patterjl

I have a 99 Mustang GT Convertable with the following Upgrades:
4:10 Racing Gears
Mac Pro-Chamber w/o Cats
Borla Exhaust
C&L Intake System
Steeda Underdrive Pulleys
Diablo Sports Predator Tuner

I installed the Diablo Sports tune, noticing a positive Increase in performance. So far the only Modification I made to the sports tune was 4:10 Racing Gears.

My questions pertain to safe and benefial changes to "Fuel Base" and "Spark Advance". I'm not too worried about Gas mileage. I'm looking for better Racing Performance. If you can give me any Tested and safe Tips for my Tune on these subjects or any others, It would be very appreaciated.

Thanks

silver03gt

if you are running 93 try maxing out the timing, if you hear any detonation, back it off till it goes away, fuel table shouldn't be messed with unless you have a dyno with a good air/fuel ratio meter

Ostang04

don't know if you have seen this

http://www.fordmuscle.com/archives/2...cate/index.php

It is funny to think that twenty years ago, when Ford Mustangs were introduced with computer controlled engine systems, many people felt it signified the end of hot rodding. "EFI and EEC controlled engines will be too complicated for the lay person to modify", the nay sayers lamented. Obviously time has proven them wrong, and late-model Mustangs have become some of the most modified vehicles on the planet. While there is no denying that today's vehicles do indeed have more complex engine systems, the aftermarket companies have stepped up and created modern tools to make tuning and modifying a cinch.

One such class of modern tools is the handheld tuner. If electronic tuning devices were subject to evolution then the handheld tuner is to the performance "chip" as humans are to chimps. When the 5.0L Mustang came out with it's EEC-IV processor companies responded to the need for modifying the factory parameters by creating piggy-back chips which plugged into the service port on the EEC-IV processor. The chip held modified parameters to affect air-fuel ratio, idle speed, and other engine functions. While chips helped many owners of wild engine combinations solve their tuning issues, they were limited in their flexibility. For one, the chip had to be burned by someone with the appropriate know-how and burning software. Secondly, because chips held custom "one off" tunes, you typically had to get on a dyno so the chip tuner could make changes while seeing the effects. A custom burned chip would likely end up costing you $600 or more once you add up the dyno time, chip tuners time and chip cost. To add insult to injury if you made a subsequent modification to the engine, such as change a manifold or throttle body, you'd have to get the chip reburned.

Bring on OBD II
That was the Mesozoic era. In 1994 the Feds mandated all vehicles sold in the US beginning in 1996 were required to have OBD-II, or On Board Diagnostics System second generation. OBD-II is a standard for emissions systems monitoring. Since virtually all of a vehicles engine and
driveline systems can potentially impact emissions the OBD-II system is a quite complex electronic integration between the vehicles PCM (powertrain control module), sensors, and dash display. The OBD-II system can detect and display a trouble code for engine components and systems failing or about to fail. OBD-II also mandates a standard 16 pin diagnostic port, or DLC (diagnostic link connector) where technicians can plug in a scan tool to monitor virtually every sensor on the vehicle. Besides diagnostics the other benefit to the OBD-II standard is that many PCM's (such as Ford's EEC-V) can be reprogrammed, or "flashed", through the OBD-II port. Flashing or programming requires a device which contains flashing software/firmware and either stored programs, or a human interface to allow parameter modification.

Enter the Diablo Predator.
While certainly not the only handheld tuner on the market, the Predator might however be the most versatile. The unit appears as a typical scan or code-reader tool. In fact while it does indeed scan diagnostic trouble codes the real brawn is in it's ability to put a performance tune into your Mustangs brain. Note that while this article features testing of the Predator on a Mustang, the unit is also available for a wide range of Ford performance cars and trucks, including the Mercury Marauder, SVT Focus, F-series trucks and Powerstroke diesels. The units comes prepackaged with a Diablo engineered tune for that specific make and model vehicle. The unit's DLC connector is attached to the vehicles OBD-II port (typically located 16" from the steering wheel under the dash or near the center console). Once connected the unit powers up and the on screen display provides instructions for loading up the performance tune, backing up the stock tune, and making additional modifications.

The Predator provides several options. The first is to load up the tune provided by Diablosport. Like many tuning companies they have done their homework on a stock Mustang, or whatever vehicle the unit was purchased for, and come up with a canned program that will result in some increase in performance over stock. This generally boils down to air-fuel ratio and timing changes, and the amount gained usually depends on how much slack the factory left in the stock tune.

When the unit is connected to a vehicle for the first time it "marries" itself to that vehicles VIN number and creates a backup of the factory settings. Then the owner is free to load up the supplied tune, modify the stock settings and effectively create their own tune, or to modify the supplied tune. The Predator enables tuning wide-open throttle air-fuel ratios to a certain percentage leaner or richer than stock, in two rpm ranges; 2000 to 4000 rpm and 4000 to 7000 rpm. Timing can also be advanced or retarded for those two wide-open throttle ranges. A host of other very useful parameters are modifiable. RPM and speed limits can be adjusted. For automatic transmissions the torque firmness and modulation can be set adjusted for all gears. There are also several emissions related settings, such as turning off the EGR or downstream O2 sensors, for vehicles using off-road components. A nice feature is if you have modified your differential gear ratio, or installed different height tires, you can use the Predator to program the correct speedometer differential. With capabilities such as this the $400 unit begins to pay for itself when you consider the savings from having to spend on external speed calibrator devices, or O2 sensor MIL eliminators.

Installing and Testing
On our test vehicle, a 2001 Mustang GT, we loaded up the supplied Diablo performance tune, version v.7r50c. Diablo's website maintains a list of updated tunes, so it is wise to check it often for new and improved files. Using a serial cable the Predator can also be connected to a PC for downloading new tunes into the unit, or uploading the backup tune and on your laptop or desktop. The Predator also has a live data view and logging utility which is useful to see actual engine sensor data. The log can be transferred to a PC for viewing with free software available from Diablosports website.

Once the Predator writes the tune to your vehicles PCM, a process which takes several minutes, the unit can be disconnected. The tune is now permanently in your engines computer and can only be removed by the same Predator unit which installed it. The Predator unit cannot be used on another vehicle until it has restored the factory tune to the vehicle from which it was backed up. Once the new tune is written to the vehicle you can opt to make additional changes, or fine tuning.


Dyno Testing
We headed to our dyno affiliate Custom Dyno Tuning in Hayward, California to spend the day with owner Arlee Taylor testing out the effects of the Predator tuner. Arlee's shop does considerable late-model tuning, Fords and otherwise, but is actually an SCT dealer. SCT (Superchips Tune) is Diablosports competitor, so naturally Arlee had some interest in seeing how well the Predator performs. We made nearly a dozen pulls ranging from the factory 2001 GT tune to the Predator's performance tune, as well as our own variations of both tunes using the units ability to adjut air-fuel ratio and timing. Our test pony has a fairly stock 4.6L 2V motor, with the only modifications being an off-road X-pipe, Plasma Booster ignition, and aftermarket upper plenum.

We had installed the Predator tune to the vehicle several days prior to
our dyno session in order to compensate for any "learning" the PCM might do as a result of the new parameters. The idea that the computer needs to spend some amount of time adjusting to new modifications is a shaky concept used sparingly by