What makes the .2 "S" so freakin' fast?
#136
Up to about 5800 rpm, your engine is running rich and then goes lean. My guess would be that your after cat sensors are fine since both read the same. The primary sensors are irrelevant at WOT. Assuming your cams are moving as designed; the most likely cause is a lack of fuel. This could be caused by several things, including a bad fuel pump, injectors or pressure regulator. However, those are less likely than is the possibility of an incorrect signal from the MAF. From you logs, the MAF signal seems irratic. Engine vacuum readings eliminates major leaks in the system.
The first thing I would do is to confirm or eliminate that the MAF signal as the problem. First clean the MAF and its connection. Data log and compare data to current log. Check the resistor connection on line 5 of the MAF cable. Check to see if you still have the screen on the intake tube where the filter connnects. This screen can effect the flow of air past the sensor. If its on, remove it and data log again.
Then, look at the resistor on line 5 on the MAF cable to determine the OHM value. Remove the resistor and replace with the next lower value resistor Data log again and you should see the MAF signal jump along with the amount of fuel getting to the engine.
What would also be interesting and may help identify the problem is what your LTFT and STFT read. Your scanner can log those too.
BTW: Your orginal dyno showing 425 rwhp is extremely optomistic and should not be your target. You're likely to acheive, maybe 400 rwhp running 4.8 psi of boost. However, a dyno can show any value you want.
Last edited by 1999Porsche911; 06-06-2009 at 08:59 AM.
#137
Up to about 5800 rpm, your engine is running rich and then goes lean. My guess would be that your after cat sensors are fine since both read the same. The primary sensors are irrelevant at WOT. Assuming your cams are moving as designed; the most likely cause is a lack of fuel. This could be caused by several things, including a bad fuel pump, injectors or pressure regulator. However, those are less likely than is the possibility of an incorrect signal from the MAF. From you logs, the MAF signal seems irratic. Engine vacuum readings eliminates major leaks in the system.
The first thing I would do is to confirm or eliminate that the MAF signal as the problem. First clean the MAF and its connection. Data log and compare data to current log. Check the resistor connection on line 5 of the MAF cable. Check to see if you still have the screen on the intake tube where the filter connnects. This screen can effect the flow of air past the sensor. If its on, remove it and data log again.
Then, look at the resistor on line 5 on the MAF cable to determine the OHM value. Remove the resistor and replace with the next lower value resistor Data log again and you should see the MAF signal jump along with the amount of fuel getting to the engine.
What would also be interesting and may help identify the problem is what your LTFT and STFT read. Your scanner can log those too.
The first thing I would do is to confirm or eliminate that the MAF signal as the problem. First clean the MAF and its connection. Data log and compare data to current log. Check the resistor connection on line 5 of the MAF cable. Check to see if you still have the screen on the intake tube where the filter connnects. This screen can effect the flow of air past the sensor. If its on, remove it and data log again.
Then, look at the resistor on line 5 on the MAF cable to determine the OHM value. Remove the resistor and replace with the next lower value resistor Data log again and you should see the MAF signal jump along with the amount of fuel getting to the engine.
What would also be interesting and may help identify the problem is what your LTFT and STFT read. Your scanner can log those too.
#138
The stock engine is not designed for the extra heat and load. The bearings among many other components inside the engine will take a lot of wear. Also the thrust bearings (the bearings that keep the crank from going forward and back). On the street this may be ok for awhile but for track duty I and my mechanic have seen too many issues. Some of the superchargers put out HP that is within the range of what the car can live with (100 ish HP) for street use. The amount of hassle in fabbing / computer issues, money, and devaluation of the car makes it a tough project.
#139
The stock engine is not designed for the extra heat and load. The bearings among many other components inside the engine will take a lot of wear. Also the thrust bearings (the bearings that keep the crank from going forward and back). On the street this may be ok for awhile but for track duty I and my mechanic have seen too many issues. Some of the superchargers put out HP that is within the range of what the car can live with (100 ish HP) for street use. The amount of hassle in fabbing / computer issues, money, and devaluation of the car makes it a tough project.
I have gotten zero feedback from VF. I sent them an email last week with no response yet. That's disappointing. I'm hoping they're just busy and not blowing me off, since they are the manufacturer of this kit and the current authorized distributor.
#140
There are literally hundreds of these kits out there. I don't know of a single person that has blown their motor as a result of the SC. That doesn't mean I won't be the first Based on the feedback I've gotten from 1999 and Todd at EVO, my guess is it will probably be a blown MAF or a bad 02 sensor. I'll probably be taking it in this week.
I have gotten zero feedback from VF. I sent them an email last week with no response yet. That's disappointing. I'm hoping they're just busy and not blowing me off, since they are the manufacturer of this kit and the current authorized distributor.
I have gotten zero feedback from VF. I sent them an email last week with no response yet. That's disappointing. I'm hoping they're just busy and not blowing me off, since they are the manufacturer of this kit and the current authorized distributor.
#141
The stock engine is not designed for the extra heat and load. The bearings among many other components inside the engine will take a lot of wear. Also the thrust bearings (the bearings that keep the crank from going forward and back). On the street this may be ok for awhile but for track duty I and my mechanic have seen too many issues. Some of the superchargers put out HP that is within the range of what the car can live with (100 ish HP) for street use. The amount of hassle in fabbing / computer issues, money, and devaluation of the car makes it a tough project.
Known blown bone stock 996 and 997 engines = too many to count
Known blown stock 996 and 997 supercharged engines = ZERO.
Last edited by 1999Porsche911; 06-08-2009 at 08:59 AM.
#142
I remember when I became the first 99 996 C2 to install an SC, people said it would not last and the engine would grenade. For the past 5 years I have been trying to prove them right. I just can't seem to find a way to destroy the engine. I have run the engine up to 7800 rpm, increased boost, bounced off the rev limiter continuously, but it just won't come apart. If anyone has any ideas how I can hasten the dead of my engine, please advise. I am open to any suggestions except running Mobil Water in the crankcase.
#143
I could be wrong but I thought he was just returning his car to stock because he was buying something else... Don't remember for sure though.
#144
Just to clarify:
Blaktout was turning his car into a 'class' car and the class he was going to compete in didn't allow alot of the mods on his car,which is why he had a HUGE sale on a ton of parts a while ago.His engine did go but nothing to do with the charger!
He was even looking at buying a different car to race.
Stacy
#145
I can't catch up on 10 pages but is the suspected culprit for the 997 .2 S being so fast due to: Supercharger heat soak vs. consistently high hp during track duty due to the direct injection?
#146
You should have read it. Then you would known that it's not that his car is so fast, it's that my car is all ****'d up
#147
This is how the rumours start...LOL!
Just to clarify:
Blaktout was turning his car into a 'class' car and the class he was going to compete in didn't allow alot of the mods on his car,which is why he had a HUGE sale on a ton of parts a while ago.His engine did go but nothing to do with the charger!
He was even looking at buying a different car to race.
Stacy
Just to clarify:
Blaktout was turning his car into a 'class' car and the class he was going to compete in didn't allow alot of the mods on his car,which is why he had a HUGE sale on a ton of parts a while ago.His engine did go but nothing to do with the charger!
He was even looking at buying a different car to race.
Stacy
#149
It was NOT due to the supercharger...it was because of another part that failed.
Stacy
#150
the '09 911's come with LSD standard from now on? damn...
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