With the discussion of porting really not being advisable with the S3 SE engine, the talk of porting just the 5 and 6 ports are inruiging and so is just boring out the sleeves. With that being said, keeping drivability at its best and same with the MPG, what should I do? Mild street port, just port 5 and 6, just bore out sleeves? Thanks.

Nate

 

Here's what Mazdatrix has to say on 6-port porting...
http://mazdatrix.com/faq/port6p.htm

 

The object of porting is to increase the amount of air that enters and leaves the engine, with a corresponding increase in fuel. Don't expect your fuel mileage to stay the same with any kind of porting.

 

Get mazdatrix's streetport templates for the 6 port, port accordingly, then put a small bridge port on the auxiliary port and cut part of the sleeves out to allow them to open the bridge along with the standard aux port. Make sure that you radius the bridge port towards the entrance to encourage the incoming air to enter it. Also get the sleeve inserts from pineapple or fill the end of the sleeves with some kind of filler and radius the end of it yourself. Just make sure that the pineapple racing inserts are secured properly should you decide to use them. The auxiliary bridge port won't affect the drivability at all if you properly utilize the sleeves. With this setup you'll gain a good bit of much needed top end. Another thing that I forgot to mention is if you are going with a carb setup, use a 12A center housing because the ports are considerably bigger, especially when you streetport them but I personally would stick with EFI and the SE center housing.