460cc RX-7 injectors dead time - 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 04-15-2012, 12:04 PM   #1
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default 460cc RX-7 injectors dead time

Hi,

as we have measured/found pretty different settings for these injectors on msextra -

460cc RX-7 red top (high imp)

I thought I make a separate thread:

Before I went sequential I used the 2squirts/4squirts method to get an equal AFR and found a dead time of 1.185ms

Techsalvager uses a dead time of 0.75ms

Here in this old adaptronic thread I found a complete chart for dead times for these injectors.
https://www.miataturbo.net/showthrea...time+injectors

Is the usage of these dead times different between Adaptronic and Megasquirt? Anyone else has got working settings for these injectors?

Thanks and please discuss!
Zaphod is offline   Reply With Quote
Old 04-15-2012, 01:22 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

i use 1.2 @ 13.4v
Braineack is offline   Reply With Quote
Old 04-15-2012, 03:07 PM   #3
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

Well one of the points why I did this thread is that all the informations I found online about the RX7 injectors were about 550cc or low impedance injectors.

@Braineack - your 1.2 are very close to the 1.185 I got - but I must admit that my car runs at about 14.4 volts and the test I did was at this voltage...
Zaphod is offline   Reply With Quote
Old 04-15-2012, 03:10 PM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

that's the reference value that ms3 uses. i have a correction curve as well.
Braineack is offline   Reply With Quote
Old 04-15-2012, 04:47 PM   #5
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

Please post
Zaphod is offline   Reply With Quote
Old 04-15-2012, 11:42 PM   #6
I'm Miserable!
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

There is plenty of posts and other data out there that point to the injector lag time of 13v being around .75ms~ for the 460 and 550 high imp injectors.
when you have improper lag times, esp with systems like ms2extra a change in voltage can easily swing fueling up or down.
both my maf and speed density setups show these swings with voltage changes.

On my maf setup I couldn't run leaner then .78 ~ .82 lambda at normal ~14v, ---- i had maf grams a second at .33g\s which isn't even right.
changing to .75ms at 13.2v put my maf g\s around 2.4-2.6 range which is where it should be for the engine size and load. and idle afr at 1 lambda
Techsalvager is offline   Reply With Quote
Old 04-16-2012, 02:07 AM   #7
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

Quote:
Originally Posted by Techsalvager View Post
There is plenty of posts and other data out there that point to the injector lag time of 13v being around .75ms~ for the 460 and 550 high imp injectors.
I always found something like this:
http://www.rx7club.com/showthread.php?t=869605

Quote:
The low impedance 550cc injectors are 0.75ms @ 13v, so I would expect the low impedance 460cc injectors to be about the same. I wouldn't be surprised if the high impedance 460cc injectors were 1.0ms.
But I am going to try out your proposed 0.75ms with the curve from the older adaptronic thread.

Again my question - I know there are differences in the understanding of the dead times - are there differences between the Adaptronic and Megasquirt firmware for the dead times calculation?
Zaphod is offline   Reply With Quote
Old 05-06-2012, 02:55 PM   #8
I'm Miserable!
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

responding back to this, couple days ago I blew off a charge pipe, of course I'm running a maf based system so we know what can happen.
Anyways I decided its probably a good time to redo my SD setup.
reattached the charge pipe.

I filled the whole table up with 59 in the main ve table with SD running fuel and spark.
Amazed at how well it idled and drove with a table full of 59s.
this is with injector dead time at .75ms
Techsalvager is offline   Reply With Quote
Old 05-07-2012, 08:37 PM   #9
I'm Miserable!
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

http://www.2shared.com/file/H7EyKv5y...07_182032.html

datalog of recent SD tune I was working, watch GVE and Lambda vs RPM and MAP
Techsalvager is offline   Reply With Quote
Old 05-08-2012, 05:56 AM   #10
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

I tried it today and the car runs pretty darn cool. Thanks!

(Although I am loosing sync at 4200 rpm... but that is another story)
Zaphod is offline   Reply With Quote
Old 05-14-2012, 04:24 AM   #11
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

O.K. just to confirm, the 0.75ms work like a charm, the VEtable is nearly flat in the non-boost area. And this is the first time that my idle VEs are matching the neighboring cells...
Zaphod is offline   Reply With Quote
Old 05-14-2012, 05:31 AM   #12
Oni
Junior Member
iTrader: (1)
 
Join Date: Jan 2009
Location: Tasmania, AUS
Posts: 164
Total Cats: 3
Default

Sweet ill try this out tomorrow, any chance you would mind SS the related screen? I messed with some low imp injectors and want to be sure im all set correctly.

Cheers
Scott
Oni is offline   Reply With Quote
Old 05-14-2012, 08:00 AM   #13
Senior Member
Thread Starter
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

There you go...

Attached Thumbnails
460cc RX-7 injectors dead time-inj_settings_460cc_rx7.jpg  
Zaphod is offline   Reply With Quote
Old 05-14-2012, 09:18 PM   #14
I'm Miserable!
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

Quote:
Originally Posted by Oni View Post
Sweet ill try this out tomorrow, any chance you would mind SS the related screen? I messed with some low imp injectors and want to be sure im all set correctly.

Cheers
Scott
are you using the rx7 460's? or the low imp rx7 injectors?
low imp rx7 injectors used correctly dead time is suppose to be around .50\.55ms
Techsalvager is offline   Reply With Quote
Old 05-14-2012, 09:54 PM   #15
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

mine stalls if i put in lower than 1.1ms.

Attached Thumbnails
460cc RX-7 injectors dead time-deadtimes.jpg  
Braineack is offline   Reply With Quote
Old 05-14-2012, 10:17 PM   #16
I'm Miserable!
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

increase VE cells of course
Techsalvager is offline   Reply With Quote
Old 05-15-2012, 12:18 AM   #17
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

doesnt even matter. if i set it to 1.0 car stalls no matter what the AFR is.
Braineack is offline   Reply With Quote
Old 05-15-2012, 12:24 AM   #18
I'm Miserable!
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

datalog? PW? ve area at idle?
Techsalvager is offline   Reply With Quote
Old 05-15-2012, 01:50 AM   #19
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,865
Total Cats: 1,790
Default

its not worth my time to discuss it any further...ive run the above for over two years.
Braineack is offline   Reply With Quote
Old 05-15-2012, 09:14 AM   #20
Junior Member
 
Join Date: Feb 2007
Location: 11368 miles from where i would like to be
Posts: 269
Total Cats: 92
Default

Quote:
Originally Posted by Zaphod View Post
Is the usage of these dead times different between Adaptronic and Megasquirt?
Dead time settings are totally dependent upon your driver setup, and, even the gauge of your wiring. They're something that should be measured with a comparable setup to what you will run on the actual car.

As techsalvager says, dead time settings being correct is absolutely critical to an easy tune. As he also points out, you can mask incorrect settings with other adjustments. Few take the time to properly setup this parameter.
rb26dett is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
LucaCarMods's Boosted Dutch Miata Build! LucaCarMods Build Threads 11 02-14-2016 07:13 AM
Someone help me with AE ihiryu MEGAsquirt 33 10-08-2015 05:56 PM
Missing/knock at idle, can someone point me in the right direction? Mikel MEGAsquirt 4 09-28-2015 05:46 PM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 07:40 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 11:25 AM.