SP Exhaust

[John_FJ]

Hi guys, just bought a nice SP can from ebay, does anyone know if I have to rejet or will it run ok on standard jets?  I will prob rejet at a later date anyways but not yet if I can help it.

Cheers John

[Dudeofrude]

If it's just the end can and everything else is stock (downpipes, airfilter etc) then it will be fine. If your gonna go down the rejet route then you may aswell put a higher flowing air filter in and change the pipes for stainless straight through ones that way you'll get the most benefit from the new jets

[John_FJ]

Thanks for the reply, I was thinking of a standard K&N replacement air filter in time.

[robbo]

I thought the availability of a decent set of new after market headers for a Gen1 was extremely limited, bordering on non existent.I believe Muzzy were the last manufacturers to make a proper set that would give any benefit over stock. Mike(Falcon) would be the person who would know for definite.

[Dudeofrude]

I thought the availability of a decent set of new after market headers for a Gen1 was extremely limited, bordering on non existent.I believe Muzzy were the last manufacturers to make a proper set that would give any benefit over stock. Mike(Falcon) would be the person who would know for definite.

Black widow still sell new ones on fleabay and delkavic make pipes for almost anything so they probably still do them. I'm not sure how good those particular brands are but there is still the option to buy new out there

[robbo]

The Black Widow ones make very nice door stops so I've been told.

The length and how the bends are formed etc are crucial in improving over the stock headers with the exup valve onthe Gen 1.If Mike sees this thread I'm sure he can explain the technical whys and wherefores  . The Muzzy stuck in my mind as they made the systems when Scott Russell was in WSB.

[Falcon 269]

Forget Black Widow or Sandy Spares (same thing) headers for the Gen 1.  They cause nasty flat spots just where you don't need them and no amount of carb work will alter that.  It's due to the (lack of) design and R&D in the header lengths etc.   

Muzzy were the only manufacturer to come up with a set of EXUP-less headers for the Gen 1 that gave top end gains without sacrificing anything low down.  That said, their peak power gains weren't as high as Akrapovic or Yoshimura, so you pays yer money etc.

Your SP can will work OK with the stock jetting and you might gain a little more power at peak rpm.  If it's a shorter can, though, you might lose a little in the low-mid range but the extra noise will probably hide this by making it at least sound more powerful. 

I would hold off fitting a performance air filter until you've rejetted.  The extra air they allow in might just tip the balance of the fuelling to point where a marginal lean mixture could show up in the throttle response and part-throttle cruise.

[John_FJ]

Some good advise there guys, thanks. Will just fit the can for now and see how it goes.

I have found in the past that once you start modding you just cant stop, there is always another mod waiting to be done 

[seangee]

Your SP can will work OK with the stock jetting and you might gain a little more power at peak rpm.  If it's a shorter can, though, you might lose a little in the low-mid range but the extra noise will probably hide this by making it at least sound more powerful. 

He's right you know (as always eh Mike). Leave the baffle in though. I have a shorter SP (on a non-fazer) and can't feel any difference low down unless i take the baffle out. Even with the baffle in I can defnitely hear the difference though 

[NorthWestern]

Are there measurements for the muzzy headers ?

[Falcon 269]

Are there measurements for the muzzy headers ?

None that I've seen anywhere on the web.  More to the point, it's not just header length ... the 'secret' of the Muzzy headers lies in the design of the collector box, which has a horizontal merge plate of a particular shape which optimizes the gas flow and scavenging effect where the output from the four pipes comes together. 

[tex]

Holeshot still have headers I think , similar to muzzy akra etc ,