3 window

iTrader: (1)

Who here uses a 4 port boost solenoid? I'm thinking of eliminating my MBC and going with a 4 port solenoid and building a duty cycle table through the Holley ecu. Obviously the objective is the adjustability of top and bottom gate port flow. Let me know your experiences.

Forcefed86

iTrader: (4)

3 port works just as well IMO and you can get them for $25 shipped on ebay. 4 ports there too but they are usually $60+ and aren't needed for most.

If you plumb it like this it will make just as much boost as a 4 port.

3 window

iTrader: (1)

Ah, I remember now. Bleed hole in the line to the top, right?

stevieturbo

A very small bleed hole. 20-30thou

3 ports respond faster than 4 ports too, so really there is almost no need ever for a 4 port.

At full duty the small bleed will lose negligible amounts of pressure, but it allows the system to work very easily.

With no bleed hole control can get quite tricky and will need a very very fast and well set up controller.

LT1PWRD

iTrader: (2)

In my situation, a 4 port solved my "lack" of boost issue.
I was running a 3 port and no matter how much I ramped DC, i wasn't seeing gains in boost, even adding stiffer Springs in the gate put the DC waay to high for good control.
I realized, back pressure was pushing my large gate open (PW66).
I knew my turbine side wasn't optimal, but i didn't realize it would be soo excessive to push the gate open. Maybe with a stock and not turbo specific cam, this wouldn't have been as bad. Cam good, turbo bad...lol.
Now i get around 22psi @ 40% DC with a 9lb WG spring.

stevieturbo

The fact it was a 4 port didn't fix it, configuring the solenoid correctly for your application fixed it.
A 3 port can do the same job as shown above.