PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Does the MAF reading look normal here on dyno (pic)

Thread Tools
 
Search this Thread
 
Old Oct 27, 2005 | 01:17 PM
  #1  
Dixit's Avatar
Thread Starter
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default Does the MAF reading look normal here on dyno (pic)

I just noticed this after about 12dyno runs, never really paid attention to the MAF values on the Chart display on HPtuners.



On this one I ran about 26* timing and it took it all the way to where I cut off. On that one it made about 414whp.

But looking at the MAF on the chart it looks like the rocky mountains, why does it fluctuate that much and is that normal? Because if I follow the histogram on the spark table, its bouncing around from anywhere between .60 g/cyl and .84 g/cyl.

Dixit
Reply
Old Oct 27, 2005 | 01:27 PM
  #2  
jimmyblue's Avatar
Moderator
iTrader: (11)
 
Joined: Mar 2002
Posts: 12,604
Likes: 7
From: East Central Florida
Default

The MAF output has some noise to it (frequency,
sampled can have some "interesting" artifacts
even if other electrical noise is not contributing;
Helm manual indicates that ignition noise can be
a significant interferer). I believe this is one reason
why there is so much "massaging" done to produce
the "dynamic airflow" value from raw MAF, and
DynAir is used instead by the fuel computation.
Reply
Old Oct 27, 2005 | 01:35 PM
  #3  
RedHardSupra's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Sep 2003
Posts: 1,904
Likes: 2
From: Laurel, MD
Default

yup, it's normal. if you wanna try something though, log a bunch of maf freq vs maf sae, and just graph it as a bunch of xy tuples. then clean your airfilter and do the same log, and the raw data log will be way less noisy. it's pretty awesome to see how not cleaning your filter throws off your maf readings.
Reply
Old Oct 27, 2005 | 01:48 PM
  #4  
soundengineer's Avatar
8 Second Club
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (16)
 
Joined: Jul 2003
Posts: 4,651
Likes: 17
From: Chicago IL
Default

thats one of the reasons I went MAFless
its supposed to be stable...but My tests and readings were unstable too...
Reply
Old Oct 27, 2005 | 01:54 PM
  #5  
Dixit's Avatar
Thread Starter
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default

Ok thats what I needed to know. I got a feeling that with the dips in the MAF reading that I see I sometimes see it knock out of nowhere like 2-4* sometimes. So that may be part of it. But for now 26* WOT timing looking good and no problems.

Dixit
Reply
Old Oct 27, 2005 | 04:34 PM
  #6  
Bombguy99z28's Avatar
TECH Enthusiast
 
Joined: Mar 2003
Posts: 618
Likes: 0
From: San Diego
Default

I hate MAFs, but I don't have a wideband so I am stuck with it.
Reply




All times are GMT -5. The time now is 07:55 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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