L Term Counts
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
L Term Counts
L Term Counts are the counts that I should be looking at right?
I should try to get them @ 128 +/- a bit?
If I'm showing 130-134 at cruise ( 73 mph @ 1650 RPM in 6th) then that means I'm a tad lean and I'll add fuel right?
But where should I be trying to get my 128 +/-? Should I be trying to hit those numbers at idle or cruise? At WOT, the numbers hit 128 and stay.
Basically should I try to get a BLM of 128 L Term at idle or at cruise?
I should try to get them @ 128 +/- a bit?
If I'm showing 130-134 at cruise ( 73 mph @ 1650 RPM in 6th) then that means I'm a tad lean and I'll add fuel right?
But where should I be trying to get my 128 +/-? Should I be trying to hit those numbers at idle or cruise? At WOT, the numbers hit 128 and stay.
Basically should I try to get a BLM of 128 L Term at idle or at cruise?
Pro
Joined: Sep 2001
Posts: 542
Likes: 1
From: Stuck in the 80's
Idealy 128 across the board. Real world that's pretty tough to nearly impossible for all RPM's/Loads. I like to error on the rich side just to be safe, so my BLM's are 124-128. After I got my part throttle/cruise in line I was still always rich at idle, so that's when I decreased my MAF1 table by 10%, worked perfect, now my idle is good too.
WOT will always show 128 because you are in Power Enrichment mode. Here you need to tune for little to no knock and your desired A/F ratio.
WOT will always show 128 because you are in Power Enrichment mode. Here you need to tune for little to no knock and your desired A/F ratio.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by black_89_vette
L Term Counts are the counts that I should be looking at right?
I should try to get them @ 128 +/- a bit?
If I'm showing 130-134 at cruise ( 73 mph @ 1650 RPM in 6th) then that means I'm a tad lean and I'll add fuel right?
But where should I be trying to get my 128 +/-? Should I be trying to hit those numbers at idle or cruise? At WOT, the numbers hit 128 and stay.
Basically should I try to get a BLM of 128 L Term at idle or at cruise?
I should try to get them @ 128 +/- a bit?
If I'm showing 130-134 at cruise ( 73 mph @ 1650 RPM in 6th) then that means I'm a tad lean and I'll add fuel right?
But where should I be trying to get my 128 +/-? Should I be trying to hit those numbers at idle or cruise? At WOT, the numbers hit 128 and stay.
Basically should I try to get a BLM of 128 L Term at idle or at cruise?
I target 125 for steady state cruise. That way it errors slightly on the rich side of things. Better safe than sorry.
Burning Brakes
Joined: Feb 2003
Posts: 1,218
Likes: 0
From: Rolla Mo
Originally Posted by black_89_vette
Basically should I try to get a BLM of 128 L Term at idle or at cruise?
The way I understand it, the only time no-load tuning is worthwhile is when you are initially working on a new combo to start getting her inline so you can load the motor. remember there is a difference between loading the motor and getting the computer into PE(pulse enrichment) mode.
my .02
Doug
Drifting
Joined: May 2003
Posts: 1,730
Likes: 1
From: Charlotte NC
St. Jude Donor '05
Originally Posted by tjwong
I target 125 for steady state cruise. That way it errors slightly on the rich side of things. Better safe than sorry.
I agree, cars typically feel better when they are a touch on the rich side. teh one time they swing lean due to weather you'll know it.
Racer
Joined: May 2005
Posts: 497
Likes: 1
From: Casa Grande Az
How low can you see a side go at idle? I understand it does not really matter, but my right bank will drop to like 110-114 at idle , while the left stays at like 120-122.
Soon as you put any load on the motor , they both pop right back up to 126-128ish till you let outa the throttle then the right side goes rich again. While crusing it stays in the proper range.
Normal?
Soon as you put any load on the motor , they both pop right back up to 126-128ish till you let outa the throttle then the right side goes rich again. While crusing it stays in the proper range.
Normal?
Thread Starter
Melting Slicks
Joined: Nov 2000
Posts: 2,469
Likes: 6
From: Winchester Ontario
Originally Posted by gbody5
WOT will always show 128 because you are in Power Enrichment mode. Here you need to tune for little to no knock and your desired A/F ratio.
Yeah, now I gotta figure out why it's pulling 7 degrees at WOT. Oh, for the A/F ratio...me without a wideband and a dyno, I should look under the O2 Volts right?
When I go WOT, the O2 volts jump around. I see numbers ranging from the high 700's to the low 900's. Is it supposed to jump around like that, and what numbers should I be ideally looking for?
I'll richen up the mixture to try to hit 125 ish L Term at cruise.
Melting Slicks
Joined: Dec 2000
Posts: 2,719
Likes: 59
From: Fremont Oh
Black 89,
At wide open throtle, you should be in the 900 mv range +/- 50 mv
If it is at like 200 or moving around at WOT that explains why it is pulling 7 degrees of timing, i should like you are leaning out on the top end.. perhaps check your fuel filter.. are you monitoring your fuel pressure?
Just a thought
Mo...
At wide open throtle, you should be in the 900 mv range +/- 50 mv
If it is at like 200 or moving around at WOT that explains why it is pulling 7 degrees of timing, i should like you are leaning out on the top end.. perhaps check your fuel filter.. are you monitoring your fuel pressure?
Just a thought
Mo...
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
Here's where your long term trims come from. There are "cells", called Block Learn Cells. You scan software might even tell you what cell it's in, mine does. Each cell has it's own trim values. So what you need to do in order to tune is run the engine in the various cells to see what your trim values are. Then adjust the fuel map in those areas that need adjustment.
I usually go for lots of test drives, trying to get in all the cells (MAP vs RPM) then average the results of each cell to determine where I'm off the mark.
At WOT your are in Power Enrich mode, no cells involved, the PCM runs off the fuel tables alone (unless it's a MAF car). Trim values will stick on 128.
I usually go for lots of test drives, trying to get in all the cells (MAP vs RPM) then average the results of each cell to determine where I'm off the mark.
At WOT your are in Power Enrich mode, no cells involved, the PCM runs off the fuel tables alone (unless it's a MAF car). Trim values will stick on 128.
