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Bridgeport vs. 1/2 Bridge ?

Old 11-05-06, 02:34 PM
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So I've been driving my car for two weeks now, and it's great.

The idle scares away all the ricers. Women and children cover their ears, old men shake their fists and dogs cower in fear...

The car will cruise all day at 2K RPM withou much drama and there's absolutely no lack at all of low end. With the stock turbo, it will spool easily at 2K under medium throttle. I'm still working out the injector staging with the 720cc/1600CC combination so above 4K it's a bit (OK, stupidly rich) rich but after 4K at light throttle (keeping only the primaries online) the car just comes alive....
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Old 08-01-07, 01:16 PM
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so i think im convinced. after reading this im thinking a streetport. now i need to do some finding on streetports and find out which would best fit me. thanks everyone
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Old 12-15-09, 08:19 PM
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intresting
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Old 01-04-10, 10:27 AM
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Aaron so what about that aux port ever do anything with it? I Might just go Full bridge n standalone
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Old 01-04-10, 02:15 PM
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Not sure what you mean. My car has been running for a long time since I commented in this thread. I do wish that I had ported down more with the bridge instead of keeping it artificially small in the idea that I would make valve-controlled bridgeports (which I didn't and don't plan on) but I can't complain at all about how it turned out. Over 400 RWHP on low boost, 500 or so at 16 PSI.

To anyone doing a bridgeport I would suggest a half bridge (secondaries only) or a full bridge. I honestly don't see the point anymore in half-assing a bridgeport. Nothing wrong with half bridge of course, but a full bridge makes more power with only a slight decline in idle quality, mileage and vacuum compared to a half.
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Old 01-08-10, 09:37 AM
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with 6 port irons, do you wire the 5th n 6th ports open? do you even bridge 5th n 6th ports? Im asking on a full bridge not half
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Old 01-08-10, 11:20 AM
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Sorry for the ?'s but if you go Half bridge the 5th and 6th ports still work right? That might just lean me toward half nstead.
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Old 01-09-10, 11:00 AM
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With 6 port irons, the aux ports will need to be left open. The sleeve will need to be removed. The bridge will extend a little into each aux port. Start with a 4 port bridgeporting template as a guide.
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Old 01-09-10, 11:34 AM
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thanks
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Old 01-10-10, 10:49 AM
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I'm bridgeporting some GSL-SE 6 port irons this weekend so I will post pictures in this thread when I have finished to show you what I am referring to.
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Old 01-10-10, 02:30 PM
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Regarding spoolup, has anyone actually done some true, no BS back to back tests with different ports?

In the import scene (Rotary and Piston) all I hear is people saying/thinking that bigger ports, more duration, more overlap, etc HELPS spoolup, and its due to more gas getting in and out, but from countless turbo cars ive played with over the years (all piston, hence the question), this is complete BS, and though maybe they will spool faster once actually in the boost threshold, the boot threshold (and powerband in general) is actually raised with bigger ports and more duration/overlap, and less torque too.

Look any any turbo race car, Offy Indy engines are a good example, very little need for low power, and even at the level where they was pushing around 1000bhp, the cams were what most JDM tunng people call "stage1" mild cams, about 264 duration. Personally, coming from a non-JDM turbo tuning background, id call 264 pretty fookin hardcor on a turbo car.

And because of all this, the Bridgeports help spool thing is something ive always been mega scepitcal of, and its true or false depends who you listen to.

Soo... Is there any true back to back testing on this?
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Old 01-11-10, 04:10 PM
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Bridgeports do indeed make a massive difference. The short technical explanation is that the misfiring at lower RPMs caused by the dilution of the intake air/fuel causes higher pressure chambers, in addition to more afterburn. Both those create a more powerful exhaust pulse.

I have run the same turbo on a stock port vs. a bridgeported car. Night and day difference.

Anyway, here are the pictures of a bridgeported 6 port iron I promised. I took them with my Blackberry (forgot my camera) so excuse the quality. I RB 4 port bridgeport timings and just ran the bridge above both the secondary and aux intake ports.





Attached Thumbnails Bridgeport vs. 1/2 Bridge ?-img00005-20100109-1526-medium-.jpg   Bridgeport vs. 1/2 Bridge ?-img00008-20100109-1533-medium-.jpg   Bridgeport vs. 1/2 Bridge ?-img00014-20100109-1634-medium-.jpg  
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Old 01-11-10, 05:09 PM
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Thanks Aaron, I had seen some that do two diffent bridges but I like the way these look. And you do the same on the 3 irons?
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Old 01-12-10, 09:36 AM
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The engine I posted is a half bridge engine, so only the end irons are bridged. It's actually a pretty healthy bridge. It cuts into the housing about 1.5MM. First time I've had to notch housings.
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Old 01-12-10, 10:23 AM
  #165  
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Nice job, Aaron.

B
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Old 01-13-10, 04:29 PM
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another question, I could get some Tll irons. Would it b worth to get the 4 port irons n bridge port them or just do it with the 6 port irons?
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Old 07-27-10, 01:46 AM
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Originally Posted by Aaron Cake View Post
The engine I posted is a half bridge engine, so only the end irons are bridged. It's actually a pretty healthy bridge. It cuts into the housing about 1.5MM. First time I've had to notch housings.
Has anyone bridged the primaries for a half bridge instead of the secondaries? Just making sure that the corner piece faces the correct side. Or is it better flow gains to be found by bridging only the secondary irons for a half bridge application.

just curious.
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Old 07-27-10, 08:47 AM
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Originally Posted by fidelity101 View Post
Has anyone bridged the primaries for a half bridge instead of the secondaries? Just making sure that the corner piece faces the correct side. Or is it better flow gains to be found by bridging only the secondary irons for a half bridge application.
just curious.
That would be silly. You'd basically end up with an engine that has all the bad characteristics of a full-bridge but none of the power. The primaries flow only a fraction of the secondaries.
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Old 07-27-10, 12:07 PM
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Originally Posted by Aaron Cake View Post
That would be silly. You'd basically end up with an engine that has all the bad characteristics of a full-bridge but none of the power. The primaries flow only a fraction of the secondaries.
that was the answer I was looking for! thanks
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Old 07-27-10, 12:33 PM
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When i rebuilt mine, I went with a full bridge, with my turbo setup making full power about 6800-9000rpm. And you can't beat the sound. As far as drive ability, its not much fun stop and go and I find that at a cruise it really likes to keep its revs above 3,000. Also fuel consumption is much higher since I bridged it.
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Old 07-27-10, 01:01 PM
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Wtf?

What kind of turbo is that?

Last edited by sharingan 19; 07-27-10 at 01:02 PM. Reason: Full "power" NOT full boost....
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Old 09-08-10, 11:40 AM
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I am understanding that you are all talking about bridging with turbos but what about an N/A car? I have a s4 that ive been looking into porting for sometime but this is the best info i have found. Yet still nothing is being said much as to how a n/a would go with it. What type of things would i need to have in order to do a HBP? would 770 injectors work?
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Old 10-28-10, 09:18 PM
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im reviving... this thread got so off topic i began to skim... too much bp vs sp...

i use to have a hbp and the motor went.. now the next motor im contemplating doing a full bridge... what are the MAIN differences? ive spoke to someone on the forum (cant remember who) but hes had both and said drivability is no different...

when you guys say "half *** hbp" what does that mean? being conservative in the porting or dont half *** it just go full bridge?
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Old 10-28-10, 11:55 PM
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Originally Posted by muibubbles View Post
im reviving... this thread got so off topic i began to skim... too much bp vs sp...

i use to have a hbp and the motor went.. now the next motor im contemplating doing a full bridge... what are the MAIN differences? ive spoke to someone on the forum (cant remember who) but hes had both and said drivability is no different...

when you guys say "half *** hbp" what does that mean? being conservative in the porting or dont half *** it just go full bridge?
Originally Posted by Aaron Cake View Post
Nothing wrong with half bridge of course, but a full bridge makes more power with only a slight decline in idle quality, mileage and vacuum compared to a half.
.
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Old 04-08-11, 07:35 AM
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Sorry to bring this back, but took me several hours to read this thread, and there is an amplitude of useful information on it and I'd like to add whatever I can.

First of all for anyone still considering a halfie or full BP, I have witnessed BDC's HBP on an FC here in Charlotte several years ago. It didn't matter what type of car meet we went to, when he showed up literally everyone's attention would be directed to the 'brap, brap, brap'... I have a vid, put you're not aloud to post **** on this forum.

Not only did the sound entice you, but when I lined up with him on the highway in my lightly modded tii and got pulled harder than any car I've ever raced (and he was still only running 9psi), I was sold (in fact BDC you will be gettin an email from me in the coming days). He would drive that FC daily without problems, the idle was loud, but not unbearable at all, (not as loud as my exhaust system with stock ports now if it idled over 1000rpms) and the entire car would rumble as it idled much like a cammed v8 would. And as others have stated previously, it pulled forever.

Personally, I wouldn't want one for a DD. I wouldn't want a stock FC for a DD, or any sports car for a DD, too many temptations, too many potential tickets or worse. But for a weekend car, or fun car, why not go big or go home?
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