I've done a bit of reading up / searching on the topic of 5/6th-port stuff, and have come across the argument of 'you'll lose low-end torque' everywhere. Still, something eludes me; WHY exactly is this torque lost? is it AFR related? and if so, can't it be negated through a present standalone?

To add a little context; We run a supercharged S2000 in the local Time Attack competitions, which had it's VTEC locked to 'always engaged' and the maps altered accordingly. Same principle or different ballpark?

Hope the hear from ya

 

Charge velocity, never mind me..

For posterity and future readers; NA, Airflow, important. The NA can't fill its lungs properly through the large bore created upon wiring the 5/6th-ports open @ low revs. Same reason you don't really wanna mess with the IM runner diameters too much. Bigger doesn't always mean better. Turbo II's don't give a darn due to forced induction, thus using a 4-port LIM.