Mixing injectors on same fuel rail? Any issues???
11-29-01, 04:17 PM
#1
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Mixing injectors on same fuel rail? Any issues???
Hi,
Any one in here mixed different injector sizes on the same fuel rail before? I currently have 2x680 pri and 2x720 on sec. However, I am getting too rich low end and leaning at 7K RPM (even with the max AFC settings). I have an upgraded turbo. now. I just got 1 850cc injector (free) and would like to do this:
1. Primary: stock 1x550 and 1x720 (or maybe 1x680 here).
2. Secondary: 1x720 and 1x850.
I know about the impedance thing and I am capable of working around that. Just wanna know if there are any drawbacks (such as flat spots, uneven fuel flow, etc...). I don't think there is an issue since the injectors would just feed fuel at there max based on the duty cycle, but I want to make sure there is no problems. Thank in advance,
Jay
Any one in here mixed different injector sizes on the same fuel rail before? I currently have 2x680 pri and 2x720 on sec. However, I am getting too rich low end and leaning at 7K RPM (even with the max AFC settings). I have an upgraded turbo. now. I just got 1 850cc injector (free) and would like to do this:
1. Primary: stock 1x550 and 1x720 (or maybe 1x680 here).
2. Secondary: 1x720 and 1x850.
I know about the impedance thing and I am capable of working around that. Just wanna know if there are any drawbacks (such as flat spots, uneven fuel flow, etc...). I don't think there is an issue since the injectors would just feed fuel at there max based on the duty cycle, but I want to make sure there is no problems. Thank in advance,
Jay
11-29-01, 06:49 PM
#2
W. TX chirpin Monkey
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Well this is my Q to u. Do you have an upgraded Fuel pump. because if not your fuel pressure could really drop causing it to go lean. Also were the injectors new or used, they could not be flowing the proper amount and therefore also be causing you to go lean up top. with 720 and 680, there should be enough fuel for over 300 RWHP. check out the fuel computer at www.rx7.com it not dead on, but it's set for a very reliable number.
11-29-01, 08:12 PM
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It sounds like a bad idea to me. With that mix and match of different injectors you could run lean on one rotor and rich on the other. I would suspect a problem elsewhere or something is not setup/tuned right.
11-30-01, 04:58 PM
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Okay...Guess I'll be buying an set of 850's then. I am pushing around 300 RWHP and if you run at 80% injector cycle like my injector setup, you cannot get 12:1 a/f. Maybe it's my car, but I am pretty sure the values are universal. Unless you start to push to 85-90% cycle, which you may lock up your injectors.
11-30-01, 05:36 PM
#6
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don't do it! it won't work, well it will work but you will blow your motor! you might need to look into a aftermarket pressure regulator,sounds like you are running out of pressure not flow
