Too big of injectors, is it possible? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 06-15-2012, 07:52 PM   #1
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Nov 2011
Location: Independence Mo
Posts: 109
Total Cats: 1
Default Too big of injectors, is it possible?

Trying to pick and choose cheap parts as I see them, and someone local has some huge bosch 1650cc low impedance injectors.
I could pick them up dirt cheap ( maybe $250 brand new. ) They were going to be going in a big turbo e85 SR20.

I am guessing even with standalone I would have to run resistors on these becasue they are low impedance?
= Me with tuning anything electronic.

I plan on going MSpnp soon ( Deciding options I want still )
Would sequential injection be enough to keep the car idling nicely on stock motor, and at lower-mid boost levels. ( I am going to learn to tune n/a while I gather/make all the boosty parts. )

I like the philosphy "buy it once" instead of out running small injectors and buying the next size.
I don't have huge power dreams, maybe 220hp, then gather forged parts ( 2 year goal? )
And if I ever get a gas station that has e85 close enough.... that might be an option that would need huge injectors.
AkaZero is offline   Reply With Quote
Old 06-15-2012, 07:54 PM   #2
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,356
Total Cats: 1,322
Default

There's no way you will be able to properly idle low-imp 1650s.
Savington is offline   Reply With Quote
Old 06-15-2012, 08:15 PM   #3
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,173
Total Cats: 2,575
Default

Quote:
Originally Posted by AkaZero View Post

I like the philosphy "buy it once" .
yet you don't live by it.
buy ID1000's and be done.
18psi is offline   Reply With Quote
Old 06-15-2012, 11:15 PM   #4
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Nov 2011
Location: Independence Mo
Posts: 109
Total Cats: 1
Default

Well currently, I haven't bought anything due to low funds.
But I am selling off other hobbies to add some power to the miata.

I'll skip the 1650s and get some 1000s then.
AkaZero is offline   Reply With Quote
Old 06-16-2012, 10:09 AM   #5
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 406
Default

also the MSPNP can't natively do low impedance injectors. you'll need either a relatively expensive add-on driver or a resistor pack. just get high impedance.
y8s is offline   Reply With Quote
Old 06-16-2012, 12:15 PM   #6
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,105
Total Cats: 518
Default

Quote:
Originally Posted by AkaZero View Post
I'll skip the 1650s and get some 1000s then.
Just to be clear, we did not suggest some 1000s, we suggested a specific kind.
curly is offline   Reply With Quote
Old 06-16-2012, 12:29 PM   #7
Elite Member
iTrader: (2)
 
triple88a's Avatar
 
Join Date: Apr 2006
Location: Chicago, IL
Posts: 9,131
Total Cats: 598
Default

1650 for a 220 hp is a headache.. trust me i'm running 820cc dws and i'm having issues getting them to idle smoothly because they just dont open little enough. 800 but they flow 820 per testing.
triple88a is offline   Reply With Quote
Old 06-16-2012, 01:00 PM   #8
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,173
Total Cats: 2,575
Default

also dw = ev6 and sucks

you want Injector Dynamics or Fuel Injector Clinic ev14
18psi is offline   Reply With Quote
Old 06-16-2012, 03:52 PM   #9
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,578
Total Cats: 40
Default

Just a question, but I think a good one for the OP: Do you understand why running very large injectors (without the need for them) is a bad idea?

Just trying to gauge if this is something we can help you understand.
kotomile is offline   Reply With Quote
Old 06-16-2012, 04:44 PM   #10
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 406
Default

because the minimum injector time is probably going to be way more fuel than you want at idle.

and the injectors are less linear at very low pulsewidths

and you probably don't have the real dead times for them which makes it worse.
y8s is offline   Reply With Quote
Old 06-16-2012, 04:49 PM   #11
Elite Member
iTrader: (2)
 
triple88a's Avatar
 
Join Date: Apr 2006
Location: Chicago, IL
Posts: 9,131
Total Cats: 598
Default

Y8S bsing u... miatas idle epically at 9:1 afr.

How about a 5th injector setup but only with 1 injector :P
triple88a is offline   Reply With Quote
Old 06-16-2012, 05:06 PM   #12
Elite Member
iTrader: (24)
 
kotomile's Avatar
 
Join Date: Oct 2006
Location: Monterey, CA
Posts: 7,578
Total Cats: 40
Default

Quote:
Originally Posted by triple88a View Post
Y8S bsing u... miatas idle epically at 9:1 afr.

How about a 5th injector setup but only with 1 injector :P
I think that's called TBI, lol.
kotomile is offline   Reply With Quote
Old 06-17-2012, 11:39 PM   #13
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Nov 2011
Location: Independence Mo
Posts: 109
Total Cats: 1
Default

I am trying to read as much into megasquirt in general, and more miata specific stuff as well. And ask questions when I don't find and obvious or specific answer I am looking for.

I understand the theory behind this, but I have not hand my hand into any actual tuning.
I just don't know how big injectors is too big, so I asked.
Seen a lot of "I need bigger injectors" but have never seen someone "I need smaller injectors"

Basically too big of injector can't cycle short enough, to get low enough fuel for correct fuel/air ratio at low rpm.
And each % adjustment is a larger amount of fuel than a smaller injector.
So 1% duty cycle out of a 1650 is is 16.5cc
While a 500cc it is only 5cc a much finer adjustment, better control etc...

I am just on the lookout for deals since I am just starting to piece stuff together.
And $250 for 1650cc, and the cost of resistors ( low imp injectors ) looked appealing to the wallet.

The injector dynamics 1000 are double the cost of these, but some research on them proved it is money well spent.
With the money I save buying a china charger I might as well get all the best electronics.
AkaZero is offline   Reply With Quote
Old 06-17-2012, 11:47 PM   #14
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,173
Total Cats: 2,575
Default

2 of the top things not to cheap out on: injectors and engine management.
Right up there with exhaust manifold for a 1.8

just keep that in mind
18psi is offline   Reply With Quote
Old 06-18-2012, 12:03 AM   #15
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Nov 2011
Location: Independence Mo
Posts: 109
Total Cats: 1
Default

I plan on going MegaSquirt ( not built by me.... ) Probably will be the most expensive part of the build, then injectors.

And I plan on building my own manifold out of mild steel. I have plenty of time to get it right before I have all the pieces assembled to go turbo.
Plan on doing thin steel tubing for the IC tubing also. If I have the tools, I will try to make as many parts of the build myself. I have time, tools, and not a lot of money.
AkaZero is offline   Reply With Quote
Old 06-18-2012, 01:39 AM   #16
Elite Member
iTrader: (2)
 
triple88a's Avatar
 
Join Date: Apr 2006
Location: Chicago, IL
Posts: 9,131
Total Cats: 598
Default

Quote:
Originally Posted by 18psi View Post
Right up there with exhaust manifold for a 1.8
I hear ebay manifolds are top notch.
triple88a is offline   Reply With Quote
Old 06-18-2012, 04:05 AM   #17
Senior Member
iTrader: (9)
 
Join Date: Sep 2009
Location: Yamato Japan
Posts: 692
Total Cats: 26
Default

I know everyone sips the ID kool-aid, but check out FIC. They sell ev14 injectors for about 1/2 of what ID does. And they are very good to work with.

Also OP, understand that the technology behind ev14 injectors allows the pintle to be much lighter, this allows it to be modulated more effectively. This translates to injectors that are stable down to extremely low pulsewidths, as well as injectors that can function with very high base-fuel pressure.

We would not be telling you to run an ev1 style injector that was 1000cc, it would probably be rough. I have a set of ev14 injectors on my VW and I think they are stable down to like 1.0ms. It lets you run absurdly large injecotors smoothly.
tasty danish is offline   Reply With Quote
Old 06-18-2012, 04:48 AM   #18
Junior Member
iTrader: (20)
 
Join Date: Apr 2010
Location: Redmond, WA
Posts: 494
Total Cats: 15
Default

yes ID injectors are worth every penny. Yes, I tried buying cheaper EV14's from fiveomotorsports, etc. and have been disappointed. ID injectors are everything they say they are and I wish I had not wasted money (shipping, reselling, etc.) and just gone straight to Injector Dynamic ID1000's from the get go
bmxfuel007 is offline   Reply With Quote
Old 06-18-2012, 08:38 AM   #19
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Quote:
Originally Posted by y8s View Post
also the MSPNP can't natively do low impedance injectors. you'll need either a relatively expensive add-on driver or a resistor pack. just get high impedance.
Yes it can, you just need to not use the high_res code.
richyvrlimited is offline   Reply With Quote
Old 06-18-2012, 09:02 AM   #20
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,173
Total Cats: 2,575
Default

Quote:
Originally Posted by tasty danish View Post
I know everyone sips the ID kool-aid, but check out FIC. They sell ev14 injectors for about 1/2 of what ID does. And they are very good to work with.
no one said fic was bad. they're just as good. nowhere near 1/2 price tho.
18psi 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 57 07-19-2017 05:11 PM
Need help - Stock Balancer and Fastforward overlay pulleys Frank_and_Beans Supercharger Discussion 13 09-12-2016 09:17 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


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 09:17 PM.