Civic EG

Posted: **Fri Feb 08, 2013 4:20 am**

tried searching but couldnt find the right answer....

plain and simple question...what is the highest compression ratio i can run with stock injectors in my LS?

Posted: **Fri Feb 08, 2013 2:07 pm**

Naturally aspirated? Head work? What cams? What elevation do you live at? What fuel will you be using?

Not really a simple question. If you're really building a car around a set of stock injectors I think you need a new hobby.

Posted: **Fri Feb 08, 2013 2:38 pm**

n/a build with stock LS head...looking to use 93 pump gas...im about 200ft above sea level

Posted: **Fri Feb 08, 2013 3:10 pm**

Depending on tuner, 12-13:1 on pump gas is about all you're going to get and that won't even come close to maxing those injectors out

Posted: **Sat Feb 09, 2013 7:39 am**

i would upgrade injectors... pending your compression and other supporting mods i would go 390- 440cc.

my b20 vtec maxed out the 310's i had for it, so i went up to 440cc and ran around an 80-85% duty cycle before i sold everything.

Posted: **Sat Feb 09, 2013 9:10 am**

rob has a point and diesel has a point also

if your going to max out the stock injectors your not really gaining any hp, ive seen people run 12.5:1 pistons with the oem injectors, however its not "safe" for an engine that is not designed for that kind of compression from the factory

you could do a somewhat cheap dsm injector swap, they are between 440cc-450cc :thumb:

easyish to install making sure you get a proper seal in the intake manifold and injector will be the difficult part... can get expensive quick if you do not pay attention, im my area the kits are sold individually per injector and are 24 bux a pop!

heres a small list of the b series

b16a
Displacement: 1,595 cc (97.3 cu in) 1.6-litre
Compression: 10.2:1
240cc injector
38psi fuel pressure
10-13 ohm resistance

b18a / b
Displacement: 1,834 cc (111.9 cu in)
Compression: 9.2:1
245cc injector
40psi fuel pressure
10-13 ohm resistance

b18c1 (gsr) usdm
Displacement: 1,797 cc (109.7 cu in)
Compression: 10.0:1
240cc fuel pressure
45psi fuel pressure
10-13 ohm resistance

b18c (gsr) jdm
Displacement: 1,797 cc (109.7 cu in)
Compression: 10.6:1
240cc injector
45psi fuel pressure
10-13 ohm resistance

b18c5 (type r) usdm
Displacement: 1,797 cc (109.7 cu in)
Compression: 10.6:1
240cc injector
45psi fuel pressure
10-13 ohm resistance

b18c (type r) jdm
Displacement: 1,797 cc (109.7 cu in)
Compression: 11.1:1
240cc injector
45psi fuel pressure
10-13 ohm resistance

b20b
Displacement: 1,973 cc (120.4 cu in)
Compression: 8.8:1 or 9.2:1
240cc injector
40psi fuel pressure
10-13 ohm resistance

b20z
Displacement: 1,973 cc (120.4 cu in)
Compression: 9.6:1
240cc injector
40psi fuel pressure
10-13 ohm resistance

OBD1 92-96 prelude injectors run 310cc
you will need pigtails
they however 1.5-2.5 ohm resistance injectors so you may need an injector resistor box, i have never tried the swap and i havent really investigated to see if they are 310cc injectors are not.

hope this gives you an idea as far as compression ratio and injector size

Posted: **Sat Feb 09, 2013 5:49 pm**

OBD1 prelude injectors for the h22a are 345cc, h23a1 and f22a1 are 240cc. just thought i might clear that one up for you. :thumb:

Posted: **Sat Feb 09, 2013 9:03 pm**

to be honest i dont want to messwith the injectors for 2reasons..
1-its more money i have to put up right now
2-i dont know where to start and whats the difference if i need a resistor box or not???

thanks for all the replies guys :thumb:

Posted: **Sat Feb 09, 2013 11:29 pm**

EHF22A wrote:OBD1 prelude injectors for the h22a are 345cc, h23a1 and f22a1 are 240cc. just thought i might clear that one up for you.

x2

i got my set of injectors cheap.

i would steer clear of DSM injectors, cause you got to wire in a resistor box, and it has a good chance of frying you ECU.

the 440cc's i got from ebay were from Alamo motorsports out in TX, they are the Lucas injectors and they worked fine. i think i forked over less than 200 bucks.

as far as the resistor box it depends on your injector DSM's run Low impedance injector while 92+ civic/integra run High impedance injectors

Posted: **Sun Feb 10, 2013 12:29 am**

asianrob wrote:
EHF22A wrote:OBD1 prelude injectors for the h22a are 345cc, h23a1 and f22a1 are 240cc. just thought i might clear that one up for you.

x2

i got my set of injectors cheap.

i would steer clear of DSM injectors, cause you got to wire in a resistor box, and it has a good chance of frying you ECU.

the 440cc's i got from ebay were from Alamo motorsports out in TX, they are the Lucas injectors and they worked fine. i think i forked over less than 200 bucks.

as far as the resistor box it depends on your injector DSM's run Low impedance injector while 92+ civic/integra run High impedance injectors

so if i get high impedance injectors i dont need the resistor box??and ill try and look for 440cc i guess??

Posted: **Mon Feb 11, 2013 3:24 am**

Don't cheap out, just make up your mind to buy the injectors.

Posted: **Mon Feb 11, 2013 5:18 am**

i would get something that would be adequate for your set up.

and yea for me personally i would avoid a resistor box all means possible.

Posted: **Mon Feb 11, 2013 9:53 am**

i would use what you have for now, besides you would need to get a decent tune and some form of engine management for your bigger injectors

Posted: **Mon Feb 11, 2013 5:14 pm**

kylenjdm93 wrote:i would use what you have for now, besides you would need to get a decent tune and some form of engine management for your bigger injectors

He's going to need a tune regardless :roll:

Posted: **Mon Feb 11, 2013 6:14 pm**

Fada Blayne wrote:
kylenjdm93 wrote:i would use what you have for now, besides you would need to get a decent tune and some form of engine management for your bigger injectors

He's going to need a tune regardless

ya he will :lol: