Half Bridge Questions

[12at]

I tend to disagree when i know of a certain engine builder who makes regularly between 5-700hp on pump with large extend on a 13b
 
If they are built and tuned right they arent needed.

[BlitzBoy]

:2Confused

I guess Ross@Dragon and Chris Impey@RxMotors didnt need to go Full bridge to go low 9s and 8s, I suppose all those Ozzies,Kiwis in the 8s and Puerta Ricans can chuck their bridgeports in the bin and can go back to streetports

[12at]

:2Confused
 
I guess Ross@Dragon and Chris Impey@RxMotors didnt need to go Full bridge to go low 9s and 8s, I suppose all those Ozzies,Kiwis in the 8s and Puerta Ricans can chuck their bridgeports in the bin and can go back to streetports

 
Correct i know of plenty of cars in aus that run large extend ports and run 8.30s.
 
As i said if done right and tuned right its not needed. unless you want the brap noise..
 
And if he is going to get someone to port the  motor make sure its done properly and not half @ssed like mine was.

[BlitzBoy]

Correct i know of plenty of cars in aus that run large extend ports and run 8.30s.
 

I assume we are talking 13Bs, could you name those race cars would be interested to have a look at their setup.

Been talking to a few guys in Oz about their bridgeport setups on their drag cars seems they swear by them.

Talking from my own experiance, like for like same boost same turbo I picked up 30 rwhp and approx 400 rpm earlier spool from going from street port to half bridge port

[Kash_]

As Blitzen said all the sub 9-sec Rotary drag cars are running Bridgeports.

[12at]

Go you tube Zoom Magazine "Project Racer" or GEO13B or look for s2bp videos  if you really want..
 
i made a statement that bridge ports arent the be all when a proper setup extend port can produce the same, at the end of the day if you want the brap noise then go a bridge..
 
From my experience like i stated if you get a bridge done make sure its done right. Its just like alot of the  engines here in the UK arent dowelled because its not neccessary - thats another whole topic!

[BlitzBoy]

A extended streetport may be able able to produce the same HP as a full bridge port at much higher boost levels if like for like turbos are used. But at the same boost levels a bridgeport will produce more power on the same turbo

Pros for Street port
better mpg,better idle, not loud
Pros for bridge
better spool, more power , bigger power band, cons loud, s....ty mpg

For a race car full bridge all the way in my eyes, if its street use and you hate your car being loud streetport

To quote Enzo who holds the world rotary IRS record in the 8s ...the power equation is simple... PP > Semi PP > bridge > streetport

THis thread can run and run, but its be done to death with arguments on both sides of the fence on the rx7club forum link here , be warned massive thread
http://www.rx7club.com/showthread.php?t=629931&highlight=bridge+overrated&page=1

btw

Ross@Dragon with his 9.1 second car drag car , his engine was never dowelled

[FD3S Efini]

Very interesting debate but I agree with what blitz is saying,

Admittedly I do like the heap heap sound but I\'m setting the car up for the future when I bolt on a single turbo kit on it and I personally think this is the way forward for me and the car

Kris

[Mir]

Whether it be a PP, bridge, Street or Stock PORTS, at the end of the day what matters the most is, what the actual owner of the car wants. Everyone, above, have spoken from their experience so I thought I can make a little input of my experience.

1 PP
1.1 Semi PP

2 Bridge Port
2.2 Half Bridge

3 Extended Street Port
3.3 Street Port

In my opinion, if you want a pure race car, then PP is all the way and there are several reasons, but it must be noted that with PP, the Engine life is reduced substantially... So its the call of the owner, what he really cares about-the life of the engine or pure fast car.

On the other hand, if you want a street car including a race car then you need a Street port.

I personally don\'t agree with Half bridge, Semi PP and extended street port business. All the aforementioned terms are confusing and also money making exercise-off course for the porters.

I would like to know the "power production difference" between "Extended Street port" compared with a mild Street Port i.e. Pineapple Racing Street port. I am just not convinced that, a normal street port will not attain the same power out put of an Extended Street port. Little bit of mapping and raising boost on the turbos will eventually achieve what an Extended Street port is producing. So why Extended then?

The above principle also applies to the other form of ports mentioned in the 2nd paragraph (above).

Moral of the Story.

PP
Bridge
Street

and thats it...terms before those ports are just not needed..believe me i have done a lot of research and I can say that I didn\'t find much of a difference. Pete (Rice Racing) has produced some figures/evidence and if you read those figures, you would not even want to port at all

No disrespect to anyone, just thought I should share what I think about porting..

Syed

[BlitzBoy]

I personally don\'t agree with Half bridge, Semi PP and extended street port business. All the aforementioned terms are confusing and also money making exercise-off course for the porters.

hmmmm Really you dont agree with Semi PP, hmmm you do realise the fastest 13Bs in the world including the 13B record holder run Semi PP 13B engines , high 6 second pass.

How can you not agree on something you have never did yourself Syed. In my own experiance I have run a street port and Half bridgeport and I personally know the difference and driven both and there is a difference trust me on this one.

And one tuners porting is different to another tuners porting, you can change the shape, volume ,closing and opening times. So this whole discussion is quite moot and in most instances its like comparing apples to oranges.

Another comment you made , that the life of PP engine is reduced substanially, this does not make sense, the port is no where near the water jacket like a J Port is and hence more likely to fail out of the two, I know cars with PP ports around the world and they havent been stripped down in years, PP ports have to be reliable as they mostly used in NA form in long races eg Le Mans 24Hrs, GT series etc etc

[Nik da Greek]

Surely the only real reason Mazda have consistently moved away from PP is for emissions, and frankly only the utterly ghey give a monkeys about that? The renesis is only full side ported to fudge it through emissions nazism, and even then it only just managed to squeak through at the cost of mad inefficienc and reduced power levels. Overlap FTW

J-ports and mega bridge are just a grenade with the pin out, for engines with operational lifespans measuered in minutes not years

Or am I talking borrocks. Again :o

[Grant Monkhouse]

I think semi pps are underrated, there\'s a build thread on rx7club where I read an na 3rotor, revving to 10,000 rpm is producing 450+ rwhp. Running semi pps which give the benefit to supply the engine with more air at the top end. The side ports are mildly ported. It give the car more power over more of a range.

I\'m sure blitz will have seen the thread.

Although they have built the car as a race car it is still proof that semi pps work well, this guy is even producing more hp than a full pp setup, imagine the possibilities if a couple of turbos were thrown on there?!

I think as blitz mentioned before, if you want a street car. Street port is the way to go. If you want noise and power you must bigger on ports. And honestly if you have a rotary and don\'t want it to brap away you should go buy something else.

My overlarge STreet port braps when I start it on cold days but just doesn\'t do it once warm, one of the reasons my currently being built engine is a full bridge!

[Grant Monkhouse]

Read this http://m.rx7club.com/showthread.php?t=937570 semi pps kick arse.

[Jit]

I hate my full bridge. The noise is ridiculous and it annoys all my neighbours. If you intend to drive it on a regular basis I would go for a street port

[Nik da Greek]

Perversely, the only reason I\'d entertain a full bridge is because it would make ridiculous noise and annoy my neighbours :Giggle