ILLS
Dedicated LVC Member
Shiloh - my advice (I know you didn't ask for it) - until you are running careful about mentioning what is and is not included in the kit. Focus on getting up and going - it's an exciting project and the first for the V6s.
IMHO - Tuning is an absolute must and that can only be done by a SCT tuning device (and likely a shop who tunes using the SCT products). You can get better performance by running closer to MBT (minimum for best torque) spark or LBT (lean best torque) fuelling. The LS already runs LBT fuel (approximately 12:1 air/fuel ratio, compared to the normal stoichiometric 14.6:1) at wide open throttle (or wide open pedal for 2003+). Spark is normally the minimum of MBT and "borderline" (the spark level at which knock begins occurring). This is normally the only place where there's room for improvement from the PCM. But running closer to MBT when you're borderline limited would mean running higher octane fuel. But the LS already runs on premium, so we do not have as much room to wiggle.
So you will not have as much PCM automatic adjustment to compensate for the additional air you are injesting since we are already running close to the limits in stock form - hence the need for tuning and the fuel system upgrade. Working in the cost of the additional tuner, fuel injectors, tuning, ....etc.
Think of it this way - if you were going to add N2O for an extra 75hp you should not simply add a dry system (hoping the fuel system would some how compensate and add more fuel - you would have to go wet to add the additional fuel since our fuel system are already running near their design limits. Gone are the days where the PCM and injectors has a 25% play.
So your BDT is doing the same thing - adding more air.
I'm sure Robert can explain it better....
The stock Gen2 tuning has the commanded Lambda coming in at .75 (10.98:1 AFR) then ramping up and commanding .855 Lambda (12.5:1 AFR) by 6,000rpms and above at WOT in the base fuel table. Keep in mind that those AFR's are meant for a naturally aspirated vehicle. When I retune most N/A vehicles for more power I usually bump the AFR up to around 12.5:1 across the board depending on what vehicle and engine it is. I could open up a stock Gen1 tune to compare but I honestly just do not feel like it right now.
With forced induction I usually command .785 Lambda (11.5:1 AFR) across the board at WOT to keep things a little safer especially on the stock Lincoln LS bottom end. I try to treat this thing like glass as much as possible so that minimal chance of breakage occurs. High CR does not favor boost but it can take it if it is tuned carefully. If I am tuning a lighter car with a built bottom end then I will lean it out slightly more than that. One thing for the people to keep in mind in here is that leaner does not always equal more power at WOT in a piston driven engine. There comes a point of diminishing returns; especially when looking at it from a safety standpoint.
Like Quik said, the stock components can only take so much. That stocker MAFS can only meter so much air before it is pegged. When that happens fuel goes static and that is not really a good thing if you are only 4,500rpm's into a 6,500 rpm pull. You can run a Diablosport MAFia to extend the stock MAFS range to allow it to meter the additional air coming into the engine with FI or you can change over to a different MAFS with more range. The stocker fuel injectors can only take so much before their duty cycle is maxxed too.
For anyone planning to run this BDT system or other form of forced induction, barring nitrous, for their LS I recommend that the MAFS and injectors be upgraded along with a full custom tune by a competent SCT tuner. Also for those pushing into the 325rwhp+ range I would also suggest either upgrading your stocker fuel pump or running a boost-a-pump. Your stocker fuel pump may be able to take it but it will be very close to maximum duty cycle which is not a good or safe thing. Heck, even just on 100wetshot of nitrous I was at 91%+ FPDC (fuel pump duty cycle) which is not maxxed yet, but still closer than I prefer to come to limits while remaining safe. I try to keep all items to a safe max of 85% duty cycle or less.
Good luck Shiloh. I want to see your car in action. :Beer