Cam Swap Question


57 replies to this topic
  • knuckleduster271

Posted July 30, 2016 - 07:28 PM

#41

I have done a ton of research on cams for the 5 valve valve yamahas-
Most any cam you swap will trade power somewhere on the power curve- usually a low end power boosting cam will take from the top and vice versa.
Some of the early hotcams for the wr had issues- im pretty sure they have it corrected but it is a fact that some of the first wr hotcams had issues.
Most of your cams that make big power are top end cams and it is a fact that you will lose low end.
From all the research i have found the best off the shelf cam was made by wiseco (wci009) and is no longer in production. The 2nd best was the hotcams 4239 series cam. All of this was dyno proven by mbirt and mixxer on a yamaha atv forum- they tested pretty much every off the shelf 5 valve cam and of every one tested those two made the most hp of all.
For what its worth, through all the testing- exhaust cams made little to no difference in dyno numbers- it was mainly the intake cams that created power over the stock cams.
The 2006 yz cam set is pretty much identical in profile as the stage 1 (low end power building) hot cam.

Edited by knuckleduster271, July 30, 2016 - 07:29 PM.


  • knuckleduster271

Posted July 30, 2016 - 07:33 PM

#42

Most of the info can be found in this thread

http://www.yfzcentra...17677?_k=hpv58i


http://www.yfzcentra...age=1&_k=kmzdfd

Edited by knuckleduster271, July 30, 2016 - 07:37 PM.


  • Krannie McKranface

Posted July 30, 2016 - 08:47 PM

#43

I have done a ton of research on cams for the 5 valve valve yamahas-
Most any cam you swap will trade power somewhere on the power curve- usually a low end power boosting cam will take from the top and vice versa.
Some of the early hotcams for the wr had issues- im pretty sure they have it corrected but it is a fact that some of the first wr hotcams had issues.
Most of your cams that make big power are top end cams and it is a fact that you will lose low end.
From all the research i have found the best off the shelf cam was made by wiseco (wci009) and is no longer in production. The 2nd best was the hotcams 4239 series cam. All of this was dyno proven by mbirt and mixxer on a yamaha atv forum- they tested pretty much every off the shelf 5 valve cam and of every one tested those two made the most hp of all.
For what its worth, through all the testing- exhaust cams made little to no difference in dyno numbers- it was mainly the intake cams that created power over the stock cams.
The 2006 yz cam set is pretty much identical in profile as the stage 1 (low end power building) hot cam.

 

It's a huge difference in partiall throttle high load performance.

Enough to ride a gear higher all day.

 

Dyno tuning is not very useful for real world off road use, unless you have a way to quantify partial throttle / constantly varying load meausurements and be consistent....



  • knuckleduster271

Posted July 31, 2016 - 08:16 AM

#44

It's a huge difference in partiall throttle high load performance.
Enough to ride a gear higher all day.
 
Dyno tuning is not very useful for real world off road use, unless you have a way to quantify partial throttle / constantly varying load meausurements and be consistent....


I didnt say the exhaust cams were useless- if that was a fact i wouldn't have a yz exhaust cam in my wr- just that not a single one added to hp #'s- they can change the power curve slightly.
As for dyno tuning not being useful for real world off road riding- i have to disagree. A dyno is an extremely useful tool- probably the best tuning tool ever invented-
its not just about seeing how much power you can get out of something- its about making useful power- most bikes are detuned to a degree to actually make the bike faster in lap times etc. for the type of riding style or conditions their facing in competition.

  • RockerYZWR

Posted July 31, 2016 - 05:27 PM

#45

'07 YZ450 intake cam is on the way. I'll work on the decomp pin when it's apart again - did you guys essentially flatten out the profile like the stock WR cam, or take the whole thing down? Searching threads here, it looks like making it about 1mm shorter works. I'll shoot for about .9 probably.

  • Pinepig

Posted July 31, 2016 - 05:41 PM

#46

This is the go to thread for the decomp pin mod to the YZ cam.  http://www.thumperta...-startability/)



  • Krannie McKranface

Posted July 31, 2016 - 06:30 PM

#47

'07 YZ450 intake cam is on the way. I'll work on the decomp pin when it's apart again - did you guys essentially flatten out the profile like the stock WR cam, or take the whole thing down? Searching threads here, it looks like making it about 1mm shorter works. I'll shoot for about .9 probably.

 

It varies.

You really have to mock it up with the stock cam and watch how it works, then duplicate the exhaust opening time/position on the YZ cam and grind down the pin to get that result.



  • Krannie McKranface

Posted July 31, 2016 - 06:40 PM

#48

...but yeah about 1mm....



  • RockerYZWR

Posted August 01, 2016 - 03:55 AM

#49

This is the go to thread for the decomp pin mod to the YZ cam. http://www.thumperta...-startability/)

I was going to claim that I'd never seen that thread, but then I saw that I had hit "like" on the OP's post and even responded... Good stuff - thanks for the link.

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  • toten

Posted August 01, 2016 - 09:53 AM

#50

Since we're talking about cams, what would work well in my 03 WR450? It's a supermoto that sees street use only. 



  • stevethe

Posted August 01, 2016 - 05:39 PM

#51

Since we're talking about cams, what would work well in my 03 WR450? It's a supermoto that sees street use only.


I have no real clue about what cam the 03's can use. But if it was a std. bore 07-11 I would say a Hot cam intake and a YZ exhaust with the pin cut down a tad as described earlier. You would need to figure out if the later cams fit. Hot cams lists the years there cams fit and I'm not certain but I think it might fit the 03.

  • toten

Posted August 02, 2016 - 11:45 AM

#52

I was under the impression that all the steel frame 450 engines are pretty much compatible, and that most parts other than the cases were compatible with the later ones... but I could be wrong.



  • stevethe

Posted August 02, 2016 - 12:52 PM

#53

It says it fits from 03 to 15 models http://www.hotcamsin...ductSearch.aspx

  • knuckleduster271

Posted August 02, 2016 - 03:29 PM

#54

Cams from 03-15 on wr450 and 03-09 on yz450 are all interchangeable

  • RockerYZWR

Posted August 09, 2016 - 08:06 PM

#55

I am all YZ cam'd up now. I am running '07 intake and '06 exhaust cams. From tear down to test ride was about three hours, not a bad job at all even with pulling the exhaust cam to grind and polish the decomp pin. I followed WRFRowdy's pin grinding directions from the other thread and it worked absolutely perfectly - thanks a lot to WRFRowdy for the good descriptions and pictures there.

While out I noted that it seemed to really idle like shit but had noticeably better power, revved more freely, and had a different and slightly quicker (easier and more "willing") throttle response, but I figured the pilot needed a little tuning or something with the idle. Got back to my garage...I had left the choke on. That'll do it. Idles fine with the choke off, go figure.

Quick note on electric starting - on initial cold start, using my normal routine of choke on and two twists throttle, it cranked up in less than two revolutions. When I start it hot, it likes hot start pulled in and about 1/8 throttle and it instantly barks to life - zero delay, and actually better than with the stock WR cams.

  • RockerYZWR

Posted August 09, 2016 - 08:22 PM

#56

Here's what my pin ended up looking like (Dremel with a worn sanding drum and 1000 grit sand paper):

0809162049a_HDR.jpg
0809162049b_HDR.jpg
0809162050_HDR.jpg

  • toten

Posted August 10, 2016 - 06:15 AM

#57

Hmm, that's tempting for me. Where did you get the cams?



  • RockerYZWR

Posted August 10, 2016 - 04:28 PM

#58

Hmm, that's tempting for me. Where did you get the cams?

I got them at boats.net - I buy most factory parts through them. Although there's an '07 YZ450F intake cam new in the box on eBay for $141 buy it now right now, which I found that is a little cheaper.




 
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