the WB boxes are junk. your bike won't start in winter. these boxes don't do much for power. i have tried several. the best one i have used is GT thunder. this box will enable your bike to start in winter. don't expect a power gain though. if you want the all out best box, which produces more spark, get the msd box. i am not saying how much power this will give you, but i bet it isn't much. it should provide the best gains out of any box though. i don't know the quality of it though. spend the cash else where. i realize with a higher revving cam you will need a rev box. it will enable you to rev higher and that is about it. it won't provide the power of a cam, piston, etc. no where near. many of these aftermarket boxes will provide better gains on other bikes. the 400ex just doesn't open up like the other bikes, even when adding a pipe.

 

Mxer250,

I dont believe I said they would. Did I? Jeez!

Marky

 

Cals400ex,

I dont believe anybody has said they will out perform cams and pistons did they? WTF? The White Bros box are not junk, but you do have to be aware that the timing curve is so advanced on top, it will naturally be too advanced on the bottom as well - this causes cold starting problems - The work around for that is putting the the stock CDI in until it warms up. The Big Gun takes care of this problem, but is not as good at low RPM launches when racing. Until Vortex comes out with its multi-curve, switch on the fly CDI - the problem will persist.

A CDI is a good way for a lot of the guys in here to experience a 1-2 hp gain and torque increase for only about a $100. Its one of the simplest ways to make ANY quad perform better with a snap in solution.

You all can hijack this thread if you want - but there is a lot of usefull reading for those that have stock quads.

 

Oh dune OregonDunePatrol I agree that it will help. But from my experence with a $100 cdi the gain is so small. Mabee with the nice $400+ cdi's there is a big difference. As far as there being a lot more gain with engine mods I thought you were indacating that there was as much or more of a gain with a cdi. There is alot of good info in here and im not trying to say there isnt.

 

Thats cool. The big CDIs are just more flexible. They have torque curves, linear curves, stock curves and of course performance curves. I dont think there are huge differences between the expensive CDIs and the other $100 CDIs in the top performance curves besides different rev limits - The differences are certainly not as noticeable when compared to the differences between the stock and aftermarket boxes. I dont think you'll ever get more than 1 or 2 hp more with any CDI. However, there are other advantages to them besides HP - Torque and RPM quickness are advantages over the stock CDI. For some, including me, these differences are huge for the ease of installation.

Also, I agree with you - I was not indicating that there was as much gain with a CDI as with other mods - I love the other mods I have done, and would in no way compare the gains of the other mods I have done with an aftermarket CDI. But the CDI is an easy mod to do, like an air filter. But nothing can replace a high performance carb, piston, cam, exhaust, and valves (to mention just a few).

 

i would like to see that WB box on a dyno and see a 1-2 horsepower gain. i am not trying to argue. i have tried several and i wouldn't let that touch my bike again if i had one. i agree, with a high revving cam you need more rpms. but i wouldn't let that one touch my bike again. the gt thunder is a much much better box. when drag racing with a stock cam, there was absolutely no difference between the stock box and the WB box imo.

 

Are you sure about that? [img]i/expressions/face-icon-small-wink.gif[/img] There will never be more than a 1 or 2 horsepower gain with a CDI box - Now I have said that about 4 times in this thread. I understand perfectly that you can have an opinion - but to be honest, I think everyone that reads your post, that has a brain, will know that there is no way an aftermarket CDI will be the same as the stock one. The ignition timing is increased as well as the rev limit. Now I am basing my opinion on 4 years of race experience, owning two quads, and playing with at least a half a dozen CDI boxes, including the WB. Now if you have a dyno chart that backs up your statement, then you'll have more credibility than me. But simply saying that " there is no difference between the stock box and the WB box" is a pretty strong opinion. Further, if you have nothing to back it up, it sure sounds like your trying to argue to me. I am not saying that there are not better CDI boxes out there for the EX - I have no opinion on the GT thunder - I've never tried it. I'll probably buy one of those too!

By the way, check that shoulder of yours, there is something on it.

Marky

 

FYI everyone, I went to Vortex website and emailed them. They now make the adjustable box for the 400ex. You can have all types with one box. They are not cheap though. http://www.vortex-performance.com.au/prod02.htm

On this page select ATV models and you will see that they have a box for the 99-03 400ex. I emailed them and they said it works for the 04 also.

From the vortex webpage they show these guys as the only ATV distributor http://www.duncanracing.com/atvprodu...x.phtml?id=270

 

I knew they were close to coming out with them - thats the one I am waiting for! But I dont think they are available yet. Duncan has lots of dealers throughout the USA.