Need some help (exhaust)

[Mellowyellow]

Hi guys,

I have origanal curved head pipes (double walled) and want to buy some VM34's from mmm, I have been told to ditch my headers and get some 1.5" pipes because my double walled will be poor performance with the vm34's.

But I really like the look of my curved headers so my question is how much power is it really going to cost me by keeping them? I kind of figure that if i wanted crazy power then I wouldnt have bought a 650.

 

[Mellowyellow]

anyone??

 

[tonyc]

Keep your headers and you will still have the same or a little better performance. I have run both but I do prefer the 1.5 headers. Tony C

 

[gentlemanjim]

The double wall headers are fine - no bluing, just a little heavier. makes no difference what carbs are used with them. Beaware there is a lot of great info here, but also some misinformation as well.

What type of bike are you building, what mufflers and air filters are you using? With this knowledge it is a jetting thing to work out, which we can sort out pretty easily if you don't go overboard.

 

[Mellowyellow]

Thanks guys

 

[gggGary]

just regurgitating misc info but I have seen it posted that the double wall stock headers will;
A: give you power torque down where you want it not up at some dyno peak RPM that has nothing to do with street riding.
B: the insulation effect of the double wall keeps the exhaust hot so expansion in a muffler /extractor can be used for more efficient savaging. The thing on exhaust / intake changes is that unless you work off the shoulders of some sharp tuner who knows the XS650 and strictly stick with ALL the changes he has engineered, and then spend the hours necessary to get the carbs dialed in the odds are good your custom work will result in a bike that is weaker than stock.

 

[Mellowyellow]

Superior mufflers (20" long, 1 1/2" inlet, 3" diameter).

I was planning on running VM34 Round slide carb kit from 650 central and not sure what filters yet.

I think the Aluminum velocity stacks from 650 central would be a nice look not sure how good they are?

 

[Mellowyellow]

Here is a pic of the set up.

 

[grizld1]

Yep, you're only talking a difference of 1/8" ID between 1-1/2" OD single wall pipes and the OEM double wall primaries. Generally speaking, pipe diameter controls where the torque peak hits while length influences the power peak. The 1-1/4" ID of the stock pipes won't hurt you a great deal, particularly if you're going for low-end grunt and aren't interested in optimizing performance up high. Like you, I like the wide-radius curve of the late pipes as opposed to two close-radius bends and wish that pattern was available in 1-1/2" OD.

Re. velocity stacks--yeah, they look nice, but your top end won't last long without better filtration.

 

[Mellowyellow]

correction the inlet on muffler is 1 3/4".

 

[Mellowyellow]

thanks griz,

So I will skip the velocity stacks. what should i run? K&N is what i have read.

 

[grizld1]

K&N and Uni filters both do a good job. K&N is a one-time expense, while Uni's (and any foam filter) should be changed every 3 seasons or so. Both can block up and cause a very rich mixture in heavy rain. I used to use Uni's, but found them too vulnerable to the wet. I now use K&N's with resized microfiber rain covers, and that combination works very well. 5twins reports less trouble in the wet with Uni's than I experienced, so don't take the above as poured in concrete; it's a judgment call, and you'll have to see what works best for you.

 

[Mattx2]

Omg!!!..............that bike is gorgeous!!!!

 

[manofsteele]

Omg!!!..............that bike is gorgeous!!!!

I was thinking the same thing.

 

[gggGary]

+3 lot of good things, all in harmony there.

 

[Mellowyellow]

Thanks guys, Just ordered vm34's k&n filters from 650 central.

 

[swbill]

Wow how about more pics of that machine. Looks bad asz.

 

[Mellowyellow]

I will try to post some new pics next week. I am out of town right now but thanks for the comments guys its nice to know im on the right track.

 

[Mellowyellow]

Ordered a set of VM34's and K&N's yesterday for her from 650central. I have always hated k&n on anything because there so dam over priced but sounds like there a good quality filter for the xs.

Oh ya and a also bought a new Kia sorento Ex awd for the family yesterday. #*ck I hate buying new vehicles such a horrible waste of money. But I am always on the road so I figure that we should have a good dependable family vehicle and I will drive my old Dodge pickup until it dies or me which ever comes first.

 

[gordonscott]

Mellow, I SOOOOOOO love your bike! It is pure art plain and simple