C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Tuning Help

Thread Tools
 
Search this Thread
 
Old May 28, 2017 | 10:07 PM
  #1  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default Tuning Help

Hey all,

I just finished installing my cam and I am working on tuning it. I am utilizing EEHack for datalogging and TunerCATS for tuning it. On my first drive utilizing a stock tune I was running pretty lean. So, I went into the MAF table and edited the AFGS by adding %10. This definitely made the car run alot better and brought my BLM's down. For some reason at partial throttle around 3000 rpm it occasionally falls on it's face, it fells like a complete misfire across the board. Looking at the datalog the MAF value spikes to 450+ g/s which is very unrealistic. I have not run the car at WOT as I know that's a different story and I want to get partial throttle down first. I have done days worth of reading so I have a pretty good idea as to what is going on.
Car info: cam: 222/226 @ 0.050, .530 life, 113 LSA, Headers, and a new Petris Opti

It wont let me post my datalog so, if someone is willing to help I can email the file to you or send it to you however you would like.

Thank you!
-Colton
Reply
Old May 29, 2017 | 12:17 PM
  #2  
93LT1's Avatar
93LT1
Pro
20 Year Member
 
Joined: Aug 2000
Posts: 700
Likes: 1
From: Florida
Default

Please keep us posted on your findings and progress.

Originally Posted by CMiller95
Hey all,

I just finished installing my cam and I am working on tuning it. I am utilizing EEHack for datalogging and TunerCATS for tuning it. On my first drive utilizing a stock tune I was running pretty lean. So, I went into the MAF table and edited the AFGS by adding %10. This definitely made the car run alot better and brought my BLM's down. For some reason at partial throttle around 3000 rpm it occasionally falls on it's face, it fells like a complete misfire across the board. Looking at the datalog the MAF value spikes to 450+ g/s which is very unrealistic. I have not run the car at WOT as I know that's a different story and I want to get partial throttle down first. I have done days worth of reading so I have a pretty good idea as to what is going on.
Car info: cam: 222/226 @ 0.050, .530 life, 113 LSA, Headers, and a new Petris Opti

It wont let me post my datalog so, if someone is willing to help I can email the file to you or send it to you however you would like.

Thank you!
-Colton
Reply
Old May 29, 2017 | 01:40 PM
  #3  
FrankieD's Avatar
FrankieD
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Default

sent you a PM
Reply
Old May 29, 2017 | 05:35 PM
  #4  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

Originally Posted by FrankieD
sent you a PM
Sent you an email
Reply
Old May 29, 2017 | 10:03 PM
  #5  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

Update:

I finished installing my wideband today and took it for another drive. The same issue arose with it cutting out right around 3000 rpms and looking at the datalog it was once again the MAF saying something like 400 g/s out of no where. So, i decided to run the car in speed density and I unhooked the MAF. This made a HUGE improvement. It was really running on the rich side as my new datalog shows but there was no miss and it was smooth across the board. So for now I will tune it in speed density and go from there

Colton
Reply
Old May 29, 2017 | 10:03 PM
  #6  
FrankieD's Avatar
FrankieD
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Default

I took a look at your datalog and I can see 3 events where your MAF took a spike. I call these spikes anomalies because they just randomly show up for 1 timestamp and return to normal. When they do occur I cannot see any pertinent change in your engine data. I would just take them as unexplained occurrences. If they continue you may want to try replacing your MAF and see if it goes away.
The MAF spikes occurred at the following timestamps in the datalog:
#1522@158.7
#4360@455.6
#5198@543.4

Last edited by FrankieD; May 29, 2017 at 10:06 PM.
Reply
Old May 29, 2017 | 11:20 PM
  #7  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

Originally Posted by FrankieD
I took a look at your datalog and I can see 3 events where your MAF took a spike. I call these spikes anomalies because they just randomly show up for 1 timestamp and return to normal. When they do occur I cannot see any pertinent change in your engine data. I would just take them as unexplained occurrences. If they continue you may want to try replacing your MAF and see if it goes away.
The MAF spikes occurred at the following timestamps in the datalog:
#1522@158.7
#4360@455.6
#5198@543.4
Thank you for looking at it! I think I am just going to run it and tune it in speed density and later move up to MAF (and installing a new one) after everything is lined out. Thank you for your help. If I am not mistaken tuning with speed density is observing the AFR on the RPM, AFR, and MAP chart and making adjustments to the Volumetric Efficiency.
Reply
Old May 30, 2017 | 06:09 AM
  #8  
FrankieD's Avatar
FrankieD
Burning Brakes
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Default

Sounds like a great plan. You may also want to look at adjusting your BLM Cell RPM Boundaries and BLM Cell Map Boundaries. By doing so you will more likely get better tuning resolution for VE adjustments

Last edited by FrankieD; May 30, 2017 at 06:28 AM.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old May 30, 2017 | 08:01 AM
  #9  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

Frankie,

Can you expand on what you mean by adjusting those boundaries to increase the tuning resolution? I am pretty sure I know what you mean but I am new at this

Thanks!
Colton
Reply
Old May 30, 2017 | 08:55 AM
  #10  
bjankuski's Avatar
bjankuski
Safety Car
20 Year Member
Photogenic
Liked
Top Answer: 1
 
Joined: Sep 2001
Posts: 4,134
Likes: 531
From: Glenbeulah Wi
Default

Originally Posted by CMiller95
Hey all,

I just finished installing my cam and I am working on tuning it. I am utilizing EEHack for datalogging and TunerCATS for tuning it. On my first drive utilizing a stock tune I was running pretty lean. So, I went into the MAF table and edited the AFGS by adding %10. This definitely made the car run alot better and brought my BLM's down. For some reason at partial throttle around 3000 rpm it occasionally falls on it's face, it fells like a complete misfire across the board. Looking at the datalog the MAF value spikes to 450+ g/s which is very unrealistic. I have not run the car at WOT as I know that's a different story and I want to get partial throttle down first. I have done days worth of reading so I have a pretty good idea as to what is going on.
Car info: cam: 222/226 @ 0.050, .530 life, 113 LSA, Headers, and a new Petris Opti

It wont let me post my datalog so, if someone is willing to help I can email the file to you or send it to you however you would like.

Thank you!
-Colton
I do not like to modify the MAF tables unless you are sure they are incorrect. More then likely your injector constant or injector data was not adjusted correctly for the injectors you are running. The spike in the MAF readings could be an issue with a poor transition from on MAF table to the other, the MAF tables must always be increasing in value from one table to the next. If you have any one cell higher up in the frequency curve that is lower then the proceeding cell it causes funny issues with the EE defination file.
Reply
Old May 30, 2017 | 01:06 PM
  #11  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

Originally Posted by bjankuski
I do not like to modify the MAF tables unless you are sure they are incorrect. More then likely your injector constant or injector data was not adjusted correctly for the injectors you are running. The spike in the MAF readings could be an issue with a poor transition from on MAF table to the other, the MAF tables must always be increasing in value from one table to the next. If you have any one cell higher up in the frequency curve that is lower then the proceeding cell it causes funny issues with the EE defination file.
I have the same injectors and at the same pressure as factory. What table do I modify to tune it utilizing the MAF?
Reply
Old May 30, 2017 | 05:51 PM
  #12  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

Originally Posted by bjankuski
I do not like to modify the MAF tables unless you are sure they are incorrect. More then likely your injector constant or injector data was not adjusted correctly for the injectors you are running. The spike in the MAF readings could be an issue with a poor transition from on MAF table to the other, the MAF tables must always be increasing in value from one table to the next. If you have any one cell higher up in the frequency curve that is lower then the proceeding cell it causes funny issues with the EE defination file.
I looked at my adjusted tables and I did not increment table 3 up %10 like I did the other 3 which resulted in a lower AFGS value as the table increased. So that may be my problem, I should get a chance tomorrow to retune it and see what happens.
Reply
Old May 30, 2017 | 08:16 PM
  #13  
bjankuski's Avatar
bjankuski
Safety Car
20 Year Member
Photogenic
Liked
Top Answer: 1
 
Joined: Sep 2001
Posts: 4,134
Likes: 531
From: Glenbeulah Wi
Default

Originally Posted by CMiller95
I looked at my adjusted tables and I did not increment table 3 up %10 like I did the other 3 which resulted in a lower AFGS value as the table increased. So that may be my problem, I should get a chance tomorrow to retune it and see what happens.
​​​​​​
Good luck, I hope that takes care of your issue.
Reply
Old May 31, 2017 | 09:04 PM
  #14  
CMiller95's Avatar
CMiller95
Thread Starter
Instructor
10 Year Member
Veteran: Air Force
All Eyes On Me
Liked
 
Joined: Nov 2012
Posts: 238
Likes: 16
From: Carrollton Illinois
Default

I decided to start with running it in speed density and I got it pretty close throughout the table. I ranging from 124-132 BLM so a little more tuning is needed but not bad progress for today!
Reply

Get notified of new replies

To Tuning Help





All times are GMT -4. The time now is 08:02 PM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE