The comprehensive GRiSO exhaust thread....

Well, the Termi sounds better.

I don't recall how much it vibrated with the current release map, but you may as well wait until after I've got the map sorted. Vibes may get reduced in the final version to the point it's acceptable.

Anyone tried the GPR???
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I read the entire thread (missed like 8 pages the first time) and answered my own question. Looking at GPR vs. Arrow for my '13 GRiSO.

I'm a big fan of the ARROW, especially if you get it from Enzo Berni at [You must be registered and logged in to see this link.] in Italy.  About $500 shipped from Perugia to the States.  The US vendor(s) charge about $1000 in comparison...

Holy Smokes Batman!! Good deal.

Ok, so now I'm down to 3. GPR, circa $360.00 USD, Mistral, circa $637.00 USD and Arrow, Circa $500.00 USD. All look and sound great, so would love to hear opinions. All research has been internet only, I have not had a chance to see any of these in person.
GPR [You must be registered and logged in to see this link.]
Mistral - [You must be registered and logged in to see this link.]
Arrow - [You must be registered and logged in to see this link.]

I have the mistral, it came with my bike when I bought it, fits well and is well made and light.
You will need to change the map as it is a bit ragged between 2,500 and 4,000 r/min with the std map.
I run mine with the db killer and one of the beetle maps and it runs cleanly.

austin_22 wrote:

Ok, so now I'm down to 3. GPR, circa $360.00 USD, Mistral, circa $637.00 USD and Arrow, Circa $500.00 USD. All look and sound great, so would love to hear opinions. All research has been internet only, I have not had a chance to see any of these in person.
GPR [You must be registered and logged in to see this link.]
Mistral - [You must be registered and logged in to see this link.]
Arrow - [You must be registered and logged in to see this link.]

That GPR is gonna be loud as shit I bet...
I have the GTE model, perfect with dbKiller.

I want a GPR. Cuz it's loud as shit. But I'm not going to do it.

The only things I want loud are my guns and women when I pull the trigger.
I have a DB killer in my GPR pictured ealier in this thread.

My new Ipothesys exaust

Sounds good, how's the tuning?
Get so distracted on you tube, just watched a bunch of café racer vids with the voice over sounding suspiciously like the guy from Anonymous.

Well, I hope he wasn't trash talking any V7 cafe' racer riders or any guzzi riders for that matter. We are the genuine 1% and will not stand for that!

I'm not a fan of the ipothysis exhaust from a stylistic point of view but knowing of the issues Mark has had with his Arrow headers I'll go out on a limb and bet London to a Brick that that mid-pipe set-up will totally screw the fueling.

Pete

At the risk of pontificating about it, my thoughts on the Ipothesys exhaust.

1. Seems nicely made. A work of art, really.
2. Appears to have bungs in both headers to allow for sensors. +1 for them.
3. Short, straight mid-pipe will rob engine of low and mid range torque. Sigh.
4. Why the hell have they made it a two-into-one-into-two? Is it style over substance?

The two 'mufflers' must have dB killers in them, surely? You know, if they'd kept left and right separate and added a couple of 90 degree bends in each side down where the mid-pipe is, this thing would work well.

5. Remapping required. No escaping that.

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Other interesting point. There is a bung in the collector presumably for a permanently connected O2 sensor. The bungs at the bottom end of each header presumably to aid dyno tuning by individual AFR readings, except I have always been lead to believe by exhaust experts that these reading should be taken at a point 6" from the exhaust port.

Makes no difference. IMNSHFO.

Just 2 clarify, there are 2 different Ipothesys exhausts; Aria and GRiSO. The Aria one is the symmetrical move-the-oil-cooler one and the GRiSO sticks with the original asymetric headers and is just a collector (with O2 sensor). Slip on mufflers look the same. The "enghera" video is the latter. Admittedly, the Ipothesys GRiSO collector does not have the oem U-bend, so may well impact the fueling?

Hopefully, the folowing post shows the components you get if you buy the GRiSO exhaust from Ipothesys;

Midpipe looks a bit different than the one on the Ipothesys site.

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I've seen the Ipothesys dyno charts for the Aria. Massive mid range power and torque increases with less top end. You don't get bolt on power and torque like that. Remapped!

Yes that does look very different - shorter and without the O2 sensor tapping. Doesn't look long enough? I fitted this exhaust last weekend (sounds great), but due to both work and the constant rain we are having here in the UK this autumn, I've not tried it out on the road so can't yet comment on seat of the pants performance impressions. Fingers crossed for the coming weekend. Personal view, but I think the looks are simply awesome!

The short one might be a prototype?

I'm very interested in your thoughts on performance/fuelling/ride.

No problem, I'll report back as soon as I've had the chance to get out on the road with her.

OK, so the weather was good today and I took the GRiSO out for the first time with the Ipothesys GRiSO exhaust. First impressions;

Sound
Like many of the other exhausts on this thread, she now sounds like she looks - meaty! The exhausts clearly have dB killers in them and I think the volume is about right with them in. Haven't tried taking them out, but I wouldn't want it any louder! I now know what people mean when they say it sounds like 1/4 of a V8. To my inexpert ear, I'm somewhat reminded of a big old British twin (Norton/Triumph?).

Ride
OK, first the caveat; I'm no expert, I don't ride every day and I swop between 4 very different bikes (an in-line 6, a horizontally opposed 4, an aircooled V2 and a turbo watercooled V2!). My seat of the pants impression is that it is a little "flatter" in the mid range, but stronger at the top end. By that, I mean that the revs build moderately between 3,000 and 5,000/6,000 and then race to the red line. Does that make any sense?

There is no popping or banging on the over run, which was something I was half expecting (I've heard a Termi' equipped GRiSO do this).

Basically still very nice to ride. I'm very pleased. I don't think it "needs" any change to the mapping. I might take a look at the plugs or do some analysis, but just out of interest.

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I like the look, and it does seem that the installed version of the mid-pipe has a bit more of the pretzel aspect to it.

Did they also include mounting lugs for the stock heat shield? It looks as though they did, which would be a first for the aftermarket nid-pipes. That's a lot of attention to detail.