Above: (Left) Inside of the Ram Air fan housing. (Right) Stock VW 36hp.
RAM AIR RACING FAN HOUSING SNEAK PEEK! (patent pending)
Above: (Left) Prototype Housing, exact size of stock. (Right) Stock steel housing. The 36hp unit is not an insert like the center mount. It replaces the heavy steel fan housing.
Our center mount fan housing plastic insert was a success. We've been road racing on ours and distributed a few to private racers for track testing. The high-temp ABS material has not warped, not even the thin lower edges close to the cylinders. The ABS can be warped, but it would take over 400 F. + sustained heat to do so. And since cooling air fills and routes through the housing, it protects itself.
But people were asking for a more conventional 36hp style housing with the same "ram air" features.
Top view of the housing shows ram air ducting. This design gives as close to even left and right cylinder bank cooling air distribution as you can get in a single-plane housing. The only thing better would be Raby's DTM blower housing.
Bottom view shows directional vanes. These act like the OEM thermostat flaps and direct the air to the cylinders and heads.
The Ram Air housing is in test now on the engine stand. We've already learned the alternator mounting to the fan housing is strong enough. The weight of the alternator is on the alternator/generator stand. No stress is carried by the very light fan housing.
This is a racing part only. There is no provision for a fresh-air heater, and either an oil cooler block-off plate has to be used or a oil cooler replacement in-out adapter. And even being of a specialized plastic, it will never endure for decades like a steel housing. Those who use this housing want the light weight and superior (to stock) forced air distribution.
It's beyond this short post to delve into our instrumented test procedures, but a fan housing project isn't a guessing game. We use a digital anemometer, VDO head temp sensors, and hand-held infrared readers.
We expect to have prototype housings and prices available soon. The center mount inserts, now proven, cost $175 each. Ram Air housing prices will be a bit more.
