WB Rev Box

[gregmcneil]

I want to know everybodies opinion on the white brothers rev box, I heard some good things and some bad things, I want to know if i should go ahead and buy it or spend my money on something else.

I really like mine. It gives me more revs in each gear. alot of people say you dont need these because the motor makes more power with torque, but I still have all the torque and the extra rev just feels like an extra advantage on a moto x track. Ive had mine on three different ex's. It works for my set up. but i guess its just personal preference.

Spend the money on something else dyno's prove you get nothing out of a WB rev box but a lighter wallet....I sold mine after 8 months of use the quad would NOT start under any circumstances and in any weather,,most say it makes it hard to start only when it's cold out....NOT,,mine wouldn't start in 90 degree weather,,spend the money on a drop in cam,,same price and big power gain..

[mansonclubpuir]

its funny because my buddy bought the box and we raced a few times... my stocker still beat him a whole bunch of times. I personally don't think its worth the money at all. Buy a cam if you want power.

by the way... if you still want it my friend is selling his.

Mike

[gregmcneil]

Well thanks alot for your feedback, I think i'm going to go with not getting the rev box, I've heard to many bad things and not enough good things. Plus if i plan on spending that money I'll get a cam so i know for sure i will get a power increase.

[Dune Surfer]

The cam will gige more power I swear to god the rev limiter works . I can really tell. Besides It's sOOO easy to install, and you don't have to open your engine. Or not. Do you want to race?

[gregmcneil]

Yeah i plan to race, i gotta get shocks first though

[Castor-426ex]

I love my rev box...no problems ever with starting..I think its a good thing to do when adding mods such as a pipe, filter, ect

mabey there was a bad batch or something...

the difference is there..i can put my stock box back on it..its not a big time difference...but you can def feel a different hit from the motor...its up to you...

Im interested to see how its gonna react with the future motor work ive got planned

[Teufel]

IT sucks !!!!!!!! do a search on this topic there was a thread on this earlier

I have one and I like it. I think They work best with no mods or just a few like a pipe and air filter. Once you get it to major engine work I don't think there is much of a gain if any.

[BigThumper33]

It does absolutely nothing to a stock atv. I have seen dyno runs at the local shop. It is a joke. If you claim any gains you need to wake up and be realistic. If anything it should work better with a higher compression piston and trick cam setup. That is where the advancement will help better if it helps at all. I own one, bought it for 10 bucks from a bud. The only things I have noticed out of it is sometimes having problems starting it, and being able to say I have it!

[Ricky g]

I put a WB rev limiter on as one of the first mods, does very little for a stock engine, an after market rev limiter will not make your engine rev higher, it just allows the engine to rev higher, but you have to do mod work to get higher rev's in the first place, put an aftermarket rev limiter on only if your mods are making the engine hit the stock rev limiter, then it's time for a higher revving limiter.

[Castor-426ex]

i just hold my throttle wide open to get more revs:D

[tahoe97]

in my opninion the 14 tooth sprocket are a great combo because the sprocket seems to make you rev shorter but you can rev high with the the box........

the box opened mine up like a dog.. even gave it more throttle repsone and you could tell the curve was more advance

[gregmcneil]

Yeah I was definetly thinkin about gettin the 14 tooth for sure, i always hear good things about it. I plan on gettin in to racin , and i hear thats a must if you race. What kind of sprocket is the best to get, i want only the best, and how much do they run for anyway?

[bansheeguy77]

yea i learned the hard way....get a 14 tooth cause then u can go faster around the track...id say get a renthal...and they go for around 20 bucks.

[Big - D Racing]

the rev limiter sucks, and anyone who says different has no clue what you are talking about. All that so called"allows engine to rev and produce more power" is all in those people's head. Your 400ex peak horse power is about 7000rpm after that peak power mark the horse power drops. The stock rev limiter cuts off at 9000 rpm, the wb cuts off at 10,100rpm. If anyone is reving there engine that high, they don't know how to ride because there engine is losing power that high not gaining. Even on a built 440ex like I have the top hp is still produced about 7500rpm, so you don't need one with a built engine either. If your riding above 8000 rpm on anything, Learn how to ride and shift! Don't belive me call Duncan Racing (the world's leader in Atv racing) at (619)258-6306, they'll tell you the same. IT"S A WASTE OF MONEY, end of story.:eek:

[Sparky416ex]

WEll when i got my 416 scott over at profab took mine off...i ask him and he said they are junk and its helping you more than hurting you...but he can make a rev box for the 300's good

[EXfireguy]

Your bike does not produce power up at the limiter... You hit the limiter, it is like hitting a wall. You see no gains from taking your motor to that high of a rev.

[Castor-426ex]

well after i had my pipe, filter, jetting, and headwork done, my quad would hit the stock limiter if i was flyin wot in fifth..so i had to eliminate that prob

Originally posted by gregmcneil
I plan on gettin in to racin , and i hear thats a must if you race.

What kind of racing you plan on doing??? A 14 tooth sprocket and 18 inch rear MX tires don't work together worth a crap..:macho

[RED121572]

Heres my 2 cts.

Ive heard more bad than good about WB's rev box. The bad being the following: Quad will be hard to start, its expensive, you MUST have a piston and cam to take advantage of the extra RPM's........just to name a few.

My dealer told me to get the XR250 CDI. He told me that it is exactly the same CDI in the stock 400EX except for one thing, the XR250 CDI has 1000 more RPM's than the 400EX CDI. The XR CDI is also only about 80 bucks. Ive seen the WB's as high as 124 bucks.

Now, I installed that CDI with the following motor mods; My current displacement, piston and exhaust. At the time I had an XR400 cam installed.

With those mods, my machine was still lacking mid to top end push, therefore, I was still not taking advantage of the Rev Box.

The cam I have in now, works so much better than the XR Cam did. It allows the machine to breath fairly well at the stock rev limiter.

........so far, that is my experience. Over this winter(when I feel like wrenchin again) Im replacing the WB's cam with a cam that is good for mid to top end. Stay tuned!!

[Big - D Racing]

The wb cdi is a xr250 cdi box. It is a stock xr250 cdi, white brothers just doesn't tell you that because they don't want you to go get one from a honda dealer for less.

[Sick0]

I had the box. ITS CRAP. There is nothing good about the CDI box. The power curve drop way before the stock CDI box even kicks in. If you have to hold a gear longer than what the stock CDI box is set at, then you will be going slower trying to rev the motoer. The 400ex like to be lugged more than it likes to be reved.

Plus the The after market makes it impossible to start the quad in cold weather. Its put extra strain on the battry, Which lead my to become worthless.

The only way I see getting a After market CDI box if you if you modify the **** out of the motor where you push the power curve beyond the point of the stock CDI box. Then Will the motor handle the extra rpm's.
I think they only sell them the CDI box to make a buck. They sound like a good Idea, so people buy them.

[Castor-426ex]

never had a problem starting my quad

[RED121572]

Hey Castor!

I gained 15 ponies when I REMOVED my oil filter. Beat that!! LOL


:D

[ranger400ex]

Spoke with Paul from WB's over a year ago when I was doing some work on the ex and trying to gain some real info. Paul is one of the tech's at WB. His extension is x242(Called him back the other day and he set-up the dealership where I help out at to even exchenge my broken e-series for the new style at no cost!!!!!) . Directly from his mouth"If you are looking for an exhaust check out the slip-on e-series it produces the same as the full exhaust and unless you have a built motor(440+ +major cam+bigger carb+ porting, etc.) you will be wasting your money because their wil be NO difference. second question was about the rev box, his response "honda part specs supplied by honda's manufacturer almost exactly like the xr250cdi. not modded just a larger swell time(higher capacitance) which can and will cause starting problems(needs to be "energized" more to produce a good spark, and the EX in warm conditions turns jsut fast enough to get it going, but problems anytime else) Does it produce any more horsepower, "To be completely honest, NO, it can assist with motors that again have been majorly modded, because it allows them to go to the top of their power." I talked with him about my setup, which is what I currently have, and he expressed that I would see no gain in HP and the only thing that I would see is the ability to rev higher, which as he put clearly "If you are reving that high you needed to shift a long time ago!!! A really honest, informative conversation and good food for thought.

BMW

[Castor-426ex]

lmao...take it out huh? i duct taped a spin on filter on mine...

[Sick0]

I toke me CDI box right it gave amazing topend. haha