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dburkett

XR650R Rev. box

8 posts in this topic

Why do you want to replace the factory box?

I think most guys are using the factory box. It seems to work pretty good regarding rev limit, ignition mapping, etc.

I would think unless 1) you are going to a full-monte, max-power race bike or 2) your factory box is fried, you'd stick with the stock unit.

My two cents.

So, why do you want to change?

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Its my opinion that the factory redline is set at that point for a reason. A small block V-8 has similar bore/stroke to the XR650R and they don't rev to 8000+ rpm.

Unless you are running a stage 2 cam with a cut side panel and a header/pipe combo, you won't get anything from overrev. Go with a cam and header/pipe combo like FMF powercore /powerbomb or Procircuit T-4 if you want some power.

Maybe I don't understand your intentions, but I'm just trying to help. Hope you find what you are looking for.

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I don't have one, but keep in mind that it may not just be a higher rev-limit that you get. A more advanced ignition curve could be a good thing, especially knowing Honda 's tendency towards conservatism.

A few degrees of timing advance, some premium fuel.... could be fun!

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I guess reading some things about them, i seen the timing change and thought this could be a good thing. Not sure, so i thought i would ask you guys and see what turned up . Thanks!

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I am on the fence with the idea of a Rev box or higher rev limit in general. While I think the stock box is what partly keeps the XR650r motor so reliable, it might be somewhat over conservative in some respects. :censored::applause:

A fully stock motor without mods to allow it to have more top end horsepower or more ability to climb closer or past the stock rev limit when wide open in the upper gears may not benefit much from a higher rev limiting box. The only bit of extra benefit that could be possible with the higher rev limit could come while hammering through the gears where there is enough power to rev past the stock rev limit. If the box does truly have an advanced timing curve there can be some benefit from that as well but there is a hitch with a few aftermarket boxes out there. Many or all of the cheaper Rev Boxes are analog type ignition controls. The stock unit is Digital. The high end= expensive, ignition/rev boxes like the Vortex are digital.

A digital unit is supposed to be more efficient, reliable & more precise. A digital mapping curve is supposed to have the capability of having more mapping points within a programmed curve. Essentially you would be taking a step down in technology by going with a analog unit such as Procom, Big Gun and a few others that are also manufactured by Procom and maybe some of chinese manufacture. :applause: They may have an advanced curve but there may be less programmed points within the curve to maintain or garner truly optimum curve characteristics. :lol: This is even more of a issue with the newer more sophisticated generation of motors and ignitions with throttle position sensors like on the CRFs.

I would venture to say that XR650Rs running at least full exhaust systems would be the required minimum for a higher rev limit Vortex type unit. A Cam and other associated mods would be a real benefactor with use of a high rev ignition.

On the other side of my thinking, I question the service life of the valvetrain. But of course that is the trade off of getting the most possible performance out of the motor. If you could ride the bike without revving it to the moon most of the time and only occassionally push the envelope of the ignitions limit, maybe that would suffice. It is a dilemma. :ride: ...

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Thanks for the info.I heard that the "chips" for cars supposedly do good things. Thought it might do same for theXR650R. Looked like relitividly cheep horsepower on the surface,and thought i would see if i could dig up some info on the variouse mfg's of them.Thanks for the info! This is a real nice service.

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One of the differences of the performance chips for cars and a rev box such as for the XR650r is that the car chips control both the air/fuel mixture along with timing. Basicly a different ballgame. Glad to be of service.

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