2008 exhaust ?

[jjk]

I picked up an 08 yz450. It came with an FMF 4.1 slip on. I realize that adding the power bomb header or an after market header would create more power, but is the slip on itself enough to open up the bike some?

[crb357]

Yes

[jjk]

Yes

Thanks.. I went riding today, seems to clean out well, but I could use some more bottom, a little more snap. Maybe I'll pick up the header and see if that does the trick.

[billygildark5007]

If you wanna go crazy the 06 cams and cdi will really wake it up.

[jjk]

If you wanna go crazy the 06 cams and cdi will really wake it up.

I actually might just do that at some point. I think there is some untapped power still to be had with a header pipe and possibly some jetting. My last bike was a 525 exc, I would of thought this bike would have more snap than my previous one, maybe I was wrong..

[grayracer513]

Just the CDI, not the cams.

[Thumper_Pumper]

Just the CDI, not the cams.

Would the 06 CDI swap be a good mod for trail riding?

[grayracer513]

Absolutely.  The '06 map is set up to have good strong low end without the aggressive snap and yank the first 450's had.  It was designed for the '06 cams, but it works very well with the '08's.  Does the same kind of thing; beefs up the low end without making the bike more difficult to control or tiring.  Once you have the CDI in place, you can decide if you still want more, in which case you can try using just the '06 exhaust cam.  Going farther to increase the grunt will require that you give up at least one full horsepower at peak because you have to move away from the '08 intake cam  The good part is that you can do all that in stages if you want or need to.

[jjk]

Absolutely.  The '06 map is set up to have good strong low end without the aggressive snap and yank the first 450's had.  It was designed for the '06 cams, but it works very well with the '08's.  Does the same kind of thing; beefs up the low end without making the bike more difficult to control or tiring.  Once you have the CDI in place, you can decide if you still want more, in which case you can try using just the '06 exhaust cam.  Going farther to increase the grunt will require that you give up at least one full horsepower at peak because you have to move away from the '08 intake cam  The good part is that you can do all that in stages if you want or need to.

That's great info, thanks! Is the 06 cdi a direct swap, plug & play?

[grayracer513]

The hardest part is getting the number plate out of the way.

[jjk]

The hardest part is getting the number plate out of the way.

Gotcha, sounds like a few mins worth of time... Thanks......

[Yzflier977]

If for some reason the '06 isn't enough low end I can attest the '03 CDI has even better low end grunt.  I went from the 06 CDI to the 03 and was able to drop a tooth on the rear sprocket and still have more bottom end.  But then again I have an 09 and I'm not sure what the differences are between the 08 and 09 as it relates to the swap?

[grayracer513]

If for some reason the '06 isn't enough low end I can attest the '03 CDI has even better low end grunt.   

 

But then again I have an 09 and I'm not sure what the differences are between the 08 and 09 as it relates to the swap?

 

'08 and '09 are identical engines and CDI's.

 

The '03 may reduce your top end over rev a bit.