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Some features of our programming

Will my custom program affect my emissions test?

Will I need to run premium fuel?

Relocating the IAT/ACT sensor for blown cars

What are jumpers?

Is it OK to "retrofit" the old Walbro pumps in my returnless fuel car by modifying the basket?

Re-usable air filters

Should I get a shift kit?

I changed injector size.  Do I need to buy a new MAF or have mine recalibrated?

MAF's "calibrated" to injectors

Larger MAF's









At American MotorSport we make many changes to attain the best driveability and safe power out of your vehicle. All of our chips are made-to-order, to take into account each cutomer's modifications, needs, and wants.

Some of the features of our programming include:

Optimized Spark/Timing
More spark is added to increase power.  Spark is optimized at each load level and RPM interval, for maximum power throughout the power band.

Eliminate Spark retard
The spark retard during tip in is eliminated for better throttle response and faster acceleration.

Optimized A/F Ratio
A lot of cars are run rich from the factory at the higher RPM levels.  We optimize the a/f ratio per your application for maximum power.

Raised Rev limiter
In most applications, the rev limiter is raised when there is power to be had higher up in the powerband.

Speed Limiter
The speed limiter is raised or removed.

Fan turn on temps
The fans are commanded to turn on earlier, to keep your car running cooler.  Because we optimize our programs to add timing when coolant temperatures are lower, this will yield some power.

Matching MAF's to injectors
Via our programming, we can match any MAF to any injector size, as long as the MAF has enough range.  It does not matter that the MAF is calibrated to a different injector size than you are running.

Max fuel economy programs available
We offer some programs with optimized EGR calibrations, shift schedules, and fuel calibrations to increase fuel economy.  This is a good option for a multi-position chip, to have a performance program when you want it, and maximum fuel economy when cruising around town.

Just about anything else
Since we have access to every parameter in the PCM, if you need it done, chances are we can do it...from changing displacement for a stroker kit, optimizing idle quality for an aftermarket cam, to just about anything you can think of, just ask!

For automatics we also offer:

Later part throttle upshift schedule
This later schedule allows the engine to rev high at part throttle. This matches the torque before and after the shift better, for less sag, or drop off in torque after the shift.

Revised torque converter lockup schedule
This allows the converter to lockup at heavy to full throttle. This improves the efficiency of the transmission, thus transmitting more power to the rear wheels.
At part throttle, the torque converter lockup is delayed to prevent the drop in engine speed normally seen when the converter lockups.

Improved manual shifting
The manual 2-1,3-1 downshifts are made faster.
The manual 4-2 shifting is made smoother and faster

Shift Feel
The upshifts are made firmer throughout the throttle range.
The torque reduction during upshifts is eliminated

Shift timing
The delays for the transmission to upshift after lifting the throttle are reduced



Will my custom program affect my emissions test?
No. In many cases, emissions are actually improved under certain conditions.

Will I need to run premium fuel?
Although American MotorSport offers a performance chip that uses regular gas, premium gas is recommended to obtain the most power out of your vehicle.

Relocating the IAT/ACT sensor for blown cars
YES, on a forced induction car (specifically supercharger or turbo) the intake air temperature/air charge temperature sensor MUST be relocated to after the power adder.

Most chip makers retain the "factory" location of the sensor. Since the sensor will then be picking up ambient temperature regardless of the actual temperature of the air coming out of the supercharger or turbo, they must "fix" timing in such a way that at the highest boost level, when temperatures are at their highest, the car will not knock. This leads to a loss in low end, since at idle and low-boost levels, when air temperatures are not so high, more timing could have been added.

The way we make chips, we REQUIRE that any blown car have the ACT sensor mounted in the discharge tube after the power adder (and after the intercooler if any) and the throttle body. By use of this method, we are able to add the maximum amount of timing for the low-end, and by design of our custom timing tables, the EEC will automatically retard timing only when needed. This also makes your car safer, as spark is modified in relation to real-time temperature readings.

Use of this method will also allow the EEC to automatically add timing for colder days, and no re-burn is needed when stepping up or down in boost level (if the increase or decrease in boost is not extreme).

01+ cars will require the purchase and splicing in of an ACT sensor and harness.


WARNING: Because all of our chips are programmed to accommodate for ACT relocation by default, failure to relocate your IAT/ACT sensor will result in too much timing being added and certain damage to your engine.

What are jumpers?
If you are using a 1998-1999 PCM for a car with an automatic transmssion, it is possible that you may not have jumpers installed on the PCM. Ford disabled the jumpers on some vehicles meeting the above description. If your vehicle falls within this group, it is possible that it will not start with our chip. Some affected PCM’s are GTG1, BTB1, and MSE1 among others (although not all PCM's with these catchcodes are affected).

The easiest way to know that you are affected: is if the car does not start with the chip installed, even after connector has been properly prepped.

Possible Solutions:
1) Install the jumpers via soldering them in yourself or contact us for info on where to send the PCM to have jumpers installed.
2) Buy from Ford a new replacement PCM and redo PATS.

Is it OK to "retrofit" the old Walbro pumps in my returnless fuel system by modifying the basket?
We do not recommend you use either the GSS317 or GSS342 Walbro Fuel Pump on a returnless car. Installation nightmares
and pump failures within 5,000 miles can result. Poor driveability without remedy is another frequent side-effect.

Possible Solutions:
1) Purchase from us and install a returnless fuel pump (supports up to ~ 430rwhp)
2) Install a 03 Cobra Dual Pump and Tank (recommended for 430rwhp and above)

Re-usable air filters
Re-usable filters, such as K&N filters do improve flow. However, when cleaning these filters, no matter how little oil you use, some of the oil will make it onto the wire in the MAF. This will cause a lean shift. If you are going to use a re-usable air filter, we recommend tossing it and buying a new one when it is time to clean. It is better to pay for a new filter than an new motor.

Should I get a shift kit?
Most find that the increased shift firmness from a chip is sufficient. If you were to desire additional shift firmness, you could always have a shift kit installed afterwards. In addition, if you already have a shift kit and feel that the shifts are firm enough, you may request a chip with no added firmness.

I changed injectors.  Do I need to buy a new MAF or have mine recalibrated?
No.  As long as your MAF has enough range for your application, American MotorSport can match any MAF to any injector size, in the calibration.

MAF's "calibrated" to injectors
Even if your MAF is "calibrated" for you injector size, a chip or reflash should still be used.  Here is why:

The MAF measures the mass of air that is flowing into the engine. The PCM also knows the mass flow rate of the injectors. If you are flowing, for example, 20#/min of air into the motor, and want to run 14.64:1 air/fuel ratio (which is the chemically correct a/f ratio for heptane, essentially gasoline). With 20#/min of air and a desired a/f ratio of 14.64, you'd need 20/14.64, or 1.366#/min of fuel. When multiplied by 60 to get #/hr of fuel, one would need 1.366 times 60 or 81.97#/hr of fuel through all the injectors. If you had say 8 injectors, each injector would have to inject 81.97/6 or 13.66#/hr of fuel. With a 24# injector, this is 13.66/24 or 56.9% of full injector opening.
This part is straight forward.

There is another side to this:
The PCM calculates what's called load, which is essentially volumetric efficiency or VE. VE is the efficiency of the engine to pump air. For a 3.0L engine, in two engine revolutions, it can move in and out 3.0L of air. If the engine only moves 1.5L of air, then it's VE is 1.5/3.0 or 50%. Since the PCM knows mass of air, air temp and barometric pressure, it knows the volume of air that is moving through the engine at all times, so it can calculate VE.

The spark and fuel tables are tables for the amount of spark to deliver and the a/f ratio to command if you are NOT open loop. Open loop is when you are richer than 14.64:1 a/f raito and no longer using the O2 sensors for feedback.   The PCM uses load in calculating spark and fuel. If your MAF transfer function is off (this is the input voltage from the meter to the PCM and what the flow is at that voltage) VE will be calculated incorrectly and hence so will timing and fuel be calculated incorrectly. This is why the MAF is so critical to making the engine work right. VE gets an input into almost everything, even what the trans feels like when it is shifting.

Most will say that you can get a MAF calibrated for a given size injector and not change the PCM. This is right and wrong. Let's say you have 19# injectors and some MAF. You want to put in 38# injectors. You purchase a MAF calibrated for 38#ers.  What they do is TRY to make it so at every voltage point the output from the MAF is original injector size divided by new injector size, in this example, 19/38 or 1/2 of the original value. The PCM now thinks there is a lot lesse airflow into the engine. Let's say before at 2 volts it was 12#/min, now with the "new" MAF, to get that same 12#/min you are at 1 volt. So, you now running at 1 volt with 12#/min of air and the PCM thinks you are running much lower flow, thus giving you a lower fuel pulsewidth. If the air meter was set up correctly, you would have 1/2 the pulsewidth and the amount of fuel going into the engine will be correct. This is the part that's right.

Now the wrong part. Load is calculated incorrectly, in this example, it's 1/2 of what it should be. So, the PCM uses the wrong values out of the spark and fuel tables. This typically ends up in knock (also known as detonation, or pinging) on some cars, since the car is leaner with more spark.

The correct way to calibrate for injectors is ALWAYS to make changes in the PCM via a chip or flash.  A "larger" (read: with more range) MAF is only needed when there is a danger of the current one pegging.  This is true of most forced induction applications.  As long as your MAF has enough range for your application, American MotorSport can match any MAF to any injector size in the calibration.

Larger MAF's
Although an aftermarket MAF will show some gains on a dyno, these gains, contrary to popular belief, are not due to the MAF being physically larger.  A larger MAF will not help by being physically larger, unless the smaller MAF was a restriction.  If the stock MAF was not a restriction (this is gauged by measuring pressure drop across the MAF) you will find very little, if any, power in a new MAF over your stock MAF from additional diameter alone.  If the stock MAF is a restriction, and such is the case on Crown Vic's, 5.0L Mustangs, and some early Supercoupe's and SHO's, among others. In these applications there is some power to be gained by a larger MAF.  This applies to larger TB's as well.

The reason the MAF does increase power by a marginal amount is that, using the logic applied in the above FAQ, the MAF calibrators will shift a/f leaner (generating some additional power) and based on the explanation of the MAF regarding load (or VE) above, the PCM will now be tricked into adding a little bit of timing because it believes that load than actual.

Tricking the EEC as above will also yield some negative side-effects, such as knock in some vehicles.  In addition, since load (calculated from the MAF) is key even to how an automatic transmission shifts, there may be other detriments.  With use of a chip or reflash, timing and a/f can be optimized correctly, at all points.