AFRs are lean at idle... surging idle and doesn't want to rev.. VIDEO ON PAGE 6!!
looks like we found the problem
03-10-2010, 12:59 AM
#63
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the part that sucks is i was told i didnt need anything else besides a chip tuned for the maf for it to work..
ok well, anyone have a used mafterburner or power perfect for sale?
or cheap used plug and play standalone?
ok well, anyone have a used mafterburner or power perfect for sale?
or cheap used plug and play standalone?
03-10-2010, 01:03 AM
#64
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Joka,
Why does he need a piggyback to manipulate the signal when he already has a chip burned/mathced for the MAF?
Would the chip not already be properly programmed for the MAF input via base tune? And would the piggyback not be just for fine tuning?
Why does he need a piggyback to manipulate the signal when he already has a chip burned/mathced for the MAF?
Would the chip not already be properly programmed for the MAF input via base tune? And would the piggyback not be just for fine tuning?
03-10-2010, 01:04 AM
#65
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this is exactly what i was told..
03-10-2010, 01:07 AM
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03-10-2010, 01:13 AM
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The piggyback is for fine tuning the setup. I have a LR maf that will run without the mafterburner. I use it to adjust the AFR to were I want it. Did you check what position your DME FQS rotary switch is in? I do believe there are several setting in the chips.
03-10-2010, 01:20 AM
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Enjoy your breakfast, 3rd shift?
Look at post #4, 11, 12 in the link below
https://rennlist.com/forums/944-turb...+rotary+switch
True MAF chips are where the AFM transfer function in the chip is changed to properly interpret the MAF voltage signal, where a piggyback would no longer be required. I've only done this for two of Lindsey Racing's MAFs. In doing so I came to the conclusion that I'm not real fond of MAFs! They are a pain. You can literally take 5 exact same units from the same manufacturer, put each on the same car without changing anything else, and get vastly different results. That's just how it is. So even vendors who have perfected the transfer function for a particular MAF still have to sell a piggyback for fine tuning, because they cannot know the exact behavior of your car. Again, that's just how it is. You can change the behavior of your MAF simply by clocking it differently in the pipe. If someone comes to me and says they are running rich/lean, that's the first thing I tell them is to try different clocking of the MAF. 80% of the time that will give them the change they are looking for to dial in their tune.
Look at post #4, 11, 12 in the link below
https://rennlist.com/forums/944-turb...+rotary+switch
True MAF chips are where the AFM transfer function in the chip is changed to properly interpret the MAF voltage signal, where a piggyback would no longer be required. I've only done this for two of Lindsey Racing's MAFs. In doing so I came to the conclusion that I'm not real fond of MAFs! They are a pain. You can literally take 5 exact same units from the same manufacturer, put each on the same car without changing anything else, and get vastly different results. That's just how it is. So even vendors who have perfected the transfer function for a particular MAF still have to sell a piggyback for fine tuning, because they cannot know the exact behavior of your car. Again, that's just how it is. You can change the behavior of your MAF simply by clocking it differently in the pipe. If someone comes to me and says they are running rich/lean, that's the first thing I tell them is to try different clocking of the MAF. 80% of the time that will give them the change they are looking for to dial in their tune.
03-10-2010, 02:55 AM
#72
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i'm going to see what my FQS is set at tomorrow.. i've never touched it or even checked it, if its set at stock im going to try and add fuel and see if it helps..
03-10-2010, 08:27 AM
#73
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The factory air meter basically measures air volume. The PCM (SAE term - Powertrain Control Module - DME and KLR serve this function for 944's) then takes that signal, as well as barometric pressure and air charge temperature (ACT), to CALCULATE a mass air flow. When you replace the air meter with a MAF meter, you need to change the strategy (which is VERY different than calibration) to bypass the correction from BARO and ACT.
Historically, when companies like Pro-M started making MAF for various cars (NOT Porsche specific, broadly speaking), they did not do anything about the strategy. The earliest systems contained manually controlled rheostats to allow the owner to tweak things as atmospheric conditions changed.
Now, I've not been able to find out for certain what companies like Lindsey, who make MAF kits, do to their strategies and calibrations for MAF conversions. But, if some sort of piggyback is needed, it is highly likley that that device is used to offset the input from BARO and ACT, which would otherwise impact the MAF signal, as processed by the PCM.
03-10-2010, 08:43 AM
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Are you running a 3 bar regulator and if you are, what is the fuel pressure with and without vacuum attached to the regulator? It is very important that the fuel pressure is correct.
03-10-2010, 10:09 AM
#75
Nordschleife Master
You got your setup second hand, or have had it sitting for a while. (My first feeling is second hand, but I threw in the NOS as a add in)
You got the chips WITH the MAF, but not calibrated to everything else you have installed.
You are just using chips, and not any other means of tuning the car.
You did the install either based on what you were told, or your understanding of what you were told, and didn't ask Lindsey about their product.
You did several other changes at the same time as adding the MAF.
You don't have a meathod to read the chips you have, and take a look at what the actual fuel values are set to on your chips..
The links above will show you that the manufacturer of the Linsey chips (Russel Berry) said he did 2 setups where the transfer function was changed, and you have already heard from someone that says they have one of them... what are the chances you DON'T have the other one?
Russel CAN make a set of chips specific to your car, but might not be willing to, or might need more info from you to acomplish this, and will most likely still tell you to get a piggyback, as even the MAF he sells himself (or used to) had a piggyback, as the DME code is not 100% compliant to the MAF code... but it does get close..
If your chips are not set up for your turbo, exhaust, intake, fuel injector size, fuel pressure regulator, and any special internal mods you may have, they have a snow ***** chance in hadies of even being close to correct for your car.
Easiest work around may be to install your AFM and see if the problems you are having resolve, if it gets batter you either have a bad MAF sensor, or desperately need the piggy back.
Have you tried to ask Lindsey about your setup?
This is where some of the other vendors really shine, they package stuff together, so everything is matched to work together, this particualr cars setup sounds to have been piecemealed together (much the same way mine was, but I decided rather than playing with chips I would do the full tune myself).
The piggy back does more than just change the MAF signal (just check out the wiring diagrams, and you will see it ties into much more than just the MAF line into the DME.
By who? Lindsey or the person who sold you your MAF? They may have had a piggy back, and not known it...
You can have it good, fast or cheap... pick 2.
Well, first of all, that is only 1 question, not a few
, but my money is on YES it was second hand...Enjoy your breakfast, 3rd shift?
Look at post #4, 11, 12 in the link below
https://rennlist.com/forums/944-turb...+rotary+switch
True MAF chips are where the AFM transfer function in the chip is changed to properly interpret the MAF voltage signal, where a piggyback would no longer be required. I've only done this for two of Lindsey Racing's MAFs. In doing so I came to the conclusion that I'm not real fond of MAFs! They are a pain. You can literally take 5 exact same units from the same manufacturer, put each on the same car without changing anything else, and get vastly different results. That's just how it is. So even vendors who have perfected the transfer function for a particular MAF still have to sell a piggyback for fine tuning, because they cannot know the exact behavior of your car. Again, that's just how it is. You can change the behavior of your MAF simply by clocking it differently in the pipe. If someone comes to me and says they are running rich/lean, that's the first thing I tell them is to try different clocking of the MAF. 80% of the time that will give them the change they are looking for to dial in their tune.
Look at post #4, 11, 12 in the link below
https://rennlist.com/forums/944-turb...+rotary+switch
True MAF chips are where the AFM transfer function in the chip is changed to properly interpret the MAF voltage signal, where a piggyback would no longer be required. I've only done this for two of Lindsey Racing's MAFs. In doing so I came to the conclusion that I'm not real fond of MAFs! They are a pain. You can literally take 5 exact same units from the same manufacturer, put each on the same car without changing anything else, and get vastly different results. That's just how it is. So even vendors who have perfected the transfer function for a particular MAF still have to sell a piggyback for fine tuning, because they cannot know the exact behavior of your car. Again, that's just how it is. You can change the behavior of your MAF simply by clocking it differently in the pipe. If someone comes to me and says they are running rich/lean, that's the first thing I tell them is to try different clocking of the MAF. 80% of the time that will give them the change they are looking for to dial in their tune.
DISCLAIMER: The following is not specific to Porsche, but rather generic. I've dealt with a lot of Ford 2.3 turbo stuff, which uses the same Bosch air meter, and has seen a similar type of aftermarket evolution as the 944.
The factory air meter basically measures air volume. The PCM (SAE term - Powertrain Control Module - DME and KLR serve this function for 944's) then takes that signal, as well as barometric pressure and air charge temperature (ACT), to CALCULATE a mass air flow. When you replace the air meter with a MAF meter, you need to change the strategy (which is VERY different than calibration) to bypass the correction from BARO and ACT.
Historically, when companies like Pro-M started making MAF for various cars (NOT Porsche specific, broadly speaking), they did not do anything about the strategy. The earliest systems contained manually controlled rheostats to allow the owner to tweak things as atmospheric conditions changed.
Now, I've not been able to find out for certain what companies like Lindsey, who make MAF kits, do to their strategies and calibrations for MAF conversions. But, if some sort of piggyback is needed, it is highly likley that that device is used to offset the input from BARO and ACT, which would otherwise impact the MAF signal, as processed by the PCM.
The factory air meter basically measures air volume. The PCM (SAE term - Powertrain Control Module - DME and KLR serve this function for 944's) then takes that signal, as well as barometric pressure and air charge temperature (ACT), to CALCULATE a mass air flow. When you replace the air meter with a MAF meter, you need to change the strategy (which is VERY different than calibration) to bypass the correction from BARO and ACT.
Historically, when companies like Pro-M started making MAF for various cars (NOT Porsche specific, broadly speaking), they did not do anything about the strategy. The earliest systems contained manually controlled rheostats to allow the owner to tweak things as atmospheric conditions changed.
Now, I've not been able to find out for certain what companies like Lindsey, who make MAF kits, do to their strategies and calibrations for MAF conversions. But, if some sort of piggyback is needed, it is highly likley that that device is used to offset the input from BARO and ACT, which would otherwise impact the MAF signal, as processed by the PCM.
Good advice for the OP, but there are also other variables that need to be taken into account (turbo size, injector size, exhaust just to name a few...) and these are variables the piggy back allows the user to tune for... if not adjusting the fuel and timing tables, the inputs to the DME have to be managed or it will never be right.