|
|
|
Contact us for details on Authorized Dealers or to become a dealer for BPT
B.P.T Direct 08 9302 3415
WE SEND GOODS ANYWHERE IN AUSTRALIA
Western Australia State Distributors of Ford Flash Tuner.
| Quality Custom Tuning Are you getting what you paid for?
What constitutes a well done custom tune?
Recently it had come to our attention about the confusion surrounding what makes the best tune. We took a donor car for analysis done by another tuning house in the Perth area and discovered some gruesome facts about what is happening out there in the Custom Tuning world.
Here at BPT we are conservative with our tuning methods and with good cause, as such factors as fuel flow inhibited by blocked filters and excessive boost can reduce your vehicles margin for correct and safe operation.
What to look for in a Custom Tune
Below is an example from another tuning house of where excessive boost has been used to obtain the desired power output levels, these levels are extremely dangerous and uncontrolled resulting in premature engine failure. Note timing adjustment via the PCM has been initiated due to uncontrolled engine knock causing power curve to look like a roller coaster.
The other killer for an engine running this much boost is the air fuel ratio, we were astounded when we had seen this air fuel ratio being too lean for the load exerted on this engine. Ideal a/f should have been around the 11.5:1 12 at the most.
How do we know what we are talking about you ask?
Well take a look at the following graph of the same vehicle that demonstrates that with careful tuning boost levels can be reduced and power maintained with manipulated timing adjustments. Also note the air fuel ratio's are at a more desirable safe level which can prevent detonation.
The power curve created by smarter tuning is more consistent and flows without interruption from detonation.
Tuning Tips B.P.T. Blown Boss 260, 290 Tuning Tips:
BOOST POTENTIALThe Eaton M112 develops 7 psi boost at 12,000rpm. Maximum supercharger rpm is 16,000rpm. The additional boost accounts for an average of 13hp per psi, depending on inlet restriction.
RECOMMENDED ENGINE & SUPERCHARGER RPMNote: At these elevated boost levels with the ultra flat torque curves of the Eaton, we do not recommend revving the Boss 4V beyond 6000. Let the supercharger work for you as it was designed. Why over rev and overstress the engine and supercharger? An extra 1000 rpm (7000 vs 6000) results in a whopping 66% higher inertial load on the rods, crank, pistons etc. Think hard about that analogy. However, if for some reason you choose not to heed our advice and insist on over revving the engine beyond 6000, then divide our maximum recommended supercharger rpm 16,000 by 6000 engine rpm to arrive at the maximum pulley ratio/boost (2.6 ratio).
SPARKPLUGSFor boost levels up to 15 psi, the Denso Iridium VT16 spark plug is more than sufficient for use. Our tests indicate that the Denso T20EPR-U groove or NGK TR6 at .025 gap will fire to 30 psi. The Denso Iridium plugs do not fire as well at high boost levels in the Boss 4V engine.
INTERCOOLER COOLINGKenne Bell was first to test and clarify this industry misconception. Intercoolers DO NOT make more power by cooling the air. That is physically impossible. Surprised? There is no way that lowering the charge temperature after the supercharger with an intercooler, a larger intercooler or ice water can increase HP. Lowering the coolant temperature AFTER a supercharger allows the engine to run more spark or boost on a given fuel octane. You can't run an ice cooler on the street for very long. That's not practical. Yes, lowering the air temperature BEFORE the supercharger will, of course, increase power 1% for every 10°.
INTERCOOLER COOLANTNever run tap water only in an aluminum intercooler or engine, unless your goal is to make it corrode and leak. Water is the best coolant known to man. If you choose to use water only, use distilled water. Coolant will not freeze, even at temperatures below 32°. Put ice cubes in a coolant container and the coolant will read 50°. Touch the probe to an ice cube and it reads 32°. As mentioned before, cooler intercooler fluid does not increase power. Cooling the air after the supercharger, with no other changes to the engine will not and cannot increase HP.
FUEL PRESSUREWarning: Leave the regulator, fuel lines, rails, and fuel line stock. The Falcon fuel system incorporates a regulator. The Falcon uses it's Speed Density and fuel pressure regulator fuel (1psi boost= 1psi fuel pressure) to regulate. The stock fuel pressure is 58psi at no boost and 62psi at 7psi boost. From our experience in tuning, that indicates the 42lb injector is all done at 500-550HP. Although 11.7 is acceptable with the right octane (AF ratios of 12.5 make best power and can be used if there is sufficient octane and the Speed Density Maps are accurate). Keep in mind that the boost increase must be subtracted from the injector pressure. Get a good calibrated fuel pressure gauge and pay particular attention to any fuel pressure drop off. New PressureOld Pressure X Old Flow Rate = New Flow Rate
IN TANK PUMPSThe Falcon uses the old style fuel system with a regulator. The Falcon pumps supply 310lbs/186liters per hour. We recommend the use of the Walbro or Fuel Miser 255 liters per hour as an upgrade alternative.
ENGINE COOLANT75% distilled water 25% coolant is best ratio vs. the OEM recommended 50/50 ratio. Nothing on this planet cools better than 100% water. Coolant is also a higher viscosity and requires more water pump HP to circulate. We recommend Water Wetter by Red Line Oil Co. which is a coolant additive that can reduce "air bubble insulation" between the engine coolant jackets and the coolant itself. When bubbles are present, they tend to air insulate the liquid from the engine metal, reduce heat transfer, impair the cooling process, and create hot spots which can cause detonation.
EEC TUNINGThere are five ways to reduce knock. Retard timing, richen the mixture, increase octane, lower the boost or lower the temperature. Retarding the timing requires reshaping the spark curve so spark advance is reduced after 2500. The downside is that you lose 3-4HP per 1 degree of retard. 1psi of boost is 13HP. The easiest approach is to install a smaller crank pulley and lower the boost-or add octane via mixing or straight 100-103 unleaded. You can "chase" knock and horsepower with a custom tune by changing fuel and spark curves (richer on top) and spark (retarding at higher rpm).
REV LIMITERSNEVER increase engine rpm limit on supercharged engines. It's higher rpm that through inertia loading places greater stresses on the rods, pistons, and crank. (12.5% increase in rpm increases the loads 50%). Let the supercharger and boost work for you. It increases power incrementally at any rpm. Never over rev the engine and hit the rev limiter. The fuel injectors are not ramped but instead shut completely off. The fuel pump remain on so there's a big fuel pressure spike. Keep supercharger rpm at a minimum by not over-speeding the engine. Another big concern is the stress loads exerted on the belt drive, idler pulleys and tensioner when the engine abruptly kicks on and off. The supercharger prefers to continue spinning when the engine shuts off. Not good.
SUPERCHARGER RPMCheck the rpm in the 1/4 mile lights and at the shift points. Divide pulley size into crank size and multiply by engine rpm. Keep supercharger to 16000 maximum. Example: 7.5" divided by 3"=2.5 ratio x 6000rpm =15000 supercharger rpm. Use the torque and HP generated by the boost of the supercharger and not engine rpm. If the supercharger rpm at the end of the 1/4 mile calculates as excessive, then raise the gear ratio (lower numeric ratio). The higher engine torque from the supercharger will pull a higher gear. The Falcon does not need to be revved beyond 6000 through the gears.
BOOSTExpect about 13RWHPper psi boost with the Eaton M112 supercharger. 1.5 octane will support 1psi boost. 1 AF ratio=2 octane. 20° ambient or charge temperature=1 octane and 1° spark advance=1/2-3/4 octane.
FUEL INJECTORS(DELTAPRESSURE) More fuel doesn't make more power by itself. Ideal air/fuel ratio makes the most power (around 11.5-12.0:1). We've seen 42 lb injectors make 690HP at 12:1 and 85 psi. Note how injector flow drops as boost increases and how it increases with fuel pressure. Yes, your 42 lb injector flow is actually only 34 lbs at 15 psi. The flow out of the injector must overcome the manifold boost/back pressure of 15 psi. Note: The 42 lb injector is 58 lbs at 85 psi and will support 650 RWHP.
NITROUSWe don't recommend any "dry" Nitrous system for a supercharged Falcon. There's no easier way to blow an engine. If you must run Nitrous; 1- use a "wet" system and 2- have it custom tuned on a dyno with an accurate air fuel meter and the necessary tuning software and equipment before you even think about stepping on it. And don't forget to monitor fuel pressure.
SUPERCHARGER SYNTHETIC OILRed Line is the best that has been tested. Documentation shows a 15HP gain and 20 degree temperature reduction from synthetic oil. All superchargers are shipped with O.E.M. Eaton oil. The next best choice is good old Mobile 1 Synthetic.
GAUGESThere are two gauges you can't do without, a boost and a fuel pressure gauge. NEVER install a mechanical fuel gauge inside the cabin.
IGNITION TIMING /OCTANE/BOOST TUNINGChanging timing (advancing and retarding) or AF ratio (rich or lean) between runs is confusing and misleading. With maximum available pump fuel octane varying from 91 to 98 in some states, it is impossible to standardize on boost levels. 1 psi of boost will require approx. 1.5 octane and 1 octane will support 2° of additional spark. Since 1° timing = 4HP and 1 psi boost = approx. 16HP, octane has a big effect on the maximum HP that can be extracted from these engines. If it knocks, add octane, lower boost or reduce total spark timing - or a combination. If your goal is to make maximum power and fuel octane is not an issue, then run 23°-25°, 12.5 AF ratio and all the boost the engine will tolerate. If there's any doubt about octane level for competition - go overboard and use 100 unleaded or a mix until you get it dialed in. Sneak up on the boost. Don't let it knock.
FUEL OCTANEWe recommend using 98 octane fuel where possible and higher in race application. A recalibration of the fuel and timing maps will be required where instances of lower than 98 octane rated pump gas are used.
LEAN MIXTURESExample: Yes, there is some power left in your 5.4 or 4.0 by leaning the engine from 11:7 to 13. Just don't go there unless you have sufficient octane and experience in tuning. We prefer to tune with timing and boost with the AF ratio set at 11.5-11.7 and avoid leaner 12-13.5 ratios. These "lean" ratios are very risky and generate relatively little power.
FUEL LEVELNever operate the vehicle in boost with less than a quarter tank of fuel. Low fuel level can cause the fuel pump to cavitate resulting in low fuel pressure. This can cause detonation that may result in severe engine damage. Get in the habit now and treat a quarter tank as if it is empty.
For More Information Contact: |
|
Send mail to
bpt@norcom.net.au with
questions or comments about this web site.
|
