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Thread: 3A92 fuel injector specs & flow rate

  1. #21
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    Quote Originally Posted by Daox View Post
    Alright, I got a package from DeatschWerks last night! They pack everything up nice for you after testing is done.

    Attachment 13961



    Inside was my paper report, the injectors, and some 'super lube synthetic grease with PTFE'. Not sure what the grease is for, but it was a heck of a lot nicer than what I sent them out in.

    Attachment 13962



    And now... the moment you've all been waiting for, the flow test!

    I am a bit surprised myself. A static flow (100% duty cycle) rating of 233 cc/min seems quite large for our engine. Theoretically, this will support around 133 horsepower (102hp if running real rich)! OEMs, I've read, like to stay below 80% duty cycle, so this puts us at 168 cc/min which supports a quite respectable 96 horsepower (that is a 23% increase over stock). Needless to say, there is quite a bit of headroom in the injector flow rates which is great news for anyone wanting to do some mods that require a bit more fuel (like my nitrous oxide project).

    Attachment 13965



    I'd like to give a big thanks to DeatschWerks for doing this testing for free! They typically charge $13 per injector plus shipping back to you. They didn't charge me anything at all. So, I thought I'd give them a plug here on MF. They also sell all sorts of fuel system components from injectors, to pumps, fuel lines, regulators, and more I'm sure.
    How are you calculating the HP the injectors can support? Using this calc - https://fuelinjectorclinic.com/hp-calculator
    the injectors you sent in can support 77hp at 80% duty cycle - but I am new to this.



  2. #22
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    This is how I calculated ~130hp:

    Name:  injector.jpg
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    Running injectors at a lower duty cycle is definitely a very good idea. However, there is really nothing wrong with running them closer to 100% except that you don't have as much headroom and are more likely to run lean. That means if it gets colder you're going to need more fuel, or if your altitude decreases you're going to need more fuel, and any other factor that increases the amount of air going into the engine like more boost if you're running a compressor. These are all things to consider as you dyno tune though.
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  3. #23
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    Quote Originally Posted by Daox View Post
    This is how I calculated ~130hp:

    Name:  injector.jpg
Views: 397
Size:  50.4 KB

    Running injectors at a lower duty cycle is definitely a very good idea. However, there is really nothing wrong with running them closer to 100% except that you don't have as much headroom and are more likely to run lean. That means if it gets colder you're going to need more fuel, or if your altitude decreases you're going to need more fuel, and any other factor that increases the amount of air going into the engine like more boost if you're running a compressor. These are all things to consider as you dyno tune though.
    Woops, I was not using the full flow rate. Thanks.

    Interesting that these injectors, even at 80% duty cycle, can handle a 40% increase in hp.



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