Power cut out!
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Power cut out!
Hey guys,
I just installed the Borla header, and am experiencing power cut out at about 4500-5000 rpm. It doesn't do it all of the time though, only when you jump on it, but not when high revs are acheived gradually. Power cuts out very abruptly and last only a second, maybe less. It has happened 3 times only today, though the car has been set up this way for a few days of driving. I didn't notice any blow-off sound either. There was a clunk that I beleive to be the effect on the drive train from the sudden power loss. I don't know if it is the header, but that Is the only thing that has changed since it has happened. My SBC-ID only peaked at 15psi. I am running a vishnu stage 1 unichip that is supposed to be custom tuned to my mods, other than the header. Has anyone experienced this, or have any Ideas? Is it fuel cutout? Injectors? The tuning on my unichip? what!!!??? I really need to figure this out. Here is a list of my power-mods:
Vishnu stage 1 unichip
Blitz SBC-ID
borla header
Perrin up-pipe
HKS Down-pipe
Tanabe SRM cat-back
Blitz BOV
Zerosports intake pipe
any help would be greatly appreciated.
Thanks you guys,
Brian
I just installed the Borla header, and am experiencing power cut out at about 4500-5000 rpm. It doesn't do it all of the time though, only when you jump on it, but not when high revs are acheived gradually. Power cuts out very abruptly and last only a second, maybe less. It has happened 3 times only today, though the car has been set up this way for a few days of driving. I didn't notice any blow-off sound either. There was a clunk that I beleive to be the effect on the drive train from the sudden power loss. I don't know if it is the header, but that Is the only thing that has changed since it has happened. My SBC-ID only peaked at 15psi. I am running a vishnu stage 1 unichip that is supposed to be custom tuned to my mods, other than the header. Has anyone experienced this, or have any Ideas? Is it fuel cutout? Injectors? The tuning on my unichip? what!!!??? I really need to figure this out. Here is a list of my power-mods:
Vishnu stage 1 unichip
Blitz SBC-ID
borla header
Perrin up-pipe
HKS Down-pipe
Tanabe SRM cat-back
Blitz BOV
Zerosports intake pipe
any help would be greatly appreciated.
Thanks you guys,
Brian
Last edited by linus011; Mar 19, 2003 at 10:00 PM.
Registered User
Joined: Nov 2002
Posts: 174
From: Ontario
Car Info: 02 wrx
The "power cut" you are feeling is fuel cut... Obviously, your ECU is not happy with something, and I think that it might be the lean condition that the header produces if no tuning is done. You will most likely need to get your unichip reflashed for the header as well......
Guest
Posts: n/a
Hey Jigga,
thanks for your thoughts, I really appreciate it, I have some more info after my recent test drive. It only does it in 1st gear. I can't get it to do it in any other gear. If i hold the gas down throughout the situation it goes like this: Whaaahhahaa- ka-thunk-Whaaahhahaaaa. There just a kathunk then power resumes. I think the kathunk is the sound of the drivetrain binding during the sudden loss of power. Also, it will do it at low boost levels like 10.5lbs. Remember though, it only does it in 1st gear. any ideas?
I tried tightening the screw on the top of the blitz bov, moved very freely, only adjusted a little, to no avail. also I returned to the stock rubber intake hose, also to no avail. I guess I will have to try the stock manifolds next to see if it really was the borla headers that are causing this, but I really doubt it. Does anyone think that this could be mechanical?
Please help,
Brian
thanks for your thoughts, I really appreciate it, I have some more info after my recent test drive. It only does it in 1st gear. I can't get it to do it in any other gear. If i hold the gas down throughout the situation it goes like this: Whaaahhahaa- ka-thunk-Whaaahhahaaaa. There just a kathunk then power resumes. I think the kathunk is the sound of the drivetrain binding during the sudden loss of power. Also, it will do it at low boost levels like 10.5lbs. Remember though, it only does it in 1st gear. any ideas?
I tried tightening the screw on the top of the blitz bov, moved very freely, only adjusted a little, to no avail. also I returned to the stock rubber intake hose, also to no avail. I guess I will have to try the stock manifolds next to see if it really was the borla headers that are causing this, but I really doubt it. Does anyone think that this could be mechanical?
Please help,
Brian
Registered User
Joined: Nov 2002
Posts: 174
From: Ontario
Car Info: 02 wrx
Hmm... I'm not sure why it does this only in first gear, but what I know is that you definitely should not run an aftermarket manifold without engine management to take advantage of them.
Perhaps your ECU is not able to adjust fuel/timing with the revs climbing so quickly in first gear, but you definitely are hitting fuel cut.. I hit it before, and it is not a pleasant feeling, especially when you are in the middle of an overtaking manouver...
get your unichip tuned for your header (which will cause your engine to run lean without tuning), and I am sure you will have no probs.....
Perhaps your ECU is not able to adjust fuel/timing with the revs climbing so quickly in first gear, but you definitely are hitting fuel cut.. I hit it before, and it is not a pleasant feeling, especially when you are in the middle of an overtaking manouver...
get your unichip tuned for your header (which will cause your engine to run lean without tuning), and I am sure you will have no probs.....
Last edited by jigga; Mar 21, 2003 at 04:51 PM.
Guest
Posts: n/a
Thanks again Jigga for your advice. I actually do have a unichip that is tuned for everything that I have except for the header. I just tried to run without the unichip, but I still get the same effect. I am gioing to try to remove the header and put the stock one back on. If the error persists, Then I will know that It isn't the header. If it doesn't persist, then I will re-install the header when I can get a custom ecutec tunning. There is a local tuner who will be getting a four wheel dyno and tuning capabilities for the wrx, by the end of april. I called Vishnu, and they don't have any tuning maps for cars with headers. any Chance that It could be the fuel pump, or something related to that?
brian
brian
Registered User
Joined: Nov 2002
Posts: 174
From: Ontario
Car Info: 02 wrx
hmm... I guess it could be your fuel pump...not sure though... Thing is that you are taking a different upgrade path than most people do around here. Most get the header as the very last thing... after the turbo upgrade (which is supported by STi injectors, and a 255lph fuel pump, and engine management) and the upgraded intercooler, etc.... It is my opinion though that you might be overtaxing the stock fuel system though with your mods and the aftermarket manifold
From what I remember, Vishnu's Stage one package is good for around 230WHP.... Headers for around 10-20WHP with tuning... Thing is that the stock fuel system is only good for between 240-250WHP, so you might be at the ragged edge of what the stock fuel system can give. You might want to think about upgrading to bigger capacity fuelpump, and STi pink injectorssooner rather than later with the manifold in place.....
note that you will need your unichip remapped for the injectors as well since the stock ECU will not run the car properly with them in place...
From what I remember, Vishnu's Stage one package is good for around 230WHP.... Headers for around 10-20WHP with tuning... Thing is that the stock fuel system is only good for between 240-250WHP, so you might be at the ragged edge of what the stock fuel system can give. You might want to think about upgrading to bigger capacity fuelpump, and STi pink injectorssooner rather than later with the manifold in place.....
note that you will need your unichip remapped for the injectors as well since the stock ECU will not run the car properly with them in place...
Last edited by jigga; Mar 21, 2003 at 05:17 PM.
Guest
Posts: n/a
Hi Jigga,
I think that you may be right. The thought of upgrading injectors and pump have crossed my mind and I may go ahead and do that. In the mean time, I think that I will remove the header and replace it with the stocker. I'll keep you posted.
brian
I think that you may be right. The thought of upgrading injectors and pump have crossed my mind and I may go ahead and do that. In the mean time, I think that I will remove the header and replace it with the stocker. I'll keep you posted.
brian
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