serious yz450 power

3 replies to this topic
  • o-lad

Posted August 27, 2009 - 05:15 AM


i am in just purely curious as to what power i can expect from a fairly heavily moddded 2008 wr450f as i am interested in purchasing one for supermoto.
so i guess what real life hp numbers can i expect from things like a hc piston cams and a little head work and an exhaust?

before you tell me this is the wrong forum i know wr and yz are seperate but i choose to ask in both as the engine is basically the same( apart from cams/ im guessing as this is the case on the 250s)

so what power can i get out of this baby say with 2-5000$

please also metion what is done to achieve this

regards ollie:thumbsup:

  • mikedabike

Posted August 27, 2009 - 05:38 AM


For that kind of coin you should be able to get 60hp if you can find someone who knows what they are doing to work the head and carb.

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  • grayracer513

Posted August 27, 2009 - 06:56 AM


First, let me point out that it's against forum rules to place the same post in multiple forums.

As to your modded '08, a stock '08 model will produce nearly 52 hp. If you started at that level and did only cams and compression, you could push it to closer to 54.

"A little port work" could be either a plus or a minus. The 5 valve head is exceptionally tricky to work with, and just going in and cleaning things up can end up costing power rather than adding it. Randomly opening things up is not the right approach with these at all, and it's important to have the job done bu someone who has already ruined a few of his own heads before he touches yours, if you get what I'm saying.

60 hp is a very big, very hard number to hit with a 449cc YZF, and I know of only one individual who has ever done it: Ron Hamp. He builds a lot of dirt track engines, and the power they make is really something to see. It took him a few years of trying a lot of different stuff before he built his 60 hp YZ450, and it involved a lot more than "a little port work", but he has it figured out now.

It involves, obviously, his own port design, cams, a bored carb, and a piston with a custom crown shape, among other things. Contact him if you're interested.

  • o-lad

Posted August 27, 2009 - 05:52 PM


thanks its jsut that im looking at making a 450 super single race bike(full fairings marchesini wheels and changed geometry of fork and shock) out of mr friends wr450f 2008.

and since its on road i was just curious as to what power they make.

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