PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

wrong MAF tuning!; (G/sec#s) for a ported MAF?

Old Nov 21, 2006 | 07:40 PM
  #1  
bulletLS1's Avatar
Thread Starter
Launching!
 
Joined: Jul 2005
Posts: 211
Likes: 1
From: Guatemala City.
Default wrong MAF tuning!; (G/sec#s) for a ported MAF?

Hi guys.
does anyone have the MAF numbers (flow Vs Freq) for a ported polished stock maf, without the "wing profile" and without the plastic suporting the "support" wires....

I kept tuning with the values indicating by my maf (3.2 G/s) at iddle @ 5000ft omsl. for tuning the start up point for the iddle maf flow until I realized that maybe my maf is off.

how did the aftermarket sellers of the ported Mafs tune their frequencies.

gain Im trying to skip a maf translator...

Thanks
Reply
Old Nov 22, 2006 | 06:47 PM
  #2  
Doc99SS's Avatar
TECH Regular
iTrader: (2)
 
Joined: Nov 2001
Posts: 456
Likes: 0
From: Mims, Florida
Default

This is actually fairly simply in principle. You tune a modified MAF for flow by watching the LTFT. If you know what were the LTFTs in several FTCs for the stock MAF, then when the modded MAF is installed, you change the flow vs freq table so that the new LTFTs equal what they were in the first place. This is the way I have tuned my GMAF.
Reply
Old Nov 22, 2006 | 07:03 PM
  #3  
bulletLS1's Avatar
Thread Starter
Launching!
 
Joined: Jul 2005
Posts: 211
Likes: 1
From: Guatemala City.
Default

I tried the numbers from the ZO6 corvette numbers... gosh! barely run, had to stop in the middle of the higway for upload last program!

non the less added 15% to the corvette #´s (still less flow than oem) and worked better, I think its truer than oem (with airfoil)
Reply
Old Nov 22, 2006 | 07:45 PM
  #4  
Doc99SS's Avatar
TECH Regular
iTrader: (2)
 
Joined: Nov 2001
Posts: 456
Likes: 0
From: Mims, Florida
Default

And you will find that you might need 15% more at lower frequencies and maybe only 5% different at top end. Modifing the MAF table is very tedious because it is non-linear. I have always had to make more change at the bottom end , and much less change at top end, and in between, well, its in between change. I will make a unique change to one cell at a time. Heck, it could take me a 1/2 hour to modify the MAF table after studing my log data files.
Reply
Old Nov 22, 2006 | 08:55 PM
  #5  
Xtnct00WS6's Avatar
TECH Fanatic
iTrader: (8)
 
Joined: Jan 2005
Posts: 1,429
Likes: 2
From: Sterling VA
Default

best way I know of is to get a Wideband 02 and tune based off of that.
http://forum.efilive.com/showthread.php?t=671
Reply
Old Nov 23, 2006 | 07:58 AM
  #6  
Black02SS's Avatar
TECH Junkie
iTrader: (36)
 
Joined: Oct 2002
Posts: 3,291
Likes: 1
From: Kokomo, IN
Default

I agree. From what I have found the wideband calibration shows the best and most accurate results.
Reply
Old Nov 23, 2006 | 08:02 AM
  #7  
SSpdDmon's Avatar
TECH Addict
iTrader: (10)
 
Joined: Jun 2004
Posts: 2,918
Likes: 0
From: Commerce Twp, MI
Default

I use this and it makes it easier...
Attached Files
File Type: zip
SSpdDmon's MAF Sheet v.2.zip (19.7 KB, 47 views)
Reply
Old Nov 23, 2006 | 08:04 AM
  #8  
Black02SS's Avatar
TECH Junkie
iTrader: (36)
 
Joined: Oct 2002
Posts: 3,291
Likes: 1
From: Kokomo, IN
Default

I am curious as to why you would use a excel spreadsheet when the same functionality is already built into EFILive?
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-1

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-2

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-3

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-4

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-5

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-6

10 Camaros You Should Never Buy

 
story-7

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
story-8

Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

 Brett Foote
story-9

10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

 Verdad Gallardo
Old Nov 23, 2006 | 08:26 AM
  #9  
SSpdDmon's Avatar
TECH Addict
iTrader: (10)
 
Joined: Jun 2004
Posts: 2,918
Likes: 0
From: Commerce Twp, MI
Default

Not all of the same funtionality is there. I can apply a fraction of the correction based on the log instead of being forced to apply 100% of what's there. I can also adjust the correction factor (manually) easier because I can see the trends that occur easier. For example, say the surrounding cells around 3500Hz indicate a need for a 4% increase over stock after a log, but those same logged values say 3500Hz needs a 6% increase over stock. I'd be more willing to believe 3500Hz is really closer to 4% over stock based on the surrounding cells. I make the adjustment and move on.

My belief is....when you're adjusting the MAF table, you don't always want to apply the full correction from the log - especially towards the end when you're trying to dial it in. By setting the correction factor to something like 50% or 25%, I can avoid overshoot.

Keep in mind, a lot of the functionality has been built into the software. But, I have had this spreadsheet since before that functionality was there. So, part of it is me holding on to something that I created. But, a bigger part is me using something that is proven to work fast and well....for me at least.
Reply
Old Nov 23, 2006 | 08:33 AM
  #10  
Black02SS's Avatar
TECH Junkie
iTrader: (36)
 
Joined: Oct 2002
Posts: 3,291
Likes: 1
From: Kokomo, IN
Default

Originally Posted by SSpdDmon
Not all of the same funtionality is there. I can apply a fraction of the correction based on the log instead of being forced to apply 100% of what's there. I can also adjust the correction factor (manually) easier because I can see the trends that occur easier. For example, say the surrounding cells around 3500Hz indicate a need for a 4% increase over stock after a log, but those same logged values say 3500Hz needs a 6% increase over stock. I'd be more willing to believe 3500Hz is really closer to 4% over stock based on the surrounding cells. I make the adjustment and move on.

My belief is....when you're adjusting the MAF table, you don't always want to apply the full correction from the log - especially towards the end when you're trying to dial it in. By setting the correction factor to something like 50% or 25%, I can avoid overshoot.

Keep in mind, a lot of the functionality has been built into the software. But, I have had this spreadsheet since before that functionality was there. So, part of it is me holding on to something that I created. But, a bigger part is me using something that is proven to work fast and well....for me at least.
That is the explaination I was looking for and I will agree with you 100%. How about I see what I can do and get this into EFILive?
Reply
Old Nov 23, 2006 | 08:34 AM
  #11  
SSpdDmon's Avatar
TECH Addict
iTrader: (10)
 
Joined: Jun 2004
Posts: 2,918
Likes: 0
From: Commerce Twp, MI
Default

Sweet!
Reply
Old Nov 23, 2006 | 09:47 AM
  #12  
Beer99C5's Avatar
TECH Addict
iTrader: (21)
 
Joined: Nov 2005
Posts: 2,209
Likes: 0
From: Maine USA
Default

Ahh the elusive spreadsheet! Downloaded and will give it a try
Reply


Thread Tools
Search this Thread

All times are GMT -5. The time now is 05:38 PM.

story-0
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-1
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-2
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-3
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-4
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-5
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-6
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-7
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE
story-8
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0

The world was a better place when it was still around.

By Brett Foote | 2026-01-23 09:20:37


VIEW MORE
story-9
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever

Slideshow: The 7.0-liter LS7 was designed for absolute cutting-edge performance.

By Verdad Gallardo | 2026-01-07 18:36:00


VIEW MORE