Proper timing and EGT at cruise - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 07-11-2012, 01:08 PM   #1
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 963
Total Cats: -1
Default Proper timing and EGT at cruise

Keep getting into 1200 degrees at cruising speeds. Not sure whats going on. I have closed loop working good so AFRs are at about 14.7, I might need to go a little leaner considering I am running E85. My timing in the area is about 45-48 advance, seems a little too much?
Rushin is offline   Reply With Quote
Old 07-11-2012, 01:18 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

it is. your map should be maxed at ~40 and that's in the 20kPa area where you never hit. unless you're running like 16.0:1 in cruise.
Braineack is offline   Reply With Quote
Old 07-11-2012, 02:04 PM   #3
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 963
Total Cats: -1
Default

What's good timing and afr for crushing? I end up being pretty high up in rpm at 65 because of my rear end.
Rushin is offline   Reply With Quote
Old 07-11-2012, 03:00 PM   #4
Elite Member
iTrader: (1)
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 4,682
Total Cats: 216
Default

You can run a ton of timing in cruise, its really something you have to tune by feel.

If you lean it out a lot youll have to give it a lot of timing to keep it smooth. Youre not going to hurt it, its under very little load.

Ive seen people lean way out to 17.x:1 in cruise in the name of mileage. Some say that you actually get better mileage by not running quite that lean, but Im not sure. Id image it depends a lot on the engine and atomization.
Full_Tilt_Boogie is offline   Reply With Quote
Old 07-11-2012, 03:08 PM   #5
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 963
Total Cats: -1
Default

I see. I went to about 48 degrees and the car started to back fire a ton. Thinking 15.5-16 afr is about the tops I should be running. I see that 45 degrees is where tuner studio shows timing maxed out on the dash board gauge.
Rushin is offline   Reply With Quote
Old 07-11-2012, 03:14 PM   #6
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

backfiring = too much fuel.

in cruise, the more you lean it out, the more timing you have to add.


i know hustler played with mpg and cruise a lot and found he made better mpg with a fatter afr and certain timing. something like that.
Braineack is offline   Reply With Quote
Old 07-11-2012, 03:14 PM   #7
Elite Member
iTrader: (1)
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 4,682
Total Cats: 216
Default

Theres not much point in running more than you need. Start down at 30 degrees and advance it until it stops bucking.
Full_Tilt_Boogie is offline   Reply With Quote
Old 07-11-2012, 03:41 PM   #8
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 963
Total Cats: -1
Default

What should I start with first afr or timing?
Rushin is offline   Reply With Quote
Old 07-11-2012, 03:51 PM   #9
Junior Member
iTrader: (5)
 
Join Date: Mar 2012
Location: Gilbert, Az
Posts: 337
Total Cats: 26
Default

Quote:
Originally Posted by Rushin View Post
I might need to go a little leaner considering I am running E85.
Are you running 100% E85? If so you need an A/F ratio somewhere in the high 9's. If you're running a mix, there's tables/calculators out there that will tell you what A/F you should run between 9.x and 14.7
SJP0tato is offline   Reply With Quote
Old 07-11-2012, 04:18 PM   #10
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 963
Total Cats: -1
Default

Yeah I run straight e85 but lc1 is just reading lambda, so when I see 14.7 it's actually at 9.76. So I tune like I am tuning gas but all the numbers are changed automatically. I hope this makes sense
Rushin is offline   Reply With Quote
Old 07-12-2012, 07:11 PM   #11
Senior Member
iTrader: (6)
 
Join Date: Sep 2007
Posts: 1,085
Total Cats: 30
Default

Hey Taras (this is Kent) IMO get your fueling right, then deal with timing afterwards. As you pass stoichiometric combustion you should see your EGTs drop.
albumleaf is offline   Reply With Quote
Old 07-12-2012, 09:13 PM   #12
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by Rushin View Post
What should I start with first afr or timing?
This is for my stock 1994.

I found that more spark angle and leaner fuel required an increase in TPS to maintain speed and ultimately and increase in PW. I played with this from Dallas to Houston 3 times, this is the end result. 27-29mpg at 79mph with a 5-speed/4.10 and a motor that's seen a ton of detonation.

This is also an 89-octane tune, lol.
Attached Thumbnails
Proper timing and EGT at cruise-cruise-tune.jpg  
hustler is offline   Reply With Quote
Old 07-12-2012, 09:19 PM   #13
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

thanks for posting that.
Braineack is offline   Reply With Quote
Old 07-12-2012, 09:20 PM   #14
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Quote:
Originally Posted by hustler View Post
This is also an 89-octane tune, lol.
Geez you run 89 craptane at 10 psi?
JasonC SBB is offline   Reply With Quote
Old 07-12-2012, 09:21 PM   #15
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Quote:
Originally Posted by JasonC SBB View Post
Geez you run 89 craptane at 10 psi?
Naturally aspirated daily driver. I'll do a 91-tune when the VVT swap goes down later this year. Maybe 93 tune and pull 3* for Oklahoma racing for the day my daily lives the life it always wanted as a PTE racecar.

Green Glory hole runs 93 but I tuned on ~92 octane, lol. I mixed a bit between the two grades because I had severe paranoia issues back then, lol.
hustler is offline   Reply With Quote
Old 07-12-2012, 09:27 PM   #16
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Here is my cruise dash for you newbs so you can hopefully put two and two together. I should not that I also used my phone as a level when road-tuning cruise to make sure I was on level ground whilst using cruise control (taped to the passenger door, lol) .

I managed to narrow down my tune to this level and about 1-point leaner with more spark angle as two really close sets of values that worked. I then looked at the cruise logs when I got home and made the decision to go richer with less spark angle due to a miniscule decrease in PW. I was very surprised to see maximum efficiency at such a rich mixture, contrary to what the Hondata hyper-mile guys do at 19:1 or so. I drove down the first time at 16.8:1 and scored a miserable 23mpg, lol. I've tried to do this on a Mustang and Dyno Dynamics but we can't consistently dial in ~10-20whp load levels, there is not enough precision that low and the barrel is too heavy.

Brain, please allow ".DASH" extensions upload-able so I can share this file.
Attached Thumbnails
Proper timing and EGT at cruise-cruise-dash.jpg  
hustler is offline   Reply With Quote
Old 07-12-2012, 09:34 PM   #17
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Also, with a better, cleaner, EV14 injector, I suspect a significant increase in fuel economy due to the atomization and better flame propogation, rather than these 200k squirters on a bad engine that I'm giving away when removed. I really wanted to work on fuel economy tuning with this engine; I'm currently very unhappy with my results. I expected to be around 32mpg with this set-up but I'm going to lower my goal and hopefully get that with the 10:1 VVT engine.
hustler is offline   Reply With Quote
Old 07-12-2012, 11:19 PM   #18
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Here's an awesome article that's light-years ahead of what we're doing, but it describes ideal combustion.
http://www.theoldone.com/articles/Ho...oft_Head_3.jpg
hustler is offline   Reply With Quote
Old 07-12-2012, 11:41 PM   #19
Senior Member
Thread Starter
iTrader: (3)
 
Join Date: Jul 2008
Location: Minneapolis, MN
Posts: 963
Total Cats: -1
Default

There are a few things that are specific to my setup. Like compression ratio. As i understand the lower the compression the more timing i need to use. And i am running E85 so my timing and fuel would be a bit different.
Rushin is offline   Reply With Quote
Old 07-13-2012, 12:00 AM   #20
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Very nice tuning hustler.

Propsies
Faeflora is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 12-13-2017 10:04 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:39 AM.