hey guys, im getting my 91 13b turbo fc motor streetported. what kind of hp increase should i expect? im still using my stock turbo.

 

Easy question...
A bit of research and you'll find you answer

 

Hey Jake,
As far as I know, a street port can gain anywhere between 10%-20% gains in horsepower over standard but I believe porting is more effective with higher flowing components such as exhaust.

There's a really usefull website on porting here Porting

 

I'd say the reason of a better mileage at higher speeds, if streamlining or Cx doesn't enter in action for increasing fuel use, is that at full throttle, and at the rpm regime of top torque, Volumetric Efficiency, Mean Effective Pressure and the result, fuel economy are on its best. The people in German Wankel Club reported that when studying the KC-27 Sachs RCE of an Hercules W-2000 motorcycle, with a catalyst, these engines do better with a three way catalyst, air injection in the middle, as stated in SAE journal for 2-Strokes, year 2000, the oil added makes the difference with an ordinary reciprocating engine, exhaust gas temperatures were lower at top power, and this is connected to what happened in early days of car and aviation engines, H Ricardo hadn't discovered yet the mechanisms under detonation, and gasolines were of poor quality, and never uniform in features, so exhaust valves and seats had to be grinded after a certain number of miles or hours of work, the lower the effective compression ratio of an engine, the higher the exhaust gas temperature is.

At 3'000 rpm of shaft, the Rotor is making 3'000 admision strokes/min, but as the time in the intake stroke of an RCE is longer in terms of grades of shaft rotation than in a reciprocating engine, perhaps this allows to some back flow of mix to the intake maniffold, or to not so good replenishment of chamber.