Hi Rev CDI

[crixal]

i was wondering if you benefit from putting an after market cdi box on? if so, what's the best one? thanks.

[wilkin250r]

It has been discussed many times (try a search) but I don't mind posting repeat info every once in a while.

On a stock engine, the power drops off right about the time the rev limiter kicks in, the engineers that design them aren't stupid. A high-rev CDI doesn't really give you any improvement, because there really isn't any usable power in those RPMS.

However, when you start adding modifications like high-rev camshafts and head porting, you dramatically increase the high-rev potential. Therefore, in that situation, a high-rev CDI would be beneficial. With those modifications, the engine is still able to produce power at the higher RPMs, so you would need a rev limiter high enough to allow you to take advantage of such mods.

If you want a little more info, take a look at the last few posts of this (http://www.exriders.com/vbb/showthread.php?s=&threadid=212609) thread.

[TheNewn]

I agree with everything Wilkin250R said, we need more people like him in the forums.

Wilkin, just to get your opinion, in the order of common mods, where should a rev box come in?

Pipe/Intake/Cam/Rev box? Or would you throw in porting or bore/stroke in there first?

I think a rev box would only be usefull on a big bore, cam, piston, intake, exhaust. Something that makes a lot of power and you can ue those extra RPM. on a rather stock motor theres nothing to gain really. And about rev boxes I hear good things about AMR.

[wilkin250r]

Originally posted by TheNewn
Wilkin, just to get your opinion, in the order of common mods, where should a rev box come in?



Really, it depends on your goal.

It's best to combine mods whenever possible, obviously, but let's assume you're doing piece-by-piece.

I'd go pipe and filter first, big-bore/high compression second, camshaft, high-rev CDI, and then porting. (and after that, a larger/better carburetor)

The only reason I would do CDI before porting is cost, porting is expensive. If you're doing piece-by-piece, it's obviously because you need time to save up your money, and the more expensive the mod, the more time you need to save up. Go ahead and get some of the benefit of the CDI while you're saving up for the porting.

Strokers are another beast entirely. They are so labor-intensive and expensive, it's just best to do the entire motor package at once if that's your goal.



Really, now that I think about it, I would suggest a pipe and filter first, then suspension mods, and then engine internals. I like my big motor, but my suspension mods increased my fun-factor way more than my motor did.