Fueling & Injection - what size injectors?




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camaroboricua
04-19-2012, 12:07 AM
Im starting to collect the parts for the turbo set up but Im unsure on the injectors. What size should I get? Heres a little info on the set up:

5.3 LM7
224/230 .538/.538 114+4
supporting cam mods(springs,pushrods, TC...)
Stock LS1 intake
P&P TB
MP T70
Intercooled

I plan on running the turbo at around 10Lbs until I get more supporting mods later on...


tt383lt1
04-19-2012, 12:13 AM
i have been doing alot of research lately for my build. what hp goal and what type of gas. and are you intercooler?

camaroboricua
04-19-2012, 12:20 AM
it will be intercooled and on 93 octane. as far as hp goals....low to mid 500 range I think would be reasonable....
of course, a little room to grow would be nice also....


tt383lt1
04-19-2012, 12:25 AM
at 750 hp on the crank and 80% duty cycle you need 76 lb min. that with room to grow.

here is a injector calculator i found and with 93 gas you need a .65 bsfc and e85 you need a .8 -.91 bsfc hope this helps

http://www.injectorrx.com/sizing.html

camaroboricua
04-19-2012, 12:39 AM
thats a nice site! thanks for the info. looks like ill be needing at LEASt a 60lb....now I know what to look for in the classifieds...lol

BottleFedZ346
04-19-2012, 01:06 AM
80lb'rs should be fine for now and when you up the boost you will have some room to grow injector wise.....

Always buy the biggest injectors you can afford, that way you never have to upgrade them later.....

denmah
04-19-2012, 07:27 AM
i just always suggest 80s

can idle a stock 4.8 on 1% IDC and lots of room to grow, youll never have to swap them out till you are doing like 900 thru an auto

123quattro
04-19-2012, 08:22 AM
60s will do 600whp. 80s will obviously do 20% more than that.

ACCLR8N
04-19-2012, 12:02 PM
I always hear this room to grow theory. Doesn't anybody take a system approach? A smaller injector is going to have better idle and driveability. Isn't the best injector the one that meets your goal at an 80% duty cycle?

123quattro
04-19-2012, 12:43 PM
A good set of 80s will have just as good of driveability as stock assuming the guy tuning them has some skill. Above that probably not.

denmah
04-19-2012, 02:09 PM
I always hear this room to grow theory. Doesn't anybody take a system approach? A smaller injector is going to have better idle and driveability. Isn't the best injector the one that meets your goal at an 80% duty cycle?

this only applys to 1990s tuning when injectors were not linear,

if i can get a 18.0 AFR idle out of my warmed up stock 4.8l car with an 80lb injector and a 15.0 cruise stumble free, what is the problem....

i have seen many friends buy 40s-50s-60s- and now 70s-80s

using the theory of only get the injector that you need.

cmon guys you are building 500+rwhp turbo cars, get a big fuckin turbo, big fuel pump and huge ass injectors. you know you are gunna use it

BottleFedZ346
04-20-2012, 02:16 AM
^^^

Pretty much!

LS1NOVA
04-20-2012, 06:04 AM
Get the 80s now.