v2 vortech

black94gt50 said:

I need to know if i need to do any computer tuning with the v2 vortech. My friend has got a 2002 gt 5 speed with underdrive pulleys and hypertech tuner, will the hypertech work with it, and what about the underdrive pulleys, will they work?? I've heard of the fmu that comes with the vortech, what exactly does this do? I just need to know if i need to do anything at all with the computer , dealing with tuning the car.

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Not sure if the Hypertech is vin locked like the SCT is or not. That being said, I'd probably lean more towards an SCT or a Diablosport hand held tuner over the Hypertech, since most of the technical support available seems to revolve around them.....at least as far as the Ford OBDII is concerned.

Underdrive pulleys and supercharger do not mix. The smaller crank pulley that comes with the underdrive pulley kit is designed to "underdrive" the accesories (Water pump, power steering, A/C, alternator, etc). In a Naturally Aspirated vechicle (non-supercharged) this is great thing, since you're cutting back on some of the parasthetic loss involved with spinning your accesories and are able to apply it on a more practical application to the wheels. Unfortunatly, Underdrive pulleys underdrive "all" of the accesores...including your supercharger pulley. Long story short, you blower pulley spins slower than it normally would with the stock crank pulley and in turn cuts down on the superchargers airflow at any given engine RPM. You might save 5-7rwhp with the underdrive pulleys because you've cut down on your parasitic loss, but you're in turn going to give up about 20-40rwhp because you blower is now spinning more slowly as a result.

The FMU (fuel management unit) is designed to......ah crap, I don't feel like explaining it. Here's Vortechs explanation directly from their site.......

What is an FMU?
The letters FMU stand for "Fuel Management Unit". Basically, an FMU is a fuel pressure regulator. The FMU is used on fuel injected, supercharged engines using the factory electronic engine management system.

When an engine is supercharged the air delivered to it is greatly increased. For the engine to run properly and make max power a 11.5:1 air/fuel ratio must be maintained. Since the factory electronic controller can compensate for this increased air flow (it was not designed for supercharger use) another way has to be found to supply the necessary additional fuel. The FMU is the device that does this.

The FMU is installed just down stream of the stock fuel pressure regulator. It does not control fuel pressure until the engine manifold pressure comes under boost from the supercharger. As the manifold pressure increases, a pressure line from the manifold to the FMU causes the FMU to increase the fuel injector rail pressure. The increased fuel pressure causes the injectors to deliver more fuel to the engine. With this system the stock factory electronic controller can be used without modification on a supercharged engine with good results. The reason the Vortech supercharging systems are smog legal is because the stock controller is retained unmodified and at part throttle the engine's performance and emissions are not effected.

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All that being said, I’m not a big fan of an FMU from a performance aspect. Yes, its reliable and will get you up and running, but it's not the most accurate way to measure incoming fuel and it does nothing to alter spark advance or timing curves. To really take full advantage of your supercharger set up, you'll want to custom tune the EEC via a chip or hand held tuner and swap out to a properly sized set of fuel injectors. You'll get the best drivability and fuel economy, as well as the most power out of this type of set up.

If you haven't already purchased the Supercharger, I'd seriously consider one of MPH's Mongoose Kits. They're reasonably priced, incorporate a supplied (and highly regarded tune) as well as needed fuel upgrades.