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Originally Posted by Andretti I think if we wanted to work with our current engines, swapping out the pistons would be the main issue prior to S/C. A drop in compression at the same time would allow a higher safe boost.
You know once you start down this road, 10K would not be enough. Trial & error, matching upgrades and mods. Years of time and devotion. And suddenly it's not a DRIVER anymore.  |
You're right! I am coming to the realization that neither Ford nor any other motor company would never give up the vital engineering info on their engines, so the only way to know where the breaking point is - is to hit it! I'm guessing that unless you're a good tuner or know a good tuner, it would be wise to install or have a motorhead install forged pistons to reduce the likleyhood that your crappy tune will blow holes in your pistons. But if you're going to put in forged pistols, you might as well upgrade the rods too while you're at it, because one is essentially pointless without the other.
By drop-in compression, what do you mean? It looks like you can change the compression depending on the kind of piston you drop in? How does that work? I think 2005 Mustangs are 9.8:1??
I found a little ditty / guideline for preparing an engine for supercharger. Here she is (I think this was in reference to LS1 bodies not Mustangs):
Pistons:
Forged pistons recommended for all applications. Cast and hypereutectic pistons can be used but should be limited to lower horsepower (approx 450-500 hp) applications.
Compression ratio:
For pump gas (91-93 octane) applications, a compression ratio of 8.5:1
to 9:1 is recommended for boost levels of 8-10 psi. Higher octane fuel
will allow you to run higher boost levels, approximately 1 psi for every
2 points of octane. To determine the maximum boost level for your
compression ratio (using pump gas), refer to the enclosed compression
ratio chart.
Heads:
The same rules for normally aspirated engines apply to supercharged
motors. Higher flowing heads will help generate more horsepower than
stock heads. Supercharging produces a percentage gain in horsepower; by starting
with more base horsepower a modified motor will receive a larger total hp gain
(from the same percentage gain).Porting, especially on the exhaust side is recommended. Aluminum heads will allow you to run approximately 1 psi more boost than cast iron
heads due to their ability to dissipate heat.
Cam:
Lobe separation: 112 to 116 degrees
Split pattern: Exhaust duration and lift approximately 10 degrees and .010, respectively, greater than intake. Install cam straight up. Contact a cam manufacturer for lifts and durations that best suit your application.
Crankshaft and rods:
Cast up to 450 horsepower, forged for higher horsepower or for rpm
levels above 6,000 rpm.
Exhaust:
Headers are recommended. The size of headers are dependent on whether you are wanting to create more low end torque or high rpm horsepower.
Intake manifold:
Dual planes are recommended to improve low end torque, however may
require staggered jetting for good fuel distribution with carbureted applications.
Carburetor :
Holley double pumper w/ mechanical secondaries.
600 cfm (#4776) for up to 500 hp
650 cfm (#4777) for up to 650 hp
700 cfm (#4778) for up to 750 hp
750 cfm (#4779) for up to 900 hp
All carburetor’s will require removal of the choke assembly and choke
horn, replacement of the floats with the solid nitrophyl floats and jetted to suit your motor.
Fuel pump (carbureted applications):
Your fuel pump must be capable of supplying the proper amount of fuel
flow at the maximum operating pressure. To determine maximum operating fuel pressure requirement, add your maximum boost pressure to your initial idle fuel pressure.
Example:
(8 psi idle fuel press.) + (10 psi boost press.) = 18 psi max. fuel press.
multiplying this figure by 1.2 (20% safety factor) gives us 21.6 psi
To determine required fuel flow, multiply your total expected horsepower
by a bsfc (brake specific fuel consumption) of .65. This will give your
fuel flow requirement in 1bs/hr. To convert to gallons per hour, divide
this figure by 5.87.
Example:
(500 boosted hp) x (.65 lbs/hr/hp bsfc) = 325 lbs/hr fuel flow
325 lbs/hr / 5.87 lbs/gal = 55.4 gals/hr fuel flow
Therefore, a fuel pump capable of providing a minimum fuel flow of 55.4
gals/hr at a pressure of 21.6 psi is required.
This can be accomplished by an all electric high pressure-high flow fuel
pump (i.e. SX #18201, B.G. 400, Magna-Flow 250 or similar type fuel
pump) and a return style, boost sensitive fuel pressure regulator
(Mallory #4309 or similar). Or by using a boost referenced mechanical fuel pump only (up to 500 hp) or a boost referenced mechanical fuel pump in conjunction with a low pressure electric pump (i.e. Holley blue, Comp 140 or similar).
What if you had $10g's extra for your '05 Stang... 
