Can a WR be made to run JUST like a YZ?


17 replies to this topic
  • KAS

Posted September 12, 2008 - 08:54 AM

#1

Just curious.

After all the uncorking, de-throttle stopping, grey wire, etc, and assuming both bikes have the same pipe, what else would be needed to make the WR put out the same power as a YZ?

If I understand correct, the only thing different would then be an exhaust cam, and heavier flywheel/crank set up (which is a good thing, right now I run a FWW on my YZ).

Anything else? :thumbsup:

  • david69

Posted September 12, 2008 - 09:13 AM

#2

As I understand both cams are different, and also the cdi is a quite a bit different.

  • trailhead2004

Posted September 12, 2008 - 09:39 AM

#3

That's a roger on the cams, but I thought the point of the Grey Wire Mod is to get the CDI to run with the YZ advance curve. Bueller? Bueller?:thumbsup:

  • tweav

Posted September 12, 2008 - 10:21 AM

#4

the cdi does not have the same curve as the yz even with the gray mod . the gray mod just makes it closer to the same . the yz cams are advanced timing wise and so is the ignition . you must rejet the carb too .suck jetting is way off . Let's take my wr as a example it is making a few more hp then a yz does stock but the power is still not the same . a yz's powerband is mostly up top . but my wr still has more bottom end power then the yz but falls off toward the top. so what I'm saying here is it will never be the same but you can get on the same page or better.

but yes with free mods , a rejet , a pipe , and a set of cams and your on the page.

  • beezer

Posted September 12, 2008 - 11:05 AM

#5

The exhaust cam is different but the intake is the same, at least it was in 08.

The cam makes a big difference, you can hear the change in the exhaust note the instant you fire it up.

My WR runs like a YZ with a heavy flywheel.

  • Bosco83

Posted September 12, 2008 - 04:00 PM

#6

Is it harder on your valves to put a yz cam in?

  • maxtherat

Posted September 12, 2008 - 08:54 PM

#7

No. The lift is the same, it's just timing

  • tweav

Posted September 13, 2008 - 01:15 AM

#8

here of late I've been hearing good things about just putting in the yz intake cam or the hot cam intake so you don't have over decompression issue " the timing of the decompresion pin is advanaced also on the yz ex cam so on the compreesion stroke it hits the pin sooner dumping more pressure . They are saying you still get a gain in power without the poor operation of the e-z button .

as far as the yz intake cam being the same I know it is not in a 06 and a 07

right now I have the yz cams in my wr and It does not start as ez as it used to but it does start every time.

  • Power

Posted September 13, 2008 - 03:07 AM

#9

I think the yz head is designed a little differently to maximize horsepower. Along with the cams and the cdi. But with the cdi you could get a vortex cdi for it and I'm betting money it'd run just like a yz if not better.

http://www.vortexcdi.com/

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  • david69

Posted September 13, 2008 - 06:16 AM

#10

Yes the part numbers are not the same on the yz intake or exhaust cam{on the 08}, but according to the local shop here you don't gain anything replacing the intake cam with yz. I've bought the yz exhaust cam and am excited to get it in. The way I understand the lobes are alot taller letting more exhaust out allowing for quicker revs and more snap. I've also purchased a Dr. D pipe and am really hoping it will run close to a YZ! My friends and I have purchased the 2MOTO snowbike kits and one is putting it on a YZ and I can stand the thought of him being able to smoke me on the snow!

  • Mosow

Posted September 13, 2008 - 07:18 AM

#11

When its all said and done all you are doing is moving power around. The total power output is about the same with the YZ vs WR.

  • lixno

Posted September 13, 2008 - 10:20 AM

#12

I think the yz head is designed a little differently to maximize horsepower. Along with the cams and the cdi. But with the cdi you could get a vortex cdi for it and I'm betting money it'd run just like a yz if not better.

http://www.vortexcdi.com/



At the Vortex site i see that the CDI for the WRF 03-06 has a different description (3D DC CDI) from the one for the YZF (3D CDI).
Is there a difference between these two and if so, do you know if the WR will run better with the YZ Vortex CDI?

  • 2grimjim

Posted September 13, 2008 - 11:14 AM

#13

The US distributor Vortex ignitions is MT Racing: http://www.mtracing....es/page0001.htm

Depending on the year of your WR (this applies to the '03-'06 models) the airbox, even after removing the snorkel, is a HUGE cork in the WR450's arse.

Because of the location of the battery, there is very little clearance between the bottom of the seat and the hole in the airbox. Yamaha made a weak fix for this on the '05 WR450's by changing the left side number plate. 5TJ-21711-80-00 is the new part number and it has a hole in the side that allows more air to make it under the seat.

The battery tray (4 screws-on top of airbox) can also be modified by cutting away part of the duct and holes can be put in the back of the airbox just above the fender.

You will never get the WR airbox to flow as much air as the YZ without sacrificing its ability to keep water out. There's just not enough room for the battery and air filter.

  • 2grimjim

Posted September 13, 2008 - 11:18 AM

#14

At the Vortex site i see that the CDI for the WRF 03-06 has a different description (3D DC CDI) from the one for the YZF (3D CDI).
Is there a difference between these two and if so, do you know if the WR will run better with the YZ Vortex CDI?


The different part numbers for the Vortex ignitions is because the WR CDI is run on DC voltage and the YZ function on AC voltage; they are not interchangable, but if you call MT Racing they will program a Vortex CDI for the WR with a YZ timing map.

  • lixno

Posted September 16, 2008 - 10:52 AM

#15

The different part numbers for the Vortex ignitions is because the WR CDI is run on DC voltage and the YZ function on AC voltage; they are not interchangable, but if you call MT Racing they will program a Vortex CDI for the WR with a YZ timing map.


Thank you very much for the info:thumbsup:

  • gdbarr1976

Posted September 16, 2008 - 05:22 PM

#16

The different part numbers for the Vortex ignitions is because the WR CDI is run on DC voltage and the YZ function on AC voltage; they are not interchangable, but if you call MT Racing they will program a Vortex CDI for the WR with a YZ timing map.


I am trying to make my yz into a wr. I need big lights. I have put on a wr crank end and stator. I also have a wr cdi and wiring harness. You say I need DC power. Do I need to run a regulator/rectifier to get dc power or is it coming out of my stator dc?

  • dougEfresh223

Posted September 16, 2008 - 07:07 PM

#17

I think the rectifier converts the power to dc...

  • trailhead2004

Posted September 17, 2008 - 07:16 AM

#18

Do I need to run a regulator/rectifier to get dc power or is it coming out of my stator dc?


You need to run a rectifier/regulator. The rectifier turns the AC voltage into DC voltage and the regulator keeps the DC voltage in a certain range. I'm not sure what that range is.

So in other words... Look at Ricky Stator or Trail Tech or Baja Designs or the dealer, get yourself a rectifier/regulator and wire it up.

Another note, at least for the '08 WR, is that the stock headlight works off of AC voltage straight from the stator. If you intend on putting the headlight(s) or other accessories on the DC buss, you will need to get something bigger than a stock regulator. That's why I mentioned Trail Tech, etc above.

I installed the Trail Tech stator and reg/rect kit on my '08 WR and everything is great. Made my own harness for everything and have been running turn signals, horn, etc for a little while.

Good luck!:excuseme:

trailhead2004




 
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