Allen vs. SVO superchargers

AED

• 6-psi of pressure
• Unit is ported and flows more air
• Kit has large and unrestricted SHORT runners
• The boost can go as high as your willing to try
• Kit is much better engineered (except for the fmu)
• AED kit uses a 50-state legal SFPR (fmu) to control the fuel delivery
• The kit requires the fmu to add more fuel under boost
• Aleen concentrates on a quality product
• It has a one year warranty

SVO

• Eaton M112 unit
• 6-psi of pressure
• Boost increases faster because of the runners on the intake
• Intake is actually a restriction
• No intercooler
• Air is rammed-in too fast than it can be used, too high for it to be cooled
• The revised water outlet location has had some problems and the belt drive has been prone to slipping
• SVO kit has a much improved 30 lb./hr. injectors and recalibrated EEC-V
• SVO stuff is overpriced
• Needs many solutions to many install problems
• No warranty

First, boost is only a measure of backpressure. Just because a gauge reads 10 psi, doesn't mean the engine is using 10 psi of boost to make a given horsepower.

In a nutshell, yes you can get more boost out of the SVO blower since it is larger displacement. But, You are not supposed to run the SVO blower faster than 12,000-13,000 rpm. It's rotors are longer than the M90 and will flex. Once they touch, it's all over. An Eaton M90 will run to 16,000 rpm. Do the math, 16,000 times 90 cubic inches is 1.44 billion cubic inches per minute. The 112 blower times 12,000 rpm is 1.344 billion cubic inches. If you include a greater friction loss due to higher rpm, they are probably a wash for power, all else being equal. Alot of mustang people like to violate the 12,000 rpm limit.

About the whipple blower. From a friction loss standpoint the whipple blower is only worth about 10 more HP. The big advantage is in discharge temperature. At 15 psi boost, and 14,000 rpm blower speed, the Eaton M90 has a discharge temperature of 175 C, or 350 F. The whipple at the same boost and speed has a discharge temp of 125 C, or 250 F. This is huge difference in outlet temperature that relates directly to being able to run more spark. They say that Eaton is working on developing a screw (whipple) blower with Magnuson. The goal is to use the durability aspects of the M90 (bearings, seals, etc) with the added benefit of the screw being able to make more power.

The SVO blower has no intercooler and thus the aircharge gains some temperature during compression which reduces air density. The Allen unit cools the charged air and increases density. The effective air density may be about the same in the two considering the lower pressure air is cooler and the higher pressure air is hot. Heat a closed can of air and it will grow, cool it and the can shrinks, the air molecule volume is the same. Intercooling can offset the temperature rise of compression and raise the effective pressure.

The SVO uses a larger M110 unit but the Allen unit is ported and is stated to flow more air. Most tuners also say over 12psi of boost should have an aftercooler to keep inlet air temp.'s down to control detonation. I like the idea of having a computer thats programed to take care of your timing and air/fuel ratio so you don't have to use an FMU to ballpark it but for the money and the diffuculty level, the Allen seems to be the best bet. SVO's unit would not fit the Tbird without major fabrications.

Reguardless, SVO produces to the masses when the AED is not even close..so the Alen Kit is going to definatley concentrate on a quality product whenever they put their name on something. Alot of the SVO stuff is overpriced, and people get a false sense of comfort buying something designed by Ford for their Ford cars and trucks, as there is alot of stuff out there made by other companies which exceed SVO in quality, price and performance.

The AED kit shows 8-psi after 5,500 rpm on a 4.6L Mustang. It's only back pressure your seeing on the gauge. Boost begins to stack in the intake manifold, indicated by the rise in boost pressure. This occurs faster on the SVO kit because of the runners on the intake. The AED kit has large and unrestricted SHORT runners. The blower forces the air upward and through the intercooler, from there the boost is redirected into the runners (and this shot is straight).

The AED kit uses a 50-state legal SFPR (fmu) to control the fuel delivery. The kit requires the fmu to add more fuel under boost. While the SVO kit has a much improved 30 lb./hr. injectors and recalibrated EEC-V, their job remains the same. Of course, adding a smaller pulley (for more boost) is much easier on the SVO kit because of the fuel system. It's not recommended, because the Eaton 112 would be over spinning (this could damage the housing or entire supercharger).

Remember back when only the SC was intercooled. Then came ATI and the Procharger, now Vortech and Paxton have after or intercoolers. The only one who doesn't is...Ford SVO! Not to knock the SVO kit, but the revised water outlet location has had some problems and the belt drive has been prone to slipping.

The AED kit comes with a one year warranty...SVO doesn't.

On the SVO unit, air is rammed-in too fast than it can be used, and/or, too high for it to be cooled, then it expands. Hot air, get's hotter, looks like more boost on your guage, but this is actually less power. The leaner it runs the hotter it runs, so it get's very bad in a hurry(adiabatic efficiency exponentially worse). Dyno charts, and data-logging have shown this in many applications... reguardless of particular device.

The fact of the matter is, if you actually properly used 8psi of boost on an eaton M90s to it's full and efficient potential, you'll be just at or past the stock power limits of the bottom end. At 8psi on the intercooled unit, you'd be making way more power than the SVO M-112.

AED will gladly expain that their kit is actually equal in this respect to the Ford FRPP kit. The SVO supercharger's intake is actually a restriction. The SVO catalog states the M-6066-D46 kit makes 6 psi of boost. It made a 63 rear wheel horsepower improvement over stock '97 GT (Super Ford, Nov. '97), with the new EEC-V computer (included). The AED kit maded an 80 rear wheel horsepower increae on a stock '96 T-Bird (without a new EEC-V). A Tbird is calculated to have increased to 100 additional rear wheel horsepower (with minor bolt-ons).

The SVO kit is not intercooled and the belt drive is prone to slipping at high rpm. AED has been selling their idler pulley to SVO owners. Just check the Corral Modular forum. AED offers an excellent tech support staff and so does SVO, but at least you'll be on a first name bases with the Allen Engine Development crew.

The AED kit fits and works just as well, if not better than the SVO with the Eaton M112 blower.

Ed, Jerry, A-Train, RichM

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