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Extended Port - Large Street Port |
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Written by Wesley Mahler
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14.10.2006 |
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Rotary Engine Porting
Extended Port - (Large Street Port, Hyper Port)
Extended ports and mild ports are similar in specification. However, the extended port is a larger version of the mild port and works best with improved intake and exhaust systems. An extended port is slightly more powerful and a tad louder .Here; the standard port shape is enlarged slightly while maintaining the same basic shape. The
Extended
Port
is as large as you can go with the primary ports. A decent
Extended
Port
is near double the size of the stock port and will produce
Both mild and extended ports are considered "street type" ports, which offer similar drivability, economy and emission properties to standard. The advantage is anywhere up to 10% more power can be reached, with the torque range extending higher up the rev scale. This port produces longer port timing which moves the torque curve higher up in the rev range.
There is also a slight but noticeable loss of low-down torque below 4,000rpm. Typically with these modifications, the engine will start to exhibit the rotary’s signature rough idle, although the extended port’s is very slight. This modification is a popular port for most turbo charged rotaries because it doesn’t allow "overlap" as larger ports do, but it still gives maximum power to play with and letting the turbo do the rest.
Importantly the increase in air-flow ability translates to a motor having the potential to produce around 220hp. These are preferred ports for a car that's 100% street driven due to their value for money and blend of drivability and power. They are also popular for those who don’t want the numerous drawbacks of a bridge-port.
PRO'S: Good power increase while retaining drivability.
CON'S: Increase of fuel consumption and noise and the need for modified intake and exhaust systems to maximize power.
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Last Updated ( 29.10.2006 )
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