Anyone have any do's or don'ts for rev boxes?

 

"Don't" waste your money on one.

 

If you get one, mount both the stocker and the aftermarket one on your quad. Reason is, if your battery has any less than a FULL charge, the quad wont start. If so, reconnect the stocker to start it, and get it warmed up...then switch back to the rev box and restart.

But i agree, dont bother...it will only shorten the life/reliability of your engine. Instead, get a 16T sprocket...it will let you hold each gear longer, and give u higher top speed.

 

The white Bros doesn't show any HP on our dyno (same timing curve as stk) however the Biggun gives 2-3hp through out the power curve. (on our trail motors 42-43rwhp) If your going to make serious HP you HAVE to have one. Our trail motors make peak power at 8800 rpm rev limiter at 9300 is no good. LOL
Dynoray

 

I disagree...you dont have to have one to make serious HP. In fact, without upgrading springs and valves (on top of mods that I have) it will be detrimental to the engine to allow revs that high...400EX runs too hot as it is.

 

Mia416, you can make about 35 rwhp with out it but to make 40+ rwhp it is a must as an engine that makes peak power at the rev limiter is really kind of useless. To use the 9300 rev limit (to be a drivable machine) you can only make 30-35 hp peak at 8000-8300 rpm. Due to the dynamic's of the EX engine, with 42-45 rwhp your power band is 8400-9800 rpm (with oversize valves we make over 40hp from 8000-10,000 rpm)

 

So you saying a rev limiter that is set higher is really useless??? I just ordered one...darn thx

 

No Husker, on a stk or low performance EX it really wont help but if you do some serious mod's you need it. As I said in my last reply if you want to make 40+ rwhp your (peak) power band will be in the 8400-9800 range and the the stk 9300rpm rev is no good.
Dynoray

 

Gotcha, Dynoray...

And that would make sence to me, as I'm pretty sure I was in the 35HP range...

 

Hey MIA, yes that's probably why you didn't notice a difference. (a 35rwhp EX is still impressive) but the rpm's are low enough that you can use the stk box, you just have to be real quick on the shifter. LOL
We've had customers ex's on our dyno that were built by other builders.
one had a 41FCR carb, Yosi ex, web cam, 416cc ported, 11:1 and only mad 30rwhp. We change the cam, re-ported the head and made 43rwhp.
even at 30hp the bike worked pretty good (a stk ex with K&N and no buffle in muffler makes 25hp on my dyno)
Dynoray