Greetings from Australia.
I program my ECU for fuel economy. I used to use a MSD6 CD ignition and found it useless for running lean mixtures. My maps use to look like the ones that you have shown, even with stock Ford TFI ignition.
Now I run a 18 volt "volt booster" to the coil and this really lights nearly any mixture you put thru it and it has changed the way I tune my car. Basically I now run 15:1 everywhere on the normal driving areas of the map except on lean cruise I can only get about 16.5:1 and on idle I do have around 14:1 . I dont bother with WOT much but it is set around 15:1 and suprisingly it goes OK. The high voltage ign really helps in my setup. I use to believe once it lit, its lit. That does not apply to lean mixtures.
The ignition setup that I converted to has been proven on cars that exceed 1000hp. It was used by AEM and by Bisimoto. It doubles the volt and amp output of the stock ignition.
My ignition setup is a coil on plug, direct fire. Mine is setup for waste spark. The coils came from a Honda CBR motorcycle and are driven by an AEM Twin Fire which is driven by the sensors in my now vestigal distributor, but I plan on replacing it with an AEM EPM when those sensors inevitably fail.
I was able to run 18:1 mixtures on the stock Honda ignition.
I finally got it to pass smog. I changed the cat converter, radiator, backed the ignition timing down, locked it into 16 valve mode, and filled it up with 91 octane (Conoco). NOx went from 4500 to 1100.
This is the O2 Feedback Target Table
This is the Ignition Timing Advance Table. Advancing the timing in the cruise region gives you as much if not more mpg improvement as leaning out the mixture.
This is the region of the timing table that is measured on the smog machine. You can see that the smog test is a very crude estimation of the engine's condition. When a new car comes out and it's emissions are tested by the federal government, they actually put a bag on the exhaust pipe and collect the total emissions during a simulated drive.
It's all in the ignition timing. The smog test is at 15 and 25mph and 2000 RPM. Load is at 35kPa and lower. This is where I dropped the timing from 24 degrees to 16. Feels like it runs better though I don't often cruise lower than 25mph.
I plan to try advancing the cruise ignition timing even further. The reason why I stopped at about 39 degrees is because I was getting misfires at very light freeway speed driving. But now I'm almost certain that it was caused by an overly sensitive ACCEL fuel triggering all the time. When running 18:1 at a very light load, any small blip of fuel makes a big difference. I felt this as a stumble that I thought was a misfire.
Work is only 3 miles away though. It will be a while until I go on another long freeway trip.
You got it to pass smog with the AEM EMS? Is the reason you were able to do this is because when they conduct a smog test on Pre OBD-II vehicles, they don't hookup to the proprietary connector like can and I think do on OBD-II vehicles?
I'm in Utah.
This is an interesting thread.
SH, have you applied any similar FE upgrades to your DA?
Anyone want to buy my hatch for 9 grand? I'm only willing to sell it because I know I could build another one when my financial situation improves. I only drive 3 miles to work so I wouldn't mind taking a MPG hit if it means getting the Integra back on the road.
Credit card debt is the only thing stopping me. Sadly the DA's clutch is history so it just sits on the side of my house. I think with the DA I'd rather build it for some decent power since I have the hatch for daily driving. But I know I would have no problem getting better than the factory mpg. This is what I'd like to do:
Integra DA Wish List
Get a GSR head and LS/VTEC the block
I might consider an aftermarket cam
*Endyn Roller Wave Pistons
*Endyn head work
Type R header
AEM 3 inch Type R intake (will it fit a DA?)
freeflowing exhaust most likely Magnaflow oval muffler and some resonators to keep it quiet
AEM Twin Fire
AEM Pencil Coils
Koni / Eibach suspension modest drop
OEM replacement bushings
install the bronze Rotas that are currently on my hatch
bodywork (there are some holes from where I removed the spoiler), tint
front components speakers and a double DIN Alpine w/navigation
easily removable fiberglass amp rack/sub enclosure in the spare tire cavity probably with an 8 inch square kicker sub and kicker or alpine amp
*would yield better mpg as well as power
The interior of the Integra is so damn clean and the body has never been hit. No rust of course since it's a CA car. It's a shame to have it sitting but I don't want to spend the money on a clutch when the engine has over 220k miles. So the plan for now is to get a no interest credit card and buy an OBD1 B16 w/cable trans and ECU for the time being.
For the past week or so I've been digging through forums looking for more information about the AEM EMS and tuning in general. I scoured efi101 and aempower.com, reading through pages and pages of old threads that go back all the way to 2002. And not just the Honda section but all the other applications also. I found some information on barometric correction, O2 feedback controls, accel fuel trim, manually setting the tps minimum voltage to prevent a bug in the software, and most recently, injection phasing.
Injection phasing essentially is injector timing similar to spark timing. It controls how early (in degrees) the injector fires in relation to tdc. This should not be confused with injector open time (in mS), which controls how much fuel is actually sprayed as a function of how long the injector stays open and how much fuel pressure is behind it. Changing the phase of the injector doesn't change how long it stays open.
Fuel actually needs a certain amount of time to travel between the injector to the combustion chamber. This time varies because when the valve opens at certain RPM, air can actually blow backwards into the intake runner working against the fuel that's trying to squirt into the combustion chamber. At other times there is actually air pressure above atmospheric forcing it's way in and pulling the fuel with it. In any case you want to fire an injector at a closed intake valve to give the fuel time to evaporate for better mixing and also to cool the valve.
The results of fine tuning injection phasing are lower exhaust emissions, better fuel mileage, more power, quicker start up, and a more stable idle. This is especially true in lean burn engines and in low to mid RPM where the injector duty cycle is low.
Before now the only way I knew to tune injection phasing was with a long and complicated equation. I didn't have all the variables to put into the equation, and even if I did, I still didn't understand when I would want to fire the injector. The worst part was that even after this calculation, you arrive at a baseline figure that still needs real-world tuning.
Finally I found someone in a forum that broke down how to tune injection phasing without doing the calculations and without using a dyno. You use the IACV to hold the engine at a steady state, zero everything out, enable logging, then make changes to injection phasing. You view the logs and look for the point where RPM's are highest, load is lowest, and AFR is richest. This is the ideal injection phase. You tune several RPM points and then draw the graph between them.
I began tuning idle and 2000 RPM (smog). I plan to tune the entire graph by hand. Then I'm going to post up the chart so that anyone with a VTEC-E motor can copy it into any standalone they're using that's capable of altering injection phase (AEM EMS and Motec are the only ones that I know of).
sweet!! i am looking forward to seeing the results of these changes!
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