Performance/Economy: Megasquirt, Cryogenics, Water Injection, lean burn O2,Firestorm?
11-20-2005, 10:48 PM
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Originally Posted by heinrich
and a **** the size of grenada 
... BUT for us, I think we're doing OK. at least, I say that for my own Porsches. Others can speak for themselves.
... BUT for us, I think we're doing OK. at least, I say that for my own Porsches. Others can speak for themselves.
The Porsche 928 is too precious to have a grenade near it. I'd suggest putting it somewhere else.
11-20-2005, 10:54 PM
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Originally Posted by FlyingDog
Dave's car has no AFM, MAF or computer. It is mechanical injection.
11-20-2005, 11:19 PM
#67
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Originally Posted by sjsj
What if you could use a Jaycar DFA to modify the throttle response of even a AFM (flapper type) air flow meter? Yes, it can do it.
11-21-2005, 02:09 AM
#68
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Originally Posted by sjsj
What if you could use a Jaycar DFA to modify the throttle response of even a AFM (flapper type) air flow meter? Yes, it can do it.
Better yet, what if the DFA would allow any arbitrary, inexpensive voltage based MAF from ebay (eg: Ford, JECS/Nissans & Subarus, Fords, or even the aftermarket Pro-Flow and Pro-M ones that provide very clean airflow passage, not GM frequency-basedo nes) to be used IN PLACE OF the existing AFM? Benefit being better flow and better throttle response because there is now no longer a spring potentiometer (flapper) in the way. Brilliant hey?
The DFA works with AFM (flapper style) air flow meters as well, allowing +50% or -50% correction of the signal at any point. One vehicle I'm doing this has the AFM working from 5V -> 0V. The MAF works from 0V -> 5V, so all I need to do is invert the signal prior to processing by the DFA. Then I use the DFA to provide fine adjustment along 128 points from 0->5V before the signal enters the ECU to as best approximate that volume of air from a spring loaded AFM.
Just need an inversion of the initial signal via an single-chip opamp circuit with a couple of resistors (or hack the DFA instead).
Still a work in progress, but it means no longer limited to crappy AFMs/MAFs from yesteryear. Always wondered how come we can upgrade computers, yet not the ECU and brains in our cars. We just buy new ones? Shame, coz the 928 is look-wise, my favorite and WAY ahead of it's time.
sjsj
Better yet, what if the DFA would allow any arbitrary, inexpensive voltage based MAF from ebay (eg: Ford, JECS/Nissans & Subarus, Fords, or even the aftermarket Pro-Flow and Pro-M ones that provide very clean airflow passage, not GM frequency-basedo nes) to be used IN PLACE OF the existing AFM? Benefit being better flow and better throttle response because there is now no longer a spring potentiometer (flapper) in the way. Brilliant hey?
The DFA works with AFM (flapper style) air flow meters as well, allowing +50% or -50% correction of the signal at any point. One vehicle I'm doing this has the AFM working from 5V -> 0V. The MAF works from 0V -> 5V, so all I need to do is invert the signal prior to processing by the DFA. Then I use the DFA to provide fine adjustment along 128 points from 0->5V before the signal enters the ECU to as best approximate that volume of air from a spring loaded AFM.
Just need an inversion of the initial signal via an single-chip opamp circuit with a couple of resistors (or hack the DFA instead).
Still a work in progress, but it means no longer limited to crappy AFMs/MAFs from yesteryear. Always wondered how come we can upgrade computers, yet not the ECU and brains in our cars. We just buy new ones? Shame, coz the 928 is look-wise, my favorite and WAY ahead of it's time.
sjsj
11-21-2005, 03:26 AM
#69
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Originally Posted by sjsj
What if you could use a Jaycar DFA to modify the throttle response of even a AFM (flapper type) air flow meter? Yes, it can do it.
Better yet, what if the DFA would allow any arbitrary, inexpensive voltage based MAF from ebay (eg: Ford, JECS/Nissans & Subarus, Fords, or even the aftermarket Pro-Flow and Pro-M ones that provide very clean airflow passage, not GM frequency-basedo nes) to be used IN PLACE OF the existing AFM? Benefit being better flow and better throttle response because there is now no longer a spring potentiometer (flapper) in the way. Brilliant hey?
The DFA works with AFM (flapper style) air flow meters as well, allowing +50% or -50% correction of the signal at any point. One vehicle I'm doing this has the AFM working from 5V -> 0V. The MAF works from 0V -> 5V, so all I need to do is invert the signal prior to processing by the DFA. Then I use the DFA to provide fine adjustment along 128 points from 0->5V before the signal enters the ECU to as best approximate that volume of air from a spring loaded AFM.
Just need an inversion of the initial signal via an single-chip opamp circuit with a couple of resistors (or hack the DFA instead).
Still a work in progress, but it means no longer limited to crappy AFMs/MAFs from yesteryear. Always wondered how come we can upgrade computers, yet not the ECU and brains in our cars. We just buy new ones? Shame, coz the 928 is look-wise, my favorite and WAY ahead of it's time.
sjsj
Better yet, what if the DFA would allow any arbitrary, inexpensive voltage based MAF from ebay (eg: Ford, JECS/Nissans & Subarus, Fords, or even the aftermarket Pro-Flow and Pro-M ones that provide very clean airflow passage, not GM frequency-basedo nes) to be used IN PLACE OF the existing AFM? Benefit being better flow and better throttle response because there is now no longer a spring potentiometer (flapper) in the way. Brilliant hey?
The DFA works with AFM (flapper style) air flow meters as well, allowing +50% or -50% correction of the signal at any point. One vehicle I'm doing this has the AFM working from 5V -> 0V. The MAF works from 0V -> 5V, so all I need to do is invert the signal prior to processing by the DFA. Then I use the DFA to provide fine adjustment along 128 points from 0->5V before the signal enters the ECU to as best approximate that volume of air from a spring loaded AFM.
Just need an inversion of the initial signal via an single-chip opamp circuit with a couple of resistors (or hack the DFA instead).
Still a work in progress, but it means no longer limited to crappy AFMs/MAFs from yesteryear. Always wondered how come we can upgrade computers, yet not the ECU and brains in our cars. We just buy new ones? Shame, coz the 928 is look-wise, my favorite and WAY ahead of it's time.
sjsj
You make it sound so easy! I did a MAF conversion on an '87 BMW 325is (to a 1998 328i MAF). It ran, but it was never perfect.
Sure, you can jury rig something that will appear to run fine, but until you spend some time properly tuning it with a wideband (at all throttle/rpm points)... its still going to be a jury rig. Oh... and there is that little issue about the temperature sensor. Does the DFA account for that?
11-21-2005, 03:53 AM
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Originally Posted by mspiegle
You make it sound so easy! I did a MAF conversion on an '87 BMW 325is (to a 1998 328i MAF). It ran, but it was never perfect.
Originally Posted by mspiegle
Sure, you can jury rig something that will appear to run fine, but until you spend some time properly tuning it with a wideband (at all throttle/rpm points)... its still going to be a jury rig. Oh... and there is that little issue about the temperature sensor. Does the DFA account for that?
Well the car I'm working in has a THA input into the ECU. Meaning I simply move the temp sensor out of the AFM into the intake piping downstream and just plug her in, then wire up a MAF using a Jaycar DFA. MAFS I've seen on Ebay have an extra pinout or two to supply to the ECU. It's the ECU that evaluates that signal and provides enrichment for colder, denser air.
sjsj
11-21-2005, 02:53 PM
#71
Originally Posted by mspiegle
Water injection didn't appear to help much on Mr. Nevada's car (Tony). He noticed a big temperature drop, but it didn't seem to add any "power" or reduce any detonation (he never had any from what I gather). Maybe if he was on the edge of stable combustion - he would have noticed something. Water injection itself doesn't create power, just allows you to run more power-creating boost.
Just adding w.injection alone does nothing. You have to either adv. timing or boost, or CR, or some combonation of the three.
It does work though, and it works well, the science is completely sound.
11-21-2005, 04:15 PM
#72
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Originally Posted by sjsj
Well the car I'm working in has a THA input into the ECU. sjsj
AND WHAT KIND OF CAR IS THIS (BRAND, MODEL, YEAR...ECT.), PREHAPS A PIC OR TWO????????
11-21-2005, 04:48 PM
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Originally Posted by m21sniper
Or timing advance. And no offense, but if it isn't setup properly, no, it will make noi extra power. If it is, it will.
Just adding w.injection alone does nothing. You have to either adv. timing or boost, or CR, or some combonation of the three.
It does work though, and it works well, the science is completely sound.
Just adding w.injection alone does nothing. You have to either adv. timing or boost, or CR, or some combonation of the three.
It does work though, and it works well, the science is completely sound.
Offense? We're on the same page except I didn't mention CR/timing... no offense taken. Or maybe offense to Tony for the "isn't setup properly" comment?
11-21-2005, 04:54 PM
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Originally Posted by sjsj
Could be a case of the pioneers set the lead, with others following correcting their mistakes
Wideband would be the one of the more accurate ways of tuning. However,the narrowband sensors I've evaluated are accurate to within 5% of wideband sensors from 12.0:1 right up tp 16.0:1, as long as the engine is at normal running temperature. Meaning a simple digital voltmeter and the chart is http://wbo2.com/sw/20-tables.xls with a stock narrowband sensor is sufficient to monitor the AFR.
Well the car I'm working in has a THA input into the ECU. Meaning I simply move the temp sensor out of the AFM into the intake piping downstream and just plug her in, then wire up a MAF using a Jaycar DFA. MAFS I've seen on Ebay have an extra pinout or two to supply to the ECU. It's the ECU that evaluates that signal and provides enrichment for colder, denser air.
sjsj
Wideband would be the one of the more accurate ways of tuning. However,the narrowband sensors I've evaluated are accurate to within 5% of wideband sensors from 12.0:1 right up tp 16.0:1, as long as the engine is at normal running temperature. Meaning a simple digital voltmeter and the chart is http://wbo2.com/sw/20-tables.xls with a stock narrowband sensor is sufficient to monitor the AFR.
Well the car I'm working in has a THA input into the ECU. Meaning I simply move the temp sensor out of the AFM into the intake piping downstream and just plug her in, then wire up a MAF using a Jaycar DFA. MAFS I've seen on Ebay have an extra pinout or two to supply to the ECU. It's the ECU that evaluates that signal and provides enrichment for colder, denser air.
sjsj
I simply don't agree with your narrowband-tuning comment. Been there, done that. That's why I bought the TechEdge Wideband unit.