streetport or brigeport
Senior Member
Joined: Nov 2008
Posts: 357
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From: Czech republic
Control C........Control V
Peripheral porting is the most extreme form of rotary breathing enhancement - and it's (by far!) the loudest. Instead of conventional metal shaping with a grinder, the side ports are actually filled and completely new circular - peripheral - intake ports are fitted directly through the rotor housing and are easily identified on an engine by its tubular intake manifold.
Low rpm torque, drivability and economy are completely lost but it's just the ticket for peak power - often, over 100% improvements can be gained over standard. (Note that with really good engine management, a PP can be driven on the street quite successfully - but you'll need injector end-point setting facilities and other such management features.)
The effective torque band is also moved way up the tacho - beginning from around 5000 and building to a theoretical 10,000 rpm! (And building an engine to rev this high is another matter!) A PP won't idle much below 1800 rpm either - so by all accounts, it's a high revving and highly stressed engine that aren’t for the street.
However, in excess of 300hp can be found at the flywheel when combined with a race intake and exhaust. In order to construct a PP, the standard side ports must be filled or blocked off somewhere upstream in the intake.
Then, relatively large diameter ports are machined through the rotor housing (yes, on its periphery!) and into these are inserted aluminum sleeves that are shaped for best results with a die grinder. A sealant is then used to form a seal between the housing and the sleeve.
PRO'S: The ultimate form of rotary porting for maximum power
CON'S: Excessive noise, extensive intake modifications, very poor drivability and fuel consumption, relatively short engine life, very expensive, narrow power band
John ny
Peripheral porting is the most extreme form of rotary breathing enhancement - and it's (by far!) the loudest. Instead of conventional metal shaping with a grinder, the side ports are actually filled and completely new circular - peripheral - intake ports are fitted directly through the rotor housing and are easily identified on an engine by its tubular intake manifold.
Low rpm torque, drivability and economy are completely lost but it's just the ticket for peak power - often, over 100% improvements can be gained over standard. (Note that with really good engine management, a PP can be driven on the street quite successfully - but you'll need injector end-point setting facilities and other such management features.)
The effective torque band is also moved way up the tacho - beginning from around 5000 and building to a theoretical 10,000 rpm! (And building an engine to rev this high is another matter!) A PP won't idle much below 1800 rpm either - so by all accounts, it's a high revving and highly stressed engine that aren’t for the street.
However, in excess of 300hp can be found at the flywheel when combined with a race intake and exhaust. In order to construct a PP, the standard side ports must be filled or blocked off somewhere upstream in the intake.
Then, relatively large diameter ports are machined through the rotor housing (yes, on its periphery!) and into these are inserted aluminum sleeves that are shaped for best results with a die grinder. A sealant is then used to form a seal between the housing and the sleeve.
PRO'S: The ultimate form of rotary porting for maximum power
CON'S: Excessive noise, extensive intake modifications, very poor drivability and fuel consumption, relatively short engine life, very expensive, narrow power band
John ny
Low RPMs torque-under 2000 rpm maybe...
theres nothing like "effective torque band", every rotary(be it streetport, bridgeport etc...) comes on live in upper revs, but PP has more power/torque EVERYWHERE.
"A PP won't idle much below 1800 rpm either"... another fallacy, Mazda comp. manual says to set idle to 1000 rpms.
"narrow power band"... again, at given power level, nothing has broader power-band than PP...
All info is on this forum, just search for "peejay" and many others who have done Peripheral ports...
Joined: Feb 2001
Posts: 29,798
Likes: 128
From: London, Ontario, Canada
What I mean is that compared to a bridge port, it's more work. Yes, obviously the stock manifold works, but have you actually tried a custom manifold? The way that the runners need to be modified on the stock manifold to bring them to a semi-PP is less then ideal, flow wise. A far better option is to build a custom lower which a gradual transition on the peripheral ports from high up in the secondary runners. Or even better, a third set of runners to the P-ports, but that would require a custom upper intake as well.
Junior Member
Joined: Jan 2008
Posts: 14
Likes: 0
From: USA
does anybody know, if you do a streetport, and decide later you want more power, or something like that, could you brideport the thing, or would u have to get a whole new engine and re-due the porting?
Joined: Mar 2001
Posts: 31,837
Likes: 3,234
From: https://www2.mazda.com/en/100th/
You are really good in copying same bullshit and crap which is all over the internet-rotary related...
Low RPMs torque-under 2000 rpm maybe...
theres nothing like "effective torque band", every rotary(be it streetport, bridgeport etc...) comes on live in upper revs, but PP has more power/torque EVERYWHERE.
"A PP won't idle much below 1800 rpm either"... another fallacy, Mazda comp. manual says to set idle to 1000 rpms.
"narrow power band"... again, at given power level, nothing has broader power-band than PP...
All info is on this forum, just search for "peejay" and many others who have done Peripheral ports...
Low RPMs torque-under 2000 rpm maybe...
theres nothing like "effective torque band", every rotary(be it streetport, bridgeport etc...) comes on live in upper revs, but PP has more power/torque EVERYWHERE.
"A PP won't idle much below 1800 rpm either"... another fallacy, Mazda comp. manual says to set idle to 1000 rpms.
"narrow power band"... again, at given power level, nothing has broader power-band than PP...
All info is on this forum, just search for "peejay" and many others who have done Peripheral ports...
from maybe 1500+ rpms its got more power than a stock 12A. mileage is a bit soon to tell, but it seems like its going to be about the same as the stock 12a, or slightly better
mine is a full PP, and it is loud, and it does not like mufflers.
full PP + turbo does NOT seem like a hot idea, turbo(S) would have to be HUGE... intake and exhaust are very well connected...
why
Just tell me why the motor is gonna blow up?What makes you think that you need to rebuild a well done bridgeport over and over again?Do you know what are you talking about?do you have a bridgeport?
Senior Member
Joined: Nov 2008
Posts: 357
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From: Czech republic
yeah, my PP starts right up like stock, the CARB has no choke, so you need to fast idle it for 30 seconds before it'll idle on its own. i idle mine about 1000rpms, but it'll go down to 750-800 WITH A CARB.
from maybe 1500+ rpms its got more power than a stock 12A. mileage is a bit soon to tell, but it seems like its going to be about the same as the stock 12a, or slightly better
mine is a full PP, and it is loud, and it does not like mufflers.
full PP + turbo does NOT seem like a hot idea, turbo(S) would have to be HUGE... intake and exhaust are very well connected...
from maybe 1500+ rpms its got more power than a stock 12A. mileage is a bit soon to tell, but it seems like its going to be about the same as the stock 12a, or slightly better
mine is a full PP, and it is loud, and it does not like mufflers.
full PP + turbo does NOT seem like a hot idea, turbo(S) would have to be HUGE... intake and exhaust are very well connected...
Full PP + turbo is actually the best what you can have(both outright power/powerband), of course it takes $$ and mainly ability to tune, but again many people did it with much success.
I wouldn´t say that turbo(s) must be huge but rather well matched. Compressor is compressor and we can only produce certain power from given airflow- PP will probably max out certain compressor at lower pressure-ratio than stock/street port. Turbine must be well matched, but I think it isn´t about huge A/R ratios, but rather IMP vs. EBP. I mean, for example, every engine can operate with 1:1 ratio when compressor/turbine isn´t mismatched... And of course its about power level, it seems that anything over 500 rwhp has usually T4 housing, 650rwhp and UP T6 and always A/R over 1.0 no matter porting...
yeah, my PP starts right up like stock, the CARB has no choke, so you need to fast idle it for 30 seconds before it'll idle on its own. i idle mine about 1000rpms, but it'll go down to 750-800 WITH A CARB.
from maybe 1500+ rpms its got more power than a stock 12A. mileage is a bit soon to tell, but it seems like its going to be about the same as the stock 12a, or slightly better
mine is a full PP, and it is loud, and it does not like mufflers.
full PP + turbo does NOT seem like a hot idea, turbo(S) would have to be HUGE... intake and exhaust are very well connected...
from maybe 1500+ rpms its got more power than a stock 12A. mileage is a bit soon to tell, but it seems like its going to be about the same as the stock 12a, or slightly better
mine is a full PP, and it is loud, and it does not like mufflers.
full PP + turbo does NOT seem like a hot idea, turbo(S) would have to be HUGE... intake and exhaust are very well connected...
pro-jay special combo sale $1000 for the complete setup (minus fuel rails, injectors, etc)
http://www.pro-jay.com/WINTER-SALE-J...BHAT-COMBO.htm
What I mean is that compared to a bridge port, it's more work. Yes, obviously the stock manifold works, but have you actually tried a custom manifold? The way that the runners need to be modified on the stock manifold to bring them to a semi-PP is less then ideal, flow wise. A far better option is to build a custom lower which a gradual transition on the peripheral ports from high up in the secondary runners. Or even better, a third set of runners to the P-ports, but that would require a custom upper intake as well.
And ive noticed that 50% of the people on this site think they know everything but ,,, they really know crap im sick of arguing about it sorry and nothing personal aaroncake is just my opinion
Joined: Mar 2001
Posts: 31,837
Likes: 3,234
From: https://www2.mazda.com/en/100th/
the idle issues you've read about are probably from people who bought ex-roadracing (imsa style, carbed) setups, racers don't care much about part throttle or idle.
the thing that's keeping me from really driving is noise, need to redo exhaust again
Yes...in that case you can. In "street porting" you are smoothing out the ports for better flow and slightly enlarging them obviously. Bridging them normally involves "street porting" while adding the eye brow cuts along the outside of the ports....thus creating a "bridge port". After you bridge it...you can not reverse it, it is permanent.
Junior Member
Joined: Jan 2008
Posts: 14
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From: USA
Well I would kind of have to agree with him cause if bridgeport really does make huge power from what I have read, and he running it on a 13bt or an older engine, it would be prone to a blow out. Unlike the rew, the bt doesn't have thicker reinforced housing around the dowel pins so if the engine is making 350+ hp, the engine won't last long
Street port to keep your low end, mpg, noise levels and reliability good. It's basically like stock but bigger.
Bridge port for max high revving power, but poor low end, dumps mpg, goes brap brap brap and doesn't last as long. Why shorter lived? Besides the greater power IIRC it's because the hole is near the cooling jacket.
From what I hear most people should get a street port, but a bridge port is fine for more power if you don't mind the drawbacks and plan on revving it high all the time.
Bridge port for max high revving power, but poor low end, dumps mpg, goes brap brap brap and doesn't last as long. Why shorter lived? Besides the greater power IIRC it's because the hole is near the cooling jacket.
From what I hear most people should get a street port, but a bridge port is fine for more power if you don't mind the drawbacks and plan on revving it high all the time.
Well I would kind of have to agree with him cause if bridgeport really does make huge power from what I have read, and he running it on a 13bt or an older engine, it would be prone to a blow out. Unlike the rew, the bt doesn't have thicker reinforced housing around the dowel pins so if the engine is making 350+ hp, the engine won't last long
WTF ??? MAN TAKE THAT BACK, MAKES NO SENSE AND YOUR CONFUSING YOUR SELF
Rotorhead
Joined: Feb 2001
Posts: 9,136
Likes: 39
From: Charlottesville, Virginia, USA
yea well i have a microtech LT10 i got a 60-1 wheel and housing on my stock s5 turbo 750cc/1600cc injectors walbro 255 fuel pump frount mount intercooler 3gen upper intake manifold custom made single 90mm throttle body 3in down pipe and hks hi power exaust im using it as a weekend worrior so i can cruse it and take it to the track and woop on a corvette or when i cruse it on the weekend and just beat the ritch punk in his viper and make him feel bad you know lol
Come to think of it, even if you choose a large street port you would probably want to upgrade to a T61 turbo or similar, T4 aftermarket manifold, external wastegate, etc.
Street port to keep your low end, mpg, noise levels and reliability good. It's basically like stock but bigger.
Bridge port for max high revving power, but poor low end, dumps mpg, goes brap brap brap and doesn't last as long. Why shorter lived? Besides the greater power IIRC it's because the hole is near the cooling jacket.
From what I hear most people should get a street port, but a bridge port is fine for more power if you don't mind the drawbacks and plan on revving it high all the time.
Bridge port for max high revving power, but poor low end, dumps mpg, goes brap brap brap and doesn't last as long. Why shorter lived? Besides the greater power IIRC it's because the hole is near the cooling jacket.
From what I hear most people should get a street port, but a bridge port is fine for more power if you don't mind the drawbacks and plan on revving it high all the time.
Low end is not poor, I used to get 12psi in 1st gear on my old T-70.
MPG does not dump. I would get 15+ MPG UNTUNED. It is not a secret to get more MPG with stand alone ECUs.
I will give you this one.... It does go brap brap brap.
Finally, this is the biggest wives tale. Loooong ago back when people used to make gigantor bridge cuts too close the cooling jackets they would cause them to give out near that area.
These days it is known you don't necessarily need a bridge cut that extreme in width. More so where you position the cut in terms of how early it opens..technically the bridge cut is exposed all the time to air flow not just in the normal intake stage.
On my old 13BT...my bridgeports outlasted the rest of my engine
here we go
Well I would kind of have to agree with him cause if bridgeport really does make huge power from what I have read, and he running it on a 13bt or an older engine, it would be prone to a blow out. Unlike the rew, the bt doesn't have thicker reinforced housing around the dowel pins so if the engine is making 350+ hp, the engine won't last long
I seen pre 85 blocks putting enough power down to run a 7 second pass without cracking a dam iron,I cracked a couple and if not cuase my is bridgeported is cause of bad fuel,tune and ignition problems.OH and those older blocks arent crap at all.
not again
Street port to keep your low end, mpg, noise levels and reliability good. It's basically like stock but bigger.
Bridge port for max high revving power, but poor low end, dumps mpg, goes brap brap brap and doesn't last as long. Why shorter lived? Besides the greater power IIRC it's because the hole is near the cooling jacket.
From what I hear most people should get a street port, but a bridge port is fine for more power if you don't mind the drawbacks and plan on revving it high all the time.
Bridge port for max high revving power, but poor low end, dumps mpg, goes brap brap brap and doesn't last as long. Why shorter lived? Besides the greater power IIRC it's because the hole is near the cooling jacket.
From what I hear most people should get a street port, but a bridge port is fine for more power if you don't mind the drawbacks and plan on revving it high all the time.
Sorry didn't notice that it was turbo not NA, and AFAIK the smaller bridgeports won't compromise water jackets. There's still stuff like the mpg costing you a couple grand each year. And noise attracting cops maybe but aaroncake says that's avoidable, and of course he knows his stuff. I mean with a street port you still might pass smog, even. A bridgeport is plenty do-able, much more so on the turbo than NA, but it still depends how much you're willing to give up.
Junior Member
Joined: Jan 2008
Posts: 14
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From: USA
and this is coming from the guy who's sick of arguing and calling half the people on rx7club morons, when in fact your the moron for trying to sound smart and not have anything to back up for it.
if your gonna post something on here, have something solid to say or else dont say anything it all, it makes you sound weak
if your gonna post something on here, have something solid to say or else dont say anything it all, it makes you sound weak