Car runs terrible at 7psi - need help
06-29-2004, 10:34 AM
#1
0.0 BAR
Thread Starter
Join Date: Jun 2004
Posts: 43
Car runs terrible at 7psi - need help
Hallo,
i need an advise from someone who has some know-how in tuning a boosted engine.
my setup: Stock B16A1 Engine 10:1 Compression ratio.
Garret T3 with 7-8psi boost.
Standalone ECU.
my AFR is ~14,7:1 until 800mbar (absolute), from 0-3psi i have ~13:1 and from 3psi on until 6psi i have ~12:1
over 6psi i'am a bit rich at the moment AFR is aprox. 10:1 to 11:1.
if i rev over aprox. 5000rpm (Vtec is active) and go over 7psi the car starts bogging.
i think it is no knocking but i have no power at this moment.
ignition is stock with 0,75° per psi retard so i have aprox 18° ignition advance in this area.
Can someone tell me why my car boggs in this conditions and what do i have to do to prevent this?
Thanks
Malte.
i need an advise from someone who has some know-how in tuning a boosted engine.
my setup: Stock B16A1 Engine 10:1 Compression ratio.
Garret T3 with 7-8psi boost.
Standalone ECU.
my AFR is ~14,7:1 until 800mbar (absolute), from 0-3psi i have ~13:1 and from 3psi on until 6psi i have ~12:1
over 6psi i'am a bit rich at the moment AFR is aprox. 10:1 to 11:1.
if i rev over aprox. 5000rpm (Vtec is active) and go over 7psi the car starts bogging.
i think it is no knocking but i have no power at this moment.
ignition is stock with 0,75° per psi retard so i have aprox 18° ignition advance in this area.
Can someone tell me why my car boggs in this conditions and what do i have to do to prevent this?
Thanks
Malte.
06-29-2004, 12:47 PM
#3
0.0 BAR
Thread Starter
Join Date: Jun 2004
Posts: 43
Re:Car runs terrible at 7psi - need help
the Problem with the details are that my standalone ecu is a selfmade one ;-) so noone would know it... ;-)
but i only want to know what to do with my engine management (more fuel (i guess not), less fuel, more advance, less advance, or if it could simply the limit of the compression ratio the engine can handle)
Thanks
Malte.
but i only want to know what to do with my engine management (more fuel (i guess not), less fuel, more advance, less advance, or if it could simply the limit of the compression ratio the engine can handle)
Thanks
Malte.
06-29-2004, 02:13 PM
#4
0.5 BAR
Join Date: May 2003
Posts: 152
Re:Car runs terrible at 7psi - need help
you think you are the only one with self made engine management? 
seriously, I had the same problem recently, I replaced the rubber line to the FPR, even tho it looked OK it was leaking under boost, and anything above 5k was lean since it wasn't upping the fuel pressure as the boost pressure climbed like it's supposed to. If you have a rubber line give it a shot.
I'm running a megasquirt as are a few others in here.
Neil
seriously, I had the same problem recently, I replaced the rubber line to the FPR, even tho it looked OK it was leaking under boost, and anything above 5k was lean since it wasn't upping the fuel pressure as the boost pressure climbed like it's supposed to. If you have a rubber line give it a shot.
I'm running a megasquirt as are a few others in here.
Neil
06-29-2004, 02:46 PM
#5
0.5 BAR
Join Date: Aug 2003
Posts: 157
Re:Car runs terrible at 7psi - need help
Originally Posted by neil85ae86
you think you are the only one with self made engine management?
seriously, I had the same problem recently, I replaced the rubber line to the FPR, even tho it looked OK it was leaking under boost, and anything above 5k was lean since it wasn't upping the fuel pressure as the boost pressure climbed like it's supposed to. If you have a rubber line give it a shot.
I'm running a megasquirt as are a few others in here.
Neil
seriously, I had the same problem recently, I replaced the rubber line to the FPR, even tho it looked OK it was leaking under boost, and anything above 5k was lean since it wasn't upping the fuel pressure as the boost pressure climbed like it's supposed to. If you have a rubber line give it a shot.
I'm running a megasquirt as are a few others in here.
Neil
over 6psi i'am a bit rich at the moment AFR is aprox. 10:1 to 11:1.
He is running a little rich.
06-29-2004, 03:31 PM
#6
0.0 BAR
Thread Starter
Join Date: Jun 2004
Posts: 43
Re:Car runs terrible at 7psi - need help
Hi,
no i'am not thinking i'am the only one but mine is nothing you can find on the internet so it doesn't help if i post some details ;-) because there is nothing special, it squirts fuel like all others also ;-)
but if you want to know some special details i give you an answer... just ask ;-)
i lean the mixture out a bit and have now 12:1 under full boost... seems to be a lot better.
my only problem now is that i have a lite bogging around the vtec switiching point (between 5000-6000rpm and another bogging at ~7500rpm) but ONLY in first and second gear, in third it doesn't appear.
the phenomen also appears only under full throttle, not in part throttle.
The hoses are all ok, the car had seen 1,2 Bar with another engine but the same hoses and so on so they must handle 0,6bar by far.
But back to my bogging problem, i though about that the map has a too big step in it so he runs into trouble in some conditions... can that be? i will check that tomorow.
Thanks
Malte.
no i'am not thinking i'am the only one but mine is nothing you can find on the internet so it doesn't help if i post some details ;-) because there is nothing special, it squirts fuel like all others also ;-)
but if you want to know some special details i give you an answer... just ask ;-)
i lean the mixture out a bit and have now 12:1 under full boost... seems to be a lot better.
my only problem now is that i have a lite bogging around the vtec switiching point (between 5000-6000rpm and another bogging at ~7500rpm) but ONLY in first and second gear, in third it doesn't appear.
the phenomen also appears only under full throttle, not in part throttle.
The hoses are all ok, the car had seen 1,2 Bar with another engine but the same hoses and so on so they must handle 0,6bar by far.
But back to my bogging problem, i though about that the map has a too big step in it so he runs into trouble in some conditions... can that be? i will check that tomorow.
Thanks
Malte.
