HIGH PERFORMANCE REV CDI UNIT - Anyone Using?


6 replies to this topic
  • twenty34

Posted August 19, 2007 - 06:12 PM

#1

So I hear an 07 CDI unit will help an 06 with better low end performance, etc.

I can also buy an aftermarket that claims:

-Increases REV limitor up 800 RPMS (at the risk of?)
-Adds up to 3 horsepower (?)
-More Low end torque (this is really what I'm after)
-Wind out each gear longer! (will this damage my valves?)

Does anyone here have any experience with changing out their CDI unit?

  • grayracer513

Posted August 19, 2007 - 08:17 PM

#2

My own experience with units such as the Vortex has been limited to helping friends fiddle with them, one on an '03, and one one an '02 426.

So I hear an 07 CDI unit will help an 06 with better low end performance, etc.

That's an interesting bit of info. How reliable do you think your source is?

I can also buy an aftermarket that claims:

-Increases REV limitor up 800 RPMS (at the risk of?)
-Adds up to 3 horsepower (?)
-More Low end torque (this is really what I'm after)
-Wind out each gear longer! (will this damage my valves?)

In order,

> The increase in the rev limit won't make any difference to a stock or near stock 450 performance wise, because they fall off so hard at about 10,500 that the increase from 11,500 to 12,300 doesn't help it do anything it's really willing to do anyway. The risk in letting it spin up even faster when you miss a gear or during a panic rev doesn't seem worth it unless there's a benefit to offset it, and unless you're building the engine to have considerably more top end than stock, like for SM or flat tracking, I don't see it.

> Really? There again, I think that's more realistic on an engine that's been modified to the point where the factory's base advance map was so far off that it was lacking 3 potential horse power because of it. OTOH, there is a big difference in the low/mid rpm torque between the different maps, so maybe that's what they're trying to say. Three hp at peak isn't something I would expect, based on either my experience, or my instincts.

>Low end torque is something you could actually get from it. Depends on the maps built into the unit, or, if it's programmable, what you dial in. Most of the differences between the '03-'05 models were a result of ignition remapping, as the cams in all three engines are the same. This claim definitely has potential to be valid.

> Revving out longer goes back to the same remarks as the first two claims, IMO. Higher rpm will stress not only the valve train, but everything in the engine, and the additional stress is exponentially greater as the speed rises. The YZ450 can almost certainly handle it, but once again, I think "for what", is a valid question.

  • twenty34

Posted August 19, 2007 - 09:00 PM

#3

my line of reasoning as well GR. I think we are on the same page. I was interested in hearing the feedback from the forum as I was attempting to validate my assumptions more than anything.

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  • grayracer513

Posted August 19, 2007 - 09:07 PM

#4

ncmountainman runs one (or has) on his 450. He hasn't been on in a while, but you might be able to contact him. Search on some of his old posts for his comments.

  • mxracer206

Posted August 20, 2007 - 04:16 AM

#5

I tried one of the REV boxes that Motosport sells and it definately pumped up the low end on my 05. So much so that it was a handfull coming out of corners and made it hard to keep the front end down. I liked the longer, smoother power of the stock unit for motocross. One more thing, the bike would mysteriously die when going into a corner and not restart until it cooled off, this problem wen't away when I put the stock unit back on.

  • 642MX

Posted August 20, 2007 - 05:42 PM

#6

I rode a WR450 with the Vortex system. I couldn't tell any difference, even after playing with the adjustments. :excuseme:

  • Mutu

Posted August 21, 2007 - 08:21 AM

#7

I rode a WR450 with the Vortex system. I couldn't tell any difference, even after playing with the adjustments. :excuseme:

Bike probably wasn't tuned correctly.

Mine works fine. Very noticable between each setting.





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