Duh! anybody know about this

Doing some maintenance on my recently acquired bike when I came across this, 2010 build 8v Tenni model.
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Notice the bottom pipe, left side header which appears to be a catalyst with no evidence of anything in the top pipe.
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Anyone come across this before.

Should it be there and can it be readily removed?
Just wondering if it is a feeble attempt to balance the gas flow in the unequal length pipes, probably unlikely.
Is it normal and someone has removed the unit from the top pipe some time in the past.

There was nothing like this in my 08 8v GRiSO.

Mark

What the heck?!?!?!

That is odd. Certainly on the stock 8V pipe the cat is in the muffler. Whether there is a secondary element in the headers I have never considered, I certainly wouldn't of expected one but I have to admit I've never fed something through the headers to find out.

One would have to assume that that element would have a profound effect on flow! My own feeling is that for whatever reason its there it shouldn't be! Is it secure? Does it move at all?

I would suggest pulling both pipes off and feeding a length of fencing wire or the like through them from both ends and seeing if the other pipe has any obstruction in it. I can't believe they would have??? If you can persuade someone else to try doing the same on their bike that would be handy otherwise it'll have to wait until I'm back in Bungendore and I'll check it out on mine.

Most odd.

Pete

VERY interesting.

I am sure there are reasons behind but why only left cylinder?

A quick check on the parts diagram shows variant for headers, midpipe and mufflers.

It seems only the midpipe is SE/standard specific, the other two are year specific.

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Neither have I ever seen anything like that in any GRiSO.  That has to be some kind of bodge put in place during previous ownership.  I can't imagine that having any benefit.  I'd say pull it out for sure.

Also, looks like some attempt was mad to seal that plug in place, why would anyone do such a thing?

I will speak to the former owner, he is not the type to bodega something up so I would be surprised if he did it.
It is firmly lodged in there so it may not be easy to get out but I will pull both pipes and check for restrictions.
Looking at the right upper section it appears as though someone has had a go at trying to pry out the edge.
Also the pipe does not appear to have a double wall like the one above, the cat or whatever it is appears to be integral with inner skin of the pipe.
I wonder if this might be an additional cat for a US California spec version and Renzo has thrown it on the Oz model because he didn't have the correct one in the parts bin?

Mark

I spent a number of hours tossing and turning over this last night. I have a couple of theories but who knows if they're right?

My first thought was maybe there are secondary cats in the headers? Thing is they aren't visible from either end and that would mean that would have to be inserted into the pipes before they were bent, a ludicrously difficult and expensive operation which would also mean hot-spots in the pipes and subsequent discolouration. And to what benefit? And would this have an effect in the O2 sensor?

Logic dictates that it is some sort of aftermarket addition put there by somebody for a reason. Question is what reason? One thought I had was it might of been someone's idea to slow down the gas flow to increase 'Back Pressure' in the belief that doing so would help combat the 'Lean Running' imposed by the evil people who want to make engine's clean. Its the sort of bizarre thinking that Harry Hometune sometimes comes up with and what could be an easier solution than whacking a bloody great plug into a tuned exhaust system?

While I won't categorically say that it shouldn't be there until I have confirmed 100% that there is nothing in my pipes I'm confident that it isn't something that should be there. Whip 'em both off and run a piece of wire through 'em or a small marble or some such. If the other pipe is unencumbered by such weirdness? Pull it out!

Pete

mark111 wrote:

I will speak to the former owner, he is not the type to bodega something up so I would be surprised if he did it.
It is firmly lodged in there so it may not be easy to get out but I will pull both pipes and check for restrictions.
Looking at the right upper section it appears as though someone has had a go at trying to pry out the edge.
Also the pipe does not appear to have a double wall like the one above, the cat or whatever it is appears to be integral with inner skin of the pipe.
I wonder if this might be an additional cat for a US California spec version and Renzo has thrown it on the Oz model because he didn't have the correct one in the parts bin?

Mark

All bikes in the US are made to California specs, and to repeat, I have never seen anything like that before.

Just had a look at the parts site and yes, there are two different header pipe variants. Because the site is so shitty though it doesn't tell me what the variants are. Just listing them all as 'Standard Version'.

Pete

WTF?


Mark, I sincerely hope that is a one off and you're the only poor SOB who got it (no offense!), because if there's more of those horrors around it would explain much with regard to fueling issues!

That's fuck up really...  
Does the bike run ok? Being obstructed on one cylinder like that doesn't make any sense.

Micah has cleaned up more sets of these headpipes than about anyone, might do to send him an

it is a cat element or flow straightner, to order the gas past the 02 sensor, they would not be the first to do this

I was just looking through my parts manual. There's a separate part number for both headers for Japan. I wonder?

Yeah but why one header though?

I was thinking maybe they replaced a header at some time with a different version but Harry Hometune didn't know any better. Just graspin' here.

That's a great point. For people whom are not getting the happy result from Mark's maps, it might be worth a peek at their header pipes. What a colossal blurp if the Mandello assembly team sort of haphazardly snuck several of these pipes in behind QC.

Has anyone pulled their headers off for a looksee? Rather than removing the mid pipe I'd just pull the headers. Much easier.

Japanese bikes have different mapping too. I'd always wondered why? Perhaps this is the reason.

Pete

Yes, I pulled my headers when they didn't separate from the middle piece.
I did not see anything that looked like gaskets.
Sean Fader told me that he thinks it has a gasket that I am just not seeing because it is so well seated and smooshed.

I also noticed Very, Very little in a ridge around the head.
Micah from AF1 mentioned working on a GRiSO that had a ridge that interrupted the pipe union and was probably worth 2-3 hp if it was smoothed out.
I didn't have any appreciable ridge.


DM

The "waxy" seals will be seated in the female mid-pipe side.

hmmmmmm
I wanna buy new ones anyway

To answer a few questions
Up close it does not look like a backyard botch job, the installation is to neat and it is firmly secured in the pipe and will b difficult to remove.
Haven't had a chance to pull the other one off yet to see if it also has something inside.
It is about 50 to 60mm deep/long from what I can see.
The bike runs ok with the stock pipe and is only slightly ragged with a low mistral on but is tardy from 7 to 8,000 revs compared to my old bike. This may just be mapping issue.
I can unequivocally say that 08 8v GRiSO definitely did not have this in either pipes.
The Japanese thing sounds interesting maybe they have different pipe and there was a stuff up with parts selection when it was first built.

When I had a shortlived right side exhaust (it was on the bike about 10 minutes as it was quite loud  ), the vendor shipped me a slip in cat exactly the same as that one separate to the pipe. I stuck it in the right side exhaust and not in the header pipe. I guess the previous owner of that bike might have put it in the yin instead of the yang and not taken it out when he returned it to the stock exhaust to sell it??????

Will a mini CAT (kitten?) placed at the upstream of exhaust system affects the lambda sensor reading and close loop fueling?

I think so. This situation with the kitten in the one header would completely screw up the fueling.

I found some really nice photos in ebay.

It is a new left cylinder header (part # 978397)

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Look at the last photo, it is double walled and swaged but doesn't seems to have a kitten stuck in it.