Throttle Response
11-11-2012, 04:04 PM
#16
Race Director
If you're handy with a wrench, and the TPC kit is user-friendly, I would consider going back-to-stock and driving it that way for a week. If the problem goes away, the list of suspects is now sitting on the workbench. I'm ignorant of how much work is involved, so this may be impractical - but at some point knowing if you have a clean baseline is going to be valuable data...
11-11-2012, 04:04 PM
#17
Three Wheelin'
Couple of things...
What the TPC tech told you regarding the Audi TB tube and his mention about the more optimal position fits right in with a point I made about the air flow past/through the MAF.
The screen is not to restrict air flow but to improve air flow. In the past there have been those that have removed these -- in other cars -- to "increase" air flow only to have the engine react in a negative manner. The screen is not to keep snow out, leaves out, or block air flow, but to improve air flow. Hot film MAF are very good at measuring air mass and are about as trouble free a device as you could hope but they need the air flow just right. As the system comes from the factory it is right. But if you mess with it you can certainly make it wrong.
That the results of your putting this screen back in may be mixed due to the other problems. The screen alone may not be able to deal with the excessive air turbulence arising from the shorter intake tube.
Before you have a custom tune or flash done you need to be sure all of the issues under your control are dealt with. The tuner will be pulling his hair out trying to come up with a tune for a sick engine. In fact, I would expect the tuner to want to experience the car before any tuning is done to ensure for himself the car is operating ok before wasting his time and your money on what would likely prove to be a futile effort to get a improved tune.
What the TPC tech told you regarding the Audi TB tube and his mention about the more optimal position fits right in with a point I made about the air flow past/through the MAF.
The screen is not to restrict air flow but to improve air flow. In the past there have been those that have removed these -- in other cars -- to "increase" air flow only to have the engine react in a negative manner. The screen is not to keep snow out, leaves out, or block air flow, but to improve air flow. Hot film MAF are very good at measuring air mass and are about as trouble free a device as you could hope but they need the air flow just right. As the system comes from the factory it is right. But if you mess with it you can certainly make it wrong.
That the results of your putting this screen back in may be mixed due to the other problems. The screen alone may not be able to deal with the excessive air turbulence arising from the shorter intake tube.
Before you have a custom tune or flash done you need to be sure all of the issues under your control are dealt with. The tuner will be pulling his hair out trying to come up with a tune for a sick engine. In fact, I would expect the tuner to want to experience the car before any tuning is done to ensure for himself the car is operating ok before wasting his time and your money on what would likely prove to be a futile effort to get a improved tune.
This.
To the other point, when you disconnect the MAF, the engine will go to the default map and then start changing the fuel trims based on the amount of oxygen it sees in the exhaust.
It is completely expected to that the car will get "worse" after some time when you unplug the maf if the ECU is falling back on the stock deafault map (ie oem from porsche) The default map is pretty rich, so near idle the mixture will be quite dead on, but as you drive it around the extra air from the blower will lean the hell out of it and I would bet you see crazy fuel trims where the ecu is trying to dump a whole bunch of gas in to bring the mixture back in the line. Then lower rpm will be too rich and bogging etc.
I would highly highly recommend just taking the car back to whoever made the blower. Also driving it around w/o a maf if it's falling back on stock map is a bad idea, as you're likely leaning the hell out of the motor.
11-11-2012, 05:55 PM
#18
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This.
To the other point, when you disconnect the MAF, the engine will go to the default map and then start changing the fuel trims based on the amount of oxygen it sees in the exhaust.
It is completely expected to that the car will get "worse" after some time when you unplug the maf if the ECU is falling back on the stock deafault map (ie oem from porsche) The default map is pretty rich, so near idle the mixture will be quite dead on, but as you drive it around the extra air from the blower will lean the hell out of it and I would bet you see crazy fuel trims where the ecu is trying to dump a whole bunch of gas in to bring the mixture back in the line. Then lower rpm will be too rich and bogging etc.
I would highly highly recommend just taking the car back to whoever made the blower. Also driving it around w/o a maf if it's falling back on stock map is a bad idea, as you're likely leaning the hell out of the motor.
To the other point, when you disconnect the MAF, the engine will go to the default map and then start changing the fuel trims based on the amount of oxygen it sees in the exhaust.
It is completely expected to that the car will get "worse" after some time when you unplug the maf if the ECU is falling back on the stock deafault map (ie oem from porsche) The default map is pretty rich, so near idle the mixture will be quite dead on, but as you drive it around the extra air from the blower will lean the hell out of it and I would bet you see crazy fuel trims where the ecu is trying to dump a whole bunch of gas in to bring the mixture back in the line. Then lower rpm will be too rich and bogging etc.
I would highly highly recommend just taking the car back to whoever made the blower. Also driving it around w/o a maf if it's falling back on stock map is a bad idea, as you're likely leaning the hell out of the motor.
Again - thank you for this advice. You can bet that if the trick using the S4 MAF tube doesn't work that my next trip is the manufacturer of the SC.
I personally dont want to blow money on these issues but I also dont mind the chase with in reason. If I wanted a perfect car within this price range I would have bought a brand new Acura (or whatever). I much prefer a car I love with a reasonable amount of fixable issues. This is my car now and hell or high water, I will pursue a reasonable repair on it. Its 95% there - just this last little bit and then I can have fun with mods (more so!).
11-18-2012, 12:12 AM
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Mostly Resolved!!!
Friends!!! Macster!
I am VERY pleased to say that today I had a chance to install the new 2004 S4 Throttle Tube, with my correct MAF and a new, smaller air filter. I must say that between the TPC tech, Macster and others here on this board, that the re-position of the MAF with the screen etc has mostly resolved my throttle lag issue!
The car seems to run unbelievably better! As you may note I have a Super Charger on this car and it too now seems to scream even more so than previously. Thank you all for your help and suggestions. I think I am close to having this close to 100% and driving now is really a joy!
Sweet!
I am VERY pleased to say that today I had a chance to install the new 2004 S4 Throttle Tube, with my correct MAF and a new, smaller air filter. I must say that between the TPC tech, Macster and others here on this board, that the re-position of the MAF with the screen etc has mostly resolved my throttle lag issue!
The car seems to run unbelievably better! As you may note I have a Super Charger on this car and it too now seems to scream even more so than previously. Thank you all for your help and suggestions. I think I am close to having this close to 100% and driving now is really a joy!
Sweet!
11-18-2012, 12:42 AM
#20
Drifting
That's good to hear, but shouldn't the TPC kit come with all the "right" bits to ensure 100% out the box success for a new owner of the TPC system without going through this hassle OP has experienced?
What about other owners of the TPC SC kit for the 996? Are they experiencing similar problems which we have not heard about?
What about other owners of the TPC SC kit for the 996? Are they experiencing similar problems which we have not heard about?
