Piggy back CPU & CPU flashing for better Perf.
02-16-2007, 07:22 PM
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Piggy back CPU & CPU flashing for better Perf.
Hello,
I have a 1992 964 c-4 with a turbo upgrade. The car has a piggy backed CPU onto the factory CPU for a hand help programmer. I was told this was installed back in 1995 when they only had 16 fuel curves for the factory CPU to choose from. Now I've been told with technology they can flash the CPU and get over 250 fuel curves to choose from. If this is the case then I would be able to remove the piggy back CPU system. I've tried a search for flashing the CPU and did not find anything under a 964. Any help would be great. I live in Florida and the weather changes by the minute. So I would think any extra fuel curves the CPU can choose from would be a plus in performance and fuel economy.
Thanks again...........
I have a 1992 964 c-4 with a turbo upgrade. The car has a piggy backed CPU onto the factory CPU for a hand help programmer. I was told this was installed back in 1995 when they only had 16 fuel curves for the factory CPU to choose from. Now I've been told with technology they can flash the CPU and get over 250 fuel curves to choose from. If this is the case then I would be able to remove the piggy back CPU system. I've tried a search for flashing the CPU and did not find anything under a 964. Any help would be great. I live in Florida and the weather changes by the minute. So I would think any extra fuel curves the CPU can choose from would be a plus in performance and fuel economy.
Thanks again...........
02-16-2007, 07:52 PM
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Three Wheelin'
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A 964 DME uses Ultra violet erasable "chip" technology so cannot be re-flashed .
Maybe they were talking about the piggy back box ?
The 16 fuel curves in the factory DME is not true .
Sounds a bit like a fishing story !!
Geoff
Maybe they were talking about the piggy back box ?
The 16 fuel curves in the factory DME is not true .
Sounds a bit like a fishing story !!
Geoff
02-17-2007, 08:21 AM
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Originally Posted by Red rooster
A 964 DME uses Ultra violet erasable "chip" technology so cannot be re-flashed .
Maybe they were talking about the piggy back box ?
The 16 fuel curves in the factory DME is not true .
Sounds a bit like a fishing story !!
Geoff
Maybe they were talking about the piggy back box ?
The 16 fuel curves in the factory DME is not true .
Sounds a bit like a fishing story !!
Geoff
Yes my car has a purple CPU box that is piggy backing off the factory CPU. The purple CPU has a hand held device that can change the fuel curves. So since the 964 CPU can not be flashed I'll just leave it alone. Any advice. ....So are you saying that the factory CPU on a 92 964 has well over 16 choices to choose from?
Thanks again
02-17-2007, 09:29 AM
#5
Nordschleife Master
Pictures would help. It appears that what you have is a factory N/A engine and engine management system that has been modified mechanically for a turbo system and an piggyback controller added to compensate fuel and ignition timing when the car is on boost. Now, I'll be the first person to say that anything is possible and this may very well be a well thought out fully functioning system. However, it has been my experience that these types of systems, ones where you add a second computer, rarely work out well. This may be due to inexperienced setup, or inflexible systems that cannot do the complete job. They are usually used when cost is a consideration and a full stand alone system was deemed too expensive. Of course there are a lot of assumptions in the above statements due to the little information that has been given.
02-17-2007, 12:02 PM
#7
"Yes my car has a purple CPU box that is piggy backing off the factory CPU."
TOTAL MICKEY MOUSE!!!!!!!!!!!!!!!
Anyone who fully understands the Bosch 964 ECM can easily re-program the
EPROM, i.e. with the use of a dyno, to properly run the modified engine
(obviously not ideally) without this "box".
TOTAL MICKEY MOUSE!!!!!!!!!!!!!!!
Anyone who fully understands the Bosch 964 ECM can easily re-program the
EPROM, i.e. with the use of a dyno, to properly run the modified engine
(obviously not ideally) without this "box".
Last edited by Lorenfb; 02-17-2007 at 12:47 PM.
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02-17-2007, 02:48 PM
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Red Line, i think you may have a PMS, Programmable Management System made by EFI Systems, Inc.
I have heard great things about the system and tried to find one last year but had no luck. I spoke to EFI systems and they no longer manufacture or support the system.
You can find the manual for the system on http://www.efisystems.com
It is very comprehensive and tells you how to setup the curves.
If you want to replace it, I would consider buying it from you.
Colin
I have heard great things about the system and tried to find one last year but had no luck. I spoke to EFI systems and they no longer manufacture or support the system.
You can find the manual for the system on http://www.efisystems.com
It is very comprehensive and tells you how to setup the curves.
If you want to replace it, I would consider buying it from you.
Colin
02-17-2007, 05:38 PM
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Originally Posted by Geoffrey
Pictures would help. It appears that what you have is a factory N/A engine and engine management system that has been modified mechanically for a turbo system and an piggyback controller added to compensate fuel and ignition timing when the car is on boost. Now, I'll be the first person to say that anything is possible and this may very well be a well thought out fully functioning system. However, it has been my experience that these types of systems, ones where you add a second computer, rarely work out well. This may be due to inexperienced setup, or inflexible systems that cannot do the complete job. They are usually used when cost is a consideration and a full stand alone system was deemed too expensive. Of course there are a lot of assumptions in the above statements due to the little information that has been given.
I'll take some pictures when I get her back from the garage.......
Sorry for the limited info.
02-18-2007, 06:55 PM
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Originally Posted by Colin 90 C2
Red Line, i think you may have a PMS, Programmable Management System made by EFI Systems, Inc.
I have heard great things about the system and tried to find one last year but had no luck. I spoke to EFI systems and they no longer manufacture or support the system.
You can find the manual for the system on http://www.efisystems.com
It is very comprehensive and tells you how to setup the curves.
If you want to replace it, I would consider buying it from you.
Colin
I have heard great things about the system and tried to find one last year but had no luck. I spoke to EFI systems and they no longer manufacture or support the system.
You can find the manual for the system on http://www.efisystems.com
It is very comprehensive and tells you how to setup the curves.
If you want to replace it, I would consider buying it from you.
Colin
Colin,
That is exactly what I have in my car.
I'll still take some pictures when I get her back.
Thanks for the EFI link.
