the contrary, even though I asked for it after you referenced it the first time. Lastly, the problem of cold starts and emissions is not limited to ecomodded and hypermiled cars: all my neighbors who fire up and jump onto the freeway each day floor those cars, stomping on the pedal and breathing down my peak BSFC butt on the on ramps. You have not presented anything that should make a reasonable person think a hypermiler at that moment is smoggering-up the world any more than they. The reality is that these are finer points; the real problem is burning fuel for transportation at all.

[PaleMelanesian]

All cars are polluters when cold. The way I drive, it takes twice as long for it to get warmed up. However, I'm using half the fuel in that time. So has the overall emissions profile actually changed? I'm burning the same amount of fuel under a cold engine condition as before, just more slowly.

In addition, I'm not burning the other half of the fuel. Even though that portion would be burning cleaner, its emissions are not zero.

[phoenix_fire2005]

Edit: Just found your sale thread again, which I had previously posted in too. So I'm asking in past-tense now, heh.

I think your build is an awesome idea and I'd love to do the HX engine + VX transmission swap in my own 98 Civic hatchback one day.

I was curious what levels of ethanol were in the gas that you used... I've heard rumors that even just the 10-15% that is commonly mixed in these days can make lean burn much harder to achieve. Did you ever encounter this problem?

[hackish]

Mine was sold a number of years ago. The buyer enjoyed it for a few years and it went off to a rusty honda heaven. I believe the engine was removed and sold to someone else but I closed my shop down and am not in touch with that anymore. I still do emissions calibrations testing but it's on more modern stuff that runs many times cleaner than engines of 5 years ago. The 25+ year old VX engine design was a significant step for honda.

For ethanol, E10 is the most they're allowed for all vehicles. Newer cars around 2008+ can all tolerate E15 but it's not as common as you'd think. It drops the CO emissions a little - maybe 8-10% average but it also consumes more fuel. It was more of a cost saving deal because of the ever increasing cost to get a barrel of oil out of the ground.

These days when people ask me how to increase fuel mileage I tell them maintenance and the seat to steering wheel interface. The second part has the biggest impact. Other than that, get rid of that old vehicle because new ones are way more efficient on both emissions and consumption.

-Michael

[Xist]

Hackish,

1. How many cars get better mileage than an old, yet still reliable Civic CX or VX?
2. How far would you need to drive one of these cars before the reduced emissions match the pollution from building the car?
3. What about start-stop engines and DFCO, which was implemented in 1996?
4. How far do you need to drive to warm up the catalytic converter in the first place? How often do people drive shorter distances than that?

[foot to the floor]

I have owned a cali VX for three years. I have been extremely happy driving it living at 1400' and driving it to 6000' elevation where I work averaging around 43mpg. I let a friend borrow the VX and the water pump seized blowing the motor. (friend held it to the floor for about 5 minuets in first gear red line having a mental breakdown) I have read somewhere that a D16Y5 motor will mount right to the trans and is plug and play for a swap getting close to the same mpg. My question is can you drop a 2005 civic HX D17A6 into a VX with the same ease. Would love to have more power with the same-ish gas mileage. Really hope it is possible due to the cost of rebuilding the D15Z1 as opposed to having more power with the high geared vx trans.

[foot to the floor]

I have owned a cali VX for three years. I have been extremely happy driving it living at 1400' and driving it to 6000' elevation where I work averaging around 43mpg. I let a friend borrow the VX and the water pump seized blowing the motor. (friend held it to the floor for about 5 minuets in first gear red line having a mental breakdown) I have read somewhere that a D16Y5 motor will mount right to the trans and is plug and play for a swap getting close to the same mpg. My question is can you drop a 2005 civic HX D17A6 into a VX with the same ease. Would love to have more power with the same-ish gas mileage. Really hope it is possible due to the cost of rebuilding the D15Z1 as opposed to having more power with the high geared vx trans.