Surprised me the first time I read it. Makes sense though. I believe Porsche also uses a similar system. And the Sportsters have no less than 5 intake ports. But according to my testing they are not high rpm runners as you would expect but rather low rpm grunt machines that just love big props and plenty of nitro. For example my K&B Sporty .20 makes 12,300 on a 10X5 Master Airscrew on Sig 15% nitro 20% castor. That is 4.32 lbs thrust at 58 mph. That should pull around my HOB Mustang well.