Installed my boost gauge this afternoon...

[Matt Monson]

It took all of 10 minutes after I went to the hardware store and got the correct parts. I got the Autometer Pro-something or other that Hallman sells off his site. It is a -30/+30 gauge. The hose that came with it was a joke. It also didn't come with a splitter to mount it to the vacuum line. So, 15 minutes and $6 later I was back doing the install. I bought real rubber vacuum line and a barbed brass fitting to replace the factory one that feeds into the back of the gauge. I went through the same rubber gasket mentioned in Dave's VDO install article. For now it is rubber-banded to the wiper wand. I will figure out where to put it permanently once I figure out how many more gauges I am gonna have and how I am gonna mount them all...

I tapped the 1st cylinder like most people around here do. I only drove it around for a few minutes, but vacuum pressure is right around 12psi. Partial throttle boost is 5-6psi. WOT, just like Dizzy experienced at this elevation, I get 11 psi...

Now I just have to surf for a bit while the car cools down. Project #2 this afternoon is to install the *NEW IMPROVED* Hallman ES MBC...

Of course the exhaust will need to be adressed before I crank it up a couple psi(getting a FCD is on the list as well). I was at Flat4 yesterday and I must have that Invidia DP. That thing is sickety gorgeous. We decided that my GF gets to keep the MRT turbo back we bought last week, and I will deal with a custom mid-pipe w/cat to a Stromung TT muffler, like I have on my RS...

[Dizzy]

Kewl. I'm glad to hear you got it in. I installed my EBC yesterday. It took longer than I would have liked, but I spent some time pulling apart the intake tract to figure out how things are routed. Compared to a WRX, the Turbo Legacy intake plumbing is a nightmare.

I'm playing it safe with the settings. I have a low of 8psi & a high of 10psi. The EBC (Blitz SSBC) that I have allows the user to toggle between the two. Overall, it is a solid (and quite simple) unit.

[Matt Monson]

I went with the super cheapo Hallman ES. Eventually I will get a better one, but that will have to wait until the other custom stuff like a new turbo and heads and manifold and stuff go on in the summer...I never got to the boost gauge, BTW

I got caught up in rotating the tires, inspecting the brakes, and pulling part numbers off of struts and stuff. Shouldn't have taken so long but the wheels were rusted onto the hubs a little bit and I had to kick them to toggle them.

I also grappled with the exhaust for a bit. I wanted to take it off and get some measurements, but the bolts were to rusted to make it worth it. Next thing I knew it was getting dark and I just called it a day.

So, I have one question now that I have driven it a bit. How does the ECU determine how much boost to give it. I have seen 5-7psi and 10-11psi in the same gear with the same throttle position. What determines what the ECU provides to it. I even have gone with the throttle to the floor and not had it go past 7psi...

[Brat4by4]

It's kind of weird. I know what you mean. The ECU doesn't really like to go for full boost all of the time. I see it go up there more often when there is more load. Say for example if you shift from 2nd to 4th then it will peg the gauge at 10-11 psi once above 2800 rpm. But if you go from redline in 2nd to 3rd and keep the revs high but only 85% throttle, it just decides to keep wastegate pressure. Another case is going up a hill, it will full boost then with the extra load on the engine.

I will often check out the gauge and see relatively low boost when I'm scootin along, I bury the pedal completely to the floor and only then will it go full boost. I'm not a pedal to the metal kind of guy and get half boost most of the time for it .

[Dizzy]

Matt -

I think we may be at the mercy of the TCU as well as the ECU. I'm pretty sure there is communication between the two. FWIW - my car seems to pull harder with the tranny in "sport" mode & boost @ 7psi than 10psi & normal tranny mode.

:shrug:

[Matt Monson]

Matt -

I think we may be at the mercy of the TCU as well as the ECU. I'm pretty sure there is communication between the two. FWIW - my car seems to pull harder with the tranny in "sport" mode & boost @ 7psi than 10psi & normal tranny mode.

:shrug:

I was suspicious of the TCU as well. I was fiddling with that "sport" mode a little. Mine calls it "manual" mode. But same thing, the car still shifts even if I don't. And what is the little green light on the dash next to the "manual" light that says "power" What determines power???

[Dizzy]

My power light comes on whenever I aggressively stomp on the gas pedal. I'm not too sure what else it does, but I get more aggressive (higher) shift points and it feels like the car pulls harder.

[mTk]

The power light indictatest that the tranny is using a more agressive shift map. Nothing else to it. Leg77 has a blurb on his site about it, i'll see if i can find it.

MK

[mTk]

http://www.surrealmirage.com/subaru/tra ... powerlight

It's prolly mentioned elsewhere on here too

MK

[vrg3]

Matt - I think you're seeing the symptoms of a failing boost control solenoid. If the ECU is unable to bleed any pressure off using that solenoid, you'll only get around 6psi of boost (that's what the wastegate spring is calibrated to). 10-11psi is what you should expect in Boulder.

Dizzy - The TCU doesn't send any signals to the ECU. The ECU sends the atmospheric pressure reading to the TCU in some cars, but that's it.

[Dizzy]

Dizzy - The TCU doesn't send any signals to the ECU. The ECU sends the atmospheric pressure reading to the TCU in some cars, but that's it.

Cool. Thanks for setting me straight.


Matt - would you be able to meet sometime? I'm getting some REALLY bad hesitation & I would like to look at your car & compare it to mine to make sure I didn't screw anything up during the controller install. I went back to the stock control mechanisms & I'm still getting the hesitation. I hope I just routed something incorrectly.