dutycycles on 16g

[crazyboost]

Does anyone have any injector (stock, 550, 650, etc) dutycycle numbers on a 16g that they could post up? Also include boost level. I'm just debating what injectors i should get when i get my evo III 16g. thanks

 

[98spydert]

Here's an equation to help you get a pretty idea of what you need.

Flow Rate= (HP*BSFC)/(# of injectors * max duty cycle)

BSFC is brake-specific fuel consumption measured in pounds per hoursepower-hour at wot. turbo charged engines are approx .55 so use that.

HP is realistic horsepower you are expecting with set up tuned properly.

# of injectors is 4 obviously

A safe max duty cycle you want is 80% so use .8

Flow rate is in lbs per hour of fuel.

Sorry this may be over some peoples head...

 

[kpt4321]

Here are some numbers: On any of those injectors, you could be between 60% and 100% duty cycle.

This is way too broad a question. I don't know what boost level you want to run, what power level, what A/F ratio, what other mods, etc...

Pick injectors that flow enough for the amount of POWER you want to make.

 

[ShapeGSX]

If you max out the Evo III 16G, you will also be beyond the fuel flow that 550s can support. So get something bigger if you plan on working your ass off to get the most out of that turbo. That means cams, FMIC, etc...

 

[Larry L]

Originally posted by 98spydert
Here's an equation to help you get a pretty idea of what you need.

Flow Rate= (HP*BSFC)/(# of injectors * max duty cycle)

BSFC is brake-specific fuel consumption measured in pounds per hoursepower-hour at wot. turbo charged engines are approx .55 so use that.

HP is realistic horsepower you are expecting with set up tuned properly.

# of injectors is 4 obviously

A safe max duty cycle you want is 80% so use .8

Flow rate is in lbs per hour of fuel.

Sorry this may be over some peoples head...

I need to go back to school!:laugh:

 

[kpt4321]

It's not that hard.

HP is horsepower. Put in what you want.

BSFC is around .55, he told you that.

Number of injectors is 4. He told you that, and it's counting.

Duty cycle is the percentage of the time you want them open. 90% = 0.90.

 

[kpt4321]

Try this:

http://www.dsmtuners.com/forums/showthread.php?s=&threadid=102787

 

[98spydert]

I tried figuring out the same thing that you are a while ago with that formula so I'll just post my findings for you.

I picked 320 hp as a goal with the EVO 3 and mild tuning.

so:
(320*.55)/(4*.7)= 62.857 gallons per hour

Due the conversion and even more math and I got 649.8cc/min so a nice 650cc ball style injector seems to be the perfect choice so far with room to grow becuse I used a 70% duty cycle in the equation. Preferably you want 60%-80% at wide open throttle.

One thing I'm still looking at is whether or not the 650cc injectors are big enough to negativly effect idle or low rpm/ cruising. Might just be something I'll have to deal with.

Hope this helps

 

[laza101]

I've been tuning my car for quite some time now (16g @ 19psi). Let me give you a suggestion: go with 650cc injectors or larger! I have tried 510cc and 550cc and I've maxed both out on pump gas. I just installed 650cc FIC ball-style injectors and with PROPER TUNING the car idles/drives like stock with some crazy top end power. I'm still running about 83% duty cycle so I could have gone with 720's. Trust me, go big or go home - small injectors are not worth the money if you're looking for reliable power.