What type of changes can be expected from this mod from having a manual boost controller? (besides probably half the p.i.t.a.)?

 

What Erik said. It also holds more pressure at higher rpms.

 

OK, Thanks for all the replies. I already ordered the GM solenoid with the pigtail from Rock Auto. Does anyone know what size are the barbs of the GM solenoid? Is it a 3/16 barb? I am planning on buying silicone vacuum tube of 5/32 (4 mm) inside diameter. Will this work?

 

5/32" is what you need, works perfect. I got 10 feet, just to have some extra, probably only used 6 feet.

 

i love my stock boost control i saved the money othewise spent and put it towards gas in my tank

 

Are you running 24 psi with the stock solenoid and modified pills? How does the boost hold at high rpm.

 

If you're running a stock-ish turbo, you can expect to hold more boost to redline, plus the 3-port reacts more quickly than an MBC. There are also gains in the midrange. You'll have 16 different points to custom adjust your boost curve.


Go check out NorCalEvo.Net, and there are a lot of 3-port vs. MBC examples. Bryan is good with getting the data out there.

 

i use 92 octane pump gas. I peak at 24-25 and hold about 21 til 7000RPM otherwise it sometimes knocks. I rather have more timing up top than boost.
I should make a video. maybe this coming few weeks

 

I just upgraded to and tuned the Perrin 3-port on my car last night. The 3-port setup is definitely superior to the stock setup. Response is much faster and spikes are basically eliminated with a well defined TBEC table. I'm now running a faster WGDC request delay (or whatever) as well.

the only thing is that the 3-port setup vents so much more you don't get the resolution that you have with the stock solenoid. I was at ~45% WGDC with the stock solenoid and I'm at around 68% with the 3-port at the same boost level (~24 psi). The resolution isn't really needed with the increased response time, but it also means that you don't have as much room for high boost.

Given, at higher RPM I'm actually running LESS WGDC than the stock solenoid ... I taper up to about 85% rather than 100% for 21psi at redline. I'm working in a 20% window rather than a 60% window.

 

Thanks!

 

I finally finish installing the GM 3 Port. I am glad I did, it works great and it is very easy to tune. I have never mess with EcuFlash before and on my third flash I am flat at 20 PSI till redline with basically no or minimum overshoot. You just need to think about how the boost control system works, do some plotting and prework in excell and you are all set. The setup works great and is is a stealth mod since there are no MBC anywere.

Next step is to make some chages so I can run 22 PSI which is my target. I have never tried the boost pill (which I also purchase already, but not installed), but the 3 port so far works great and it even install in the stock BCS location with the included holder tab.

 

If your car is tuned right, you don't need the pill. You already have the GM Solenoid. You did replace the stock vacuum lines coming off of it right? If so, then you have no boost pills in there, and you're good to go for whatever boost you tune for. Skip the pills.

 

Yes. I replace everything. What I mean is that I was going to go with the stock 2 port with pills (and already have the pill) but after I bought it decided to go GM 3 port. I have new vacuum lines, new wiring, etc.

 

Ah... gotcha... you're all set then... crank up the boost and have fun!

 

good info


how is the reliability of the GM and what hapens if it fails?