boost question...what is the cause of pressure drop at transition on a seq setup??
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boost question...what is the cause of pressure drop at transition on a seq setup??
hey all
what is the typical cause for a boost pressure drop at transition...say 12-6-14 boost pattern...or a 12-7-15 boost pattern??
I have my own ideas but am wondering if anyone has any good input.
am finally done tuning for a 12-9.5-15 boost pattern and am ready to inch up the boost and retune..however I noticed today that Im getting a pressure drop at transition to around 7psi from 12 primary to 15 secondary.
Im using the manual boost controller and the pfc to control boost until i get the profec b.
both are installed correctly...I have new sensors and actuators.
j
PS...Im also having a problem controlling primary boost...with the precontrol closed and not allowing any prespool I am able to get full boost on the primary turbo...but with the precontrol open enough for prespool I cant boost past 12 lbs.
my goal is a 16-14-16 boost pattern or thereabouts...
the pfc sucks at controlling boost btw. hahah
what is the typical cause for a boost pressure drop at transition...say 12-6-14 boost pattern...or a 12-7-15 boost pattern??
I have my own ideas but am wondering if anyone has any good input.
am finally done tuning for a 12-9.5-15 boost pattern and am ready to inch up the boost and retune..however I noticed today that Im getting a pressure drop at transition to around 7psi from 12 primary to 15 secondary.
Im using the manual boost controller and the pfc to control boost until i get the profec b.
both are installed correctly...I have new sensors and actuators.
j
PS...Im also having a problem controlling primary boost...with the precontrol closed and not allowing any prespool I am able to get full boost on the primary turbo...but with the precontrol open enough for prespool I cant boost past 12 lbs.
my goal is a 16-14-16 boost pattern or thereabouts...
the pfc sucks at controlling boost btw. hahah
Last edited by artguy; 09-07-02 at 08:00 PM.
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"what is the typical cause for a boost pressure drop at transition...say 12-6-14 boost pattern...or a 12-7-15 boost pattern??"
-Got the same problem on my 95 FD. Was a Missing restrictor pill in the wastergate actuator line.
Serge
-Got the same problem on my 95 FD. Was a Missing restrictor pill in the wastergate actuator line.
Serge
#4
Hi Artguy,
Is your Profec installed into the Pre-control line? Or just the Wastegate line?
If your getting a big drop during the switchover then I think your pre-control pill is the wrong size. I think you might want to add a larger pill in the pre-control line.
However not to large... you might get boost spikes.
I think My pattern is 12.5 - 15 - 14.5. I'm using the Blitz SDC-ID.
Check the Lightning site before attempting to change pills though...
jc.
Is your Profec installed into the Pre-control line? Or just the Wastegate line?
If your getting a big drop during the switchover then I think your pre-control pill is the wrong size. I think you might want to add a larger pill in the pre-control line.
However not to large... you might get boost spikes.
I think My pattern is 12.5 - 15 - 14.5. I'm using the Blitz SDC-ID.
Check the Lightning site before attempting to change pills though...
jc.
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im ordering the profec...still using the manual boost controller...was thinking i might need to go with larger hoses and needle valves possibly...or wait for the profec
j
j
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Re: boost question...what is the cause of pressure drop at transition on a seq setup??
Originally posted by artguy
hey all
what is the typical cause for a boost pressure drop at transition...say 12-6-14 boost pattern...or a 12-7-15 boost pattern??
I have my own ideas but am wondering if anyone has any good input.
am finally done tuning for a 12-9.5-15 boost pattern and am ready to inch up the boost and retune..however I noticed today that Im getting a pressure drop at transition to around 7psi from 12 primary to 15 secondary.
Im using the manual boost controller and the pfc to control boost until i get the profec b.
both are installed correctly...I have new sensors and actuators.
j
PS...Im also having a problem controlling primary boost...with the precontrol closed and not allowing any prespool I am able to get full boost on the primary turbo...but with the precontrol open enough for prespool I cant boost past 12 lbs.
my goal is a 16-14-16 boost pattern or thereabouts...
the pfc sucks at controlling boost btw. hahah
hey all
what is the typical cause for a boost pressure drop at transition...say 12-6-14 boost pattern...or a 12-7-15 boost pattern??
I have my own ideas but am wondering if anyone has any good input.
am finally done tuning for a 12-9.5-15 boost pattern and am ready to inch up the boost and retune..however I noticed today that Im getting a pressure drop at transition to around 7psi from 12 primary to 15 secondary.
Im using the manual boost controller and the pfc to control boost until i get the profec b.
both are installed correctly...I have new sensors and actuators.
j
PS...Im also having a problem controlling primary boost...with the precontrol closed and not allowing any prespool I am able to get full boost on the primary turbo...but with the precontrol open enough for prespool I cant boost past 12 lbs.
my goal is a 16-14-16 boost pattern or thereabouts...
the pfc sucks at controlling boost btw. hahah
Do you have access to a datalogit? We did alot of testing on minimizing the down curve during the transition ( Nocab72 and I ) If you log, lets say, a 2000rpm->7000rpm pull in 3rd gear, that will give you a good idea on what is happening with the boost. Doing a 16-14-16 is not granular enough to tune the boost and minimize the drop.
Nocab got his transition down to less than .5 seconds by adjusting prespool settings (using a datalogit) and 1.5 turns out on the prespool actuator arm. I tuned the time down with the AVC-R.
If you can get a repeatable curve (get a couple of logs done) I can give you my spreadsheet and graph that will allow you to visualize the overall curve like below.
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#8
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wow...nice chart! the datalogit is great isnt it?
Ill do some logs...Im thinking i may have to adjust the length of my actuator as well...actually tried that yesterday and thought it solved the problem...but no luck...
j
Ill do some logs...Im thinking i may have to adjust the length of my actuator as well...actually tried that yesterday and thought it solved the problem...but no luck...
j
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a needle valve is in place where the pill used to be I believe....Its been so long since i ran the stock setup that I cant remember if there was a pill in the precontrol line or not.
j
j
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