Yesterday I was reading some threads and somewhere in there someone was talking about bridge porting the aux ports and the bridge port is opened up with the 5th and 6th ports. Also they were saying how much power it would add and stuff like that... I really need some more info about this.

Does anyone have anymore info about this? any pictures of what it should look like, and does it make engine life go down a lot just like regular bridge porting?

 

How about 7th and 8th ports for the intermediate housing? opened by some extra actuators?

 

that would be way too complicated to make 7th+8th ports.

There was car from Ito that was bridge-ported on all 6 ports, and they got something around 250 at the wheels. I guess with bridged aux's and ported exhaust you might, with a lot of tuning, be able to get up to 200 whp.

 

Yes kinda, but I has not been don with succes for reason.

If you'll do bridgeport on 6 port engine, you won't be able to do a full size bridgeport because N/A housings have already 2 ports and bridgeport is actualy port divided by bridge so are you planning to have 3 ports on housing (? WTF ???) of are you planning to conect those 2 ports together and than do bridgeport on the top of them? I can't really imagine that... I think it's going to be hard, unless you'll use TII side housings because N/A housing don't have much material behind the ports, so you won't be able to go too far. The other thing is that bridgeport is very fragile due it's specific design so the car won't be streetable much, won't idle right, etc. I would say track only. Than, how about exhaust ports? You would have to get rid of those diffusers on N/A housings and those are extremly hard to grind off and port. Normally engine builders won't port N/A exhaust ports, they would require you to supply TII rotor housing. Too much trouble in my opinion!!! Just do TII swap. And that's too much trouble too! JUST GET AND TII AND THAN DO BIG STREETPORT! It will last you longer, you'll make more power and you'll spend less money/time/effort.

just my $0.02

 

Wow. Its amazing how little people know about porting 6 port motors....

 

What about the "hey look what I did" cool factor with doing something like this?

 

That is the first thought that entered my mind reading this thread.

 

And were learning everyday! There are no stupid questions...

The reasoning behind the actuators is that they can be closed during low rpms and opened higher up. Thats what I was thinking about the 7th & 8th. That way you can still have low power and get more high end power. Is there a flaw in this reasoning?

 

well if you're such a super genius about auxiliary port porting then post some information for all of us retards.

 

I'm going to defend mazdaspeed7 on his post although he really doesn't need my help.

Like every other "miracle", "new" port design that pops up here this has been done before. Many times. There is even someone on this forum that has this running in his car. The concensus is that after the aux (5th and 6th) port sleeves rotate to open there is a very nice gain in power as is shown by the car pulling harder and harder right up to fuel cut. It is a very good, usable port design. The 7th and 8th port design would add too much complication although it is original. Since the aux bridges are so small they don't kill the power band when they first open yet don't require 10000 rpms to be useful. There are so many different porting styles that there probably isn't an original one or one that hasn't been tried yet. There are 1/4 bridges, 1/2 bridges, 3/4 bridges, and full bridges. Add to that several different widths. The full bridge is the full length of all the ports. Half bridge is only one port. 1/4 bridge is only half the length of one port (this is equivalent to the aux port). 3/4 bridge is full length on one port and half length on another. Theres some definitions for you.

 

No, it's a good idea, it's just a LOT of trouble, and for a street-car it's not worth it IMO. It'd be much easier, durable, and cheaper to go forced induction. I'm an N/A guy, but the fact is, you want real power, go turbo (or supercharged).

 

...changed my mind about posting info on this topic...

 

...nothing to see here...

 

I was told by a very good Rotary builder that it would be a LOT of money for not much of a benifit. The reason they said this was that there is a positive pressure wave that is transferd from one aux port to the other, and putting a bridge on there would mess up the port timing for that.

 

I'm with Mazdaspeed7. Typical misinformation from non believers that have probably never tried what they say will not work.

 

That or just the typical joe just looking at the early 90s information that was put out about rx7s and porting. times change theories change ideas change. Get with it.

 

What if it was a forced induction on all ports including 7th and 8th port? Possibly controled by 2 small turbos instead of sequencial or just one as in the Turbo II's case?

 

Im glad it was an original idea. I was just throwing an idea out there, when you shot them down at least you gave me good reason why not and a pat on the back for trying.

 

Its not worth my effort to post information ive spent time and money to learn. The simple lack of tuners willing to push the limits of n/a motors is what has nearly killed innovation, Jim langer of RB told me 6 port motors were mild motors, and not worth modifying, especially porting. How backwards is that? The 6 port motors have identical castings on the center ports(who is the jackass who said TII housings have more casting in the first place?), and the end housings have more casting area than 4 port motors can even dream of.

The stock manifold sucks with anything other than stock ports. If you expect decend power n/a, plan on a custom intake manifold.

 

I agree with M7 on this also, there are quite a few options for different intakes for our cars, the only problem is that to use them you either have to switch to a carb or standalone and for some reason that scares a lot of N/A ppl.
And M7, there is more space to port on 6 port housings? Wow that is the totally opposite of what everyone has told me, you rock dude.

 

Bump! this got interesting while I was gone.

 

Even doing a simple street port is very complex. Bowl shape, intake opening and closing timing and how gradual or abrupt it is plays a role on the engine's running characteristics. Then there is the tournament effect taking place (why the S4 manifold has curved loop shaped runners as opposed to S3 square runner paths near the surge tank). . sixth port sleeve blunt flowless design . . restrictive throttle body and especially the mass airflow sensor . . and if you have a cone filter w/o a real cold air intake you will only get its full benefit before the engine bay warms up.

Stuff like that is what you work on with NA motors. It is all in the details.

 

I've thought about this for awhile too, i thre this together real quick. The main problems would be;
1. 6-port sleeve size would restrict flow and minimize any gains
solution: You could use a european style LIM, possibly modifyed with bigger butterflys and hod the 6-port holes out, or build a custom LIM like the Europena 6-port model, also a bit of extra flow ccan be found by skellitonizing the existing 6-port sleeves, but not much.
2. Because the bridge is so high up the port would open far latter than a full bridge
solution: In the attached image i put the point which i think is the lowest you could go, the last area of the aux bridge wouldnt be directly connected to the runner, but just scored in, you could probably get say, 40-60 degrees BTDC
3. The AFM and runner diameter would be to restricive.
Solution: The runners wouldnt be that bad, and if they were you could either port it, or use a s4 manifold, The AFM problem however, is a porblem, one people have only solved so far with stand alones, some oneneeds to take a larger AFM from some car and modify it to work properly on out NA's

 

The TB is not a restriction. It is huge compared to most cars. The intake runners are a restriction though. Like I said before, the runners become an issue with SP's. And on top of that, a BP requires different runner lengths to be tuned. The stock manifold(esp the S5) is WAY off on runner length for a bp. And with a BP, anything other than a free exhaust will choke power badly, much worse than any SP because of the overlap. So using the stock ECU is out.

 

I just said that if you want more power on your street car you should consider something else than porting... TII swap or buy TII, etc... That's it! PERIOD!!!
Porting and building engines is not that easy as it might look for someone. I'm not saying that it's hard, but...

:mazdaspeed7: are you sure you know what are you talking about when you say this: quote:"The 6 port motors have identical castings on the center ports(who is the jackass who said TII housings have more casting in the first place?)"
I really doubt that you ever seen 6PI and TII intermediate housings!

I don't come here to read insults from closeminded people, I come here to share advices and informations about our cars!