Bridgeport info.

[Mazdabater]

Hey guys, I'm dropping the engine out of the FC next month, my tuner currently doesn't work at a workshop hes a guy from works son in law, he has built alot and is gonna be doing it with me. Just doing the research at the moment, the car is currently extend ported, running a to4z. However I love the sound of bridgeports and am looking at going that way. Not so much doing it for a power increase as I am aware that a bridge is overkill for the 450hp I'm aiming for.

Can I bridgeport it if its already extend ported?
Are turbo bridges quieter then n/a bridges?
Does it decrease turbo lag? (heard even less bottom end power but more midrange and top end)

[89fc3s]

:Suscribed:

wanting to bridgeport my n/a

[RICE RACING]

This is the basics Best to Worst

Spool response:
Stock Port
Bridge Port
Street Port

Sensitivity/tolerance to any type of normal exhaust:
Stock Port
Street Port
Bridge Port

Power band to suit stock gearbox:
Stock Port
Bridge Port
Street Port

Overall if you want response & most average power, tolerance to a normal exhaust system, best power band, nothing will beat the standard ports as Mazda made them. It's been proven many times over you can make well over 600bhp (engine power *insert what ever rwhp measure you wish for your country dyno type etc etc) on them with the turbo you are running. Bridge ports shit themselves any time you run them at tolerable noise level, street ports narrow up the power band and give you a another 500rpm peak power range but you loose a hell of allot in mid range power and spool. < If you combine the street port with a large turbo you will always loose response and mid range power.

Bridges are the worst idea ever for a road car, they are bad for many track cars too unless you can run it loud enough, and with a large enough turbo, otherwise they will make no more power than other types, but be double as loud, use twice as much fuel and generally be an outright pain in the arse. When you run it with the correct size turbo (or even the one you have) they have a really bad power band as the tq curve is flat so it will lack mid range power and only make maximum power at near it power peak, this give you less average power as you are pulling through that gear.

Best thing about turbo cars is to use the turbo and match the gearing so you have the maximum amount of power possible from your shift point to the beginning of the next gear and the only port that delivers that best is the stock standard one Mazda makes. If the power is not enough for you all you do is increase the boost pressure so far as the nature of the power nothing will be better than stock ports especially in the real world.

[RICE RACING]

Originally Posted by Mazdabater

Hey guys, I'm dropping the engine out of the FC next month, my tuner currently doesn't work at a workshop hes a guy from works son in law, he has built alot and is gonna be doing it with me. Just doing the research at the moment, the car is currently extend ported, running a to4z. However I love the sound of bridgeports and am looking at going that way. Not so much doing it for a power increase as I am aware that a bridge is overkill for the 450hp I'm aiming for.

Can I bridgeport it if its already extend ported?
Are turbo bridges quieter then n/a bridges?
Does it decrease turbo lag? (heard even less bottom end power but more midrange and top end)

If you have a look under my web page on water injection you will see a 13B bridge port RX2, this makes around 730bhp on ~27psi as a road car.
I have data of this car recorded on my VBOX equipment at a local circuit track and overlaying the acceleration on the main straight for ~600m (starting off in second gear to a variety of other car I have tested) it paints the picture of power band, outright power, response) a dyno sheet tells you little about this in reality.

Have heaps of data of another FC with bridge port and GT35R on same track and the acceleration is nothing exciting nor is the response, this was done and tuned by a Sydney workshop running a haltech recoded on the same track day too.

My tip to you is leave it, maybe post up some pictures of your ports and I can tell you some more information from there, but porting anymore in most cases will send you backwards, turn the car into an unwanted attention grabber, and not make it any faster in most cases.

[N.RotaryTech]

Just to give my experience,
I have recently half bridge ported my s4 n/a on stock ecu with 550 primary's and resistors inline with the secondary injectors circuit.

My thread: http://www.rotarycarclub.com/rotary_...ad.php?t=11402

How it drives:
It has starting issues, cruising issues, ie hesitations, bucking.
For it to drive good, I have to basically have the throttle on an off. Non of the half throttle stuff when cruising on a normal engine.
It pulls its best after 5k rpms.
I can chirp the tires on start off, and going into 2nd.
Gas mileage is around mid teens.
It is louder than my previous engine with the same RB presilencer an mufflers.

And... (thinking of anything else to add)
I would do it again.



btw: This engine pulls better than the previous s5 na.
The only thing that's different from the s5 setup is the block an the primary injectors, an resistors.

[Mazdabater]

Your sites not loading for me at the moment rice =( I'll try later. I was more looking at the bridge for the idle sound. Cars running one of the proboost to4z's and I wanna ditch it for a 42r eventually. I guess I'll wait till the engines actually apart next month, was just trying to do some research before hand. Everyone seems to have a different opinion on bridgeing.

[RICE RACING]

Originally Posted by Mazdabater

Your sites not loading for me at the moment rice =( I'll try later. I was more looking at the bridge for the idle sound. Cars running one of the proboost to4z's and I wanna ditch it for a 42r eventually. I guess I'll wait till the engines actually apart next month, was just trying to do some research before hand. Everyone seems to have a different opinion on bridgeing.

That massive turbo and bridge port = fail. The RX2 had a T51 (same shit) and bridge and while it makes stupid power, when combined with OEM 5 speed and a road car its just slow. When you compare it to others that are well set up and much milder in specifications.

nice for dyno comps and noise, but pretty shit for a road car.

To make that combo work at all you will need a dog box, close ratio's, and about $50,000 for spare motors, turbo, gearbox's, slick tires. You can get them to work but its just pointless mate, they make no power below 5500rpm at all, then they come on like a hand grenade (and that is only on low boost like 18psi. Shocking set up, poor response, then too much power resulting in wheel spin, lug it at 4000rpm out of a corner and its a nugget.

The largest turbo I would ever suggest anyone to run on the road is a T04Z or similar, stock ports, and wind the boost in you need to satisfy your power goal. If you want the brap brap brap then ignore all this advise and go with your heart

[TitaniumTT]

Originally Posted by RICE RACING

That massive turbo and bridge port = fail. The RX2 had a T51 (same shit) and bridge and while it makes stupid power, when combined with OEM 5 speed and a road car its just slow. When you compare it to others that are well set up and much milder in specifications.

wow......... someone who gets it. We should chat and exchange dyno sheets

[Mazdabater]

Haha yeah I wanted the brap brap wasn't for a power gain, was actually after more response and had a mate tell me that a bridge will help spool a bigger turbo. Guess I'll end up sticking with the extend port.

[RICE RACING]

Originally Posted by Mazdabater

Haha yeah I wanted the brap brap wasn't for a power gain, was actually after more response and had a mate tell me that a bridge will help spool a bigger turbo. Guess I'll end up sticking with the extend port.

spooling and when and how they make power are two different things, i have done lots of these things and even a bridge port with a small turbo like a GT35R or larger T04Z sill have poor mid range power, its due to the flat torque curve these engines make.

A stock port has massive mid range tq as does not so large street ports, they have a much fuller power band as a result. If you want to improve the response and take into account all the stuff I mentioned in the first post then smaller ports are always better, if your fixed with the block you have then turbine size is your only other option. There is other stuff you can do like shorter exhaust manifolds and smaller intercooler pipe lengths and intercooler volumes that will greatly increase response too.

Excessive Porting of the engine is one of the worst things, and anything you do to it in that race only category makes it much more sensitive to exhaust system pressure and we all know how rotaries hate that. Anyway don't want to come across as a know it all, but i have done lots of these cars with heaps of different set ups and power levels, street to full on drag animals running 160mph in 400m. Me and my friends who do the same talk about this stuff allot and all the old boys say pretty much the same, porting when you are talking turbocharged is one of the last things you should look at and the more you do of it the more sensitive and less usable the engine will become especially for anything driven on the street. The headaches are not worth the crap................. sorry brap hahahaha

[RotaryProphet]

Originally Posted by RICE RACING

spooling and when and how they make power are two different things, i have done lots of these things and even a bridge port with a small turbo like a GT35R or larger T04Z sill have poor mid range power, its due to the flat torque curve these engines make.

A stock port has massive mid range tq as does not so large street ports, they have a much fuller power band as a result. If you want to improve the response and take into account all the stuff I mentioned in the first post then smaller ports are always better, if your fixed with the block you have then turbine size is your only other option. There is other stuff you can do like shorter exhaust manifolds and smaller intercooler pipe lengths and intercooler volumes that will greatly increase response too.

Excessive Porting of the engine is one of the worst things, and anything you do to it in that race only category makes it much more sensitive to exhaust system pressure and we all know how rotaries hate that. Anyway don't want to come across as a know it all, but i have done lots of these cars with heaps of different set ups and power levels, street to full on drag animals running 160mph in 400m. Me and my friends who do the same talk about this stuff allot and all the old boys say pretty much the same, porting when you are talking turbocharged is one of the last things you should look at and the more you do of it the more sensitive and less usable the engine will become especially for anything driven on the street. The headaches are not worth the crap................. sorry brap hahahaha

I'll throw in my $.02.

I had a very nice stock port 12a with a set of IDA style EFI throttle bodies, custom manifold, and a 3" straight back exhaust. It made 238 RWHP @ 13.5 psi, and it felt -fast-. It also didn't spool until 4400 RPM, thanks to the rather large 70mm turbo on it. As a result of the huge turbo, the pre-spool torque numbers were very high for a little 12a, and of course once it spooled, it was gone.

Then the clutch went out, and as an experiment, we dropped in a bridgeport motor. We had run it NA, and it's balanced and clearanced and setup with carbon apex seals to rev to 12,000 RPM. On Weber carbs, it was reasonably streetable; below 3500 RPM or so at steady throttle it would demonstrate the bucking that N.RotaryTech mentioned. The power became reasonable by 4000 RPM, and at 8000 RPM the power band really started. It also felt very fast, even with stock 12a gears behind it.

Now, putting this bridgeport on, we decided to use the same intake and exhaust setup as the stock port turbo 12a, just bolted to the bridgeport. A rather oversized turbo and a bridgeport... should be really fast, right?

It felt dog slow. It cranked out just shy of 400 horsepower at the flywheel on the engine dyno... but average power across the band was lower than either the NA bridgeport or the turbo stock port. It spooled 1400 RPM faster, but that's thanks to the pressurized air-fuel mix venting straight out of the exhaust via the massive port overlap. I've never felt a car at 14 psi going nowhere fast before. Plus, it was louder, it overheated easier, it idled higher, it still acted like a bridgeport at cruise, which made it unpleasant at best to drive it on the road.

I messed with it for about a 1000 miles, and decided a stock port 13B-RE would be a better home for my turbo and nice intake setup.

[N.RotaryTech]

Just more general bridge port opinion...

I really think with these bridge port discussions, the clarification of whether its going to be turbo or n/a, should be stated first.

Ive seen a lot of discussions on this.

I feel it needs to be separated into sections.
Cause I know that turbo in it self is a whole different ball game. The turbo can do a whole lot on its own.

I was just wondering if there is such a thread like a sticky about porting in general in regards to n/a or turbo, and think there should be.

Ive seen lot of threads asking about porting, and imo i've seen answers that say (depending on turbo or n/a), turbo: will do alot on its own, n/a: bigger the better.

Anyway

Imo,
If you want the bridge port / braping & Just be aware of and ready to deal with the drawbacks.

I kind of laugh at this. For the longest time I wanted to do a bridge port, I read a lot of threads about it, almost did it before but back out, and it always seemed to me not a lighthearted decision. I think a lot of others think that way about it too.

But imo, Id say just research it, think about it, make the decision, deal with it. lqtm.

[Whizbang]

for me im solely considered with naturally aspirated applications, in which case, much of the "dowsides" remain true, but in terms of achieving more power, its different. I have to start piecing another engine for my hillclimb car some day soon (old one is a stocker with 220,000 miles or so).

[SLIDN2]

Why not go half bridge, I got a half bridge on my TII engine (NA) and I love it, this is NA tho.

We just did a 12a full bridgeport pined engine with a t72 turbo on a 83 RX7 and ran a 10.85 in the quarter mile the first pass wich got us trown out of the race park cause we had no roll bars, this was with a gsl-se rear end and street tires so there is power but this is a track car not street.

[Whizbang]

anyone know anything on p ports??