Sequential Fuel injection - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


ECUs and Tuning Discuss Engine Management, Tuning, & Programming

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 03-22-2011, 07:28 PM   #21
Newb
 
Join Date: Mar 2011
Posts: 29
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
its more efficient, yes. playing with injection timing (spraying the fuel based on crank angle and load/rpm) can improve it even more so. So you're only injecting once per cycle and you can time it so all the fuel is where it want it when the intake cycle starts.

OT, sorry : Braineack, have you read my PM? I have problems and and your help would be essential
eTiLiKo is offline   Reply With Quote
Old 09-19-2011, 07:57 AM   #22
Junior Member
iTrader: (2)
 
Join Date: Jun 2011
Location: Tyler, TX
Posts: 254
Total Cats: 0
Default

^lmao @man/boy love.
85z28 is offline   Reply With Quote
Old 09-19-2011, 06:35 PM   #23
Junior Member
 
Join Date: Jul 2010
Posts: 89
Total Cats: 0
Default

Another advantage would be that you can run low impedance injectors without needing resistors?
giblets is offline   Reply With Quote
Old 09-19-2011, 06:47 PM   #24
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

Quote:
Originally Posted by giblets View Post
Another advantage would be that you can run low impedance injectors without needing resistors?

for seq. injection? not necessarily.
Braineack is offline   Reply With Quote
Old 09-19-2011, 06:49 PM   #25
Junior Member
 
Join Date: Jul 2010
Posts: 89
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
for seq. injection? not necessarily.
I thought you could only run one low impedance injector from each injector driver with the MS unless you use resistors in series with them?
giblets is offline   Reply With Quote
Old 09-19-2011, 06:50 PM   #26
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Quote:
Originally Posted by giblets View Post
Another advantage would be that you can run low impedance injectors without needing resistors?
No thats a hardware limitation, nothing to do with how many times and at what point the injectors fire, which is what sequential is all about.

To run low impedance injectors without dropping resistors, you just need an injector driver capable of PWM.

You can have sentential with or without low impedance injectors if you want. The two are not mutually exclusive.
richyvrlimited is offline   Reply With Quote
Old 09-19-2011, 06:51 PM   #27
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

its more about the power draw and grounding than anything else.

you can run low ohm injectors in batch.
Braineack is offline   Reply With Quote
Old 09-19-2011, 11:13 PM   #28
Junior Member
 
Join Date: Jul 2010
Posts: 89
Total Cats: 0
Default

OK, I was thinking in terms of it being an advantage of doing the sequential mod for MS specifically, but then I made the mistake of thinking this was posted in the MS specific forum too.

This is getting a bit off topic, but are you suggesting that I could run two low ohm injectors per injector driver on my MS2 DIYPNP without resistors? because my understanding was that that would require the injector drivers to sink more current than they can handle.
giblets is offline   Reply With Quote
Old 09-20-2011, 06:02 AM   #29
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

I don't think the uS card can handle 2 paired low impedance injectors.

The V3/3.57 with a MSI/II/III card can however.

Similarly the MS3X card can't handle low impendance injectors.
richyvrlimited is offline   Reply With Quote
Old 09-20-2011, 09:33 AM   #30
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

Quote:
Originally Posted by giblets View Post
This is getting a bit off topic, but are you suggesting that I could run two low ohm injectors per injector driver on my MS2 DIYPNP without resistors? because my understanding was that that would require the injector drivers to sink more current than they can handle.

You could if you ran the P&H board. But running PWM drivers directly off the uS module will result in ground noise and flyback issues.
Braineack is offline   Reply With Quote
Old 09-20-2011, 09:44 AM   #31
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

A customer of mine run low impedance injectors on the DIYPNP for several months, without knowing. He always had problems with the USB to serial converter randomly disconnecting from the PC. At some point he did burn one of them, so we found out and replaced the injectors.
Reverant is online now   Reply With Quote
Old 09-20-2011, 10:08 AM   #32
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Great thread. Can someone post pics of the sequential fuel menus in MSII and what they should be? I want to do this on both cars soon.
hustler is offline   Reply With Quote
Old 09-20-2011, 11:22 AM   #33
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

Attached Thumbnails
Sequential Fuel injection-seq_mod_settings_page.jpg  
Braineack is offline   Reply With Quote
Old 10-18-2011, 04:00 PM   #34
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

Thanks. Is it a good idea to upgrade to really large and or EV14 injectors over my 550RX7 injectors? Will a shorter injector opening time benefit me in any way?


Quote:
Originally Posted by Braineack View Post
here's what I use.



I might want to alter it slightly, this is based around the idea that you want to have all your fuel at the valve around 10 before the intake valve opens. So I'm using End-Of-Squirt.

NA intake valve opens 5BTDC, so I have it at 375. which is 10 before that. 360TDC + 5BTDC + 10 = 375.

I inject fuel another 10 sooner every 1000RPM or so, stopping at 5000RPM. I did this from reading through out the web as the accept "norm".

In boost I also inject the fuel even soon every few psi.



I didn't do extensive trial and error, but this map help reduce the over VE% by a few points throughout and seems to work well for me.

You entered 375* to account for your 10% cam opening...is this back-timed or is the ECM counting 375* of rotation?
Attached Thumbnails
Sequential Fuel injection-injection_timing.jpg   Sequential Fuel injection-injection_timing.jpg  
hustler is offline   Reply With Quote
Old 10-18-2011, 05:01 PM   #35
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

(Posting from my phone.)

You want larger injectors to keep. The duty cycle below 80% to be able touse the timing tables properly.
Braineack is offline   Reply With Quote
Old 10-18-2011, 06:39 PM   #36
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

More like 60% DC

At WOT it's pretty unnecessary, it's quite helpful for economy at part throttle though.

Honestly if you don't have any issues currently with your injectors, then leave them. If however you're hankering after more headroom and a much improved idle quality at stoich, then hell yes upgrade.
richyvrlimited is offline   Reply With Quote
Old 09-19-2012, 02:49 PM   #37
Newb
 
Join Date: Jun 2012
Location: Helsinki, Finland
Posts: 30
Total Cats: 3
Default

First of all, i want to apologize for bringing this thread back from the grave but it seemed to have the best information about sequential injection which is relevant to my case..

So, i'm running a '91 miata with MS2 extra (by reverant). I thought i'd reconfigure the batch injection into sequential, but it did not quite go as planned..

So, i rewired the injectors according to Dimitris's instructions:

- Pin 1 (INJA) goes to cylinder 1
- Pin 2 (INJD) goes to cylinder 2
- Pin 3 (INJB) goes to cylinder 3
- Pin 4 (INJC) goes to cylinder 4

- Switch from "standard drivers" to "additional drivers" in megasquirt

Then i checked (and double checked) that each injector is only connected to the corresponding pin in the right order.

Now, the car would not start up. It fires after cranking and dies immeadiately afterwards. I did manage to get it run (barely) by pushing throttle. This caused the engine to run very lean. As soon as i release the throttle, the engine stalls.

Now, if i change back to "standard drivers" the engine runs just fine! Any ideas what might cause this behaviour?
Attached Thumbnails
Sequential Fuel injection-sequential.png   Sequential Fuel injection-settings.jpg  
Attached Files
File Type: msl standard.msl (92.9 KB, 66 views)
File Type: msl additional.msl (128.8 KB, 74 views)
File Type: msq sequential2.msq (89.2 KB, 107 views)
[Ode] is offline   Reply With Quote
Old 09-19-2012, 02:57 PM   #38
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,872
Total Cats: 1,790
Default

did he build yours with the abillity to run seq injection?
Braineack is offline   Reply With Quote
Old 09-19-2012, 02:59 PM   #39
Newb
 
Join Date: Jun 2012
Location: Helsinki, Finland
Posts: 30
Total Cats: 3
Default

Yes.. He said it supports sequential.

Edit: Reverant's customer support has been excellent. I just wouldn't want to bother him constantly since i bet he's got loads of things other things to do as well..
[Ode] is offline   Reply With Quote
Old 09-19-2012, 03:02 PM   #40
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

Yes, all my Enhanced MS2 provide sequential. Otto, please replace each injector with a 12V auto tester,
like this one like this one
, and using the test mode, see if you can get all 4 "injectors" to light up properly. When you test each injector, only that injector must light up and none other.
Reverant is online now   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
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 AM
"Chimney Ethanol" E100 MiataGarage Engine Performance 5 09-30-2015 12:04 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 05:59 AM.