Yosh exhaust ?'s 2008 450

Trying to find the difference between a couple different Yoshimura exhaust.




Anyone know which one would be best for the 08 450? Plus with the header being bigger on the 08 (correct?) would running the entire exhaust for a 2006 be any better or worse? Would it be best to just get a slip on for the 2008and run the stock header?

I run a RS-2 muffler and it runs real strong, scary almost. I left the stock header on as well. Have not had to rejet yet either.

I hate to even have to buy a exhaust. I have a 2006 as well and it still has the stock exhaust on it. Everyone say's the 06 motor is a monster and the 08 is a turd down low with the stock exhaust. I found a RS-2 complete exhaust for a 2006 but the head pipe is smaller for the 06 (but it will work, I am being told) just trying to find out if this set up will improve over just running a slip on as you did with the stock 08 header? Plus which Yosh exhaust is the top of line (power/durability wise/difference between) the RS-2, TRC and Comp series. I can't find a break down of the differences?

If you look at Yoshimura's website they only have the RS-2 stainless, ti-model and the carbon-ti RS-2's. I did not see the others so maybe its safe to say the RS-2 is a really good pipe. The 08 header is titanium and its a high flow design. Its just a way to save a little $ by not buying a different header. I bought my bike with the RS-2 on it, and sold the stocker on ebay. I have never used the stock exhaust.

Ya, I saw that on Yosh's site. However, I have seen the other two Yosh's for sale elsewhere. I can get the full RS-2 Ti for $400 and that's the only reason I am considering the full exhaust. Just want to be sure the entire set up for a 2006 (that's the full RS-2 I"m looking at is for) would not restrict with the smaller head pipe? If for some reason it would then I will just get a slip on. Thks and keep the info. coming.

For $400? I would buy it! Thats a really good deal. If the header does not work the way you want it to, and you decide to use the stock one you could sell the RS-2 header. Just an idea.

That would work but the 2006 silencer has to be used with the 2006 header. A 2006 slip on won't work with the 2008 header (I'm guessing do to the size of the header)

I have the full RS-2 on my '08 and it makes the bike stronger everywhere. The trc will not work on the '06-08, it was designed for the 03-05 model. For $400 buy the full system. The only difference between the early release 06 pipe and later RS-2 is the later ones have a floating bracket, well the nut floats inside the bracket where the pipe mounts at the bottom of the subframe, which makes it easier to line everything up. A RS-2 in the comp version adds some weight and a removable spark arrestor-spark arrestor is not available for the ti system. I would go full system either way.

With regard to the header size, the '08-9 header is as big as it is to compensate for the restrictive nature of the shorty muffler. With a freer flowing silencer in place, the header is no longer optimal, and I have seen two dyno sheets showing losses in peak power resulting from the use of slip-ons (one lost 0.5 hp, the other 1.1). It should be mentioned that both gained at least 6 hp at 5500 rpm, where the soft spot in the original power curve is.

But the bike has peak power to spare, and I wouldn't worry too much about it if you are on a budget. You'll still get much better mid range with just about any slip-on, and I don't think you'll really notice the drop in peak. The best thing to is to use a full exhaust, or a slip-on with an earlier header. The '07 has the same large outlet diameter as the '08, but it's a stepped header, and in actually smaller in the first 8 inches than the '06 header is. No full system I know of for the the YZ450 has a header diameter as large as the OEM '08.

Thanks Gray. That helped a lot, just bought the Full RS-2 Ti. I hate spending money on any exhaust. Next suspension (springs and PR2 revalve) as I can't get my big ass down to lower 200's even running 20 miles a week.:lol:

I can't get my big ass down to lower 200's even running 20 miles a week.:worthy:
It's a little off topic, but did you know that riding a bicycle at 20 mph burns 1000 calories an hour? (it is NOT easy to ride at 20 mph continuously, BTW). If you work hard enough, you will loose weight. My son went into Marine boot camp at 6'4"/195# and came out at 6'5"/180# eating 3 big squares a day.

Of course, I don't know that you aren't just basically really big. :lol:

When I went into basic, I was 5'9 153lbs and came out 16 weeks later at 5'9 175lbs of muscle. And we ate alot ( 3 squares) but we burned it quick! I just got out and I weigh 210 and I am 5'10 now. Just lifted alot of weights and bulked up for urban assault s**t! You should ride the bike though! I do.:lol:

I run an RS2 full stainless system for an 06-07 on my 08 and IMO it works amazing. It is tuned for more mid to top end power and has a fairly soft bottom end compared to the full Dr.D system that I rode on which to me felt like it was tuned for more bottom to mid power and fell off a little bit earlier in the top end.

All in all I think it is a GREAT exhaust that performs very well on the 08 bikes!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now