PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

I thought STFT & LTFT range from -25 through +25?

Thread Tools
 
Search this Thread
 
Old Jun 17, 2005 | 09:10 AM
  #1  
God Forgives I Dont's Avatar
Thread Starter
Launching!
 
Joined: Mar 2004
Posts: 233
Likes: 0
From: Dallas Texas
Default I thought STFT & LTFT range from -25 through +25?

I thought STFT & LTFT range from -25 through +25?

I have been looking through the CSV files of my recent scans and noticed that my STFT's have been ranging from -50 to +18 and I thought that the PCM only had range to self adjust to -25 and +25?

I'm just trying to figure out if those are valid readings or if something else is going on and causing HP Tuners to read bogus values?

Thanks for the Help!
Reply
Old Jun 17, 2005 | 09:20 AM
  #2  
RedHardSupra's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Sep 2003
Posts: 1,904
Likes: 2
From: Laurel, MD
Default

PCM should throw a code if the values are bigger than 25 (either way, plus or minus). sometimes you just get garbled/junk data, and you want to filter these out. HPT doesn't do the greatest job on filtering, so i just get the raw data, clean it up, and create my own histograms. kinda annoying, but i gotta do something while waiting for 2.0
Reply
Old Jun 17, 2005 | 09:34 AM
  #3  
dvanorder's Avatar
Staging Lane
 
Joined: May 2005
Posts: 54
Likes: 0
Default

What he said.

I've seen trims in my histogram read 00 and even 99, almost always in the lowest MAP range at lower RPM. Really threw me at first. If you look at these spots in the chart data you can see the other data params are usually crap too. Like Marcin said, you chuck it so it doesn't mess with any other data you're massaging.
Reply
Old Jun 17, 2005 | 10:01 AM
  #4  
God Forgives I Dont's Avatar
Thread Starter
Launching!
 
Joined: Mar 2004
Posts: 233
Likes: 0
From: Dallas Texas
Default

Cool that’s what I was thinking too. I'll just sort data by STFT and Delete any lines with values above or below the 25 mark. I knew it geeks out on some of the LTFT I'll see values of -100 or +100 and have always deleted them out, but up tell now I've never really sorted by STFT and checked to see if those values were with in the valid range. Believe it or not in the log I did on the way into work this morning there were 100 lines that were below the -25 boundary and I normally only see like 2 to 6 lines of invalid -100 for the LTFT so it made me wonder why so many out of range for STFT (100 out of a total of 4700 lines in the CSV file).

Thanks again for your input on this!

Last edited by God Forgives I Dont; Jun 17, 2005 at 10:19 AM.
Reply
Old Jun 17, 2005 | 10:38 AM
  #5  
RedHardSupra's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Sep 2003
Posts: 1,904
Likes: 2
From: Laurel, MD
Default

the only way to do it 'easy' is to log a crapload of data, if you have 100 '+3' and 1 '-30' then the result is gonna be (3*100-30)/101=2.67 instead of 3, so that's not too far off.
the problem is when you get these 'funky' values in 'edge' cells, high or low map/rpm values, because you don't hit them as often.

with raw data in excel, use the auto filtering, and set up rules that make sense (map!=0, -25<LTFT/STFT<25, 0<=TPS<=100 etc) THEN you use that data...you'd be suprised how much junk is in there.
Reply




All times are GMT -5. The time now is 05:58 AM.

story-0
6 Gifts Neither Your Dad Nor Grad Will Shove Into the 'Trinket Drawer'

Don't get dad new socks or a grill brush this year.

By Brett Foote | 2026-06-04 18:13:20


VIEW MORE
story-1
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-2
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-3
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


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