So I get questions quite a bit regarding tuning the speed density ECU in the Lincoln Mark VII. I have the D9S ECU as a reference in this topic.
Basically people are worried the ECU will not work with boost. This is inaccurate. It can indeed work on a boosted car with a little manipulation. I will outline them in this topic below.
First, you have to decide if you're setup is for blower or turbo. Also, how much restriction (boost) will the engine create. Narrow down your efficiency of the compressor based on those factors too. Base all of your fueling needs off of your findings. I am not going to touch on the multiple Scalars that need to be configured in this either.
- Volumetric Efficiency is the main focal point in the SD ECU mapping. Without complete understanding of this tables power, you will be lost. Since the SD ECU has no real time measuring ability of air being consumed or ingested, VE is what it considers the car is running at a certain load, at a certain RPM.
- Spark and timing have a few tables and functions that are important as well. These are adders and subtractors that calculate total spark based on load, RPM, ECT, ACT and BP. When the SPOUT is pulled, and base timing set to 10°, these tables and functions are the number you get delivered. More timing doesn't always equal more power either. MBT is based off of the head design on the car too. E7 will have a different MBT than the GT40 head--- and GT40P different than the GT40 Cobra head. Best practice is to run the timing and fuel that the engine wants and not what you want. Can you tune for boost on 87 octane?? Sure you can.. Is it wise? Nope..
- Adaptives are nice to have but not 100% needed in every case. If you want the ECU to calculate AND correct fueling, I would keep them going. This can be adjusted for fueling needs at any time. I won't cover too much on this yet, but the table should be set up to make corrections based on time passed at whatever load and RPM.
- Open and Closed Loop Fuel ---- Well basically this is the section that the O2 sensors play a role in. Closed Loop = O2's are doing their job at reporting, Open Loop, ECU is delivering fuel and spark based on what is set. This is where it can get tricky... Say you have your VE table to hit peak load/RPM at 3k and the table see's .95 load. If your fueling tables for Closed Loop are not on point, it can throw the fueling off. If you command Open Loop at .50 load, you have to ensure the Open Loop tables/functions are dialed in. Best practice is to command Closed Loop fueling whenever possible.. It's NOT 100% a must tho. You can eliminate the O2's all together and step back to a carb setup fuel tuning ability style and set/forget the fueling. NOT recommended unless you have a WBO2.
- Transmission Tuning is not a required part of tuning the D9S for boost as it has very little control in the ECU. You will need to make adjustments if you manual swap it.
If you need to know more about certain things, post up. I will answer whatever you need info on.
