PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Possible to delete MAF?

Old Apr 24, 2009 | 05:20 AM
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Default Possible to delete MAF?

Some friends and i have been talkin about this because it seems to popular on various makes and models but generally a little older.

Whats done is an EFI system with a MAF has the MAF removed and a MAP installed. You find out the output signal of the MAF and find a MAP with a similar or identical signal and just plug it in. The benefits are that the motor will adjust to a wider range and also doesnt freak out as much when a vacuum leak occurs. the cars Ive seen that have it run just fine. This all came up in talking about the PCV, CCV, and EVAP systems. EVAP i can live with, CCV is already gone, I wanna remove the PCV, at least stop it from feeding the motor.

Does the PCM know that its recieving some unmetered air from these systems and account for it or does it just read the o2's and adjust that way?
Anybody done it/ heard of it? I really dont plan on trying it but im open to the idea if itall actually work. Seems like fbods have both for a reason is what im thinkin.
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Old Apr 24, 2009 | 05:35 AM
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Huh. Plug a MAP into a MAF circuit Plug and Play. I don't think so buddy. One would suggest you do some research on how a Speed Density Tunes works.

On the LS1 you have a MAF and a MAP sensor. Disable the MAF and its pure SD ie MAP.
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Old Apr 24, 2009 | 05:56 AM
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You already have a MAP. Of course you can delete it! SD all the way
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Old Apr 24, 2009 | 09:26 PM
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SD is the way to go it seems.
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Old Apr 25, 2009 | 12:44 AM
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Huh. Plug a MAP into a MAF circuit Plug and Play. I don't think so buddy. One would suggest you do some research on how a Speed Density Tunes works.

On the LS1 you have a MAF and a MAP sensor. Disable the MAF and its pure SD ie MAP.
Hence me asking the question. Plug and play is how ive seen it work just fine with my own two eyes, but like i say, similar signals, and Older Vehicles with just a MAF, not both. Obviously I know theres a big diference or we wouldnt be having this discussion.
Are yall happyer with just map than both? This is a very new thing for me. I know how EFI works but im a carburetor guy. Any major cons/pros? its my dd and my only car for right now so i wanna hear it all before i make a choice.

By the way, thank you for being the One to suggest i reasearch a SDT, that is why i ask questions.

Last edited by CarsandWomen; Apr 25, 2009 at 12:50 AM.
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Old Apr 25, 2009 | 12:57 AM
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When you unplug your maf, the car goes into SD mode which uses VE tables... mafless tuning is awesome.
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Old Apr 25, 2009 | 05:04 AM
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It will run fine without the MAF but it should be tuned for it.
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Old Apr 25, 2009 | 08:55 AM
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98 cars have issues running in SD with the MAF removed.
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Old Apr 25, 2009 | 09:12 AM
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Originally Posted by CarsandWomen
Hence me asking the question. Plug and play is how ive seen it work just fine with my own two eyes, but like i say, similar signals, and Older Vehicles with just a MAF, not both. Obviously I know theres a big diference or we wouldnt be having this discussion.
Are yall happyer with just map than both? This is a very new thing for me. I know how EFI works but im a carburetor guy. Any major cons/pros? its my dd and my only car for right now so i wanna hear it all before i make a choice.

By the way, thank you for being the One to suggest i reasearch a SDT, that is why i ask questions.
The MAF is a frequency output Hz and the MAP is a voltage out put so the signals are totaly different.
I really don't see the advantage of goint straight sd on a street car.
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Old Apr 25, 2009 | 06:48 PM
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Originally Posted by spaz1
The MAF is a frequency output Hz and the MAP is a voltage out put so the signals are totaly different.
I really don't see the advantage of goint straight sd on a street car.
I do. For instance, quicker throttle response and less restriction in the inlet track allowing for a higher air charge.
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Old Apr 26, 2009 | 04:23 AM
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I have a 98 T/A and I have always ran SD on all my other car - 3rd gen Camaro, 3000GT VR4, so I am interested in the details and options for my 98 Bird. Free BUMP!!!


DM
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Old Apr 26, 2009 | 04:52 AM
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hopefully itall make my car a little less of a bitch in the rain, she hates wet weather with a passion. im finding in my searches, and getting in responses, good info and I really appreciate that but.......
Would anybody care to explain, or show me where to find a very detailed and in-depth expanation of it? Maybe even start a sticky on it.
I understand the concept but im curious about the process and so on and so forth. Rather than makin the thread pages long from askin questions im lookin for a complete rundown i guess.
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Old Apr 26, 2009 | 07:31 AM
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Go to www.efilive.com and download the AutoVE tutorial. At the end it says to re-enable the MAF. To run SD simply skip this step but do everything else. If your going to run SD, it's important that you spend enough time on the VE table so that your fueling will be accurate.
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Old Apr 26, 2009 | 08:33 AM
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Originally Posted by 98Aggie
98 cars have issues running in SD with the MAF removed.
I found this out one day when I tried unhooking it
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Old Apr 26, 2009 | 11:33 AM
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Originally Posted by CarsandWomen
hopefully itall make my car a little less of a bitch in the rain, she hates wet weather with a passion.
If your car runs poorly in the rain then something is wrong. You should correct this problem before you consider further modifications.
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Old Apr 26, 2009 | 03:50 PM
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Originally Posted by 98Aggie
98 cars have issues running in SD with the MAF removed.
Originally Posted by Joshiedoom
I found this out one day when I tried unhooking it
So we who have 98's can not use SD? I am beginning to dislike my 98 due to all these 98 specific issues I keep reading or hearing about



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Old Apr 26, 2009 | 03:54 PM
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Originally Posted by 98Aggie
98 cars have issues running in SD with the MAF removed.
Disagree, my tune is pretty good. 14.7-15.1 afr part throttle, idle and cruising. WOT I have it set for 11.57 and its 11.5-11.6
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Old Apr 26, 2009 | 07:27 PM
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I wouldnt jump to conclustions so fast. we have the better flex plate. Ive also been pm'ing 98aggie about it. hes told me its kind of a toss up. Also theres no way that we know of to find out if it will run speed density till u tune it. I just got done running mine with the MAF unpugged and it ran fine but im told this means nothing.
I did notice a little crisper throttle response on sd tho. its pugged back in, well have to see how it turns out
Would it be best to have it dyno tuned for SD or a mail order tune sufice?
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Old Apr 26, 2009 | 07:37 PM
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DaveX, thank you sir, exactly what i had in mind.
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Old Apr 26, 2009 | 11:03 PM
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Originally Posted by CarsandWomen
.... Also theres no way that we know of to find out if it will run speed density till u tune it......

that's just not true...
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