rev box ?

[TYayo420]

i have a stock motor right now but a slip on..if i get a stage 1 hot cam installed, jetted and keep my pipe, will is ee any gains with a rev box?

also what is the best rev box on the market?

[CarGuy7a]

the only thing a rev box does is raise the max rpm rev limit.

[GPracer2500]

They can also change the ignition advance. It's difficult to obtain information on exactly how much advance is programed into the various rev boxes available. The exception would be high-end units such as the MSD or Dynatek. They have well documented ignition curves.

[zrpilot]

Originally posted by GPracer2500
They can also change the ignition advance. It's difficult to obtain information on exactly how much advance is programed into the various rev boxes available. The exception would be high-end units such as the MSD or Dynatek. They have well documented ignition curves.

I have the one from GT Thunder and really like it, but when I asked about the curve changes (if any?), I got stoned-walled...:(

[400exrider707]

GT Thunder and TC racing are the only non programmable ones I would consider (as far as I know) they are the only ones that are actually made for the 400ex. All of the other non programmable ones are XR250 cdi's and you will experience starting problems with them.

[GPracer2500]

Or you MIGHT experience starting problems with them. I ran a WB box for years without issue. Keeping your battery in excellent condition does the trick.

Originally posted by GPracer2500
Or you MIGHT experience starting problems with them. I ran a WB box for years without issue. Keeping your battery in excellent condition does the trick.

you are in arizona where it stays warm, he is in new york where it gets cold...he WILL have starting problems

[gcart2]

rev boxes r great for huge motors. 400ex isnt huge. unless u have a 440es from he11 dontworry about it. check out my thread under .... 400ex vs 450r is the 400ex forums

[GPracer2500]

Originally posted by speedyquad
you are in arizona where it stays warm, he is in new york where it gets cold...he WILL have starting problems

Good point. I just get tired of seeing things stated so black and white. I'm glad no one ever told me not to bother with a WB (or similar) rev box because I was satisfied with mine. :)

Perhaps my comment should have been: If you live in a warm climate and keep your battery in good shape the WB box is fine.

i had my battery on maintenance charger and i killed two batteries in one day...one was only 3 months old and out of my wifes 300ex...that is when i found out why they are not a good idea...

not only that, but how often are your really at the max rpm? running full throttle in 5th gear? not very often. you have to reach that max rpm and hold it for there to be any real noticeable difference...

i have said it before and i will say it again...after i took mine out, my friend still had one on his 400ex...comparable riders(weight, skill, etc.) he had a wb e-series full exhaust and i have a big gun full race exhaust...everything else was the same...essentially...i could accelerate faster and i pulled away from him when we were topped out on the road for a few miles...

[GPracer2500]

Well, my experience was that I never had any starting problems. I kept my battery on a battery tender most of the time while it was parked in the garage. I used the same battery for years.

I never used the extra RPMs when trail riding. But I've run the stock box and the WB box back to back in the dunes and immediately missed the extra RPM. With the stock box I would hit the rev limiter when I needed/wanted more overrev. This was on a typical 416 build.


ETA:

Originally posted by speedyquad
...after i took mine out, my friend still had one on his 400ex...comparable riders(weight, skill, etc.) he had a wb e-series full exhaust and i have a big gun full race exhaust...everything else was the same...essentially...i could accelerate faster and i pulled away from him when we were topped out on the road for a few miles...

So you raced with your aftermarket box and then immediatly switched to your stock box and raced again with different results? Or you're saying that on some particular occasion you didn't have a box and your freind did have a box and yours was faster?

If the latter (which is what I think you said), well--ok. But I'm not sure what that is actually telling me. There could have been all kinds of things going on that accounted for that difference. What you could have done to confirm your results is switch the boxes between the two bikes and then retest. If the OTHER bike was then suddently faster then I'd buy that the CDI was accounting for the difference. Otherwise I'm just left wondering.

If you didn't like your aftermarket rev box, that's fine. Maybe yours was junk. I'm certainly in no position to comment on that. Nonetheless, I had tested my WB box back-to-back with the stocker and decided I wanted to keep the WB.

[1965 honda]

i have my orginal battery from 2001 and ive been running a wb box as well, the only time i had a problem was when i moved my battery into my air box i didnt ground it wright. and when i left my lights on. other than that never had an issiue. i live in michigan.

[buster024]

You guys are all smart guys, so I'm sure you've heard of this tip before.....but maybe some hadn't. I don't have a cdi (yet), but have heard of battery problems in cold weather, so it would be wise to zip-tie your old stock box to the new cdi box, in case of low charge battery situations, i.e. cold mornings, long sits in the garage etc. If the quad won't turn over, flip over the box to the stock side, get 'er started & warm, kill it and flip it back over.

As far as performance, again I can't speak from direct experience so you'll have to discount this some, but my riding partner (who rides mostly dunes) claims it was one of the more noticeable "power" mods he has made.

:D