Injector sizing

[Punisha00]

Hi guys,
Just was reading AEM's FAQ about fuel and working on the the formula that they say to use on working out the size of the injectors for your car, I worked out that a 650hp 4 cylinder engine only needs 265cc injectors, now i'm pretty sure that cant be right can anyone tell me where i'm going wrong?:confused:

[KC.]

I think on the RC website they've got a calculator to check what sized injectors you would need, I got told for the DC2R I would need 330cc injectors so i'm guessing yours is quite off the mark haha

[CivicEH9]

I just did it and it worked out as 1025cc which is the same as the RC calculator tells you
What numbers were you using to figure it out?

[Punisha00]

I got the formula from AEM POWER and this is it :((Power x BSFC) x (1 + Safety Margin))/Number of Injectors = pounds/hour. I did ((650x0.68) x (1+0.15))/4 = 127lb/hr http://www.aemelectronics.com/faq.php?cID=1&osCsid=t7g7v0bu722r19m4m9druv1ej4 its abt 2/3 down the page

[CivicEH9]

That's exactly what it should be so it must just be your conversion that's gone a bit funny
To convert from lb/hr into cc/min it's 127 x 10.5092 = 1336cc

[Punisha00]

yea my converter was wrong lol and the AEM doesnt take in duty cycle either. thanks for ur help. Is there a well known company that sells big injectors, RC only goes to 750cc for honda on there website?

[CivicEH9]

Yeah looking at it, the AEM one comes out as about 85% duty cycle which is just a bit high. Not a clue where you could get injectors that big though sorry. Might have try emailing them to see if they do go any bigger

[TODA AU]

Injector Dynamics