ok, so i am planning to do an engine build, and right now i am just trying to finalize what i want to do.
this will be my first rebuild, done over the winter (6 months or so). i am not going to be using the engine that is currently in my car (i don't drive my car anyways in the winter), so i can make this a slow and meticulous process.

this discussion is about the 6-port non-turbo route, using a S5 13b.
my PRIMARY goal for this project will be to get a solid 200 whp

i don't see any way of getting this number without porting, which brings me to a major issue.
i had originally thought that an aggressive street port could yield this output. and yes, i have HEARD of people getting these numbers, and there are some that will argue it's possible. however now i personally don't think a streetport will cut it. so this is the main thing i'm trying to figure out.
so that leaves bridgeport i guess, but this opens up a whole can of worms, lol.
i'm still learning a lot, and have been playing around with a lot of ideas. one method that interests me is doing an agressive steetport on the primary and secondary ports, and then doing a bridge on the auxilary ports (is this what some people call a 1/3 bridge?). i'm not quite sure though if there's anyway to to retain the stock aux port system so that they still remain closed under a certain rpm? this would certainly help with the idle and also maintain the a good low end powerband.
what about those Euro-spec 6-ports? i heard they don't use sleeves...hmmm...

i have also been playing with the idea of using RX-8 or beveled rotors to get slightly more intake opening. maybe this would help get 200whp just on a streetport?


other issues:

engine management - i need SOMETHING for timing control...originally thinking of standalone (Haltech), but could i possibly use the e-manage with full fuel and ignition control? (i can get the e-manage for cheap...).

intake manifold - does the 1/3 bridgeport require a custom intake manifold? or even rather will it only run well with one?

AFM - i'm thinking this becomes an issue at this point? or maybe not, there are TIIs running 200whp+ with stock AFM...this is of course dependent on choice for engine management, but could influence whether a standalone is REALLY needed

drivetrain - will the stock NA transmission and rear end need to be replaced with something stronger? i want try to keep the weight down as much as possible, i don't feel like putting in the heavier TII components...

fuel - can the stock injectors and fuel pump handle this power level?


so anyways, i'm just looking for some advice and comments. the porting is definetly the most confusing and intimidating aspect of the build. hopefully i can get some junk irons also for practice...i'm interested also to hear how others would go about getting the stated power goal from a 6-port.


thanks

 

ok, as far as the porting issue goes I cant help you there. I'm still deciding on what I want to do with my own motor.

Engine management: Although I dont have one, I've never heard anything bad about the haltech. But you should research that one separatly.


Intake manifold: You shouldnt have to mess with it at all.

AFM: With a proper stand-alone you can eliminate it.

Drivetrain: The non-turbo unit should be fine for the power levels you want. But I'd still invest in a better clutch, flywheel, some 4.30 gears, and a good lsd.


Fuel: Upgrade the pump, and slap in some bigger injectors. You can always down tune from there with the stand-alone.

I hope that helps a little.

 

thanks for the comments. definetly a lot of the drivetrain components i will be looking to upgrade...

for engine management though, it was more of a matter of if full standalone is needed or not. i am interested in the e-manage. that's also why i was wondering how much of an issue the AFM is.
if i went standalone, i know the Haltech is good and would probably be going with that.

- Aaron

 

you want a good 200hp reliable NA. Weber 48 down draft, big exhaust ports, either a nice primary port or use a TII intermediate plate and clean it up a little, mild secondary ports, and a huge aux port. You could add a bridge, but I think if you had some well designed ports with good port timing, you will see that 200hp. Ditch the factory ecu.

 

sorry, i'm only looking at a fuel injected setup at the moment
although carbs have their charm (not to mention simplicity).
of course exhaust porting is another story, but i am more worried about the intakes right now.
using the TII intermediate is something i have heard before, could you explain further why to use this?

you mentioned a few things about the aux port, either really big or bridge them. what about my question about keeping them closed like stock until a certain rpm/load, anyone have experience with this?

 

i'm also thinking of TII housings, since the exhaust port will be much easier to work with, and i can port it nicely...

there wouldn't happen to be templates for an aux port bridge, would there?

 

the tq of a ported motor will pretty much stay the same so you really dont need to upgrade the drivetrain, syncro failures are a drivers fault and have nothing to do with the parts.

for an aux bridge to work preoperly you need a custom manifold, the more you port the motor the longer the runners have to get in order to keep the power at the same rpm.
1/3 bridge or a 1/2 bridge are pretty useless on the stock manifolds.

a streetport can easily get you to that 200+ mark if you build it properly
here is a link to a car that woudl have been over 200 if it wasnt for the leaning out isue on the top end.

https://www.rx7club.com/time-slips-dyno-128/na-6port-streetport-dynoed-195whp-update-418805/

 

yup, i have actually read that thread before, you do good work
but like i said it's not exactly easy. i am looking at 200 whp minimum...at least with a proper 1/3 bridge or 1/2 bridge there may be the potential for even more...but yeah, it's a lot more trouble and cost. maybe a streetport is still the way to go...

i'm kind of unclear on the whole custom intake manifold thing. could someone explain this a little more?
and where would i get one of these manifolds? are we talking independent throttle body style?

 

im am no expert with engine management but ill repeat whet my freind (owner of a 450hp subie wrx ) todl em abtou stand alones vs. piggybacks....basically in his view a stand alone is nice but whens its all said and done, if you have a piggyback tuned properly its going to give you about the same performance as a stand alone, mainly because the car will perform only as well as its parts allow...if those parts are tuned correctly they will be opperating at max......then u get into issues with what features a stand alone might allow you to tune that a piggyback may not......again...im no expert (and i cant spell sorry )