Optimization of the MAP type system with new CAI and catcack on 2.0l

[Fokyl]

I put a magnaflow catback 2.25" (custom fab'd) and a 3" cold air intake which locates the KN style cone filter outboard of the battery.
Question: Does the limitations of the MAP system (speed-density) make this a futile effort?
Everybody says they slap on a header/catback/CAI and then their car comes to life. Am I to consider that they have a predecessor MAF type system or is there something else I must do to gain optimal performance?
Already reset the ECU after install and overall I may have realized 1-2 mpg improvement.
Any other suggestions?

[Jonny666]

To be totally honest the limitation isnt the maf system. it seems to be our ECU. Basicly our ecu is too smart for its own good. It runs our tib's rich from the factory, once you put on a cold air intake and exhaust the car runs a tiny bit more lean. the problem is the ecu figgures this out and richens up the air fuel in a big hurry back to the factory setting (pig rich). no problem, a fuel tuner will take care of that right? Wrong. apparently the ecu has outsmarted many a fuel tuner. it eventually adapts to the new tune and richens everything back to the factory tune (once again pig rich). and that is basicly where we are all stuck. trying to find a way to fool the ecu so that it wont reverse your tune.
No one has been sucessfull yet.

[KeWLKaT]

Dude.... I have ZERO problems with the UNICHIP piggyback.... The settings are still all original.

The secret is to NOT screw around with the stock injectors... EXTRA INJECTORS ARE THE KEY!

Look at yamaha that is going through that route right now after his smt-6 fiasco

[Jonny666]

that's great for the turbo guys but us N/A guys get the short end of the proverbial anal blasting stick

[KeWLKaT]

true, true :)

[ricerrx7]

What limitation of the speed density system are you referring to?

[Fokyl]

From sportcompactcarweb.com\\ "Suck, Squish, Bang, Blow. part 2[
"B]Tuning issues[/B]
If a car has a MAF (Mass Air Flow) monitoring fuel injection system, then chances are, it can accept the modification covered in this article with no tuning changes. Cars like Nissans, Toyotas and Mitsubishis made in the mid '80s and later for the most part are equipped with MAF's. These types of fuel injection systems measure the amount of air coming into the engine so the engine control computer knows how much fuel to inject for a proper mixture. If the new exhaust and intake system causes more air to be induced, then no problem, the ECU compensates. On these cars it may help to disconnect the battery for a few minutes to reset the self-learning function of the ECU so the ECU can relearn the new mixture required. It may take a little driving for the engine's ECU to adjust to the parts so you can get all of the power they can make out of them. Generally, the engine will run better and better for the first 20 or so minutes of engine operation after installing the parts.

A few popular imports use what is called a speed density system. Honda and Acura are the main examples. These cars use a MAP or Manifold Air Pressure sensor to help the ECU determine how much fuel to inject for a correct mixture. Unfortunately, since they must calculate airflow based only on manifold pressure and rpm, their calculation must be based on the pumping efficiency of the stock engine. If you improve the pumping efficiency of the engine, most speed density systems do not compensate for modifications very well.

All is not lost, however. Add a device called a fuel pressure riser. This is an adjustable pressure regulator that goes in the return line to the gas tank from the injectors. With a fuel pressure riser, the fuel pressure to the injectors can be controlled, a process allowing an increase in the pressure to add more fuel to make up for the additional air being drawn into the engine.

For best results, a fuel pressure riser should be tuned on a chassis dyno, but good results can be obtained by measuring the time to make 10 to 50 mph accelerations in second gear or from 2000 rpm to redline if you have no dyno access. Stillen makes fuel pressure riser kits that can be adapted to many Speed Density-equipped cars. Additional fuel and air can increase cylinder pressure also. This may cause detonation necessitating a reduction in timing. We discussed timing adjustment in detail during out last segment in this series. On some engines, cooler air from a cold air intake may allow more ignition advance. IN other words, to optimize a new setup, take advantage of information available and do some tuning to optimize your set-up. This is what seperates the winners from the also-rans."

...So there seems to be some solution if you have a return line in your fuel system, but I think the fuel system on the '05 Tucson 2.0 L has a returnless fuel system (can anybody verify?), and the fuel pressure riser needs a return type fuel system.

I would like a proven bolt on tweak and not a chip (lost warranty coverage from having a chip before!).

[BlueRush]

You by the kit, APE has one too I think, and put a fuel pressure regulator on the end of the rail with a returnline outlet. Then you set it whatever is needed.

[ricerrx7]

I don't necessarily agree with what that article says. No, the tune won't be perfect with the map based system, but it won't with the maf based either. And there's an O2 sensor to help correct this. If you want to have the car actually tuned you're going to need to find someone to tune the stock ECU.

[OH_Beta_Accent]

MAP systems aren't as blind as suggested by sportcompactcarweb.com (at least not ours). Anything thing you do like I/H/E will slightly increase the Volumetric Effienciency.

When our ECM's are reset they go into "learning" mode. While in learning mode, they disable their emissions monitor, bring up a base map, and start monitoring 4 sensors, Oxygen Sensor Bank 1 Sensor 1 (the first one), the knock sensor, cam position sensor, and crank position sensor.

It then watches the first O2 sensor for lean/rich condition and makes adaptations to the base map to compensate for changes in VE of the motor. While it's doing this, it's also slowly advancing the ignition timing while watching the knock sensor to determine how much ignition advance it can safely run without pinging(fuel octane).

Once it's got enough data, it'll saved the modified map into memory, reactivate all the emissions systems, and run off that map until reset or detecting a serious problem (blinking check engine light).

If you want to know how long it takes to adjust the map, unplug the rear O2, reset the ECM, and notice the check engine light will be off. Drive around for a while and when it comes back on, the computer is done learning.

[FordFasteRR]

What the article says about older style MAP systems is true...
However, the (01-03 XD) MAP based systems will adjust the fuel trims based on oxygen sensor readings, and only takes a few minutes of driving to do it.

It is not as efficient as a MAF system (04+ XD2's elantras are all MAF based), but you end up with the same result once the ecu adapts..

[Jonny666]

hey, i just realized something. if you've got a CAI and a catCACK, the Map system is the least of your problems. if i had a catCACK i'd be sooo embarassed.

[Fokyl]

Thanks Oh Beta Accent, ricerrx7 and FordFasterr. Your answers seem like knowledgable and explain the slight perf gains and behavior of the vehicle.
Fokyl

[Proteus]

It then watches the first O2 sensor for lean/rich condition and makes adaptations to the base map to compensate for changes in VE of the motor. While it's doing this, it's also slowly advancing the ignition timing while watching the knock sensor to determine how much ignition advance it can safely run without pinging(fuel octane).


Interesting. So, does this mean if you put 91 octane in and reset the ECU, it'll actually take advantage of the higher octane? Or is it always going to settle at 87 once it's done checking things out?

[OH_Beta_Accent]

To an extent. Some cars will take advantage of octace changes more than others, while others will only work toward retard in cases of bad gas or using lower than recommended octane.

[Proteus]

To an extent. Some cars will take advantage of octace changes more than others, while others will only work toward retard in cases of bad gas or using lower than recommended octane.

I see. Anyone tested an Elantra's response? I might try it sometime, but I don't really have access to a dyno or anything, so it'd just be a matter of my opinion. I think last time i reset my ECU, I had 89 octane in the tank... and it seemed a little faster for a while, but it could have just been my imagination, or the weather.

[ricerrx7]

Our elantra's don't work like that. It works off a base map for 87, and retards if needed. It doesn't advance to make use of 93.