Okay so I have an s4 13BT that I'm getting rebuilt and ported. The engine has good compression but I'm playing it safe and getting the port done first and replacing seals if need be. But anyways,

What would be the best porting for my goals? 350? hp, mild streetport?
What internals such as seals should be replaced and with what? 3mm?

I'm looking for a reliable (lol) build that will last a long time. Thanks!

 

I will eventually be running a hybrid turbo, walbro 255, fmic, and the car already has an aftermarket exhaust. Injectors will come as well. and then a computer. Most likely haltech.

 

extend port should be fine. you get a bit of brappin idle too

 

Extended street port will give you a slight brap at idle, and a wide powerband. it really is the ideal street port since you can continue upgrading well into the 600's if you decide to go that far.

 

How's longevity? And how aggressive is this compared to a 'mild' streetport? and what seals should i run?

 

as long as its maintained meticulously shouldn't be much if at all worse longevity wise than standard. aggressive? you know what an extend port is? (actually asking if you wanted info not being a smart ***) as for seals talk to your engine builder. see what they recommend as they will know more about the rest of your setup, boost levels wanted and power goals so can make a more informed recommendation on seals.

 

Its slightly bigger than a mild port right? but how much of an increase in power would you say? Just wondering

 

its just an elongated version of a mild port. http://www.rotaryengineillustrated.c...t-port-14.html quick read for you. will be a notable increase in performance. best option short of bridgeport.

 

I made a thread on seals a while back ( https://www.rx7club.com/general-rotary-tech-support-11/what-apex-seal-use-916777/ ). I hope that will at least narrow it down for you a bit on your seal choice. I would just tell you what I'm running and what I would prefer to run but, only you know what you want to do later and whats best for your budget and build.

 

I'm gonna check that out however I'm open to any suggestions. I just wanna be able to boost and know I have a reliable setup.

 

RA classic seals if you want 2-piece seals but honestly the Mazda OEM seals are the best bang for your buck. with a good tune all apex seals are about even.

 

I just looked at that thread and it seems like a lot of people have complaints with the RA seals. At this point I'm leaning towards OEM or ALS seals

 

Ceramics are far to expensive and when they do fail it's a HOT mess. Turbine wheels need replacing housings rotors. I will never again fall into the trap of ceramic seals being some magic solution. RA seals are fine. Like I said it's more the tune your running than anything. I would go with Mazda OEM 2 or 3 piece seals. FD corner springs and an extended port. I have an engine on the shelf that I'm selling built with 3 piece seals and upgraded corners. Extended port. that has never been started. but has 90+ psi on all faces for sale. PM me if your interested.