motronic questions
10-30-2006, 11:40 PM
#91
"I was very interested in your comment that both 993 and 996 have MAF reliability issues. My European market experience is that the 993 HFM2 is very reliable whereas the 996 HFM5 is cr*p ! Got me wondering why the HFM2 is giving problems in the USA ?"
- Geoff -
I agree. Many of my Porsche repair shops and dealers see less 993 MAF sensor failures than 996.
- Geoff -
I agree. Many of my Porsche repair shops and dealers see less 993 MAF sensor failures than 996.
10-31-2006, 05:14 AM
#92
Racer
ok I may need a maths lesson here.
Edited as message no longer needed now that jason has edited his text above,
Edited as message no longer needed now that jason has edited his text above,
Last edited by Laurence Gibbs; 10-31-2006 at 06:01 AM. Reason: text removed as Jason has edited previous message
10-31-2006, 05:34 AM
#93
Technical Guru
Rennlist Member
Rennlist Member
Originally Posted by Laurence Gibbs
ok I may need a maths lesson here.
Originally Posted by Laurence Gibbs
Why do we divide by C/S rotation to get mass?
10-31-2006, 08:18 AM
#94
Nordschleife Master
I think what Colin is saying is that it makes sense from a software programming perspective, however, in practice, at high throttle openings (75%-80%), the airflow may pin the AFM at 5 volts. This means that even though mechanically, there is more airflow going through the engine, the AFM won't recognize it.
10-31-2006, 08:54 AM
#95
Burning Brakes
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This is a bit off topic, but the right people are reading this thread.
Is it possible to create a chip for the eary style dme's [with the fqs] that instead of doing what the settings normally do, make them all change the ignition timing to small degrees.
so say 0 is 0, but
1=2%
2=4%
or whatever makes sense.
Is it possible to create a chip for the eary style dme's [with the fqs] that instead of doing what the settings normally do, make them all change the ignition timing to small degrees.
so say 0 is 0, but
1=2%
2=4%
or whatever makes sense.
10-31-2006, 09:17 AM
#96
Three Wheelin'
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Heirsh,
Yup, you can have pretty well whatever you like !
Jason,
That is a much better explanation which I fits with my understanding !By the time you are done a book looks in order ! On second thoughts could be dangerous .Just think of all the blown motors running 50 degrees of advance !!
All the best
Geoff
Yup, you can have pretty well whatever you like !
Jason,
That is a much better explanation which I fits with my understanding !By the time you are done a book looks in order ! On second thoughts could be dangerous .Just think of all the blown motors running 50 degrees of advance !!
All the best
Geoff
10-31-2006, 09:50 AM
#97
Burning Brakes
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/drool
You could run race gas and adjust your fqs to compensate, or a bad tank of 87 and retard, or back to normal for 93...
So the next obvious question... Why hasnt anyone done this?
You could run race gas and adjust your fqs to compensate, or a bad tank of 87 and retard, or back to normal for 93...
So the next obvious question... Why hasnt anyone done this?
10-31-2006, 12:22 PM
#98
"You could run race gas and adjust your fqs to compensate, or a bad tank of 87 and retard, or back to normal for 93..." - Heirsh -
That's what the knock sensors are for, or not use Mickey Mouse performance chips
which "push" the timing, e.g. 48-50 degrees.
"So the next obvious question... Why hasnt anyone done this?" - Heirsh -
It's not that easy to disassemble, correctly understand, and re-write the assembly language,
e.g. the fix for the idle undershoot with the LWF which has better merit but has yet to be
done properly. It's all a function of time & money, for most neither is there.
"On second thoughts could be dangerous .Just think of all the blown motors running 50 degrees of advance !!" - Geoff -
And that's what some performance chips do now.
That's what the knock sensors are for, or not use Mickey Mouse performance chips
which "push" the timing, e.g. 48-50 degrees.
"So the next obvious question... Why hasnt anyone done this?" - Heirsh -
It's not that easy to disassemble, correctly understand, and re-write the assembly language,
e.g. the fix for the idle undershoot with the LWF which has better merit but has yet to be
done properly. It's all a function of time & money, for most neither is there.
"On second thoughts could be dangerous .Just think of all the blown motors running 50 degrees of advance !!" - Geoff -
And that's what some performance chips do now.
Last edited by Lorenfb; 11-01-2006 at 11:36 AM.
10-31-2006, 12:50 PM
#99
Three Wheelin'
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Heirsh,
The 962 has a FQS / mapping rotary **** on the firewall behind the drivers head. I recalibrated a pair of those for Historic Le Mans cars .
How anyone was supposed to remember where the switch position was when reaching behind and to the side of your head while wearing a helmet and seriously strapped in was beyond me !
The general idea was to be able to back off fuelling in pace car periods and wind everything right up if needed.
Fabulous car and the motor was something I could seriously covet !!
All the best
Geoff
The 962 has a FQS / mapping rotary **** on the firewall behind the drivers head. I recalibrated a pair of those for Historic Le Mans cars .
How anyone was supposed to remember where the switch position was when reaching behind and to the side of your head while wearing a helmet and seriously strapped in was beyond me !
The general idea was to be able to back off fuelling in pace car periods and wind everything right up if needed.
Fabulous car and the motor was something I could seriously covet !!
All the best
Geoff
10-31-2006, 01:10 PM
#100
Burning Brakes
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Sounds awesome Geoff. I toyed with richening mine up a bit from time to time, but even with a perfectly fitting triangular point driver I never knew where I was without putting it back to 0. I bet those guys had a real time. Sounds similar to the afm idle screw. 
10-31-2006, 06:26 PM
#101
Burning Brakes
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Originally Posted by Red rooster
Heirsh,
The 962 has a FQS / mapping rotary **** on the firewall behind the drivers head. I recalibrated a pair of those for Historic Le Mans cars .
How anyone was supposed to remember where the switch position was when reaching behind and to the side of your head while wearing a helmet and seriously strapped in was beyond me !
The general idea was to be able to back off fuelling in pace car periods and wind everything right up if needed.
Fabulous car and the motor was something I could seriously covet !!
All the best
Geoff
The 962 has a FQS / mapping rotary **** on the firewall behind the drivers head. I recalibrated a pair of those for Historic Le Mans cars .
How anyone was supposed to remember where the switch position was when reaching behind and to the side of your head while wearing a helmet and seriously strapped in was beyond me !
The general idea was to be able to back off fuelling in pace car periods and wind everything right up if needed.
Fabulous car and the motor was something I could seriously covet !!
All the best
Geoff
10-31-2006, 09:19 PM
#102
Three Wheelin'
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Simon,
Dont get me started on the 962 , especially the twin turbo ! Somehow a Diesel Audi just doesnt do it for me.
I started going to Le Mans in the late 70s and I was hooked on the greatest race in the world. Thats where Porsche built their reputation and its sad to see them playing corporate politcs as a major VAG shareholder.
Oh well , maybe they will come back as a front line competitor someday.
All the best
Geoff
Dont get me started on the 962 , especially the twin turbo ! Somehow a Diesel Audi just doesnt do it for me.
I started going to Le Mans in the late 70s and I was hooked on the greatest race in the world. Thats where Porsche built their reputation and its sad to see them playing corporate politcs as a major VAG shareholder.
Oh well , maybe they will come back as a front line competitor someday.
All the best
Geoff
