which injectors for my application?

9

9150ho

New Member

Mar 20, 2004

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Sep 11, 2004

#1

• Sep 11, 2004

• #1

I have a stock motor besides cobra intake, 1.7's, and some edelbrock (1.9's) heads. Im putting a novi 1000 with a power pipe and the crank pulley, which should put me at 8lbs, give or take. What injectors do i need? 30's will be ok for this setup? tell me what you think.
sean

 

D

Daggar

New Member

Jul 19, 2004

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Sep 11, 2004

#2

• Sep 11, 2004

• #2

I'm sure you know that you'll need a new MAF with those injectors. You could get away with 24lb but if you plan on doing more modding you might as well go for the 30's. The computer should handle the rest (as well as it can without a custom chip anyway).

 

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Scorcher2005

Member

Apr 17, 2004

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South Carolina

Sep 11, 2004

#3

• Sep 11, 2004

• #3

lets just assume your engine will make 400 hp. If it does and assuming a bsfc of .6 and 80% duty then you will need at least 36lb injectors.

 

T

TheUser

Active Member

Jul 25, 2003

1,859

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36

Springfield, MO

Sep 11, 2004

#4

• Sep 11, 2004

• #4

i can't find the link, but I had one to a chart. Either way, I believe 24's are good for 375 hp w/ Forced Induction (blower, turbo, nitrous) and around 420-425 N/A, so I'll concur w/ Daggar and say you could use 24's; if you plan to upgrade more in the future, maybe 30's would be your best bet.

 

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Scorcher2005

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Apr 17, 2004

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South Carolina

Sep 11, 2004

#5

• Sep 11, 2004

• #5

i dunno how u guys keep coming up w/ 24lb'ers. iused the formula:

(HPxBSFC)/(# of injectors x duty cycle)

 

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onefastlx

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Sep 9, 2004

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Sep 12, 2004

#6

• Sep 12, 2004

• #6

I would go with 36 lb..Its better to have a bigger inj then you need and back of the fuel pressure a bit to get the right AF then run your pressure sky high with a smaller set of inj's.Running the crap out of the pulse width on an inj is a great way to fry them...

 

houstonstangguy

Founding Member

Mar 16, 2002

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Houston, Texas

Sep 12, 2004

#7

• Sep 12, 2004

• #7

EDIT I just reread your post and saw that it was mostly a stock engine except for the intake and heads and rockers, so I think that the 30's would probably be fine. If you have to use an FMU later then it won't be a problem. if you already had a built motor with all the fixins then I would say 36's.......I still think that the 24's by themselves would be too small, but maybe 24's with the FMU would be ok too, but again, you optimally would rather not have to use an FMU. and for the advice of going bigger. that isn't always the best thing. I agree that you would rather have bigger than smaller, but you would rather have the right ones now over a bigger injector.

the question is, do you plan on leaving it like that for awhile? no additions?

 

Bone Racing

New Member

Sep 7, 2003

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Long Island, NY

Sep 12, 2004

#8

• Sep 12, 2004

• #8

could use 24...i WOULD use 30's

 

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SlowGT

Founding Member

Jun 17, 1999

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Columbia Co, PA

Sep 12, 2004

#9

• Sep 12, 2004

• #9

9150ho said:

I have a stock motor besides cobra intake, 1.7's, and some edelbrock (1.9's) heads. Im putting a novi 1000 with a power pipe and the crank pulley, which should put me at 8lbs, give or take. What injectors do i need? 30's will be ok for this setup? tell me what you think.
sean

Click to expand...

I think you should do some reading here: Accel Fuel Injectors--> start on page 12 and continue until you're satisfied. It's a 6MB file. Probably easier to download it and then you can print it for future reference.

Here's some good injector math from MSD.

Here's a table of injector flow data for various manufacturers. Checkout the Homepage there for some calculators and good head flow data.

 

9

9150ho

New Member

Mar 20, 2004

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Sep 13, 2004

#10

• Sep 13, 2004

• #10

good info slowgt, thanks.
with 6lbs, and stock motor with just heads, and thats the way it will stay for awhile...i think i will go with the 30lbers. doing that calculator thing, if i get 350 hp ( which is a little skeptical...right?), the 30lbers would be fine. if anyone thinks this a bad idea, or sees a fault in my math, let me know in the next......couple of weeks. thanks guys.
sean

 

CRASH7772

Member

Apr 27, 2003

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NH

Sep 13, 2004

#11

• Sep 13, 2004

• #11

Here's the link--> http://www.pro-flow.com/tech info/sizing.htm

 

giddyup306

Founding Member

Oct 22, 2002

3,041

2

59

Sep 13, 2004

#12

• Sep 13, 2004

• #12

I have a set of 30# injectors and maf for sale. PM me if interested.

 

PhLoBuS

New Member

Aug 15, 2004

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Beverly, MA

Sep 13, 2004

#13

• Sep 13, 2004

• #13

30's if u plan on modding more