Injector Calculators

[Big T]

Hey all,

Just wondering... how accurate are those injector calculators littered all over the net? Has anyone used one that was particularly good?

Here's a couple i've been using:

http://www.z31.com/software/injector.pl
http://www.witchhunter.com/injectorcalc1.htm

After all my upgrades, i'm thinking the injectors i have won't be up to the task of supplying up to 200rwkw+ Using my data i get

Injector size: 440 cc/min injectors(41.9 lbs/hour)
Number of injectors: 4
BSFC: 0.60
Duty cycle: 0.85

This combination will supply fuel for 237 horsepower

which is obviously waaay short of the power i need (this is power at the flywheel) According to this thing... i'll be needing at minimum, 550ccs to get close. So, who thinks i need new injectors?

Eddie.

[1JZ-Rolla]

Those calculators sound a little on the high side compared to "real world" figures

If I compare to my 4AG turbo, basically I would still not have enough fuel at 100% duty cycle with the 550cc injectors to make the power it did, with a "guesstimated" 15% drivetrain loss [ready to open another can of worms on drivetrain losses )

[Big T]

Indeed... i actually tried plugging in your figures off your old 4agte Phil and the calculators were trying to tell me you needed 650cc+ at 85% duty to get 195atw. I remember reading you were using 550s so they seem to over-compensate a bit.

Either way, the 440s were going to be too small and with Rod having nice sets of 660s for sale, how can i say no to an upgrade?

Eddie.

Edit: hehehe, i estimated your drivetrain loss at 20% and the calculator still went high

[The Witzl]

eddie, i'll kill you if you buy my injectors!
lend me the money instead

[1JZ-Rolla]

What ECU are you planning to use Eddie? Make sure it can control the injectors sequentially, otherwise it may be a bitch to tune at idle & light load with such large squirters on a 1.6L with batch fiiring

[Big T]

Autronic SM4. I'll be heading down to SAS to discuss my ignition system and stuff in detail this week so i'll remember to ask about it.

I'm pretty sure the SM4 has sooo many features i could probably get it to cook me my dinner.

And Witzl, i'll most probably be taking the duel spray SARDS so im hoping those aren't the ones you want.

[1JZ-Rolla]

sweeeeet. should be all good then.

[The Witzl]

SM4 is the shit, and definitely has sequential firing capabilities on both ignition and injection. Dont forget to call me when you need the wiring done eddie

p.s. no i dont want the tards
p.p.s. did you ever finish that ae71?

[Big T]

Thanks Witzl, i'll definately call you when i need wiring done

And you can have the single spray for the p00 8 valve

Oh and if you mean by "finished" the ae-71 you mean "sold and got towed away" then yes... yes i did manage to finish it

Eddie.

[steve_t647]

Remember guy's if you do the injector's you may need to look at the fuel rail pressure and the fuel pump's to run a 450 horse evo I had 2 seperate fuel rail's and 2 fuel pump's running high pressure and only 2 cylinder's each so # 4 would not be low 2 return's too. 1 ran 1and 2 the other ran 3 and 4 so the pressure was up there quick some rally guy's in NZ do the same (so they can damage 1 supply or return raik and not loose huge power)