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Old 01-24-2007, 01:30 PM   #11
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The heat is created during compression. And the boost-stacking he'* getting is going back up through the system, pushing the heat up into the SC. He'* losing efficiency in the compressor in a big way.

In what conditions do you get higher boost readings? Cold or Hot weather?
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Old 01-24-2007, 01:32 PM   #12
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Cold, but that'* because the air is denser to begin with.

Take air of the same temp, heat it up more on the way in... wouldn't that increase pressure?
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Old 01-24-2007, 01:39 PM   #13
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Not if you're boost-stacking already. You have to take into account boost stacking, reversion, and heat transfer. It'* a complicated mess.

Regardless, that'* WAY too small of a pulley for his setup, particularly since we don't even know how his PCM is managing anything. We know the limits of the stock PCM in our cars, and what needs to be done to get a pulley that small to actually work (with MUCH higher octane, I might add), but on his, it'* a crapshoot, and a BOOM waiting to happen.
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Old 01-24-2007, 01:46 PM   #14
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Not to mention..he'* near the equator and while it'* been cooler, it'* not that much cooler to reverse the effects B1 is talking about.
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Old 01-24-2007, 01:49 PM   #15
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Let'* also not overlook the fact that he'* probably got MAJOR belt slip. That'* why I added another idler.
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Old 02-03-2007, 01:26 PM   #16
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Took the car to the dunes with better results.

Only ran 110 race fuel.
Ambient Temp 60-75 degrees.
Elevation 600 feet!!
2.2 pulley with NGK 7IX plugs.
New Belt.
De-carbon the motor and injector cleaning. - Which resulted in me having to lower my idle after the cleaning. (Involving a 15 minute spray from a machine directly into the plenum, followed by attaching the injector cleaning machine tapping into the fuel rail with the fuel pump off, and running for about 8 minutes)

I experienced no belt slip, no knock, no ping.

Max 10lbs of boost, but it comes on right now!!! Much better throttle response. I have 10lbs of boost at 1/3 throttle, but it never exceeds 10lbs.

My previous reading was actually, consistently 9.5 lbs, so there was a small net increase. Just not what I expected.

I think the smaller pulley helped me burn more fuel. I estimate about 20% more than the other pulley. Not sure if the computer has anything to do with it.

I'm now considering changing back to a larger pulley to improve fuel consumption. On our long rides, I am the first to request heading back to camp because of low fuel.

I appreaciate your thoughts and comments.
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Old 02-03-2007, 02:18 PM   #17
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110 octane? Leaded or unleaded? Are you running an O2 sensor? Or do you have some other method to determine fuel ratio?

That 20% decrease in fuel mileage is way too much loss. Most of us only see 5% or so if we're hammering it.
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Old 02-03-2007, 02:29 PM   #18
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There has to be some reason you get full boost at 1/3 throttle and it doesn't go any higher. Maybe a vac leak between the BCA and SC inlet?
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Old 02-03-2007, 03:57 PM   #19
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15 minutes of cleaner in the plenum may have removed some of the coating from the rotors.
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Old 02-03-2007, 09:34 PM   #20
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110 Octane unleaded. My Comp utilizes the O2, I'm not aware of any leaks.

Agreed, Shouldn't I have more boost? I have 3 vacuum lines from the boost diaphram, can anyone verify where they should go?

What is a BCA? I would guess is is a boost control actuator (the diaphram thingy?)

I have a feeling the wastegate is dumping all boost over 10 lbs.
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