Aftermarket CDI Boxes, very interesting!

[oregonrider89]

This thread is just to inform everyone how tricky an aftermarket CDI box can be. I bought a White Brothers CDI 2 years ago and didn't have any trouble with until now. After functioning properly for 2 years it just up and quit. To anyone using them always carry your stock box with you, you never know when the aftermarket box will quit.

oregonrider89

[Glamis400ex]

I use my stocker when I ride, and carry my WB as a spare.

Glamis

[Steve-o 400EX]

I was thinking about getting one but everyone told me it wasnt worth it. I heard they dont like to start cold and thats when i do a lot of riding.

[Quadfather]

Anyone have a newer stock box they'd like to part with?

[wheeltrax]

Originally posted by Steve-o 400EX
I was thinking about getting one but everyone told me it wasnt worth it. I heard they dont like to start cold and thats when i do a lot of riding.

Reason being if im right that it doesnt start in the cold well, is because it requires a really well charged battery to function good. And when the machine is cold the oil is thicker and the battery sometimes isnt as strong.. causing it to turn over slower and also it wont start your quad. correct me if im wrong..

[hawiianpwr]

you wanna real ignition get MSD Ignition!

[NTPRacing#19]

yea MSD is the ***** i shoulda bought one from them but i got the sparks and had to switch the stock back over cause it was reallly cold out today

[hawiianpwr]

MSD is sweet! You can do anything with it. You can adust your timing up to seven degrees, you can adjust the rev limiter to whatever you want, it has more than twice the spark of stock. I had to open the sparkplug another .010. It is very nice burns alot cleaner and runs a whole lot better!

[oregonrider89]

What does MSD cost? Where is the best place to get it? How much power gain do you see?

oregonrider89

the hard starting HAS NOTHING TO DO WITH COLD WEATHER...:macho

Mine wouldn't start in 90 degree weather...it's a battery issue..i'm sorry but i don't charge my battery every night to insure the POS WB cdi is gonna work everytime I start my quad..don't waste your money..this has been brought up so many times and there's been proof they do nothing for your quad but hurt it..yet people are still wasting hard earned money on them..:(

[RIDER11X]

Originally posted by Rico
the hard starting HAS NOTHING TO DO WITH COLD WEATHER...:macho

Mine wouldn't start in 90 degree weather...it's a battery issue..i'm sorry but i don't charge my battery every night to insure the POS WB cdi is gonna work everytime I start my quad..don't waste your money..this has been brought up so many times and there's been proof they do nothing for your quad but hurt it..yet people are still wasting hard earned money on them..:(

I agree! The 400ex makes its peak power up to the stock rev limiter, and anything past that rpm limit is wasted energy doing far more harm than good. This info is dyno proven on www.geocities.com/gtthunder.geo/testbed_set.html

Check it out. It really is true.

[RIDER11X]

Here's the dyno run I'm referring to:

I like the comment that it didn't shut off at 11.2 I chickened out...

Hopefully those of you running this POS WB cdi understand what this feller is talkin about..:eek:

[nakomis0]

Yup you little 400s, keep the stock cdi, you can barely hit the rev limiter anyways... and thats downhill with the wind to your back.

The way I look at it, when you have a modded bike 'thats built for top end' that actually has the Hp to pull the limiter, its a different story.

Heres an example I think of...

You rev the stock limiter out at 8500rpm@40hp, you shift, it takes you down to 6500rpm@33hp.

Now you have the WB limiter, rev'd out at 9500rpm@40hp, you shift, it takes you down to 7500rpm@38hp.

So basically I'm saying, it keeps your revs up closer to the peak Hp. Which makes you faster.

**note: Im just guessing the rpm drop on shifts, ...you get the point. Also thats one dyno, depending how your bikes ported, cam'd, and carb'd will determine where your power will drop. That bike just happens to drop after 9500, I think my bike doesn't start to drop till about 10500.

If I'm over looking something let me know.

[DGR Designs]

very interestin nakomis.... you have a good point there

[Doibugu2]

Originally posted by nakomis0
Yup you little 400s, keep the stock cdi, you can barely hit the rev limiter anyways... and thats downhill with the wind to your back.

The way I look at it, when you have a modded bike 'thats built for top end' that actually has the Hp to pull the limiter, its a different story.

Heres an example I think of...

You rev the stock limiter out at 8500rpm@40hp, you shift, it takes you down to 6500rpm@33hp.

Now you have the WB limiter, rev'd out at 9500rpm@40hp, you shift, it takes you down to 7500rpm@38hp.

So basically I'm saying, it keeps your revs up closer to the peak Hp. Which makes you faster.



I see what your saying, but if you look at the chart your almost at peak horsepower from 7500 - 9000. That is a lot of rpm's to play with, especially if your riding that high in the rev's.

Also, wouldn't you only be riding that high in the rev's if you were drag racing?

Do you guys that MX ride that high in the rpm's all the time? I think I might be babing my quad a bit. I get scared running it that high all the time.:confused:

[RIDER11X]

[QUOTE]Originally posted by nakomis0


**note: Im just guessing the rpm drop on shifts, ...you get the point. Also thats one dyno, depending how your bikes ported, cam'd, and carb'd will determine where your power will drop. That bike just happens to drop after 9500, I think my bike doesn't start to drop till about 10500.

Out of curiosity, did you ever dyno your machine? Strangely alot of people that sink big money into motor mods don't run them on a dyno. I would as I would want to know what I gained for my $$$$. Not flaming anyone, I'm just always looking to learn more and you do have an interesting point in your post.:cool:

[nakomis0]

I had it dyno'd before without my FCR and I was around 33-35hp/rear wheels. I lost the dyno sheet somehow... all I can remember is my HP, and my powerband started at about 7500rpm.

[RIDER11X]

Do you remember at what rpm the powerband signed off on your dyno run?:confused:

[nakomis0]

no I can't really recall.