Pulleys:
If the supercharger belts slip you can loose a lot of power so it is very important that they do not. To test if the belts are slipping simply made a few wide open acceleration runs so the supercharger is pumping full boost for 30 seconds or so then pull over and turn the engine off and feel or measure with a IR temperature meter all pulley temperatures. If any are warmer to the touch then the water pump pulley they are slipping.

A simple cure is to sand blast the pulley groves with a coarse grit media and replace the weak stock tensioner springs with Magnum Powers New High Pressure Tensioner Springs, a set of two is only $40 plus shipping.

We recommend Gates Green Strip Belts as they have less of a tendency to slip then any others tested, you can order them from Fast Specialties, see our dealer list.

Aftermarket Pulleys:
There are lots of aftermarket pulleys out there that slip because the belts after a little wear bottom out and begin slipping badly. What do we mean by "bottoming out"? Micro groove belts work because the angle of the groves creates a "wedging" action as the load applied to be belt pulls the belt into the pulley groves. If the tips of the pulley grooves touch the bottom of the belt's groove (root) that contact will keep the belt from wedging, unloading the angled part of the belt causing slippage. Magnum Powers pulleys have a unique shape that eliminates the possibility of the pulley groove tip from reaching the "root" or bottom of the belt's groove. Even the stock supercharger pulley is make such that it can slip also. To determine if your pulleys are slipping inspect the tip of the pulley groves and the "root" of the pulley groove to see if it is shinny or dull as the angled part. If tip and root are shinning it is a sure sign the belt is slipping and polishing the metal. A cheap solution is to chuck the pulley up in a lathe and take a pass across the pulley tips creating a flat .040" wide. This will not help if the belt is also bottoming out in the pulley groove roots though. Also inspect the belt for signs of slippage, if the root of the belt grooves are smooth or rough as the angled part. The MPIII flows more air then the MPII or "S" model supercharger meaning more boost. If the pulleys are slipping they can act like a governor limiting boost and HP.

Supercharger overdrive ratio :
The MPIII is a high speed supercharger. The long duration intake and exit ports allow the supercharger to be spun fast without loosing volumetric efficiency thus allowing the MPIII to force more air into the engine, if it is spun faster. The faster the MPIII is spun the more air it will force into the engine. Stock engines with proper exhaust, fuel injectors, MAF, fuel pumps and dyno tune should run at least 15% overdrive. Built motors should run 20% minimum or more, up to at least 30% over the stock T-Bird SC overdrive ratio. If you are interested in making serious HP give us a call as we can make you a 20% Jackshaft pulley that will not slip that along with our 10% crank pulley will give you 30% overdrive ratio with the stock supercharger pulley.

Exhaust:
For the street we recommend an exhaust starting with 2 ½" pipes from the manifolds to a single 3 ½" free lowing muffler back and splitting out to 2 ½" again behind the rear end to two 2 1/2" free flowing mufflers.

If you are looking for maximum power we recommend headers and dual 3" exhaust pipe running through 2 Flowmaster mufflers without a cross over pipe. Kevin Leitum used this setup when he made his record setting 11.30-second pass.

Fuel Injectors:
42# Injectors are good for 375 rwhp and 50# injectors are recommended above that power level.

Bypass Valve Actuator Adjustment :
When installing the MPIII Intake Plenum and Bypass Valve Actuator ensure the spring in the actuator is pressing the bypass valve lever against the stop set screw when the mounting bolts and screws are tightened. The stop setscrew is set at the factory at the "closed" position. If the lever is away from the set screw when the engine is off the bypass valve will be open some amount allowing boost pressure to leak past lowering boost and HP. It is very important that the Bypass Valve Actuator is adjusted and mounted correctly.

Spark Plug Gap :
Air is an insulator, the higher the boost the denser the air is in the cylinder and the more air molecules there are between the spark plug's electrodes. Therefore when running high boost it is important that there is enough voltage to jump the gap. One simple way to ensure your engine does not miss under high boost conditions is to gap the electrodes closer together. If you are running 18 psi boost, as you will if you are running 15% blower or more OD, we recommend you gap your spark plugs to .028".

Overheating :
There has been some reports of the engine running hotter then normal in the summer if the MP FMIC is used in particular when running at highway speeds. This condition can be caused by several factors. First check to see if the black plastic air dam beneath the radiator is in good condition and present. If you car has a cowled hood block of the vents as they pressurize the engine compartment and inhibit good airflow through the radiator. If you car has been lowered there will be insufficient area for the air leaving the radiator to escape causing overheating. A simple solution is to install an additional air dam beneath the car that will create a positive pressure in front of the radiator and a negative pressure behind it. We can make an air dam for you. Call MP at 503 357 5444 and speak to Charles as we can help cure your overheating issues.

Not Making Expected HP?:
If you have problems making the HP we advertize please give us a call at 503 357 5444 and I, Charles Warner, will be happy to speak with you and walk through the process of figuring what is wrong.