What size injectors for Supercharger with mild mods? 30, or 36#?

BlackFox5.0

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Aug 7, 2000

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blackfox.ath.cx

Apr 6, 2004

#1

• Apr 6, 2004

• #1

I put an A-trim on my car, and i think my injectors are giving my misfire problems, so.....

I'm just going to upgrade to bigger ones anyways....

My big mods are explorer intake, ported stock heads, A-trim (set for around 4-7psi) full exhaust....

So which size should I go with? 30#, or 36#?

 

Starscream88

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Mar 8, 2003

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#2

• Apr 6, 2004

• #2

You could actually get away with 24# ers

But To be on the safe side 30 will do just fine,

36 is overkill for that amount of boost and power

 

P

PRO50SC

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Dec 28, 2003

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Apr 6, 2004

#3

• Apr 6, 2004

• #3

BlackFox5.0 said:

I put an A-trim on my car, and i think my injectors are giving my misfire problems, so.....

I'm just going to upgrade to bigger ones anyways....

My big mods are explorer intake, ported stock heads, A-trim (set for around 4-7psi) full exhaust....

So which size should I go with? 30#, or 36#?

Click to expand...

I run 30's in mine. No problems. Check my sig for my web site to see my mods.

 

Starscream88

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#4

• Apr 6, 2004

• #4

Heres an injector Flow chart,
Check your estimated HP and match it up,

As I said 24# will be ok, But as you can see 30# is your best bet

 

5.0 HOtrain

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#5

• Apr 6, 2004

• #5

I ran 30's with my 303rwhp 302 w/no problem. Ran them because I was planning on nitous, but plans change

 

RydeOn

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#6

• Apr 6, 2004

• #6

If you are upgrading, do it the right way and get the 36ers, minimum. Do not get 30s, you will still require an FMU. One thing no one is taking into account is that chart shows exactly what it is labeled: MAX HP. When you choose an injector you DO NOT choose it based on its maximum injector duty cycle. When an injector is maxed out, it does exactly what it is doing in your car, or worse case it can 'freeze' open. When choosing, you want to allow at least a 20% buffer so you dont push the injector to its limits. So if you are making 400fwhp which is very feasible you will go 400/537 which comes out to 74% injector duty which is PERFECT. Dont lowball your fuel requirements.

 

Reactions: GreyMare88

Rick 91GT

Mustang Master

Nov 29, 1999

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Apr 6, 2004

#7

• Apr 6, 2004

• #7

I also say 36# no FMU....the large injector will not hurt.

We made 425/465 to the wheels with our A -Trim combo on our blown 93 Cobra, 36# inj no FMU, 255lph HP pump and a T-Rex. If we made any more power we would have to go to a larger injector.

 

BlackFox5.0

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#8

• Apr 6, 2004

• #8

Won't I run really rich when not in boost?

 

RydeOn

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#9

• Apr 7, 2004

• #9

Not at all. The ECU tells your injectors how much fuel to give. This is why we calibrate injectors to the MAF and this is also why you should finish off the combo with a dyno tune.

http://www.pro-flow.com/flow sheets/36flow.htm

 

stangbear427

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Nov 11, 2002

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Apr 7, 2004

#10

• Apr 7, 2004

• #10

Right. It's always better with injectors to go bigger than you need than smaller. I say 36# too. Plus, what are the odds you're going to keep those stock heads in there? Just my presumption, but now that you have the Vortec in there I'd say their days are numbered. Uncork that blown engine with some good heads, and 36# won't seem like an overkill anymore.

 

BlackFox5.0

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#11

• Apr 7, 2004

• #11

If I get new heads they'll be ported (by me) GT40's I can't afford aluminum heads lol