O.K. here is a rundown on my PCM modifications.
the trick piece is a Tweecer, this device when fitted to the J3 port of the Ford PCM enables the factory tune to be mirrored into the Tweecer.
the Tweecer RT is the particular model i am using as this one allows for changes to be made, it also will store 4 different tunes and revert back to the factory tune by the turn of a knob.
the time that it has taken to get to this point has been long and arduous due to the afore mentioned PATS and a lack of strategies that are known to work with this PCM catch code, but now we have cracked it, the door is wide open.
this endevor could not have been undertaken if it was not for the exceptional assistance of Mike Glover the inventor of the Tweecar and indeed others that have been enlisted with regard to code cracking and fuel and spark requirements for my particular set up.
there are no set tunes available as yet to run the M90 supercharger on a 2.3 duratec from anyone as far as i know, but this seems to be strange as it should be a common mod.
the duratec has a floor, a big floor in that it only uses friction washers to hold the timing gears in place and is a disaster waiting to happen, the washers are designed to grip the crank, sprocket and damper and prevent it from moving, i have to ask how a diamond encrusted washer will embed itself into a sprocket that is so hard that it can't be machined for a keyway and to get one with a keyway needs to have it spark eroded, fortunately Cosworth make such a device among others so all you need to do is have the crank machined with a keyway and likewise the damper as this is controlling the spark.
the crank machining will cost you around $150 as this is mostly setup time, alternatively the is a setup from Massive which has the sprocket and crank pre machined for a woodruff key but it is a smaller key at 3mm than the Cosworth one at 5mm, i do not know if Massive do a keywayed damper.
in my case the blower needs to be slowed down but i cannot fit a larger blower pulley due to hood clearance so i will be using a smaller crank pulley, these are available from Cosworth with a keyway to suit their 5mm key or with no keyway from others but are made of aluminum and i doubt if sufficient torque could be applied to the crank bolt without distortion when trying to tighten the bolt with friction washers.
GOLDEN RULE FOR A DURATEC REBUILD !!!! IF THE CRANK HAS TO BE REMOVED FOR ANY REASON< GET A KEYWAY CUT IN IT OR BUY A PRE KEYWAYED CRANK!!!!!
a new pre keywayed crank is available from Massive together with a sprocket.
crank = $365.77 sprocket = $79.93
if the above operation is not done , then you may have a disasterous failure, its called insurance, i know that some are getting away with it but if Cosworth see the need then they have a reason to do so.
i believe that this is the reason that supercharger kits are not readily available for the duratec, they have been in the past so i can only assume that some have got their fingers burnt and discontinued them in favor of a turbo set up.
i will be going with a Cosworth sprocket with the larger key 5mm, as i am also driving the blower, it is more expensive at $140.00 but again insurance.
while the motor is apart, i will also do some other improvements, a thick head gasket from Cometic at .051" instead of .018", forged pistons and forged rods.
the cams and valve gear will remain stock as i do not feel the need to spin the motor above 5000 rpm
the above changes should allow a little more boost at peak 8lbs. and slow the rise in boost a little to make it "softer" to drive.
the engine runs in closed loop most of the time so is quite economical and only makes boost if you get on it. due to the bypass system the cruising load of the blower is minimal.
so the advantage of using a factory computer and a Tweecer are in my opinion, parts replacement, starting with a stock factory tune the ability to have everything work from day one, no modification to the factory engine harness, total control over fuel and spark maps, ability to return to stock tune with the turn of a knob, all the things that the factory PCM offers like electric fans, rev limiters and the flexibility to run mass air with all the self tuning that closed loop offers.
you just stick it on the J3 port, download the stock tune and save it in the free software, reload the tune to the software with a new name, make the changes you would like and upload to the Tweecer, you will be uploading a modified factory tune with only the changes you have made, everything else stays the same.
yes there is a learning curve to tuning but the engine starts with no inputs from you other than making the needed engine connections and with a factory harness then turning the key, if the motor is stock or close to stock it will start, run and idle with an A/F ratio of around 14.8 - 1, how long does that take to achieve with mega squirt, then you can fiddle with it to your hearts content knowing you can always go back, even change injector size if your tune needs it as in my case.
you can check your changes in the software and datalog when driving, the hardest part of this to me was getting round PATS and learning the software.
in the future i will be adding some intercooling which will require a total re design of the intake manifolds and blower mounting, this will affect my tune somewhat but i can make adjustments to the tune in the Tweecer to compensate, being the factory based tune, moving the intake air temperature sensor to the boost manifold should then compensate for the cooler charge temps automatically in closed loop and my modifications should only need to be made in open loop boost conditions.
_________________ this story shall the good man teach his son, and chrispin chrispian shall ne'er go by, from this day to the end of the world. but we in it shall be remembered.
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