The comprehensive GRiSO exhaust thread....

rick pope wrote:

Where are you in Colorado?  We get out there to play most years.  We have family in Arvada and Ft. Collins.

South Denver area

Thanks for the reply!

lcjohnny wrote:

@Buellbloke
Nice carpet

carpet showroom sample squares, picked them up for nothing but effort, useful to move them about as you want

So I installed my Agostini Hydroformed with a beetle map and the fit was super tight onto the stock exhaust pipe so I didn't reuse the gasket on the OEM silencer, but it sounds like there's an exhaust leak on cold start until the bike warms up a bit then it goes away. There were definitely no installation instructions that came with the Agostini can, can anyone here verify if the gasket that's on the OEM silencer is needed for the Hydroformed?

I have installed pipes that do not use the gasket and I use copper colored anti-seize on the fit, seals the exhaust plus makes it nice to come off next time.

GuzziSteve wrote:

I have installed pipes that do not use the gasket and I use copper colored anti-seize on the fit, seals the exhaust plus makes it nice to come off next time.

Can one use copper anti-seize instead of that aweful goes off like cement exhaust sealant paste and it will seal?

FYI, there is an equivalent exhaust gasket available from, I believe, a 600 Kawasaki Ninja application. I'll have to check my notes to be certain, but they can be had for under $10 per.

Another option.[You must be registered and logged in to see this image.]

Seems it would be a good place for a v-band flange/clamp instead of the slip-fit and compression clamp.
I think that silicone product (or similar products that take a set) would take a judicious hand- super thin bead and probably at the very end of the muffler flange- otherwise working it free again would be a real bear.

Can some of you guys show some pictures of the DB killers pulled out of the muffler.

Steak wrote:

FYI, there is an equivalent exhaust gasket available from, I believe, a 600 Kawasaki Ninja application.  I'll have to check my notes to be certain, but they can be had for under $10 per.

Hmmm, this one? [You must be registered and logged in to see this image.]

Bill Dee wrote:

Can some of you guys show some pictures of the DB killers pulled out of the muffler.  

This is the Db killer out of the official Moto Guzzi Termignioni pipe
[You must be registered and logged in to see this image.]

Anyone have a lead on a Mistral Hi with removable cat? 2013 GRiSO.

Hoping to use the Beetle map and all the new ones appear to have a non-removable cat.

Here's an update that might help others in sourcing a cat-free Mistral Hi for use w/Beetle map.

Prior to my request above, I'd reached out to AF1. They checked directly with Mistral and replied all new Mistral Hi's now had a non-removable, integrated cat. They suggested the Agostini HF as a cat-free option.

I swapped emails with MG Cycle as well, and was considering a different exhaust from one of these two vendors - but MG Cycle reached out to Mistral, and was told the Mistral Hi could be custom ordered without cat. Not sure why AF1 wasn't given that option when talking to Mistral, but I've ordered one up from MG Cycle.

austin_22 wrote:

2013 GRiSO with GPR can.

That sounds great!

[quote="SorryOciffer"]

austin_22 wrote:

2013 GRiSO with GPR can.

That sounds great![/quote

Super brzmi!

Hi everyone,
I'm coming back to this old thread to try to get your expert opinions on this.
I have this QD exhaust in my 1100, which I like a lot.
I'm not a very big fan of loud pipes, so I kept the db-killer. But I had allways the impression that this db-killer could be very restrictive...Even though it is a straight tube, it has only 26mm of ID...
Can this create overpressure in the exhaust system?
Thanks guys
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Not really such a thing as "overpressure' in the exhaust system. You have a partally open container receving really violent explosive waves of pressure from the cylinder head end (s). Those positive pressure waves travel much quicker than the flow of gas and reflect back as a negative wave from the open end of the silencer and also as positive wavelets from the restrictions they encounter.

If multiple positive waves arrive back at the exhaust port as the valvr opens, the exhaust will be restricted. If negative waves arrive as the valve opens the exhaust will be free flowing.

On a big ole lump like the GRiSO has with uneven firing and unequal length down pipes coming into one silencer the harmonics of exhaust pressure waves and how they effect gas flow will be somewhat complex.!

Experienced people on this site say Db killers should be kept in and that the original silencer works well.
I cant do the physics so I go by Ghetto lore.

Amen

I say it. Do it.

I've read this whole thread and have noted the big takeaways (keep dB killers and midpipe pretzel, Mistral and Agostini are good performers, etc). What I haven't see is any OEM pipes from other bikes being used, which may be lighter than the stock boat anchor. Specifically, I'm wondering if silencers off a BMW R Nine T would do the trick as there are several different OEM Akraprovic (single, dual, high, low) units which can occasionally be picked up used for a few hundred bucks and look nice (particularly the dual).

Similar engine (1200cc 2 cylinder making 109hp and 85ft-lbs) and exhaust (pipe on left side). Is there any reason this setup is a bad idea besides needing a custom midpipe extension/fitting?

Never considered it. No idea.

The R Nine T has the cats in the headers. The dual pipe is essentially straight through with noise reduction packing and non-removable dB killers. I don't see it being an issue. It's essentially no different to any aftermarket pipe for the GRiSO.