really bad knock all of a sudden
There must be some table somewhere thats a fast spool fuel modifier or somthing that hasn't been found in the rom.. If your airflow/load are mapped out properly you shouldn't have lean spoolup unless theres a modifier to the main fueling table just for this purpose. I think you'll notice it richer with less intake advance because your spool will likely be somewhat slower with less intake advance. Next time I have an evo x on the dyno I'll put it in steady state and try to hold the areas where spool occurs and see if after X amount of time does the fueling change within the same load area.. This would be a clear indication theres a modifier table somewhere..
yep..
well i have been looking at all my previous pulls (start of dec 2009) and they all have decent AFR during spool, ie 18psi i am at 12:1, but soon after that I get to 11.5:1
all my most recent pulls I see 13:1 @ 18psi.
that WITH the fuel map richened up by 1 full point...
Bryan - do you have any AFR data for a HFC configuration? ie how much did you have to richen up the fuel map when adding a HFC (or TP i guess)
well i have been looking at all my previous pulls (start of dec 2009) and they all have decent AFR during spool, ie 18psi i am at 12:1, but soon after that I get to 11.5:1
all my most recent pulls I see 13:1 @ 18psi.
that WITH the fuel map richened up by 1 full point...
Bryan - do you have any AFR data for a HFC configuration? ie how much did you have to richen up the fuel map when adding a HFC (or TP i guess)
Thread Starter
Joined: Feb 2007
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From: Melbourne, Australia
I think I will have to "bite the bullet" and swap the cat back (As previously suggested by Noise)
Surely the 3" front(down in the USA) pipe wont make much difference in terms of airflow/AFR...
If my car consistently richens up then I can say the HFC caused the lean condition.
Otherwise we are back to looking at the fuel system (IMHO)
Surely the 3" front(down in the USA) pipe wont make much difference in terms of airflow/AFR...
If my car consistently richens up then I can say the HFC caused the lean condition.
Otherwise we are back to looking at the fuel system (IMHO)
Thread Starter
Joined: Feb 2007
Posts: 9,486
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From: Melbourne, Australia
Thread Starter
Joined: Feb 2007
Posts: 9,486
Likes: 67
From: Melbourne, Australia
so rather than trying to reduce that affect we need to compensate by throwing a LOT of extra fuel at the map...
remember MIVEC makes dramatic changes to spool characteristics , thus we need to make dramatic changes to the fuel map.
make sense?
This is my fuel map difference for stock everything from just tuning MIVEC (and leaning the car out to make a decent AFR)
You can see that uptop we needed to pull out about 2points of fuel - but down low i actually needed to ADD fuel over the stock map.. this was due to MIVEC
Last edited by tephra; Feb 4, 2010 at 09:25 PM.
Thread Starter
Joined: Feb 2007
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From: Melbourne, Australia
^^ makes sense, although if you were getting cylinder contamination then wouldn't that be a problem of having too much exhaust cam timing?
^ which two? #1 and #2? or my current and stock, or intake #2 and exhaust #2?
^ which two? #1 and #2? or my current and stock, or intake #2 and exhaust #2?
Well I know if you get really aggressive with mivec timing you will also get compressor surge with the stock turbo. There is no way around it. So yes you want MIVEC aggressive but you also don't want to destroy your thrust bearing in the turbo due to the surging. Plus being too aggressive with intake up top loses power. Also you want a bit less exhaust retard at peak boost having too much generally takes away performance.
Well we all know MIVEC plays a bit part for spool, so having aggressive MIVEC is desired, since it spools the turbo up quicker.
so rather than trying to reduce that affect we need to compensate by throwing a LOT of extra fuel at the map...
remember MIVEC makes dramatic changes to spool characteristics , thus we need to make dramatic changes to the fuel map.
make sense?
This is my fuel map difference for stock everything from just tuning MIVEC (and leaning the car out to make a decent AFR)
You can see that uptop we needed to pull out about 2points of fuel - but down low i actually needed to ADD fuel over the stock map.. this was due to MIVEC
so rather than trying to reduce that affect we need to compensate by throwing a LOT of extra fuel at the map...
remember MIVEC makes dramatic changes to spool characteristics , thus we need to make dramatic changes to the fuel map.
make sense?
This is my fuel map difference for stock everything from just tuning MIVEC (and leaning the car out to make a decent AFR)
You can see that uptop we needed to pull out about 2points of fuel - but down low i actually needed to ADD fuel over the stock map.. this was due to MIVEC
Thread Starter
Joined: Feb 2007
Posts: 9,486
Likes: 67
From: Melbourne, Australia
Well I know if you get really aggressive with mivec timing you will also get compressor surge with the stock turbo. There is no way around it. So yes you want MIVEC aggressive but you also don't want to destroy your thrust bearing in the turbo due to the surging. Plus being too aggressive with intake up top loses power. Also you want a bit less exhaust retard at peak boost having too much generally takes away performance.
This is the example from a FP RED c 1000cc. Notice the spool up AFR MAP.
ACTUAL AFR FROM WIDEBAND
The ECU will not go above 12.88, it is capped.
Thread Starter
Joined: Feb 2007
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From: Melbourne, Australia
well I just did a couple of pulls on the way home to see if anything has changed.
So the same configuration (3" DP + HFC) and same tune (original tune + 1pt in the fuelmap)
and it KNOCKED to absolute F&*^
looking at the log now...
unfricking believable...
there are 4 rows of logs missing, right when the knock appears WTF!!!!!!!!
So the same configuration (3" DP + HFC) and same tune (original tune + 1pt in the fuelmap)
and it KNOCKED to absolute F&*^
looking at the log now...
unfricking believable...
there are 4 rows of logs missing, right when the knock appears WTF!!!!!!!!
Code:
sample time RPM PSIG Timing Knock Load IPW TPS AFR WGDC FuelTrim_Current 15678 1179.160 2375 10.6 13 0 154 10.968 86.7 13.7 85.5 0.0 15680 1179.310 2391 11.6 12 0 162 10.968 86.7 13.4 85.5 0.0 15681 1179.385 2445 13.2 10 0 164 10.968 86.7 13.4 71.5 0.0 15682 1179.460 2461 13.8 11 0 166 10.968 86.7 13.8 71.5 0.0 15683 1179.535 2488 14.7 9 0 173 13.648 86.7 13.8 71.5 0.0 15684 1179.610 2539 15.6 6 0 186 13.648 86.3 13.7 71.5 0.0 15685 1179.685 2559 17.1 6 0 189 13.648 86.3 13.2 64.0 0.0 15686 1179.760 2586 18.2 5 0 198 13.648 86.3 13.1 64.0 0.0 15687 1179.835 2633 19.2 4 0 205 17.84 86.3 12.9 64.0 0.0 15688 1179.910 2637 20.5 4 0 213 17.84 86.3 12.7 64.0 0.0 15689 1179.985 2688 21.4 3 0 218 17.84 86.3 12.5 66.0 0.0 15690 1180.060 2719 22.5 4 0 225 17.84 86.3 12.4 66.0 0.0 15691 1180.135 2738 23.6 3 0 232 20.96 86.3 12.4 66.0 0.0 15692 1180.210 2801 24.4 2 0 246 20.96 85.9 12.2 66.0 0.0 15696 1180.510 2922 25.8 -9 30 246 20.96 85.9 10.9 65.5 0.0 15697 1180.585 2969 25.4 -9 29 251 20.96 85.9 10.9 65.5 0.0 15698 1180.660 3000 25.5 -7 26 249 22.072 85.9 10.8 65.5 0.0 15699 1180.735 3000 23.1 -5 26 212 22.072 17.2 10.7 65.5 0.0
Last edited by tephra; Feb 5, 2010 at 12:03 AM.