WR450 Grey Wire Dyno Charts

8 replies to this topic
  • Beef

Posted April 10, 2006 - 12:53 PM


I was just wondering if anyone has dyno charts of before and after the grey wire mod only? I'm looking at buying a new bike, and am waffling between a WR450 or a WR250.

I have read through the free-mods, and like the idea of hooking up the grey wire to a handlebar mounted switch so that I can switch between full power and reduced power depending on riding conditions, etc. It would be nice to see a before and after dyno run of just the grey wire mod with no other mods.

  • old man dan

Posted April 10, 2006 - 01:24 PM


As I understand it the ignition module only looks at the grey wire at start up. If its connected you get one map and if you disconnect it you get the other. So you would have to shut down the engine and restart to get the map you want. Plus I don't think there's that much difference anyway.

  • Dirtmizer

Posted April 10, 2006 - 01:49 PM


I agree the difference on my 03 450 is minimal, I just disconnected and left it that way.

  • WheelsUp

Posted April 10, 2006 - 02:44 PM


There's one on http://www.thumperfaq.com for the 250... 450 would be a comparable change.

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  • Beef

Posted April 10, 2006 - 03:18 PM


I found the ignition timing dyno charts by McGrath, but couldn't find a HP/Torque graph...could you be more specific? :thumbsup:

  • odonnks

Posted April 10, 2006 - 04:18 PM


I've seen curves somewhere but I can't find them.
You'll want the WR450.
It is more powerful than a 250 but with good throttle control you can do the same.
Claimed dry weight of only around 15 lb more and tons of power. The way these things can 'lug' hills is unbelievable.
If you still want less power than a 450 leave the pipe plugged up and just do tother free mods and jetting.

  • WheelsUp

Posted April 10, 2006 - 06:03 PM


I found the ignition timing dyno charts by McGrath, but couldn't find a HP/Torque graph...could you be more specific? :thumbsup:

That might be what I was thinking of.

  • Beef

Posted April 10, 2006 - 10:02 PM


That was my thought with the grey wire as well, but rather than corking and uncorking the exhaust, simply flip a switch...

I'm still a rookie on bikes, but can ride well enough to have fun on any bike as long as the terrain isn't too technical. I have a CRF450 now, and it is way more power than I need, and in fact, almost hurt myself pretty bad last fall because I let the power get away from me once, and let me tell you, it can happen in the blink of an eye!

Anyway, knowing my own abilities and the types of riding that I do, I think I would outgrow a 250 pretty fast, which is why I am leaning toward the 450. Perhaps a WR450 bone-stock, out of the crate would be a perfect bike for me to get my big-bore-thumper legs under me and learn better throttle control, then start doing the free mods as I grow into the bike...?

  • WheelsUp

Posted April 10, 2006 - 10:49 PM


There are no disadvantages to having the grey wire disconnected. It has no impact on anything below 6000rpm.
For a very long time it was not even there on non-US models. I think it's on Canadian models now.

Everyone who has gone to the trouble of putting it on a switch says that they never turn it "on" (connected). Yes, the bike has to be shut down and restarted every time the status of the wire changes.


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