nofxpunk_541

what is streetport and bridgeport?, or not so much what is it, what is the difference, and how much do each usually cost?

Project84

http://www.mazdatrix.com/s.htm

that page will have a list of different types of ports with pictures. Porting means opening up the intake and exhaust ports. Its similar to increasing the cam timing on a piston engine.
On a rotary, the bigger the port, the sooner it will open and the later it will close. This means that more air/fuel mixture will enter the rotors chamber. More fuel= bigger boom.
Increasing the size of the exhaust gives the extra gases time to escape. Again, the sooner it opens and the later it close gives it a longer open duration.

O 16581 72452 5

Do a search, this has been discussed numerous times. Do NOT bridgeport a street car unless you want it practically undrivable and you don't mind rebuilding it every 30k miles or so. If this is a street car, use a streetport.

851stgen12a

I am going to have to say I disagree very strongely with this statement.
A buddy of mine in our local rotary club, has a PP 12a in his 1st gen. Has about 60,000 miles on it (mostly street miles). The car is first an formost a race car, and second a street car.
He receantly drove the car from WA state, to Florida, and back. Said he averaged 20mpg, and zero problems the entire way.
It simpley comes down to how the motor is built, and how hard you drive it.
I know numerous people running BP, and PP motors as halft time daily drivers.

BUT, if you are using the motor as a daily driver, and you go BP, your fuel milege is going to drop very dramaticely.

Also, with a PP or BP you will have to have a completly non restrictive exhaust, which means it will be pretty damn loud.

So really it is all about what you want, and what you want to do with it.

Micah

O 16581 72452 5

I was going by what i've heard, not what i've expirenced.

Rotary7s

I have to pull the bullshit flag on the 20mpg on a PP 12A.I dont think I was even getting that on stock ports.. thats to long of a drive for a PP..on a straight run..


BTW
*Also, with a PP or BP you will have to have a completly non restrictive exhaust, which means it will be pretty damn loud. *

The intake port..has nothing to do with exhast port..I can have a bridgeported engine allday..if you dont **** to the exhast it will run like ****..the intake port work is difrent from exchast.. I can run no exhast sleaves on a street port...But why?

I got to see the numerous people you know runnning PP as a daily driver..


Where are they..

Fennix_sr

i think he meant 20mpg on the highway... that still sounds prety good for a PP but i have no experience so...

REVHED

PP's actually have better BSFC under load than stock ports. It's generally at idle and light load that the fuel consumption suffers. So 20mpg on the highway is possible.

No ****. He meant that you need to have a very free flowing EXHAUST SYSTEM for the engine to make decent power.

I've known many people who have run bridges and pp's on the street over the years. A mate of mine has a fuel injected 13B pp in his Rx-3 at the moment. 150db's a pure terror.

79+80+84_rx-7

can you even use stock seals on a PP?!?



If so.. Can you cut the ports to make power at 3500-8500 and for best use with a turbo?


Just curious....

851stgen12a

Thank you Revhead.
Yes thos gas milege figures were from the freeway. Hence, driving to Florida and back. He did say that it was getting somewhere around 6MPG in the city.

REVHED

Yep, by changing the size and style of porting and tuning the intake and exhaust systems you can change the powerband. Read this thread... https://www.rx7club.com/forum/showth...hreadid=202924. 13B pp making good midrange power and peak power of around 270hp at 8400rpm.

12abridgeport

I know a guy he used to have a 12a PP with factory seals and a 140 shot. He said he was shifting it around 9.6-9.8k rpm.

I think that with a small enough turbo PP, it would be possible to make it peak out around 8500k.

79+80+84_rx-7

umm... KICK ***!


So I can use factory seals and springs?

Directfreak

iTrader: (2)

Everytime I hear how someone wants to have a daily driver full bridge or PP, I am pretty sure that these people never heard them in person.

You guys don't understand how UN-FUCKINGLY LOUD these things are with the free-flowing exhaust.

Streetable? Not Really.

79+80+84_rx-7

loud ness doesnt bother me........ just keep the revs down by cops..... im running around basically with straight pipe off my header on my ported 13b... sounds goooooood!


I have heard bridgeys before...... SEXY!





Laterz, Andrew


If you turbo'ed a pp that was cut to make a decent power band with the turbo, ect..... wouldnt that turbo muffle the exhaust noise, and then have 3" all the way back.. so it would just sound like a turbo rotary?


Thanks, Laterz, Andrew

12abridgeport

Even though i do have another beater car, i love driving full bridge on the street...and stop lights don't bother me at all when i'm in it However, i do have to watch out for the cops. If i see one i try to turn somewhere.

rcurrier44

There must be a big difference between a turbo and non turbo system. I know there is with desel trucks. My 12 a with just a header is ungodly loud. It is running a 600 holly with a prety agresive street port.

Oh my F--king God! I had ear plugs in when we first started it up and it still hurt my ears. With a 2 foot exaust (3.5 inch) and a high flow muffler it is tolerable, but still very loud.

bliffle

Is it just a foregone conclusion that improving breathing will make an FB loud? And reduce gas mileage? What's the worst noise, turbo or improved NA?

I want to improve power on one of my nice FBs, but don't want to make it (much) noisier, and don't want to suffer MPG too much either. Else I'd have bought the nice SE I looked at the other night.

What I want to end up with is an FB with a little more on-demand power, but the same smooth corner-hugging ride. A little more throat in the exhaust sound is just fine, but I don't want a lot of mechanical noise. I used to have cars with lots of mechanical noise, and I enjoyed it, when I was 30, but now I want a smooth quick car for the tight roads around here.

B

Chemical

Is it possible to turbo a PP.. Wouldnt that just blow the mixture right out of the combustion chamber?

REVHED

Scoot secondary pp turbo... 700hp.



Does that answer your question.

The most powerful tubo engines are full pp BTW.

rotarygod

iTrader: (1)

Actually to whoever said it, on an engine with as much overlap as a peripheral port or a bridgeport, the exhaust port has everything to do with the intake port. A free flowing exhaust will most certainly help the intake out by creating a lower pressure zone in the engine which in turn helps to suck in more from the intake. Before I write a book on the subject I'll just stop there.

JLIU

Hello Fred:
How is going? I really enjoy the RB exhaust. The only thing I had to do was to wire the actuators open as there was not enough backpressure to open them with the RB system. Have you finish your turbo project yet?

Jeff

alien_rx7

Are you talking about the guy that went to the Grassroots $2003 challenge? I love the trailer he has for hauling the rest of the stuff behind the 7

The_7

have you ever heard of someone running a street/bridgy and PP at the same time? you could have the street port or bridge run for low and midrange and in the high rpms the PPs kick in while still using the other ports.

rotarygod

iTrader: (1)

Whats going on Jeff? The 6 ports worked fine on my car with that exhaust. I kind of miss it now that its gone. Turbo FB project is still under developement. The V-mount intercooler system on my 2nd gen has been getting the funds lately.