Bigger Injectors - 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 10-28-2006, 05:28 PM   #1
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default Bigger Injectors

I seem to remember there being problems with running low impedance injectors with MS in our configuration. Is that still the case? If so how do I get around it so I can fit bigger injectors? I plan on going FI pretty soon, and I seriously doubt by stock ones will cope considering I hit 75%DC as a stock car...

Thanks!
richyvrlimited is offline   Reply With Quote
Old 10-28-2006, 05:53 PM   #2
Junior Member
 
Join Date: Feb 2006
Location: Greenville, NC
Posts: 211
Total Cats: 0
Default

Quote:
Originally Posted by richyvrlimited View Post
I seem to remember there being problems with running low impedance injectors with MS in our configuration. Is that still the case? If so how do I get around it so I can fit bigger injectors? I plan on going FI pretty soon, and I seriously doubt by stock ones will cope considering I hit 75%DC as a stock car...

Thanks!
Search for some posts by AlHounos I think he is running DSM 440 injectors.
ecugrad is offline   Reply With Quote
Old 10-28-2006, 06:06 PM   #3
Senior Member
 
Join Date: Oct 2005
Location: Knoxville
Posts: 1,168
Total Cats: 0
Default

Yeah, but I'm using resistors. I had trouble with tach signal using the MS PWM.

They're 450s, which seems like just big enough for the limits of the stock 1.6.
I'm at 80% DC at 11.5:1 at 7000rpm at 180kpa.
Al Hounos is offline   Reply With Quote
Old 10-28-2006, 07:13 PM   #4
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Quote:
Originally Posted by Al Hounos View Post
Yeah, but I'm using resistors. I had trouble with tach signal using the MS PWM.

They're 450s, which seems like just big enough for the limits of the stock 1.6.
I'm at 80% DC at 11.5:1 at 7000rpm at 180kpa.
sounds good to me! which DSM injectors did you use? (I'm in the UK so it may a be more difficult tracing them?)

Can you describe whats involved with adding resistors to the injectors? is is just a case of addin one in-line with the signal line. I assume this converts them to High Impedance and the Impedance settings in MS don't need adjusting?

Thanks!
richyvrlimited is offline   Reply With Quote
Old 10-29-2006, 12:16 AM   #5
Senior Member
 
Join Date: Oct 2005
Location: Knoxville
Posts: 1,168
Total Cats: 0
Default

They're from a first gen turbo eclipse. They are blue.
I actually used a resistor pack that I got with the injectors that comes stock on the eclipse. But you can just wire separate resistors inline with the power wires.
Yes, just set them up in MT as high impedance.
Al Hounos is offline   Reply With Quote
Old 10-29-2006, 01:16 AM   #6
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 richyvrlimited View Post
I seem to remember there being problems with running low impedance injectors with MS in our configuration. Is that still the case? If so how do I get around it so I can fit bigger injectors? I plan on going FI pretty soon, and I seriously doubt by stock ones will cope considering I hit 75%DC as a stock car...

Thanks!

lots of larger injectors available for PnP. see my FAQ.
Braineack is offline   Reply With Quote
Old 10-29-2006, 05:04 AM   #7
Elite Member
iTrader: (5)
 
akaryrye's Avatar
 
Join Date: Jul 2006
Location: Central California
Posts: 2,526
Total Cats: 0
Default

i bought some high impedence 550cc injectors off of kungfu jesus on this forum. Should be arriving monday, ill post how it goes.
akaryrye is offline   Reply With Quote
Old 10-29-2006, 06:35 AM   #8
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Quote:
Originally Posted by braineack View Post
lots of larger injectors available for PnP. see my FAQ.
hrm, looks like I need a set of early RX7 injectors for plug and play high impedance then!

great FAQ thanks!
richyvrlimited is offline   Reply With Quote
Old 10-29-2006, 09:53 AM   #9
Junior Member
 
Join Date: Feb 2006
Location: Greenville, NC
Posts: 211
Total Cats: 0
Default

Quote:
Originally Posted by Al Hounos View Post
They're from a first gen turbo eclipse
Watch out which ones you get from the 1st Gen DSM's. Automatics have smaller 330cc injectors.
ecugrad is offline   Reply With Quote
Old 10-29-2006, 02:53 PM   #10
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Thanks for the heads up.

There's little pickings on UK ebay, but there's a lot on US ebay, this is donna sound dumb, however, are all injectors the same fitment into the rail? I'd assume not, but how do you tell if they will fit?

I've searched for DSM injectors and there's quite a few 450cc ones, from Mitsubishi Talons, and Eclipse's. Would they fit? Are honda Injectors a similar fitment?

Thanks!
richyvrlimited is offline   Reply With Quote
Old 10-29-2006, 05:40 PM   #11
I'm Miserable!
 
Join Date: Oct 2006
Location: QLD, Australia
Posts: 44
Total Cats: 0
Default

The ones in the FAQ will fit.

I got a set of Supra 305ccs and they were AU$72 delivered to Australia from the US. $72 is only a couple of quid!

HTH
white90na is offline   Reply With Quote
Old 10-29-2006, 06:45 PM   #12
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

for the sizes I need the FAQ's slim pickings I need 420's minimum, 305 is way too small!

I'm just hoping all DSM injectors will fit.
richyvrlimited is offline   Reply With Quote
Old 10-29-2006, 06:56 PM   #13
Senior Member
 
Join Date: Oct 2005
Location: Knoxville
Posts: 1,168
Total Cats: 0
Default

They will fit, they are just a little shorter than the stockers. The best injectors for a miata is the rx7 550s, truly PNP and the perfect size. DSM are easier to find and probably cheaper though, and only too small if you plan on building the engine.
Al Hounos is offline   Reply With Quote
Old 10-29-2006, 07:44 PM   #14
Elite Member
Thread Starter
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Quote:
Originally Posted by Al Hounos View Post
They will fit, they are just a little shorter than the stockers. The best injectors for a miata is the rx7 550s, truly PNP and the perfect size. DSM are easier to find and probably cheaper though, and only too small if you plan on building the engine.
I've got an M62 on the way so I doubt I'll need much higher.

Many thanks for the info Al!

(there's a set of RX7 injectors on the bay now.... hrm!!
richyvrlimited is offline   Reply With Quote
Old 12-06-2006, 12:21 AM   #15
Junior Member
 
Join Date: Jul 2005
Location: Alexandria, VA
Posts: 125
Total Cats: 0
Default

question about the resistor packs: Since MS is batch fire, do you need 1 resistor for each injector, or can you use 1 resistor for each bank?

I know there are PnP high ohm injectors that work. But it seems it's easier to find the low ohm injectors (more abundant), and Honda resistor packs are about $10 or so on ebay, so that seems like an inexpensive/easier way to go.
MiaTurbo is offline   Reply With Quote
Old 12-06-2006, 01:32 AM   #16
Senior Member
 
Join Date: Oct 2005
Location: Knoxville
Posts: 1,168
Total Cats: 0
Default

Buy the resistor pack. It will be easy to see how to wire it up once you get it. it basically is a 1 into 4 adapter, with resistors.
Al Hounos is offline   Reply With Quote
Old 12-06-2006, 02:17 AM   #17
Junior Member
 
Join Date: Jul 2005
Location: Alexandria, VA
Posts: 125
Total Cats: 0
Default

So I gather from what you are saying is the resistors are wired on the 12v side? so is would be: 12v+ -> resistor pack -> injectors -> MS ?
MiaTurbo is offline   Reply With Quote
Old 12-06-2006, 12:57 PM   #18
Senior Member
 
Join Date: Oct 2005
Location: Knoxville
Posts: 1,168
Total Cats: 0
Default

yup.
Al Hounos 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 Yesterday 10:04 PM
Changing from 460cc to flow force 610cc in diypnp 90 Turbo MEGAsquirt 19 10-19-2015 04:23 PM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 01:15 PM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 AM
"Chimney Ethanol" E100 MiataGarage Engine Performance 5 09-30-2015 12:04 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 04:47 PM.