weirdness in the Throttle Cracker; stalling fix.
#42
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Originally Posted by WS6FirebirdTA00
throttle follower airflow and follower decay values, reduce the decay in the areas you have issues
The decay values in gear & in park what are you strating to reduce those by? Sorry for all the questions.
#44
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Originally Posted by WS6FirebirdTA00
i would go 10% cause 2 isnt much. I actually went 25% on mine to get it inline. but yes the in gear and pn tables. i forget exactly how they work, i set one decay to zero, i think p/n, and the rpms never came down lol
#45
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Why do all of the throttle cracker tables look SOOO different from mine?
2002 M6 stock table:
0.00000 0.00000 0.00000 0.20020 0.35840 0.35840 0.35840 0.35840 0.35840 0.35840 0.35840 0.35840
0.20020 0.20020 0.25000 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289
0.23340 0.29980 0.50000 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945
0.50000 0.50000 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027
0.50000 0.50000 2.50000 2.50000 2.50000 7.00000 7.00000 7.00000 7.00000 7.00000 7.00000 7.00000
0.50000 0.50000 2.50000 2.50000 2.50000 2.50000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 2.50000 2.50000 2.50000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 4.00000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 3.00000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
2002 M6 stock table:
0.00000 0.00000 0.00000 0.20020 0.35840 0.35840 0.35840 0.35840 0.35840 0.35840 0.35840 0.35840
0.20020 0.20020 0.25000 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289 0.46289
0.23340 0.29980 0.50000 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945 0.68945
0.50000 0.50000 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027 0.78027
0.50000 0.50000 2.50000 2.50000 2.50000 7.00000 7.00000 7.00000 7.00000 7.00000 7.00000 7.00000
0.50000 0.50000 2.50000 2.50000 2.50000 2.50000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 2.50000 2.50000 2.50000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 4.00000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 2.50000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
0.50000 0.50000 3.00000 6.00000 9.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000 12.00000
#46
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I have very similiar problems on my cammed car and referring to my stock tables they are no where close to what Jimmy posted, more in line with the above post. They vary from 0 - 12. But it seems like the basic "jist" of it is to tell the pcm that you have less airflow coming in and rely more on your VE...am I close or just more confused??
#48
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Jimmy you're the man ![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
I've been battling some surging issues, could reduce it but not really low enough to my taste.
I copied your craker table to mine and wham, like it wasn't there.
Thanks for the info.
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
I've been battling some surging issues, could reduce it but not really low enough to my taste.
I copied your craker table to mine and wham, like it wasn't there.
Thanks for the info.
#52
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The cracker I believe is only to provide a soft landing or
entry to the loop-controlled idle position. The idle loop is
slow and if you depend on it to hold minimum live RPM
it had better not be dropping fast enough to get by it.
If your idle loop params are set up better and there is no
undershoot then, OK. For example having an idle airflow
target that is above the observed Dynamic Airflow value
at idle, makes the RPM loop have to bring it down instead
of make a diving catch. Having underspeed spark helping
rather than hurting, etc.
IAC pintle is moved by prediction (calculated IAC air vs
steps) and feedback (airflow, RPM error loops). The
prediction side is where some surge can come from
when you port the TB and fill the hole too much, making
it so the top end of the table airflow can't really be made.
Or when the blade is drilled and there is an excess air
baseline at the other end. These compromise range of
control and let the loop bury itself at one end without
knowing to quit trying (saturated).
entry to the loop-controlled idle position. The idle loop is
slow and if you depend on it to hold minimum live RPM
it had better not be dropping fast enough to get by it.
If your idle loop params are set up better and there is no
undershoot then, OK. For example having an idle airflow
target that is above the observed Dynamic Airflow value
at idle, makes the RPM loop have to bring it down instead
of make a diving catch. Having underspeed spark helping
rather than hurting, etc.
IAC pintle is moved by prediction (calculated IAC air vs
steps) and feedback (airflow, RPM error loops). The
prediction side is where some surge can come from
when you port the TB and fill the hole too much, making
it so the top end of the table airflow can't really be made.
Or when the blade is drilled and there is an excess air
baseline at the other end. These compromise range of
control and let the loop bury itself at one end without
knowing to quit trying (saturated).
#53
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OK I try do describe my problem. I'm not sure it's related to air / throttle cracker...
With the supercharger belt installed my car shifts really slow: it takes up to 2 seconds for the synchro's to match the gears speed. This happens at every RPM.
The tranny is not new and may take some more time to shift than a fresh rebuilt unit, but it's not too bad. Same for clutch and hydraulics.
During a shift, when I scan for RPM, TPS and G/sec I notice that RPM drops about 1/2 sec after the TB is completely closed. If I shift at 3000 rpm it will show about 15 G/sec (TB closed).
Same scan, same RPM but with the supercharger belt disconnected the RPM drops as soon the TB is closed. At this point there is an airflow of about 10 G/sec.
It takes 0.5 - 1 sec for a complete shift.
It may be the bypass valve (I have the original unit supplied by Vortech with a very weak spring). The TB is stock.
Maybe there is too much pressure before the TB and some air is going through the hole in the blade.
Maybe the idle pintle is just too opened and there is more air going through than expected.
But maybe the pintle is always completely closed during a shift... who knows?
Autotap doesn't show any value for the pintle position. it's always at 0.
The pintle works because it idles fine, so it's just a scanner issue.
I noticed that for the same year (97 and 98) the corvette has much lower values in the throttle cracker table (2.2 G/Cyl for the F-Body and 0.7 G/Cyl for the Corvette).
Does it make it "sportier? Shift faster?
With the supercharger belt installed my car shifts really slow: it takes up to 2 seconds for the synchro's to match the gears speed. This happens at every RPM.
The tranny is not new and may take some more time to shift than a fresh rebuilt unit, but it's not too bad. Same for clutch and hydraulics.
During a shift, when I scan for RPM, TPS and G/sec I notice that RPM drops about 1/2 sec after the TB is completely closed. If I shift at 3000 rpm it will show about 15 G/sec (TB closed).
Same scan, same RPM but with the supercharger belt disconnected the RPM drops as soon the TB is closed. At this point there is an airflow of about 10 G/sec.
It takes 0.5 - 1 sec for a complete shift.
It may be the bypass valve (I have the original unit supplied by Vortech with a very weak spring). The TB is stock.
Maybe there is too much pressure before the TB and some air is going through the hole in the blade.
Maybe the idle pintle is just too opened and there is more air going through than expected.
But maybe the pintle is always completely closed during a shift... who knows?
Autotap doesn't show any value for the pintle position. it's always at 0.
The pintle works because it idles fine, so it's just a scanner issue.
I noticed that for the same year (97 and 98) the corvette has much lower values in the throttle cracker table (2.2 G/Cyl for the F-Body and 0.7 G/Cyl for the Corvette).
Does it make it "sportier? Shift faster?