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Old 07-30-2003, 10:31 AM   #1
Porkchop-WRX
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Question Utec Boost question

Hey I was driving on the way to work today and stomped it in 4th gear to pass some one and I got 15.5 psi which is a little low then whee I set it last but whatever. I was thinking it could be the weather or whatever. Here is the kicker. I stomp the throttle again a little later and got 15 psi in 2nd. I got some knock around 4k rpm so I let off . But anyway how does it happen to get 15psi in 2nd and only 15.5 in 4th. Isn't that impossibe.
Boost is controlled via UTEC closed loop set at 400 and the abc is open 3 turns.

~Danny
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Old 07-30-2003, 11:31 AM   #2
Davenow
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its perfectly possible.
In closed loop the utec is seeking a certain boost pressure, it will do whatever to get to it.
in 2nd, it lets the boost build till it hits that pressure, then cycles the boost controller accordingly to maintain it as long as possible (but due to the low loads in 2nd, thats not always that long)
In 4rth, it does the same thing, load increases, boost builds, and when it reaches its target, it cycles the boost controller to maintain that pressure.
A perfect boost control system would give you the EXACT same boost pressure in all gears. If you are only building .5psi more in 4th, its doing its job very well

As for why you are only getting 15-15.5
So many things will cause variations in boost. Ambiant temperature, wierd barometric pressure changes, and I am fairly certain that huge changes in the humidity will do it.
Along with timing changes due to bad/good gas

There are so many factors.
Wait a tank or two of gas and see if it changes, wait for different weather see if it changes, or suck it up and take the 10 sec it takes to open the ABC up another turn.
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Old 07-30-2003, 12:18 PM   #3
Porkchop-WRX
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Could of just been a weird fluke I guess. I'll try it again tonight and see what I get.
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Old 07-30-2003, 02:53 PM   #4
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yeah take all of what I said as a POSSIBILITY
You may have problems, or it could have just been some temporary weirdness.
it happens.
I wouldnt worry about it. If it continues, adjust your boost maps a bit. If you do, watch the gauge in case it returns to the way it was (you would boost higher)
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Old 07-30-2003, 02:53 PM   #5
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although I gotta say, ABC at 3 turns, 400 seems like a high value to only be at 15PSI.
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Old 07-30-2003, 03:12 PM   #6
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Well, UTEC CLB acts in mysterious ways.
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