03-07 yZ cam Differences in power delivery

[bluebike1999]

Now, the reason i posted a YZ cam question in the WR forum is that all the YZ cams I sell go into wr's.

Can someone provide a technical answer, graphs would be appreciated or supply a link to where I can learn more about the differences in power delivery between 03 YZ 450 cams and 07 .

the part numbers for an 03-04 one is

5TA-12180-00-00

05 is 5TA-12180-10-00

08 is 2S2-12180-00-00

and i read in bike magazines that the power delivery is altered with each improvement. (being the 3rd and 4th numbers from the right)

I also understand that a wr is designed to grip, and not spin, like a YZ, and therefore the result of not as savage a power delivery equals faster acceleration due to not breaking traction, BUT, most wr owners are 'revheads' and im trying to find out which Cam would be regarded as the more 'savage', and trying to put into words the differences as to how and where the power is delivered....

if anyone can help with some technical data, that would be great

[dirtysouth]

Now, the reason i posted a YZ cam question in the WR forum is that all the YZ cams I sell go into wr's.

Can someone provide a technical answer, graphs would be appreciated or supply a link to where I can learn more about the differences in power delivery between 03 YZ 450 cams and 07 .

the part numbers for an 03-04 one is

5TA-12180-00-00

05 is 5TA-12180-10-00

08 is 2S2-12180-00-00

and i read in bike magazines that the power delivery is altered with each improvement. (being the 3rd and 4th numbers from the right)

I also understand that a wr is designed to grip, and not spin, like a YZ, and therefore the result of not as savage a power delivery equals faster acceleration due to not breaking traction, BUT, most wr owners are 'revheads' and im trying to find out which Cam would be regarded as the more 'savage', and trying to put into words the differences as to how and where the power is delivered....

if anyone can help with some technical data, that would be great

The '05 is a 5TA-12180-00-00 too then the '06 jumps to the 5TA-12180-10-00 and the '07 is a 5TA-12180-20-00? ( at least here in the states)

I think that all three of these cams, although unique, are savage beasts and that should be the explanation you use. In my experiences with a YZ service manager I have heard from various individuals that the power goal from yamaha (over the last several years) has been geared toward smoother power curves...yet savageness has not left the beasts.

Technical data Schmechnical data....raw savage beasts eat technical data for breakfast.

[bluebike1999]

dirty south, thanks for having a shot at it.

short of saying " this one is a savage beast.. and this one is a savager beast... and this one is the savagest beast, is there anyone out there who can explain in useable details the differences between the years???.

Logic would lead me to believe that if anything, the savageness may have been either reduced or altered, so that the power comes on either later or in a more usaeable manner, creating faster acceleration... even if someone can just agree with this, i can sculpt some sale guff from it, i just dont want to develop a line for the hell of it..

any cam doctors in the house??

[JSanfilippo]

The '03 cam was supposed to be the end all be all as far as "uncaged animal" power delivery.

IIRC the '04 and '05 cams are the same but in '05 Yamaha made some changes that lowered the compression ratio (12.5 to 12.3:1) and that made the '05 mellower. Its important to note that from 03-06 the WR had the same intake cam as the YZ. The exhaust was the same as well but it was timed different for more mellow delivery. The only reason why you can't just re-time the exhaust cam is because of the auto decomp. The '07-'08 WR uses different intake and exhaust cams.

The '06, '07, and '08 yz cam sets are totally different from each other. One reason was because each model year had a different exhaust, and the second reason was to make the power more manageable. The '08 cams were designed to work with the corked up exhaust. From what I've read in the mags, the aim on the cams for the '07 YZ was to soften the hit off the bottom but really rip up top.

According to a buddy of mine on here (erickdj) opening up the exhaust on the '08 YZ 450f makes it really gnarly...hopefully one of these days I'll have the opportunity to verify that.

[bluebike1999]

JSanfilippo

thanks for that, thats pretty much exactly what im after

[erickdj]

According to a buddy of mine on here (erickdj) opening up the exhaust on the '08 YZ 450f makes it really gnarly...hopefully one of these days I'll have the opportunity to verify that.

that is correct, getting rid of the stock 08 exhaust really opens up the 08 yz450f. Even if using a stock yz exhaust from previous years, I used a stock 06 exhaust on mine and it made a huge difference. Going to the full Dr.D exhaust made it even better, different power curve though. The powerband is silky smooth, and yet it will pull your arms quite good. A buddy of mine that rides a crf230 likes to ride my 07 wr450f once in a while, but the 08 yz scares the crap out of him. One time I told him to try it at a local track we were riding, he agreed but came right back after the first jump. he wouldn't even dare take one whole lap around.

Don't worry Joe, you'll get your chance to verify such claims next time we meet at carnegie. ?