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Discussion Starter #1 (Edited)
What is the deal with flapper valve removal on RC51's. Will this single procedure give better engine performance, or will I need to add exhaust, and fuel management to make it work. I know all the links on the web, but I want first hand experience, and opinions.
 

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It just lets the bike breathe like it's supposed to throughout the entire rpm range.

All in all it's not much of a mod & the significance is small because we are still restricted by the emissions controls on the ECU & even with a PCII or PCIIIr we still aren't getting a 100% optimal mapping just simply because of EPA BS, however every little bit helps & since it is free & only takes 30 seconds to do, I suggest you just do it... I mean in the time it took you to type this thread up you could have already done it.

In truth most people can't tell the difference as it is barely detectable on the dyno, but the placebo effect works wonders for their imagination & some people claim that it gives them boost like performance which is BS too, but hey the mod does work...
 

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LOL! What Mike said. :D

I have done the mod but I did it with several things since I wouldn't be able to tell the difference. The advantage I see is that is takes unnecessary components off of the bike and cleans things up a little. I remove it with all of the PAIR valve crap. This got rid of some weight and a few feet of tubing. :cool:

Anyone that says it adds noticable performance gains with that mod alone is totally full of shit or is getting totally shafted by HRC by letting Colin ride the factory bike instead of them. :)
 

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Discussion Starter #4 (Edited)
Ok, but my next question is

will my stock ECU freak out if the flapper valve is removed. I know that exhaust mods sometimes piss them off, and removal of emissions stuff will do the same. I will wait until I have a PCII or PCIII to complete the job if that is what it will take. I am hoping that this is not the case. I appreciate the help:D
 

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Re: Ok, but my next question is

maley2000 said:
will my stock ECU freak out if the flapper valve is removed. I know that exhaust mods sometimes piss them off, and removal of emissions stuff will do the same. I will wait until I have a PCII or PCIII to complete the job if that is what it will take. I am hoping that this is not the case.
I don't think the flapper removal causes any problems with the ECU. Actually, I believe it helps with the stock ECU when view on the dyno.
 

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Discussion Starter #6
Re: Re: Ok, but my next question is

RCjohn said:


I don't think the flapper removal causes any problems with the ECU. Actually, I believe it helps with the stock ECU when view on the dyno.
:cool: COOL:cool:
I'm off to get my tools:D
 
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