My advice would be to find a shop that has a DynoJet, and tune your car on the dyno. If you are not familiar with the Predator I would either find someone who is, to go with you to the dyno. Or find a dyno shop that is a distributor for, and or licensed with Diablo Sport.
Be sure NOT to mess with the fuel or the spark advancement(AKA timing) without having the car on a dyno. If you do it could turn out to be a very bad day the first time you go WOT.
Once your car is on the dyno and you find out your A/F mixture, you will know if you need to add or take out fuel from either the 2k-4k range or the 4k-7k range.(The spreads that the Predator allows for addtion/subtraction of fuel) If your car is running lean then you have too much air and need to add fuel to richen up the mixture. Now if your car is running rich then you might want to take out some fuel to lean the mixture a bit. A guideline to always remember is that: Rich=Safe while Lean=Mean but not for long. If your car runs lean then you will usually make more power then if you are running rich, but if too lean you run the risk of damaging your engine. From my experience with Ford's 4V motors they seem to like a A/F around 12.5-13.0, while the 2V motors like an A/F around 13.1-13.4. I have found that the 4V motors like a little more fuel then the 2V motors. Another word of advice when working with adding/subttacting fuel is: its always better to work in SMALL increments rather than in large ones.
As for spark advancement/timing, it is hard to say, I have seen wide ranges of what cars like. I would start with 2 degrees increase in timing, as again with my experiecne, I have seen this to yeild the best gains on a fairly stock/mildly moded N/A mustang(4V or 2V). If you are running NOS then timing becomes a whole different story.
It is always better to tune your car on a dyno, as most cars react to changes differently than others. And use of a dyno is about the only "sure" way to know what exactly is going on with YOUR car verus just "copying" someone else's tune. Its good to have an idea where to start but just remember that all cars are unique and may require different changes than did others.
Sorry for the long post, and again this is just my advice. I am sure that there will be others join in on the post and either agree or disagree with my comments. Either way I can only post these remarks from my experiences as I am sure many have had different experiences than mine; or either the same. I hope that I have helped you with your question and as always Mach On!
