Hmm, NO!

Higher sound leves = Yes
Horrible MPG = YES
Everything else = NO

 

MAXT can get a full pport engine to idle as low as 900rpm

 

How much did you spend on bridgeport? Thank you

 

Sell your car and buy a 240 if you wanna be a drifter fad dousche.

 

I have the biggest bp availible(for street use) i get anywhere from about 12-15mpg. Id have to say its worth it. COMPLETELY worth the little extra.i spend around like $180(3 fill ups) a month in gas,and im 16 so i drive all the time.My advice is have a steady job.My idle is like a normal bp except it dont go higher than 1.5k. Ill make a video of it. one more thing, the guy with reving up to 5k to take off,you might need a new clutch soon,because i take off same as you(possibly not) as soon as i start to touch the pedal it goes right to 1.1k and then i go.

 

One of my good friends got me addicted with rotaries with his 84 pp. I use his mech who gives him really good discounts, So i got it ALL done with paint and cleaning for 2k.

 

lol, I wouldn't be able to afford 15 mpg! My daily drive eats up way too much gas.

 

All I can say is buy a bike to commute with. I bought a 250 Ninja in 06' because my 7 was eating too much gas. The $125/month bike payment more than makes up for the money you save on gas. Plus then it saves your car from wear and tear.

 

I do a little over 2000 miles a month on a s5 stock port block (s4 ecu). I neve top it off. I find the added weight hurts my MPG in a big way. Half tanks for me. 10-12 fills at half tanks.

 

IMO, NA bridgeports (and beyond) are only good for two things; race cars that aren't allowed to use turbos and little boys desperately seeking attention. Given the almost complete lack of of advantages a BP engine has over a 13BT providing similar performance, it's hard to see any other worthwhile uses...

 

Better airflow characteristics then a bridge, and a streetable PP (not baseball sized holes in the housings...) will pull better and more steady vacuum.

So can almost anyone with a little tuning experience. Though at that low of a speed the engine is going to suck more fuel then is necessary and it's very difficult to compensate for engine loads (like the e-fan coming on).

 

IF you only BPed the secondary ports, would the engine idle better then if you BPed the primary port considering the secondary runners are closed? Also, if you some how kept the secondary runners closed till say 2500rpm or so, would you still have the low end power or would you still suffer a lot of low end loss due to the BP.

 

I wonder about the NA 2/3 BP. I know there's a cult following of the HBP, though I don't know how that would work in an NA application. Though, I do know a lot of people hate the NA 1/3 BP or the Aux Bridge as it's so commonly referred to.

 

I really, really wish people would understand how overlap works.

No. The secondary runners are open, it is the throttle plates that are closed. Exhaust is going to still enter the eyebrow port and fill the runner near the port. It will then be sucked in as the rotor sweeps around. Hence the lumpy idle. Though it is not quite as lumpy as a full bridge, and pulls slightly more vacuum.

That would be crazy. It would highly restrict the engine as the primary ports are tiny and have very little duration. After some porting this would be improved but they just won't have the flow.

The aux bridge is not at all ideal. If you are just going to bridge the aux ports, it's a huge waste of time and money in an NA application. And in a turbo application, a proper half bridge is a much better choice.

I did the aux bridge because originally I wanted to keep the aux port actuators functional. Moving to a larger turbo then stock immediately made that impossible due to packaging concerns, the manifold needed to be simplified and the restriction of the sleeves at high HP was to great. If I had to do it all over again knowing I would not use the aux port actuators I would have treated the engine to a full bridge. While the aux bridge clearly works for me, in an NA application there is no benefit and even my setup would benefit greatly from a proper half bridge.

Those "cult" followers of the aux bridge just don't know enough to realise it's pointless when NA, and a big disadvantage over a half/full bridge when turbocharged.

There is a major reason why the next NA-turbo engine I build (for my '76 Cosmo) will have fully functional aux ports, a minor streetport on the secondaries/aux, and only widening on the exhausts. Also a small turbo.

 

I don't totally, which is why I asked...

Thanks for the info.

 

well, in a 6 port engine, the 2/3 BP would be the equivalent of the HBP on the 4-ports, correct?

Wouldn't you be able to use a BNR hybrid turbo with the stock 6PI actuators? How would that go for drivability on the aux bridge turbo?

 

Let me get this strait....you are claiming that bridge porting the aux.port is pointless?
How then have guys around here and in NJ built some pretty impressive bridge ported NA's? I recall this past summer talking to a guy at the PanAms with a bridge ported NA (and nos) 6 port, running high 11's on the track. I honestly never understood why soooo many people are quick to judge without seeing a 1st hand display of what a 6port 13b can do.

 

^^

lol, waiting for the hammer to hit

Aaron's saying just bridgeporting the Aux ports and leaving the primaries/secondaries stock or streetported doesn't work very well.

 

No. Just bridgeporting the aux ports has totally different timing then a proper half bridge. It opens later, closes later, and flows less.

No. Even with a spacer, the turbo sits in the same space the actuators occupy. Making a custom manifold to move the turbo out is an option of course, but I'm not big on hybrid stock turbos for a number of reasons.

The drivability of an aux bridge car is exactly the same as any bridgeport. Lumpy idle, poor fuel economy down low. It's also more difficult to tune as it draws far less vacuum then a stock/street port car.

Bridge porting only the aux ports is pointless, yes.

They did a half bridge or full bridge. It's not rocket science.

Perhaps you should take a closer look at my setup:
http://www.aaroncake.net/rx-7/projec...x.html#phaseII

 

The 1/3 BP is the Aux Bridge
the 2/3 BP is the Aux and Secondaries Bridge. I'm asking is the 2/3 BP the same as a HBP on a 4 port?

 

There is no such thing as a "2/3" bridge.

An aux bridge is just the aux ports. I guess it could be acceptable to call it a "1/3" bridge but that's very akward.

A half bridge is a bridgeport applied to the end irons (which in a 6 port config includes the secondary and aux).

A full bridge includes the primaries as well.

 

I'm just thinking of it as number of ports bridged, since the 6-ports have three sets of ports, primaries, secondaries and auxillaries.

 

Yes, but those are unconventional terms and most people don't think that way.

That said, a half bridge is a half bridge no matter which engine it's applied to. I've seen a bunch of half bridged 6 port plates but have not yet done one myself. The limitation is the stock intake manifold. Everything works great at full throttle, but at part throttles I expect it to run very poorly.

 

I had 240sx at 5 years ago. So, I want to try this rx7 now. 240sx is a great drift car. Thank you.

 

a classic. First off to the thread opener, I will tell you like I told the last kid that bought his 7 and wanted to throw mods on it. Learn the girl first. Make sure she's perfect or good, internally and externally. Compression test...the works. Once you get all that out of the way, then start modding. You were going good, till you mentioned you wanted to make it into a drift car....then I lost all hope. Anyways, get some seating hours...in her. I use to be that way when I got my first 7..minus the drifting. Now, I just want another one to drive and that's it. 3rd Gen will be my bitch...or I'll be an S2k's bitch. Sad. I know.