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Advantage of top feed vs side feed injectors.


Old 07-21-07, 11:56 PM
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Question Advantage of top feed vs side feed injectors.

I am installing vinton hose on my car right now, as well as installing ceramict coated intake mans, vmic,plugs,mid pipe, taking double t-body out, simplfying seq.,removing AWS, coolent line to t-body, and was thinking of up grading my injectors to 1200cc or 1300cc on the secondaries.

I would lke to know what the differance is between side feed and top feed injectors. I do not have the time right now to reseach this topic at the moment. I have school, work, a family and I am working on the car at home. I also have work being done to my house. So if you are going to tell me to search dont bother.

I seach most of the time when it comes to things like this. i just do not have the time. So If anyone can help I would be greatful.

I am getting things ready so when I buy a second engine and have it ported and buy some BNR 3s I have all other things in place. I would like to hit 400 rwhp with twins in seq. That i why I am looking to up grade injectors. I already have a PFC. hope I can have my car done when Steve comes out to LA. on Sept 15th.

Thanks for your help.

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Old 07-22-07, 09:10 PM
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As for the physical difference, a top feed injector sucks fuel in from the top ("normal" fuel injectors are top feed). The fuel snakes through the injector (around the coils), and out the nose.

A side feed injector pulls fuel in at the bottom - the coil is at the top, and the fuel comes in under it, and has less between the feed and the tip.

Side feed injectors require a larger fuel rail wrapping around them, as opposed to the fairly small rails feeding top-feed injectors.

As for performance/etc, I can't help a whole lot, other than to say that there's a reason many massive flow injectors are side feed - there's a limit to how much fuel you can pump through a top feed injector. I don't know where 1200cc is compared to that limit.

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