Car lost power in 5th under boost for a second?
Feb 15, 2007, 07:53 PM
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Car lost power in 5th under boost for a second?
I just got my Buschur 02 housing and UR 3inch turboback installed and I was doing some pulls to see how it felt. I went into 5th gear under boost at around 115mph and it lost power for a second and then came back. I did it again and nothing happened. I couldn't have hit fuel cut, what could have happened. Possibly the computer re-learning itself?
Thanks
Thanks
Feb 15, 2007, 07:56 PM
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Do you have a tune or mbc?
If you hit a brick wall its fuel cut, or you might have a slight mis-fire (I would check your plugs)
You also could have a slipping clutch, I know it sounds crazy, but its a possibility.
If you hit a brick wall its fuel cut, or you might have a slight mis-fire (I would check your plugs)
You also could have a slipping clutch, I know it sounds crazy, but its a possibility.
Feb 15, 2007, 07:58 PM
#3
I would guess boost limit. There' a value in the ecu called, well, 'boost limit' and there's a 'boost cut delay timer'. So you probably exceeded the 'boost limit' for longer than the 'boost cut delay timer' value (1000 milliseconds) so it cut power for a bit.
Reflash your ecu.
Reflash your ecu.
Feb 15, 2007, 08:24 PM
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I would guess boost limit. There' a value in the ecu called, well, 'boost limit' and there's a 'boost cut delay timer'. So you probably exceeded the 'boost limit' for longer than the 'boost cut delay timer' value (1000 milliseconds) so it cut power for a bit.
Reflash your ecu.
Reflash your ecu.
What is the boost limit value?
And it is possible for me to hit that on a basically stock car with 02 housing, 3inch turboback and k&n drop in filter?
Yeah it was just a split second as you said and then it didn't happen the second time.
It is not a slipping clutch I know what that feels like. Plus the car only has 1,800 miles, NEVER been launched and this is my 3rd manual transmission car so I know how to drive.
I should check my plugs but didn't think to this early on.
It was probably boost cut. When I get my EBC and fuel pump, I will get it flased.
Feb 15, 2007, 08:31 PM
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it was def a boost cut.the samething happened to me and still will happen in 3rd and 4th if i am at 5k rpm or so. the ecu reads overboost and my CEL light comes on sometimes when it happenes.got the code read and it was overboost. you need an mbc and a tune. but it only happens to me when it is cold out.
Feb 15, 2007, 08:36 PM
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it was def a boost cut.the samething happened to me and still will happen in 3rd and 4th if i am at 5k rpm or so. the ecu reads overboost and my CEL light comes on sometimes when it happenes.got the code read and it was overboost. you need an mbc and a tune. but it only happens to me when it is cold out.
I didn't have a CEL light come on, but I was in my buddies pathfinder before I went to make a few pulls and his car read 19 degress, so it was damn cold out.
Atleast I know what it is now, I will get a tune and MBC as soon as I can.
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Feb 15, 2007, 09:00 PM
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Boost cut or there was knock and the car retarded timing severly. My guess is the ECU detected knock and the timing was retarded. This won't trigger a CEL and it will feel like a momentary lack of power. It will also happen in a larger gear which causes more load on the engine which in return triggers more boost. Combined with the cold air you probably went lean in a A/F cell and timing was cut.
Last edited by Max-Q; Feb 15, 2007 at 09:03 PM.
Feb 15, 2007, 09:31 PM
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Boost cut or there was knock and the car retarded timing severly. My guess is the ECU detected knock and the timing was retarded. This won't trigger a CEL and it will feel like a momentary lack of power. It will also happen in a larger gear which causes more load on the engine which in return triggers more boost. Combined with the cold air you probably went lean in a A/F cell and timing was cut.
Damn thanks for all of that information...
MrevolutionRed yes Sean Ivey will be tuning the car.
Feb 15, 2007, 09:35 PM
#11
I don't agree with the car retarding timing and this is why.
His mods allow the car to breath better making more power (and therefore load). They also allow the turbo to spool up more quickly.
It only happened in 5th gear. The higher the gear, the higher the load per rpm that you can achieve. Also the faster the turbo will spool when you floor it.
It was very cold out. The colder the air, the more power/load, the faster the load ramps up, and the quicker the spool. Also, the colder the air, the less likely you should get detonation (unless you run out of injector).
So, my guess is being at fairly high rpms in 5th gear and flooring it, the turbo spools up super quick due to the cold air and the stock boost control system can't control the spike quickly enough leading to the boost cut.
Like my car, I have my Boost Desird Engine Load set to 220 at 3500 and 4000 rpms. It'll still spike up to and the load will stay at 250 for a bit before the ecu reacts and brings it down. That's in 3rd gear in 70 degree weather. I can only imagine how high it's spiking in 20F in 5th gear.
His mods allow the car to breath better making more power (and therefore load). They also allow the turbo to spool up more quickly.
It only happened in 5th gear. The higher the gear, the higher the load per rpm that you can achieve. Also the faster the turbo will spool when you floor it.
It was very cold out. The colder the air, the more power/load, the faster the load ramps up, and the quicker the spool. Also, the colder the air, the less likely you should get detonation (unless you run out of injector).
So, my guess is being at fairly high rpms in 5th gear and flooring it, the turbo spools up super quick due to the cold air and the stock boost control system can't control the spike quickly enough leading to the boost cut.
Like my car, I have my Boost Desird Engine Load set to 220 at 3500 and 4000 rpms. It'll still spike up to and the load will stay at 250 for a bit before the ecu reacts and brings it down. That's in 3rd gear in 70 degree weather. I can only imagine how high it's spiking in 20F in 5th gear.
Feb 15, 2007, 10:54 PM
#14
it was def a boost cut.the samething happened to me and still will happen in 3rd and 4th if i am at 5k rpm or so. the ecu reads overboost and my CEL light comes on sometimes when it happenes.got the code read and it was overboost. you need an mbc and a tune. but it only happens to me when it is cold out.
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