6 port bridge build
01-10-15, 05:06 PM
#1
Ratchet_Brap
Thread Starter
6 port bridge build
Hi my names Josh, I'm currently in the middle of a 6 port bridge swap for my gsl, currently has 2 piece RA classic seals, Adkins 1 piece corner seals, and FD corner springs, with a full bridge on the primary's and the secondaries froze open, I was building this to run boost but I'm currently having trouble finding out what turbo or what boost it would survive, it is an s4 block, with 9.4:1 rotors. Thanks!
01-11-15, 10:19 AM
#2
Engine, Not Motor
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Full bridge on the primaries?
A "full bridge" typically indicates bridges on both the primaries and secondaries. Bridging only the primaries would be a half bridge, and a backwards half bridge at that. A proper half bridge is a bridgeport on the secondary ports.
Bridging the primaries only is sort of pointless. You'll end up with some extra port area and loads of overlap. But since the primaries are much smaller runners and far earlier closing time you won't see the flow a Bridgeport is supposed to create. The result is an engine that idles like a bridge, pulls low vacuum and gets poor fuel economy. With no real performance improvement.
Freezing the secondaries open is a very, very, very bad idea. The moment the car is started it will scream to redline and begin bouncing off the rev limiter.
Unless you are referring to the auxiliary intake ports and not the secondaries.
As for the turbo, that will depend on several things:
1. Budget?
2. Power goals?
3. Use for the car?
A "full bridge" typically indicates bridges on both the primaries and secondaries. Bridging only the primaries would be a half bridge, and a backwards half bridge at that. A proper half bridge is a bridgeport on the secondary ports.
Bridging the primaries only is sort of pointless. You'll end up with some extra port area and loads of overlap. But since the primaries are much smaller runners and far earlier closing time you won't see the flow a Bridgeport is supposed to create. The result is an engine that idles like a bridge, pulls low vacuum and gets poor fuel economy. With no real performance improvement.
Freezing the secondaries open is a very, very, very bad idea. The moment the car is started it will scream to redline and begin bouncing off the rev limiter.
Unless you are referring to the auxiliary intake ports and not the secondaries.
As for the turbo, that will depend on several things:
1. Budget?
2. Power goals?
3. Use for the car?
01-16-16, 12:02 PM
#3
Ratchet_Brap
Thread Starter
Sorry for the late response, I forgot my password for the longest time lol, the car is now running on ms3-pro using your wiring diagram with the exception of ls2 coils, the car is currently starting (by pouring oil down the intake due to used housings and new apex seals) but then slowly Boggs itself down, I'm trying to figure out a decent fuel table for the bridge,
01-17-16, 10:49 AM
#5
Engine, Not Motor
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See my reply in the Megasquirt forum.
That much port area needs a LOT of fuel to start up. Especially on a new rebuild. The is virtually no air velocity at cranking RPMs and low RPM. In fact you'll find this while tuning. Large amounts of fuel will be required at light load, it will stay level as the RPMs increase, then at one point spike up.
Depending on the intake manifold arrangement, that engine will make power from 7K to the limit of the stock flywheel.
That much port area needs a LOT of fuel to start up. Especially on a new rebuild. The is virtually no air velocity at cranking RPMs and low RPM. In fact you'll find this while tuning. Large amounts of fuel will be required at light load, it will stay level as the RPMs increase, then at one point spike up.
Depending on the intake manifold arrangement, that engine will make power from 7K to the limit of the stock flywheel.
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