Haven’t heard anything in a long time regarding several BIG HP cars . . .
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the stock safety features (knock supression etc...) are truly are awesome. It's on a different level... from the OEM standpoint. I think because most tuners keep the code in tact is why there really haven't been a string of blown engines etc....
how've you been man? This thread is like an old-school reunion... Wondered where you went
how've you been man? This thread is like an old-school reunion... Wondered where you went
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And what about knock sensors? More timing certainly, since there is nothing to pull it back. Then you start seeing not 800hp, but 600hp, 996tts blowing their engines when the owner decides to run a supra from 60mph and press the "race" button.. why mess with the Bosch Motronic since it is able to give more power than you can put on the ground? I hope Todd doesn't love this standalone!! 
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Man I didn't see that in there... Must be something else eh! NA, good high-revving (and fast revving) motor like that is great on the track eh?
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Tym Switzer has been running one for awhile. Maybe he'll chime in.
I doubt he is on Motec though.... time will tell I guess.
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2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
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What has this place become? 
A few months back a thread like this one would have stayed at the top of first page for several weeks
Ohio GT2
Given that I don't know much about EFI systems, and even less this AEM, I did some research, and it seems like it does not really have knock sensors of its own, but rather looks like a piggyback unit that "reads" from engine "noise" frequency and interprets knock.
This is the same issue that Motec and other EFI systems face, the tricky part is not whether the aftermarkt ECU detects knock, but rather how does it know this is actually knock! The most difficult aspect is to be able to program it in a way that you can get the exact frequency at different rpm levels and know that this IS knock indeed and therefore the ECU automatically retard timing, then increase it again untill knock is sensed again, over and over again and then act on the boost to cut it down when timing retardation is not enough, the way the Bosch ECU does.
Aftermarket ECUs, usually can be confused by normal engine mechanical noise, which obviously changes in frequency as RPMs change, making it very difficult to detect rightly.
By flicking through the AEM forum and a few others, namely US and Japanese cars, it seems that this still remains one of the main weaknesses, and most, if not all, people are having issues with misreading noise for knock....Same old issue like other EFI systems. This is where Bosch's multi-million dollar development and R&D program makes a difference and works with its own developped sensors.
What the above tells me is that I doubt this system will work better than the factory Bosch system and extract more power, since if I was the tuner and working on these expensive engines, I would take extra care not to blow up one of them, and would be rather conservative on timing and boost. And if I was the customer, I would make sure that I get some sort of warranty, since most likely when one of these blows up, it will be presented as engine internals weakness or poor Porsche engineering, rather than "ouupps did I go too far with my tuning?"
I hope this is not the case, and this EMS really turns out to be a revolutionary EFI EMS that has fine tuned all of this to give maximum performance together with factory-like safety.
A few months back a thread like this one would have stayed at the top of first page for several weeks Given that I don't know much about EFI systems, and even less this AEM, I did some research, and it seems like it does not really have knock sensors of its own, but rather looks like a piggyback unit that "reads" from engine "noise" frequency and interprets knock.
This is the same issue that Motec and other EFI systems face, the tricky part is not whether the aftermarkt ECU detects knock, but rather how does it know this is actually knock! The most difficult aspect is to be able to program it in a way that you can get the exact frequency at different rpm levels and know that this IS knock indeed and therefore the ECU automatically retard timing, then increase it again untill knock is sensed again, over and over again and then act on the boost to cut it down when timing retardation is not enough, the way the Bosch ECU does.
Aftermarket ECUs, usually can be confused by normal engine mechanical noise, which obviously changes in frequency as RPMs change, making it very difficult to detect rightly.
By flicking through the AEM forum and a few others, namely US and Japanese cars, it seems that this still remains one of the main weaknesses, and most, if not all, people are having issues with misreading noise for knock....Same old issue like other EFI systems. This is where Bosch's multi-million dollar development and R&D program makes a difference and works with its own developped sensors.
What the above tells me is that I doubt this system will work better than the factory Bosch system and extract more power, since if I was the tuner and working on these expensive engines, I would take extra care not to blow up one of them, and would be rather conservative on timing and boost. And if I was the customer, I would make sure that I get some sort of warranty, since most likely when one of these blows up, it will be presented as engine internals weakness or poor Porsche engineering, rather than "ouupps did I go too far with my tuning?"
I hope this is not the case, and this EMS really turns out to be a revolutionary EFI EMS that has fine tuned all of this to give maximum performance together with factory-like safety.
Last edited by Jean; Feb 24, 2008 at 11:40 AM.
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What has this place become? A few months back a thread like this one would have stayed at the top of first page for several weeks
Ohio GT2
Given that I don't know much about EFI systems, and even less this AEM, I did some research, and it seems like it does not really have knock sensors of its own, but rather looks like a piggyback unit that "reads" from engine "noise" frequency and interprets knock.
This is the same issue that Motec and other EFI systems face, the tricky part is not whether the aftermarkt ECU detects knock, but rather how does it know this is actually knock! The most difficult aspect is to be able to program it in a way that you can get the exact frequency at different rpm levels and know that this IS knock indeed and therefore the ECU automatically retard timing, then increase it again untill knock is sensed again, over and over again and then act on the boost to cut it down when timing retardation is not enough, the way the Bosch ECU does.
Aftermarket ECUs, usually can be confused by normal engine mechanical noise, which obviously changes in frequency as RPMs change, making it very difficult to detect rightly.
By flicking through the AEM forum and a few others, namely US and Japanese cars, it seems that this still remains one of the main weaknesses, and most, if not all, people are having issues with misreading noise for knock....Same old issue like other EFI systems. This is where Bosch's multi-million dollar development and R&D program makes a difference and works with its own developped sensors.
What the above tells me is that I doubt this system will work better than the factory Bosch system and extract more power, since if I was the tuner and working on these expensive engines, I would take extra care not to blow up one of them, and would be rather conservative on timing and boost. And if I was the customer, I would make sure that I get some sort of warranty, since most likely when one of these blows up, it will be presented as engine internals weakness or poor Porsche engineering, rather than "ouupps did I go too far with my tuning?"
I hope this is not the case, and this EMS really turns out to be a revolutionary EFI EMS that has fine tuned all of this to give maximum performance together with factory-like safety.
A few months back a thread like this one would have stayed at the top of first page for several weeks Ohio GT2
Given that I don't know much about EFI systems, and even less this AEM, I did some research, and it seems like it does not really have knock sensors of its own, but rather looks like a piggyback unit that "reads" from engine "noise" frequency and interprets knock.
This is the same issue that Motec and other EFI systems face, the tricky part is not whether the aftermarkt ECU detects knock, but rather how does it know this is actually knock! The most difficult aspect is to be able to program it in a way that you can get the exact frequency at different rpm levels and know that this IS knock indeed and therefore the ECU automatically retard timing, then increase it again untill knock is sensed again, over and over again and then act on the boost to cut it down when timing retardation is not enough, the way the Bosch ECU does.
Aftermarket ECUs, usually can be confused by normal engine mechanical noise, which obviously changes in frequency as RPMs change, making it very difficult to detect rightly.
By flicking through the AEM forum and a few others, namely US and Japanese cars, it seems that this still remains one of the main weaknesses, and most, if not all, people are having issues with misreading noise for knock....Same old issue like other EFI systems. This is where Bosch's multi-million dollar development and R&D program makes a difference and works with its own developped sensors.
What the above tells me is that I doubt this system will work better than the factory Bosch system and extract more power, since if I was the tuner and working on these expensive engines, I would take extra care not to blow up one of them, and would be rather conservative on timing and boost. And if I was the customer, I would make sure that I get some sort of warranty, since most likely when one of these blows up, it will be presented as engine internals weakness or poor Porsche engineering, rather than "ouupps did I go too far with my tuning?"
I hope this is not the case, and this EMS really turns out to be a revolutionary EFI EMS that has fine tuned all of this to give maximum performance together with factory-like safety.
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There was a discussion that someone is installing a standalone on a 996 and 997TT and being very promising and succesful. Also people mentioning that this would be the key to more HP.
Maybe it is not AEM that you were talking about and I misread, but any standalone would face the same issues with knock sensing, at least so far and from what I know, including Motec.
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Jean,
Most modern standalones (such as the one installed in my 993), read the outputs directly from stock knock sensors the same way the OEM ecu does. Keeping the OEM knock sensor (as opposed to some aftermarket add on) is a good idea because they are typically selected to respond in the most useful frequency regions for that particular engine.
What is different is of course the program logic to determine what is real knock, and what actions are taken once actual knock is seen. The amount of noise “filtering”, the rate and max amount of timing pulled/fuel added, along with the rate at which timing and fuel are restored to base values, is all programmable and operates in a real time feedback loop. As you guessed, setting these values is left up to the tuner. This is why having an experienced tuner is key to keeping things reliable with a standalone (or any setup for that matter). I have attached a screen shot as an example to show some of the typical user inputs.
While no aftermarket shop has the factory money backing that Bosch does, tuning correct knock thresholds is not exactly something new, so it's not the black art it may appear to be. Most standalones also have a fairly complex method to monitor knock voltages. To determine what are real knock events, the input channel is integrated according to the crankshaft tooth count values so that only events occurring in a particular window near top dead center are considered, minimizing false positives from other things such as valve train noise. Of course you can also log/view raw values to see all knock sensor inputs, but obviously a particular cylinder is not going to knock when it’s on it’s exhaust stroke or at bottom dead center, so those areas are typically ignored.
Also keep in mind, that with increased horsepower, normal engine combustion noise (non-knock related) is increased as well across the board. So while the factory knock noise filtering curves may be perfect for a stock car, they will be less then perfect for a car making say twice the factory hp levels. Without having the knock cals "retuned", you can run into a situation where knock feedback control pulls timing and adds fuel unnecessarily.
Anyway, I think that it’s very impressive how far the 996TT’s can go with a reflashed stock ecu and still be reliable. I just wanted to provide some general info about the knock feedback capabilities of most modern aftermarket standalones, because they really work very well in the right hands. I think what Switzer and others are doing is great, I look forward to seeing the results.
Most modern standalones (such as the one installed in my 993), read the outputs directly from stock knock sensors the same way the OEM ecu does. Keeping the OEM knock sensor (as opposed to some aftermarket add on) is a good idea because they are typically selected to respond in the most useful frequency regions for that particular engine.
What is different is of course the program logic to determine what is real knock, and what actions are taken once actual knock is seen. The amount of noise “filtering”, the rate and max amount of timing pulled/fuel added, along with the rate at which timing and fuel are restored to base values, is all programmable and operates in a real time feedback loop. As you guessed, setting these values is left up to the tuner. This is why having an experienced tuner is key to keeping things reliable with a standalone (or any setup for that matter). I have attached a screen shot as an example to show some of the typical user inputs.
While no aftermarket shop has the factory money backing that Bosch does, tuning correct knock thresholds is not exactly something new, so it's not the black art it may appear to be. Most standalones also have a fairly complex method to monitor knock voltages. To determine what are real knock events, the input channel is integrated according to the crankshaft tooth count values so that only events occurring in a particular window near top dead center are considered, minimizing false positives from other things such as valve train noise. Of course you can also log/view raw values to see all knock sensor inputs, but obviously a particular cylinder is not going to knock when it’s on it’s exhaust stroke or at bottom dead center, so those areas are typically ignored.
Also keep in mind, that with increased horsepower, normal engine combustion noise (non-knock related) is increased as well across the board. So while the factory knock noise filtering curves may be perfect for a stock car, they will be less then perfect for a car making say twice the factory hp levels. Without having the knock cals "retuned", you can run into a situation where knock feedback control pulls timing and adds fuel unnecessarily.
Anyway, I think that it’s very impressive how far the 996TT’s can go with a reflashed stock ecu and still be reliable. I just wanted to provide some general info about the knock feedback capabilities of most modern aftermarket standalones, because they really work very well in the right hands. I think what Switzer and others are doing is great, I look forward to seeing the results.
