These are following questions we get asked here daily at JDM Engineering, and we hope this helps you make an educated choice of choosing JDM for your vehicles needs. Let us know if this helped you in pursuit of making your Ford faster, drop an email or shoot us a call.  We would be happy to hear.

Q: What coils should I be running in my vehicle?

A: JDM Strictly in all applications only uses FORD OEM coils, and under no circumstance do we suggest you deviate from the OEM coils.  If you suspect an issue with your coils, only replace with new OEM complete sets at a time.  For 20+ years we have never had an issue resolved by an aftermarket coil, only issues arising from them.

Q: My supercharged vehicle feels sluggish as of late what can be the culprit?

A: 95% of all power loss issues with Ford Supercharged vehicles are a function of the intercooler pump going bad and causing no flow of coolant to the intercooler and heat exchanger.

On a cold start and ONLY cold, after 5 minutes while the vehicle is idling pop the intercooler reservoir tank open and check for fluid motion.  It should look like a spa with bubbles and circulation.  If there is no fluid motion, you have a problem with the function of the intercooler pump.

Q: Should I use octane booster if I cannot get enough octane at the pump?

A: No.  Octane booster can take out o2 sensors and spark plugs in a flash leading to failure of an engine.  If you have to mix fuels, use a true unleaded race fuel that is o2 sensor safe.  It is important you notify the tuner beforehand to make sure the combination is safe.

Q: I have a 91 or 93 octane tune, and I put 87 in the tank, can I run the vehicle?

A: Yes but only very slowly at best.  Most importantly, do NOT let the engine see load at all.  Drive like a grandmother until 1 full tank of 93 octane has ran through the vehicle.

Q: Why do I have to run a colder spark plug?

A: To delay the onset of detonation and preignition from too much heat in the combustion chamber around the spark plug.

Q: Why do I have to gap my spark plugs, and do you pre gap them?

A: Gapping your plugs is essential to prevent spark blow out, where as there is too much resistance for the spark to jump to the electrode.  Tightening the gap makes the jump easier for the spark.  We only pre gap the autolite HT-0, as it is inconsistent to do so with any other plugs due to settling during shipping.

Q: Why doesn't JDM use ARP head studs on our builds?

A: ARP makes industry leading fasteners, with amazing tensile strength, and there is no denying that.  What we at JDM have found is the fasteners tend to be so strong, in the event of excessive cylinder pressure or detonation, the ARP fasteners have zero yield.  When the head bolts don't move from detonation, something else has to give.  If you are lucky, you get excessive blow by, if not valves can tulip, spark plugs can blow out, or holes can form in the head, piston, or even the block.  Would you rather blow a head gasket or put a hole in your chamber?

Also, on any aluminum 5.4/5.8 Block the distortion of the bores when torquing must be accounted for when honing.  If you use studs the block may distort so far as to hurting the structural rigidity of the PWTA liner in these blocks.

We have multiple 1300+ horsepower Cobra Jets without head studs with ZERO issues.

Q: What Automatic Transmission Fluid should I use in my lightning?

A: STRICTLY Mercon Dextron III (3.) WITHOUT EXCEPTION Anything else can take out the transmission in less than 10K miles in the wrong conditions.

Computer code and strategy code explained—

In order to tune your vehicle, we need to interface with your computer.  Each Ford vehicle comes with a computer code and strategy code signifying what software and version the respective vehicle is running off of.

The computer code is normally a 4 digit code with 3 letters followed by 1 number, and is printed on a white sticker present on the PCM (Until the year 2015) This computer code signifies what strategy the vehicle was running when it left the factory.

The strategy is usually a 7 digit code, and only be revealed with OEM software or tuning devices such as an SCT Device.

There are instances where the strategy can be changed or updated such as when a vehicle goes to a dealership and the PCM is updated, when a vehicle is previously tuned, or sometimes even if there is a running program update when the car leaves the factory.

It is important to give us as much information about the vehicle as you can, and if possible the strategy code along with the computer code.

This allows for complete accuracy of the tuning process.


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