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Discussion Starter · #1 ·
I'm thinking of using RC Engineering to bore out the stock Viper side feed injectors to flow more. Anyone have any experience with this or ever heard of it being done?
 

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I think you need to fire your engine tuner /images/graemlins/laughing.gif First the fuel pump questions now he cant get injectors to work. There are injectors that work with custom external rails and some companies already offer high-flow stock style injectors. Can you take a picture of the hole in your block after he is done frankensteining your viper? /images/graemlins/laughing.gif :leaving:
 

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I've heard of it but have no experience with it. Why do that over getting replacement injectors?

The injectors in US cars are saturation injectors, meaning the fuel pressure is constant, and they get grounded by a power transistor at a fixed current, causing them to open. There is an "open time" and a "close time" that it takes for the pintle to seal the injector nozzle. If you looked at a graph of injector operning, it would be like a parabola. From an electrical standpoint, the coil in the injector is sized to open the injector at a predetermined rate and it closes at a predetermined rate. If you bore out the injector, it's going to change the characteristics of how the injector opens and closes, and the coil isn't sized for a larger pintle.

That is my thoughts on the matter, but I have a bunch of stock Viper injectors on my desk and I've been doing various tests on them over the last few weeks, so I'm not talking out my ass or anything /images/graemlins/smile.gif.

I would say getting factory injectors bored is inferior to getting new injectors sized for the application. You should be able to get higher flow injectors for $50/ea... how much is it to get the stockers bored? The other problem is if you ever need to replace an injector, you gotta go to RC and get it done over. Next guy who owns the car has to know where to get 'em and what to ask for, etc, etc. Sticking with a stock injector of different specs would be my suggestion, partly because it's easier and it's repeatable, and partly because in my work with fuel injectors, I don't believe many (if any) aftermarket companies are as knowledgeable about fuel injector design and implementation than guys like Bosch. Even Chrysler doesn't make their own injectors and IMO there is a reason they leave it up to the experts.
 

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never heard of this, ever. Fuel systems usually go in steps.

fuel pump
fuel pump + injectors
fuel pump + injectors + bigger fuel rails
fuel pump + injectors + bigger fuel rails + fuel lines
completel custom fuel syestem.

this is from what little i know.
 

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The stock injectors are bottom feed injectors....not too easy to find replacements for. It seems that the ONLY reason that you would go for this solution is to keep from having to front hte cost for custom fuel rails, new fuel line, etc. Why not do it right?
 

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what do you mean by bottom feed injectors, please be specific.
 

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Discussion Starter · #7 ·
The injectors are just part of a fuel system I'm building. The original plan was to use custom fuel rails with top feed injectors. I'm gonna be using a Paxton 1000HP pump with -10 lines, pump controller, Paxton regulator, -8 return lines, and a standalone. What I wanted to find out was if anyone has done or heard of using bored out stock injectors running in the stock fuel rails, because it would be a way to simplify things. Alot of other cars use the bored out stock injectors with good results.
 

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Dchan415, Yes it can be done. I had mine done on my cobra, and it worked. The mod was done by JMS racing, he's got a lot of experience so I trusted him..
I had 36lbs Bosch's changed to 77lbs, A lot of people were skeptical but after the car ran [email protected], that was enough for me to be a believer. RC engineering builds injectors, so I am sure they know what they are talking about.
I do know one thing though, the mods can only be done on certain type of injectors plus if not done right the flow pattern will suffer, that could lead to a lean condition on the cylinder.
Hope that answered your question, good luck
 

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Discussion Starter · #9 ·
Thanks for the info RSI. I'll talk to RC about it today.
 

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Sounds like a great idea if the fuel rails in the intake can support the extra flow. I prefer the stealth look of stock injectors rather than advertising performance modifications with external fuel rails. Post the details if you follow through with this.
 

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Discussion Starter · #11 ·
I just spoke to RC and he said its been done and can be done up to about 40lbs/hr. Wouldn't go any further than that though. I guess I'm using top feeds.
 
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