GUZZITECH "SHORTY" exhaust on 2007 griso

[harrytief]

I have been looking at a 2007 griso but have questions about its fueling and exhaust. This bike has very low miles and just taken out of a four year storage. It has a Guzzitech supplied right side "shorty" exhaust. It starts well when warm (was already warmed from a previous start) but idles with some vibes and when run up with the throttle the vibes increase. There are no plates or insurance so I could not test ride the bike to see if the vibes and some popping would lessen on the road. the owner says the fuel map is stock and the muffler just went on before the bike was stored.  He cannot recall any changes in performance.
Does anyone have experience with the guzzitech shorty muffler and able to tell me if it is an upgrade? Will I need any fueling mods to improve fueling with this muffler? Is there an OEM map or aftermarket freeware map that should be matched with this exhaust?
Any thoughts that would help deciding on this purchase?
Thanks
Harry

[beetle]

No comment on the pipe, but I could do a lambda-off, no-pop map that should work much better than the stock map.

[harrytief]

Hey Beetle.
I am so glad you are in the room. First off, is the Guzzitech contributing or likely to contribute now or later to any fueling issues...and vibes? Does it need to come off? Can you do a map if I buy the bike and keep the Guzzitech shorty and its exhaust pipes?
Harry

[ITSec]

2v engines of the time (and I believe the Griso still was 2v in 2007) did need some help with mapping even with the stock exhaust. You mention that the current unit is 'Guzzitech supplied' - but did you note what brand it actually is? They supply a number of brands depending on suitability and customer demand.

I'd certainly suggest considering Beetle's offer, or another reputable source, to get the best out of the bike. Beetle has justifiably earned a strong reputation with his Griso maps as well as ones for other Guzzis.

[pete roper]

Hey Beetle.
I am so glad you are in the room. First off, is the Guzzitech contributing or likely to contribute now or later to any fueling issues...and vibes? Does it need to come off? Can you do a map if I buy the bike and keep the Guzzitech shorty and its exhaust pipes?
Harry

If the pipe is short and unbaffled in any way not only will it be offensively loud but will also contribute to the engine running like a 24 carat solid gold munter. Yes, it will pop and fart and vibrate like a cheap sex aid. Can it be *Fixed*? Yes, probably, but it will still run a lot better with a longer pipe with some form of dB killer installed and mapped appropriately.

Pete

[beetle]

First off, is the Guzzitech contributing or likely to contribute now or later to any fueling issues...and vibes?

Yes and No.

If it's the stock map, then the GT pipe will be the equivalent of a big gaping hole. The ECU won't be able to cope.

Does it need to come off?

Up to you. If it were me, I'd turf it into the nearest skip.

Can you do a map if I buy the bike and keep the Guzzitech shorty and its exhaust pipes?

Sure. I did a map for an 8V Griso with one. I pulled the numbers out of my arse, and it took a couple of iterations, but I got it working. As I said, even simply turning the lambda off, it would run way better.

[molly]

With a conventional baffled silencer the factory map works well on the 1100 Griso. Switching off the lambda and a few minor map tweaks does improve the fueling further.
The only vibrations that have occurred on my 1100 Griso were resolved by loosening the front engine/frame mounting bolts, applying thread lock and then re-tightening to 10nm.

[jlburgess]

I know a guy named me with a zero mile Griso 1200 stock pipe that will bolt right on.  Postage plus $40 would do it.

[harrytief]

Well I bought the bike today and hope to have it in my garage next week. I ran the engine again today and the vibes calmed as the it warmed. No backfire or spitting but the bike was in neutral without load. Beetle, be forewarned, I will be calling. Thanks to all who with their kind advice have entangled me with another guzzi.
Harry

[Gliderjohn]

Hope it works out for you.
GliderJohn

[zebraranger]

I know a guy named me with a zero mile Griso 1200 stock pipe that will bolt right on.  Postage plus $40 would do it.

If Harry doesn't take you up on your offer, Id be interested in your stock Griso 1200 can.

[beetle]

Beetle, be forewarned, I will be calling.

I shall consider myself warned.

[harrytief]

Jlburgess;
Thanks for the offer but I'll see if beetle can sort the fueling with the can now on the bike.

[JohninVT]

I rode with someone years ago that had a Griso 1100 with a Guzzitech exhaust.  It was insufferable at anything over idle.  I was running a Mistral with the DB killer out on my 1200 Sport at the time and my bike wasn't exactly quiet.  I politely declined to ride with him again whenever he asked.     

[erice]

I have a 2007 Griso with a Guzzitech right-side exhaust installed for several years now. The exhaust is baffled, and I'm not sure I'd call it a "shorty".
I have beetle's map installed.  I've had no issues and have about 60K km on the bike now.
My overall gas mileage is a bit better than a friend's 8v Griso running beetle's map with the stock exhaust (observed over several years of side-by-side touring around Canada and the US), but generally pretty consistent.
So, in my case the exhaust wasn't an issue, but no question beetle's map was far better than the stock Guzzi map.

Eric

[harrytief]

Thanks Erice ! That is what I wanted to hear.
Harry

[Huzo]

With a conventional baffled silencer the factory map works well on the 1100 Griso. Switching off the lambda and a few minor map tweaks does improve the fueling further.
The only vibrations that have occurred on my 1100 Griso were resolved by loosening the front engine/frame mounting bolts, applying thread lock and then re-tightening to 10nm.

I think I read that when you first posted it Molly.
Do you agree that you are only masking the real issue ? Also IF you have been successful in isolating the vibes in this way, the bolts and interface between the frame and casting, must be moving independently to some degree, and as a result would be copping sweet buggery...!

[molly]

I think I read that when you first posted it Molly.
Do you agree that you are only masking the real issue ? Also IF you have been successful in isolating the vibes in this way, the bolts and interface between the frame and casting, must be moving independently to some degree, and as a result would be copping sweet buggery...!

I haven' t really thought too much why the vibes are evident when the frame bolts are tightened correctly. When I bought the bike five months ago I noticed the frame bolts were a bit on the loose side and tightened them up, result more vibration. I have no idea what the previous owner had been up to and everything else seems ok so it is a mystery at the moment.

[harrytief]

Anyone know or recommend a db killer or baffle for this muffler? It looks like an Arrow brand Street Thunder model stubby muffler with an oval exhaust port. The inlet side is 51mm round so I thought to add a generic 51mm db killer there or in the connecting pipe. Will that work?
Harry

[ohiorider]

I haven' t really thought too much why the vibes are evident when the frame bolts are tightened correctly. When I bought the bike five months ago I noticed the frame bolts were a bit on the loose side and tightened them up, result more vibration. I have no idea what the previous owner had been up to and everything else seems ok so it is a mystery at the moment.

Reminds me of an issue with early BMW K Bikes.  The engine was used as a stressed member of the frame (it wasn't a cradle frame.)  It was discovered that many of the frames, when torqued down correctly to the engine, were under stress, amplifying the engine vibes. The solution was to remove mounting bolts, place the appropriate thickness shims between the frame and engine, and re-torque, to relieve the frame stress. 

[guzzisteve]

You could contact Todd at GuzziTech, after all, it is his pipe.

[harrytief]

I've contacted todd and asked him to supply the db killer. He did not think he could do that as Arrow no longer has a US office. I've asked him to send me a part number.
Harry