EFI Beginner Guide

What Honda/Acura vehicles can be chipped/reflashed/tuned?:

What is a chipped obd1 ecu?
A chipped ecu is a modified factory engine control unit (ECU) which is setup to read a 28 pin eprom chip which contains custom fuel/timing maps along with other settings. Phearable.net offers chipped ecus for those who don't have a obd1 ecu or for those whom do not want to experience any downtime by mailing in their ecu to be chipped. Phearable.net customizes ecus specifically for your vehicle.

What is ecu chipping?:
Ecu chipping is the modification of a factory engine control unit (ECU) to read a custom programmed chip with custom fuel & timing maps for your vehicle's application along with custom options such as revlimit, vtec activation points etc. Phearable.net allows you to mail in your obd1 ecu for chipping/socketing services.

What Honda obd1 ecus are chipable?:
Only a few select type of obd1 92-95 honda/acura engine computers are chipable to use with popular engine management software's.
USDM Vtec: P28, P72, P61 JDM Vtec: p30, p72, p08, p27, pr3, p91
USDM Non-Vtec: P75, PR4, P05, P06
Some obd0 honda/acura ecus are chipable but these ecus are not compatible with updated eprom editors, hence we do not support obd0 ecus. Obd1 ecus will plug & play into 92-95 honda/acuras, while pre-92 & 96-01 vehicles will require a ecu plug conversion harness to use the ecu (sold separately).

How do I know if I need a conversion harness to run a obd1 ecu?:
Any Honda/Acura vehicle newer then 95 requires a obd2 to obd1 conversion harness.
Most Honda/Acura vehicles older then 92 require obd0 to obd1 conversion harness.

What is a obd2 to obd1 conversion harness?:
A conversion harness is a jumper harness which plugs and plays into an obd2 vehicle and allows you to run an obd1 ecu.

What is a obd0 to obd1 conversion harness?:
A conversion harness is a jumper harness which plugs into an obd0 vehicle and allows you to run an obd1 ecu. Obd0 to obd1 conversions require you to run a obd1 distributor along with a 4 wire oxygen sensor if you plan on using narrow band oxygen sensor feedback which not needed if your car is properly tuned.

Picture of an obd2 to obd1 conversion harness:

What can a chipped ecu do for me?:
A chipped ecu will allow you to make the most horsepower you can possibly make on your vehicle via custom fuel maps, ignition timing etc. Phearable.net ecus come with basemaps specifically for the specifications you provide.

What program do I ask for when I have my ecu chipped or I order a chipped ecu?:
Phearable.net provides you with the best basemap possible for your vehicle/motor.
The phearable.net order form will ask you for specs/details on your vehicle which will allow for the best basemap possible to be put onto your ecu. If you are unsure about a setting such as vtec activation point, leave it blank so that we can provide you with the best setting for your setup.

What is Hondata, eCtune, Crome, Uberdata, Neptune etc?:
These systems are different eprom editors that allow you to edit the tune for a chipped obd1 honda ecu. They all have the same concept of editing fuel & timing values along with other settings to properly tune a obd1 honda ecu for your motor setup. All of these eprom editors edit binary data which is programmed onto a 28 pin eprom chip using a chip burner like the moates burn2 chip programmer. We only recommend Hondata or Neptune for end user tuning as most software/hardware other then Hondata or Neptune is no longer developped or supported.

What is Hondata S300?:
Hondata S300 uses it's own hardware instead combined with the software included to tune the vehicle live via a usb cable or bluetooth. It does not require a an emulator, datalogging hardware or chip burner as they replace the need for all of that hardware, It uses a single usb cable to allow you to program them without the use of a chip being programmed. It also allows you to datalog without the use of a datalogging cable. We HIGHLY recommend the use of one of these systems!

- Tuning Systems:
* Apexi AFC, Greddy Emanage units: These units are piggy back systems which alter the signals being sent to your factory ecu. We do not recommend using these solutions.
* eCtune, Neptune, Crome, Hondata, Uberdata: These systems are all obd1 eprom editors. They work off the factory ecu. Some systems have more options then others.
* Aem EMS, Motec: These systems are standalone systems which operate on their own ecu. They have a lot more features then a system based on a factory ecu.
* There are a lot more systems on the market but these are the most popular.
~ So which system should you run?
We always recommend you choose a system which your tuner recommends for your application & needs.

Screenshot of Crome (Neptune/eCtune/Hondata/Uberdata look similar):

How does an eprom editor or tuning software work?:
Most systems such as Hondata, eCtune, Crome, Uberdata, Neptune are based of the factory honda ecu. These programs allow you to edit the factory values in a socketed/chipped obd1 ecu.

There are several different things which you can modify which will allow you to properly tune your car using an obd1 honda eprom editor.

A brief run through: Low Cam = Non Vtec / High Cam = Vtec

There are high & low cam fuel & ignition maps on a vtec ecu. As you can imagin a non-vtec ecu does not have a high cam map.

Now each map can be edited cell by cell via rpm & load. For example, most motors idle around 21" of vaccum which is about 288 millibars. These figures are measures of pressure. Using the low cam fuel map, you can add or remove fuel to the idle via editing the proper rpm & vaccum collums. Using the low cam & high cam fuel maps a vehicle can be properly tuned via load/rpm using a wideband oxygen sensor by monitoring the air/fuel ratios per load cell etc.

The low cam & high cam ignition timing maps are maps which work the same way as the fuel maps except for the fact that you are editing ignition timing values per load & rpm instead of fuel values.

What is a basemap?:
A basemap is an ecu program that is specifically modified for your vehicle & its modifications. A basemap contains fuel & ignition timing values along with other important settings such as revlimit etc. Phearable.net uses basemaps which are only from actual vehicles which have been tuned by phearable.net using a wideband oxygen sensor and a dynojet. This is what separates phearable.net from other modified ecu distributors.

What is a wideband oxygen sensor?:
A wideband oxygen sensor is a sensor which allows you to monitor parts air to fuel. Most people have the preconception that a basic autometer air/fuel guage using the stock oxygen sensor in their vehicle will give them all the information they need about being in a lean or rich condition. This information is false, the factory narrowband oxygen sensor will not provide you with an accurate reading because the oxygen sensor is a narrowband sensor which does not have a wide enough of a range to accurately sense air/fuel mixtures needed to properly tune a vehicle. The purchase of a wideband oxygen sensor is not required due to the fact that almost every tuner provides one with his services etc.

What is a 4bar, 3 bar or 2.5 bar map sensor or an aftermarket map sensor used for?:
An aftermarket map sensor is used for forced induction vehicles which are to be tuned over 11 psi of manifold pressure. The factory Honda map sensor only supports up to 11 psi of map pressure.

Can I run my vehicle on a basemap & not worry about it?:
A basemap should not be relied on to be used as a final tune unless you use a
widbeand oxygen sensor gauge to monitor your vehicle's air fuel ratios.
You should monitor your air fuel ratios to make sure they are within spec of being safe.
If they are not within spec you should seek a local dyno tuner to have the vehicle dyno tuned using a tunable ecu.

* Tuning introduction / check list:
A lot of people do not understand the importance of tuning a vehicle.
Most people assume tuning is to make horsepower, what they do not realize is tuning is extremely important due to the fact that an untuned engine will eventually fail without proper tuning by an experienced tuner.

Before you have your vehicle tuned check list:
- Oxygen Sensor Bung: You must have a oxygen sensor bung which is accessible & installed in a proper location to where a good air/fuel pickup can be achieved. The oxygen sensor bung MUST have clean threads & be clear of any welds which may stop a larger wideband oxygen sensor from being installed into the bung.

- Fuel Pump & Injectors: You must have the proper size & type injectors & fuel pump for your vehicle setup. Please consult with your tuner to ensure you have the proper combination.

- Spark Plugs: Proper spark plugs & spare spark plugs for your application.
Please consult with your tuner if you are unsure as to what spark plugs to run.
Most all motor applications call for NGK BKR7E-N-11 [NGK-1283]
Most sub 400 whp forced induction applications call for NGK R5671A-7 [NGK-4091].
Most sub 400whp forced induction applications should use plugs gapped to around .028.

- Check engine light: Resolve all check engine codes before you have your vehicle tuned.
- Charge piping: Charge pipe couplings must be secure to prevent pipes from blowing off during tuning & causing delays.
- Engine compression (No more then 20psi between cylinders.)

- Electrical issues: Please resolve all electrical issues before tuning.
- Brakes, Suspension, Tires: All of these components are extremely important, especially if your going to have your vehicle street tuned. Please make sure they are all in good condition.
- Proper octane fuel for your application: Please inform your tuner of what fuel you are running. You should run the highest octane which is widely available in your area such as 93 octane. Try to prevent having your vehicle tuned with gas which has been sitting in your vehicle for more than 20-30 days.
- Forced Induction vehicles should invest into a catch can system such as the endyne kit.

What is required to have your vehicle tuned:
1. A vehicle/motor/setup in good mechanical condition.
2. A chipped/socketed obd1 or tunable ecu & a obd conversion harness if your vehicle requires one.
(Consult with your tuner to provide you with a chipped ecu or ecu chipping services)
3. The proper sized & resistance injectors for your application. (Ask your tuner)

92-00 Civic/Integra vehicles require Saturated HIGH RESISTANCE injectors (11-14 ohm)

LOW RESISTANCE injectors maybe used in 92-00 Civic/Integras using a resistor box.

4. The proper sized fuel pump. (Most street applications: Walbro 255lph fuel pump).
5. A couple of sets of spark plugs. (NGK BKR7E-N-11 for most applications under 400 whp.) Consult your tuner for his recommendation. Your spark plugs should be gapped properly (.018-.030 depending on the application)
5. Optional: Fuel pressure regulator & Guage
6. Optional: Cam Gears for dyno tuning purposes.

What is Air Fuel Ratio & Ignition Timing:
Air/Fuel ratio is the ratio of air to fuel. Ignition timing is the point at which spark is produced to create combustion. 25-30% of air/fuel mixture energy actually becomes "work" aka thrust. The remaining 70-75% becomes exhaust. Ignition timing & A/F ratio are both used to control the heat which an engine produces during combustion. For example, in most cases forced induction motors require a richer air fuel mixture of 12 parts fuel to 1 part air at wide open throttle using pump gas. Where as naturally aspirated motors usually run 13 parts fuel to 1 part air at wide open throttle. Running a richer air fuel mixture on a forced induction motor, helps absorb the heat which is produced due to the higher charge density.

What is detonation:
Detonation occurs in the combustion process when the advancing flame front, which is pressurizing and heating the unburned mixture ahead of it, does so at such a rate that unburned fuel in that zone achieves its auto-ignition temperature before the arrival of the actual flame front. The result is that the unburned mixture combusts "spontaneously" and over the entire zone where the auto-ignition temperature has been achieved. The apparent flame speed in this zone is many orders of magnitude faster than that in conventional combustion initiated by a normal flame front, with the result that the local rise of pressure and temperature is significantly sharp. This produces the characteristic "knocking" or "pinking" sound, and the local mechanical devastation that this can produce on piston crown or cylinder head can be considerable. Actually, "knocking" is the correct terminology for what is a really a detonation behavior over a small portion of the combustion charge. A true detonation process would be one occurring over the entire compressed charge. However, because detonation in this strictly defined sense does not take place in the spark-ignition engine, the words "knocking" and "detonation" are used interchangeably in the literature, without loss of meaning, to describe the effects just discussed.

What causes detonation?:
Detonation occurs when several conditions / factors inside the combustion chamber exist at the same time. Increased compression, high temperatures, lean fuel/air mixture, advanced ignition timing, and lower octane fuels are all factors that PROMOTE detonation conditions. The good news is that, because there are so many factors in play, you can always find a way to eliminate detonation if it exists.

What is cam timing:
Cam timing is the rotating position of your camshaft(s). This position maybe altered using an adjustable cam sprocket. Using cam timing adjustments a tuner can usually change an engine's working environment & create more horsepower.

What is a wideband oxygen sensor:
A wideband oxygen sensor is a sensor which allows you to monitor parts air to fuel. Most people have the preconception that a basic autometer air/fuel guage using the stock oxygen sensor in their vehicle will give them all the information they need about being in a lean or rich condition. This information is false, the factory narrowband oxygen sensor will not provide you with an accurate reading because the oxygen sensor is a narrowband sensor which does not have a wide enough of a range to accurately sense air/fuel mixtures needed to properly tune a vehicle. The purchase of a wideband oxygen sensor is not required due to the fact that almost every tuner provides one with his services etc.

What is dyno tuning:
Dyno tuning is the use of a dynamometer to measure wheel horse power and torque. Using a dyno to tune a vehicle is very important. A dyno provides a controlled platform for a tuner to make adjustments & see the repercussions to those adjustments. This will allow your tuner to make the safest horsepower/torque with your vehicle.