Overboost peaks - A good thing ?
#31
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Join Date: Nov 2000
Location: 32 cylinders and many cats
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My ECU just does not like significant peaks of boost. It just does not run smoothly and fuel cuts, sometimes even if they are not held for long. I have loosened the actuator another turn and put D back into my algorithm and it works better. (So actuator 2 turns tighter than standard). The boost control algorithm works far neater the less peaks you have. Other methods I am sure may work better with a peak.
#32
John,
To be sure you have done marvellous things with some of the engine management related devices on you car. Is the next step to get to grips with all key variables fuel, air, ignition and boost and then 3D the lot i.e. Custom MAP??
Julian
To be sure you have done marvellous things with some of the engine management related devices on you car. Is the next step to get to grips with all key variables fuel, air, ignition and boost and then 3D the lot i.e. Custom MAP??
Julian
#35
CC ...
No not sure ...but my mapper said it was undesirable. I guess during mapping it is important to get the safety margins right. i.e. Trace det/full Det then the cushion figure in terms of ignition retardation.
My mapper has done 70 or so motors now and is well used to the hot spots on the STiV rev band. 3600 is a particularly troublesome load site.... with det on pre and through pick up??? don't know why...
It is this load site that was tricky, and as such we dropped off a little advance here and added a bit more fuel. The latter was also well disguised and not shown on the KLink. I do still get very faint trace det.... BUT only at say 130mph and if the throttle is snapped open and closed ...even then no KLink lights flicker and with the headphones on it was almost inaudible.
I don't want scare anyone by posting this info. My intension is purely to make sure that people know the facts or at least inquire about them.
IMHO I think my Knock related statements are most useful to other post 1996 STi owners. These motors run more advance/boost and on our fuel >>DO<< Det whether shown on the KLink or not. My thoughts are backed up by the number of STi engines that have to get overhauled !!!!!
Later all,
Julian
No not sure ...but my mapper said it was undesirable. I guess during mapping it is important to get the safety margins right. i.e. Trace det/full Det then the cushion figure in terms of ignition retardation.
My mapper has done 70 or so motors now and is well used to the hot spots on the STiV rev band. 3600 is a particularly troublesome load site.... with det on pre and through pick up??? don't know why...
It is this load site that was tricky, and as such we dropped off a little advance here and added a bit more fuel. The latter was also well disguised and not shown on the KLink. I do still get very faint trace det.... BUT only at say 130mph and if the throttle is snapped open and closed ...even then no KLink lights flicker and with the headphones on it was almost inaudible.
I don't want scare anyone by posting this info. My intension is purely to make sure that people know the facts or at least inquire about them.
IMHO I think my Knock related statements are most useful to other post 1996 STi owners. These motors run more advance/boost and on our fuel >>DO<< Det whether shown on the KLink or not. My thoughts are backed up by the number of STi engines that have to get overhauled !!!!!
Later all,
Julian
#36
One of the reasons I asked was that when I had my Knocklink in a different position, I had more 'activity' and had to turn down the sensitivity a bit.
I was uneasy doing this as others claimed to use full sensitivity although their K/L was in a different position. I moved mine to the 'standard' position in front of the starter on the block. In this position I was able to turn up sensitivity to max and only see 1, sometimes 2 greens at full rpm/boost.
Someone suggested that in the initial position the K/L was detecting more background noise. Now I'm not so sure, it may have been trace det ?
The position I had it located was on the block, above No 2 cylinder. As this was only 2" from the top of the bore it was right "at the action" so to speak. The flip side to this is that it may be insulated somewhat from No1 & 3 cylinders but probably no more than it is now at the rear of the block.
I think I'll move it back to position 1 and monitor closely.
This wouldn't concern me if I was conservative with my settings but I run my car right at what I consider the edge of the AFR/boost/timing/temperature limits of the standard parts.
I want to know how it's feeling about it
Andy
I was uneasy doing this as others claimed to use full sensitivity although their K/L was in a different position. I moved mine to the 'standard' position in front of the starter on the block. In this position I was able to turn up sensitivity to max and only see 1, sometimes 2 greens at full rpm/boost.
Someone suggested that in the initial position the K/L was detecting more background noise. Now I'm not so sure, it may have been trace det ?
The position I had it located was on the block, above No 2 cylinder. As this was only 2" from the top of the bore it was right "at the action" so to speak. The flip side to this is that it may be insulated somewhat from No1 & 3 cylinders but probably no more than it is now at the rear of the block.
I think I'll move it back to position 1 and monitor closely.
This wouldn't concern me if I was conservative with my settings but I run my car right at what I consider the edge of the AFR/boost/timing/temperature limits of the standard parts.
I want to know how it's feeling about it
Andy
#37
Hi Andy,
I agree!! best get the sensitivity back up. The KLink is supposedly designed to filter out unnecessary noise and focus on the det frequency.
This can be illustrated if you try hitting the block with a spanner. You can get the LED's lit but only with one hell of a wack!
Better still can you get a mate or acquaintance with Det cans to sit is the car with you??? this would help determine if there is an issue or not....
Later
Julian
I agree!! best get the sensitivity back up. The KLink is supposedly designed to filter out unnecessary noise and focus on the det frequency.
This can be illustrated if you try hitting the block with a spanner. You can get the LED's lit but only with one hell of a wack!
Better still can you get a mate or acquaintance with Det cans to sit is the car with you??? this would help determine if there is an issue or not....
Later
Julian
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