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

[turbovr41991]

Sorry for the delay in my responses. I was out of town all weekend and without a computer.

Originally Posted by California98Civic

Right now I just am using the 93 CX's VSS unit that was already in the trans.

I would swap in the stock DX vss. It is best to go with one you know is good rather than a used one with an unknown history. They my be listed as the same part number, or ratio's but it might have issues or could have been modified for a different output.

Originally Posted by MakitaDiesel

could I fix the CX trans & just swap the HX VSS into it, put it all back in the car & be where you were at before the tune? The main question is will a '92 CX trans + '98 HX VSS = same odo/speedometer readout with all other variables constant? I'm also curious as to whether the shop could tune my other lean burn mule, an '89 CRX HF + '95 VX (D15Z1 running bits)Mak

I would think you could just swapp in the CX trans. I used a VX trans and used a 97 CX vss with the HX engine, ECU and cluster and it is working perfectly. The odometer/tripometer is nearly perfectly inline with my GPS.

One odd thing I did notice is the odometer/tripometer and speedometer are not in lune with eachother. My speedo reads 2-3 MPH faster than the GPS/ actual speed. I was told the springs within the cluster on the speedo gauge itself get weak and causes this issue. It never bothered me enough to fix (If you search there are right ups on this.) Honesty, if my wife things I am going 65 and I am really going 62, I am perfectly fine with that! Just don't tell her! O

As for the tuning of a D15Z1, they work on those as well. They actually were only doing those until I suggested the need in the HX community.

[hackish]

The VSS is the same across all the D-series, B-Series and H series transmissions.

How did you get your engine to run in lean burn mode given it's an HX not a VX lump? I don't recall the HX having EGR or vtec-e that made the VX engine so efficient. I've left the honda world a while ago but I always wanted to machine a VX head to accept GDI injectors then see if I couldn't rig up lean burn with stratified running mode. Hard to say if the power loss from running the HP pump would offset the gains in efficiency.

-Michael

[California98Civic]

Originally Posted by hackish

How did you get your engine to run in lean burn mode given it's an HX not a VX lump? I don't recall the HX having EGR or vtec-e that made the VX engine so efficient.

Actually, the HX is the successor to the VX, with vtec-e and EGR but with the 1.6L engine and significantly shorter gearing (especially final drive, about 3.75, instead of 3.25). Even the wheels are the same design, though an inch larger.

[figit090]

Originally Posted by turbovr41991

Figit, thanks for the kind words. I love the choice of the MK3 supra! I currently am using the transmission of an MK3 supra(R154) in my IS300. It is a very solid unit!

For the efficiency questions, the lean burn technology of this year car was specific to the HX. The DX was just a normal engine. A few things that give me an edge is the CX is lighter and lacks power steering. Another thing is the lower rpms I am using on the highway thanks to the VX transmission I am running.

Running lean is normally dangerous to mot engines, but the Honda Vtec-e were designed in such a way to support it. I believe they have enhanced cooling and the air spirals in a unique fashion to allow the lean burn without causing engine failure.

Most people believe the government is to blame for limiting this technology. For example, they would not allow the full lean burn models in California. They claim the Nox is too high for the economy car class or the engine size. Meanwhile a hummer that has 4x the nox levels is perfectly legal to drive and California while getting a measly 8 mpg… They claim they want more efficient cars, but not enough to hurt the sale of gas. I am sure you can read all the conspiracy theories out there and make your own decisions on it.

As for the drivability, the tuned ecu really improved things and made it easier. Nothing tricky to getting it to run right, just got a chipped ECU tuned for the car from Northwest auto solutions, and hooked it up in the car.

Totally! Thanks! Haha, that's cool. Yeah they had good trannies in supras.

I never knew about the efficiency engines, that's terribly they don't promote it. The pollution claims are also totall bull$hit... aside from Hummers I imagine soot producing diesels are bad, too...and they seem to run open don't they? They piss me off...so loud.

Glad your car is working well! Are all the parts hard to find? we should make a fleet of these and start showing what can be done to more people beyond ecomodder.

[hackish]

Originally Posted by California98Civic

Actually, the HX is the successor to the VX, with vtec-e and EGR but with the 1.6L engine and significantly shorter gearing (especially final drive, about 3.75, instead of 3.25). Even the wheels are the same design, though an inch larger.

Ah, cool, I didn't realize the HX was in fact a newer revision of the VX. An interesting question then is which ECU was used? I think the P2N was the HX which obviously will support the proper EGR and lean burn but we never bothered to develop any OBD2 tuning stuff.

The VX, which was a P07 had those features too. That's the ECU I used in my swap and it required the ever-expensive L2H2 wideband O2 sensor. I would normally swap ECUs in a '96+ car, with a conversion harness to go to OBD1. Adding extra wires for the 7 wire sensor was pretty simple.

The downside with my own swap is that the VX ECU is not chippable. So you either go down to a P06 series and lose the wideband, EGR and lean burn or you live with the factory tune. Like a barefoot shoemaker I never had the time to do any tuning stuff for the P07. Not like it would make any money as a product...

-Michael

[hackish]

Originally Posted by turbovr41991

I would be careful with this. the OEM D16Y7 was not designed to run very lean. The HX engine (D16Y5) was designed to run lean without any problems. I am only running 17.5 air fuel ratio, so nothing too crazy. The timing was also set to be on the safe side of lean as well.

Common mis-conception that running an engine lean of peak is dangerous or will melt things. LOP means lean of peak (EGT) or lean of power (the two are essentially the same idea) this is exactly what you're trying to do.

The key with the VX or vtec-e design was that the head was designed to increase swirl to permit efficient lean running - which means it can run leaner without misfiring. The swirl also allows you to run more EGR to reduce pumping losses. At cruising RPM and MP you can run any honda engine as lean as you want and it will make 0 difference in longevity.

Extra fuel is added for cooling at higher RPM and higher load. Even so I've tuned over 1000 honda engines, have seen some pretty shotty tunes but the engines put up with being run lean (even at higher RPM) quite well.

Originally Posted by turbovr41991

I was told by the tuner that honda cars read better off the MAP sensor than they do the O2. He can run the car with or without an O2 sensor. If you choose the O2 sensor route, he uses a 5 wire wideband for better monitoring. I think he said the sensor was $50 or less and recomended a good brand to go with.

The trick with a wideband is that you also need a wideband controller. There was one built into the P07 (obd1 VX ecu) but I'm not sure about the HX ECU since they always went into the trash. A Bosch LSU is about $50-$80. Most controllers are about $150ish. Techedge in AU used to make a DIY kit and I built several in early 2000 when widebands cost over $2000.

Given all the limitations of the technology you're using there isn't too much that can be done. The average cell phone has many times more processing power than a honda ECU. If I remember correctly (been over 10 years since I worked on that ECU) it was 32k. Modern ECUs now have over 1mb of data.

Originally Posted by turbovr41991

Emmissions are sacrificed any time you are in lean burn. That is eccentially why these cars are no longer made. I still dont get why a Hummer is street legal in California while these lean burn civics were not allowed. It just shows where their priorities are... Helping the oil companies!

The EPA standards are based on engine size and category of the vehicle. It is probably the most fair way to do it. We expect an 8 seat people hauler to require a larger engine thus pollute more. Why should something the size of a Smart car be permitted to pollute the same amount as a Hummer?

There are always politics involved but I've spoken to the EPA people enough over the years to know that most of them really are interested in saving the environment. This is most effectively done through dealing with the law of averages. More and more strict regulations are making a difference. Even in the past few years we're seeing new vehicles with EPA ratings in the 60mpg range. Unheard of even 5 years ago!

Originally Posted by turbovr41991

I have not noticed any side effects for the long term use. I believe the state of lean burn it is in is not as agressive as the one from the factory. I head insights getting into 24-25 ratios, where this one is only at 17.5. The tuner even said there was alot more room to gain, but if I choose to go more lean he would want EGT gauge to monitor cylinder #3 (I guess it is the one that gets the hottest). I might go this route down the road as I have a couple extra EGT gauges laying around, but for now I am just enjoying the lassle free lean burn.

It's not as aggressive as factory because it's most likely non-existant. It's not the easiest thing to get a chippable ECU to run EGR. It's also unlikely that you'll get a honda engine, even a HX/VX to run efficiently or smoothly in the 24-25:1 range.

On honda engines (most engines for that matter) the EGTs will be approx 75-100 degrees lower at 17.5 than 14.7. If you can get it to run at 19:1 you will probably see an additional 50 degrees dropped. If they were not insanely expensive I'd suggest getting a 4ch EGT off an airplane since we use them pretty routinely to lean out for cruise.

One way you can really increase fuel economy is through cylinder balance. Most OE vehicles are not terribly good at this but in your case you'll have tuning issues since per-cylinder fuel trims is reserved for modern cars and sport bikes... For fun you could try 4 individual fuel pressure regulators but it would be very very difficult to tune.

If you google them up check out GAMI as they have some good articles on the subject of cylinder balance.

-Michael

[turbovr41991]

Originally Posted by figit090

Glad your car is working well! Are all the parts hard to find? we should make a fleet of these and start showing what can be done to more people beyond ecomodder.

That is hard to do. There is a company in Columbus, OH that is trying to do just that. They are still working on the prototypes, but aiming for the mainstream, non-ecomodder crowd.

Originally Posted by hackish

The trick with a wideband is that you also need a wideband controller. There was one built into the P07 (obd1 VX ecu) but I'm not sure about the HX ECU since they always went into the trash. A Bosch LSU is about $50-$80. Most controllers are about $150ish. Techedge in AU used to make a DIY kit and I built several in early 2000 when widebands cost over $2000.
Given all the limitations of the technology you're using there isn't too much that can be done. The average cell phone has many times more processing power than a honda ECU. If I remember correctly (been over 10 years since I worked on that ECU) it was 32k. Modern ECUs now have over 1mb of data.

I would assume the stock HX would have a wideband controller built into the P2N ECU. It also had a 5 wire O2 sensor from the factory.
I am still working on a few other things before I pick up a wide band and a controller. Will probably be another month or more before I add it and an ETG gauge. It will be interesting to see the results though.

Originally Posted by figit090

The EPA standards are based on engine size and category of the vehicle. It is probably the most fair way to do it. We expect an 8 seat people hauler to require a larger engine thus pollute more. Why should something the size of a Smart car be permitted to pollute the same amount as a Hummer?
There are always politics involved but I've spoken to the EPA people enough over the years to know that most of them really are interested in saving the environment. This is most effectively done through dealing with the law of averages. More and more strict regulations are making a difference. Even in the past few years we're seeing new vehicles with EPA ratings in the 60mpg range. Unheard of even 5 years ago!

I am not saying the EPA does not care about the environment, but they also have another agenda or people to answer to… Big oil companies and the auto manufacturers. They choose the method of worked best for them. Why base it on engine size? If you put a big engine in a small car, you suddenly are immune to most restrictions? It just seems silly. Rate them on function, rate them on the number of passengers it can hold, etc etc… But restricting lean burn was a joke. Chevys corvette had trouble passing EPA, but they worked with each other so the cars could be produced. Under light to moderate acceleration when you try to shift from 1st to 2nd it will not let you. A light in the dash flashes “1st to 4th.” So to pass epa restrictions they installed a servo that blocks you from shifting into second gear at lower speeds. How silly is that. I am just saying a lot more effort goes into selling high dollar gas guzzling cars than it does to develop efficient cars that use little to no fuel at all.

[hackish]

Originally Posted by turbovr41991

I am not saying the EPA does not care about the environment, but they also have another agenda or people to answer to… Big oil companies and the auto manufacturers. They choose the method of worked best for them. Why base it on engine size? If you put a big engine in a small car, you suddenly are immune to most restrictions? It just seems silly. Rate them on function, rate them on the number of passengers it can hold, etc etc… But restricting lean burn was a joke. Chevys corvette had trouble passing EPA, but they worked with each other so the cars could be produced. Under light to moderate acceleration when you try to shift from 1st to 2nd it will not let you. A light in the dash flashes “1st to 4th.” So to pass epa restrictions they installed a servo that blocks you from shifting into second gear at lower speeds. How silly is that. I am just saying a lot more effort goes into selling high dollar gas guzzling cars than it does to develop efficient cars that use little to no fuel at all.

I think you could have an mandate to improve emissions. So a carmaker has to pass your mandate of improving emissions, sometimes those old pushrod engines designed in the '60's just can't do it. So call this a compromise.

Emissions are very very complex. I know the name of this forum is ecomodder and many here are trying different ways to burn less fuel. It is still a balancing act and a lot of the advice here produces significantly more emissions, decreases the safety and causes hazards to other road users. P&G is a good example releasing about twice the pollutants with maybe 5% less consumption?

The small picture is how much fuel was burned going from A to B. The big picture is how waste was emitted per day for everyone. Sometimes larger engines do emit less, sometimes smaller ones emit more. The idea here is a good one but its easy to get lost in the complexities.

When you look at the efficiency of most 2010+ models you see a significant increase. All of what EPA does may not be perfect but you can largely thank them for that.

-Michael

[turbovr41991]

Originally Posted by hackish

I think you could have an mandate to improve emissions. So a carmaker has to pass your mandate of improving emissions, sometimes those old pushrod engines designed in the '60's just can't do it. So call this a compromise.

If I recall correctly my friends 91 corvette ZR1 had the LT5 engine in it which was not a push rod engine. I thought that was one of the major differences between it and the LT1, but I could be mistaken. It had the “1st to 4th” servo in it. This servo was even on the late 90’s and 2000’s corvettes with the LS1. We should not be talking about 60’s technology here… We are talking about the same era in which they made lean burn so regulated it was no longer a viable option to be produced.

Originally Posted by hackish

P&G is a good example releasing about twice the pollutants with maybe 5% less consumption?

I would think this fact is highly skewed. Perhaps you are getting your pulse and gliding data from a vehicle that is horribly inefficient with a hideous drag coefficient… Most cars show much higher gains from this without doubling emissions... Not to mention, you can regain speed under low engine load thus further lowing emissions as well. I believe a stock Prius showed this best getting 117 mpg! Over 100%+ gain over EPA. I am not sure on the emissions on that test, but before you are going after people trying to conserve resources, I suggest you try to enlighten the masses who romp and stop to get from point A to point be… How many times to edomodders coast up to a stop light with the engine off while getting passed by and SUV accelerating to the light only to slam on their brakes. That is where the problem is… People in a hurry to get to a stop light and sit there…

We should probably get back to topic here. We have be sidetracking for a while now. Surely there are many other threads open on these topics.

[hackish]

Originally Posted by turbovr41991

If I recall correctly my friends 91 corvette ZR1 had the LT5 engine in it which was not a push rod engine. I thought that was one of the major differences between it and the LT1, but I could be mistaken. It had the “1st to 4th” servo in it. This servo was even on the late 90’s and 2000’s corvettes with the LS1. We should not be talking about 60’s technology here… We are talking about the same era in which they made lean burn so regulated it was no longer a viable option to be produced.

The old ZR1's had a lotus engine in them. Effectively it was a race engine and racing and emissions or fuel economy seldom go hand in hand. When you look at the GM V8's I wouldn't exactly call their technology modern.

Originally Posted by turbovr41991

I would think this fact is highly skewed. Perhaps you are getting your pulse and gliding data from a vehicle that is horribly inefficient with a hideous drag coefficient… Most cars show much higher gains from this without doubling emissions... Not to mention, you can regain speed under low engine load thus further lowing emissions as well. I believe a stock Prius showed this best getting 117 mpg! Over 100%+ gain over EPA. I am not sure on the emissions on that test, but before you are going after people trying to conserve resources, I suggest you try to enlighten the masses who romp and stop to get from point A to point be…

The test data is in fact skewed because my 5 gas analyzer wouldn't read that high. It would peg at max until midway through the pulse when the cats lit off again. When I have time I'll see about getting a new analyzer (they are about $5 grand) and put some more time into collecting data.

Ideas promoted in threads did things like advance timing (NOX goes through the roof) or special cutoff switches to turn the engine off on their glide (COX & NOX goes through the roof until the cat gets back up to temp). All of that to say what feels like you're saving the environment may in fact not be.

In your corvette example is a minority. You need to consider averages to have the most significant gain for effort spent. This is why they instituted emissions offsets for carmakers. 1 type of dirty car has a smaller footprint with 1000 models sold than a small improvement on the most common vehicle.

My line of work is driven by the cost of fuel. If fuel were cheap it would be difficult to cost justify having your fleet modified for fuel economy. Your gas stompers and stoplight racers could be encouraged in similar ways.

-Michael