PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Since a C5 doesn't have a true IAC ......

Thread Tools
 
Search this Thread
 
Old Oct 21, 2005 | 09:58 AM
  #1  
Billiumss's Avatar
Thread Starter
TECH Addict
iTrader: (11)
 
Joined: Nov 2001
Posts: 2,975
Likes: 15
From: Erie, PA
Question Since a C5 doesn't have a true IAC ......

What do you guys use to see the "IAC" counts? Throttle %?

If you use HP Tuner 2.0, what PIDs should you use on a C5 to get the IAC table correct?
Reply
Old Oct 21, 2005 | 10:32 AM
  #2  
Phil99vette's Avatar
7 Second Club
iTrader: (11)
 
Joined: Jul 2002
Posts: 8,758
Likes: 9
From: Port Tobacco, MD
Default

My memory is rusty...

Desired Idle Airflow
and
Dynamic Air
or
MAF

Use your ETC Area Scaler and modify the value to make the lines overlap.
Phil
Reply
Old Oct 25, 2005 | 08:25 PM
  #3  
Billiumss's Avatar
Thread Starter
TECH Addict
iTrader: (11)
 
Joined: Nov 2001
Posts: 2,975
Likes: 15
From: Erie, PA
Default

Any more on this, going to scan a C5 tomorrow to see how far his IAc tables are off.
Reply
Old Oct 25, 2005 | 08:37 PM
  #4  
Dixit's Avatar
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default

Hey Phil, what do you mean by using the ETC Area Scaler to make the lines overlap. Better yet, what did you end up putting in that value for your 90mm TB? Im still highly confused on the whole ETC and tuning.

Dixit
Reply
Old Oct 26, 2005 | 11:19 AM
  #5  
Phil99vette's Avatar
7 Second Club
iTrader: (11)
 
Joined: Jul 2002
Posts: 8,758
Likes: 9
From: Port Tobacco, MD
Default

basically the ETC scaler is a multiplier that will trigger your desired air flow vs actual(MAF or dynamic). do a log, adjust the scaler and you will see.
Phil
Reply
Old Oct 26, 2005 | 11:23 AM
  #6  
Dixit's Avatar
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default

So you basically want to try to get the desired as close to actual airflow as possible by playing with the scaler? What value did you use for your 90mm TB?
Reply
Old Oct 26, 2005 | 12:00 PM
  #7  
HumpinSS's Avatar
FormerVendor
iTrader: (1)
 
Joined: Feb 2002
Posts: 3,059
Likes: 0
From: Waldorf, MD
Default

Originally Posted by Dixit
So you basically want to try to get the desired as close to actual airflow as possible by playing with the scaler? What value did you use for your 90mm TB?

B4349 = .0320
Reply
Old Oct 26, 2005 | 12:11 PM
  #8  
Dixit's Avatar
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default

Cool, will give that a shot and use what Phil said about getting it close as possible
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

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

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

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

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

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

 Verdad Gallardo
Old Oct 26, 2005 | 07:10 PM
  #9  
Bink's Avatar
TECH Addict
20 Year Member
 
Joined: Jul 2002
Posts: 2,261
Likes: 0
Default

Dixit- Use value HumpinSS gave. Set the IAC park table to "Stock" values. Recalc your RAF table as the values will be less.

As the ETC scalar value increases the Desired idle airflow (g/sec) decreases - i.e. the "steps" of the throttle blade increase in size resulting in more actual airflow. More actual airflow results in a need for fewer steps (less TPS%) at idle. Fewer steps = Less Desired Idle Air. Hope this helps some.
FWIW.
Reply
Old Oct 26, 2005 | 07:27 PM
  #10  
Dixit's Avatar
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default

Will that value still be the correct one when I install a ported 90mm TB?

Bink, excuse my ignorance, but Im slightly lost now. Isnt Desired Airflow what the PCM is commanding to get a good idle? Isnt that always going to remain the same no matter what value I put in there, or is there something Im missing.

I definetely understand the whole part of the fact that im going from the stock 78mm to 90mm TB means that the TB has to open up less than before because the same the amount of steps are still the same however because of the larger opening the same step will provide more air.

The part I dont understand is what Phil was talking about scanning and figuring out where you sit and adjust the scaler accordingly. What am I scanning to see how the scaler is correct or off and how am I doing this?

Thanks
Dixit
Reply
Old Oct 26, 2005 | 07:41 PM
  #11  
Bink's Avatar
TECH Addict
20 Year Member
 
Joined: Jul 2002
Posts: 2,261
Likes: 0
Default

.0320 is for a 90 mm tb. I don't know if a ported 90 mm tb will change this. This should not be used for a 78 mm tb.

The Scalar value is the conversion constant. Basically it's defining the size of a single unit of blade rotation ( think of the "steps" of the IAC vale on an Fbod).
As you increase the value above .0255 (stock) the "desired airflow" values are less because they are scaled by the conversion constant. This is why your RAF values will also be less. Make sense??


Here's the info you need -> http://www.efilive.com/forum/viewtopic.php?t=1169
Reply
Old Oct 26, 2005 | 08:13 PM
  #12  
Dixit's Avatar
TECH Regular
iTrader: (1)
 
Joined: May 2005
Posts: 434
Likes: 0
From: Canton GA
Default

Right that makes sense, but did you understand the part Phil wrote about scanning to figure out what Scaler works best?

Dixit
Reply
Old Oct 26, 2005 | 09:20 PM
  #13  
Bink's Avatar
TECH Addict
20 Year Member
 
Joined: Jul 2002
Posts: 2,261
Likes: 0
Default

Scan DESIAC and/or MAF and/or Dynamic Airflow. You should be able to get the MAF values to be nearly equal DESIAC. Dynamic Airflow will line up/coincide with DESIAC but (with a 90 mm tb) won't be equal. If the Eff Area Scalar is too great the LTIT and STIT will be erratic and unstable - I guess system is out of range due to the larger steps/% of the blade.
Reply




All times are GMT -5. The time now is 02:18 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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-9
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