injectors cant decide
#2
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I'm going with 550cc primaries and 1000cc secondaries. I'm hoping that will be enough fuel for once I get my BNR Stage 4 upgrade. But the injector size depends more on your mods and what you're going for in the long run
#6
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There's no such thing as "best".
There is such a thing as "big enough"!
Stock 4 x 550's supports about 250bhp.
2 x 550 + 2 x 720 (720's in secondaries) supports almost 300bhp.
4 x 720's supports about 320bhp.
4 x 550 + 2 x 1600 (stand-alone required) supports about 420hp at the wheels (DynoJet).
Those are the popular combinations that most people run.
-Ted
There is such a thing as "big enough"!
Stock 4 x 550's supports about 250bhp.
2 x 550 + 2 x 720 (720's in secondaries) supports almost 300bhp.
4 x 720's supports about 320bhp.
4 x 550 + 2 x 1600 (stand-alone required) supports about 420hp at the wheels (DynoJet).
Those are the popular combinations that most people run.
-Ted
#7
Originally Posted by RETed
There's no such thing as "best".
There is such a thing as "big enough"!
Stock 4 x 550's supports about 250bhp.
2 x 550 + 2 x 720 (720's in secondaries) supports almost 300bhp.
4 x 720's supports about 320bhp.
4 x 550 + 2 x 1600 (stand-alone required) supports about 420hp at the wheels (DynoJet).
Those are the popular combinations that most people run.
-Ted
There is such a thing as "big enough"!
Stock 4 x 550's supports about 250bhp.
2 x 550 + 2 x 720 (720's in secondaries) supports almost 300bhp.
4 x 720's supports about 320bhp.
4 x 550 + 2 x 1600 (stand-alone required) supports about 420hp at the wheels (DynoJet).
Those are the popular combinations that most people run.
-Ted
Would 4 by 720 be maxing out the injectors for 320 hp?
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#8
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You don't want to push the injector duty cycle over 80%.. I think that 4X720's would WORK for 320 HP.. BUT... Its pushin it....
Here's my take... Ted's numbers are good... except that its "2" 550's and 2 1600 to support 400 HP (not 4 550's)
FIRST... decide what ECU.....
If you are using the STOCK ECU.. then stick with the STOCK 550 primaries... This will give better driveability because the stock fuel curves will still be relevant for normal driving loads.
If you are using the STOCK ECU and an SAFC... go with the SMALLEST secondary injectors possible, this will make it MUCH easier to tune your SAFC or whatever fuel adder you are using...
If you are using a STAND ALONE... then, you can use damn near anything you want!!!!
I use Marren 750's in the primaries and Marren 1000's in the secondaries with a BNR Stage III and have plenty of duty cycle left
I've found the 750's to be much smoother than the stock injectors and having the 1000's instead of 1600's, gives a much smoother transition to boost.
Again.. with a standalone.. you want to use the smallest secondaries possible as it will aid greatly in tuning the car.
Quad 1000's work great with a high horsepower car (over 400) and a Microtech.
Here's my take... Ted's numbers are good... except that its "2" 550's and 2 1600 to support 400 HP (not 4 550's)
FIRST... decide what ECU.....
If you are using the STOCK ECU.. then stick with the STOCK 550 primaries... This will give better driveability because the stock fuel curves will still be relevant for normal driving loads.
If you are using the STOCK ECU and an SAFC... go with the SMALLEST secondary injectors possible, this will make it MUCH easier to tune your SAFC or whatever fuel adder you are using...
If you are using a STAND ALONE... then, you can use damn near anything you want!!!!
I use Marren 750's in the primaries and Marren 1000's in the secondaries with a BNR Stage III and have plenty of duty cycle left
I've found the 750's to be much smoother than the stock injectors and having the 1000's instead of 1600's, gives a much smoother transition to boost.
Again.. with a standalone.. you want to use the smallest secondaries possible as it will aid greatly in tuning the car.
Quad 1000's work great with a high horsepower car (over 400) and a Microtech.
Last edited by YearsOfDecay; 08-03-05 at 09:50 AM.
#9
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Originally Posted by WrongWay
Would 4 by 720 be maxing out the injectors for 320 hp?
The last number (420) is rear wheel.
I was going to convert them all to rear wheel, but I got lazy.
![Frown](https://www.rx7club.com/images/smilies/frown.gif)
320bhp at the flywheel is like 270 at the rear wheels.
-Ted
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