Wildguzzi.com
General Category => General Discussion => Topic started by: n3303j on May 23, 2020, 07:21:40 PM
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So I got my tumor through eBay today. Appears to be in excellent condition.
Looking at the unit it appears the shell is made in two halves from identical stampings.
Only difference is one side has a Moto Guzzi part number stamped into it.
It looks like this unit could be mounted with either side up.
Is there a TOP and BOTTOM to this unit or does it install either way?
Thanks.
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When in doubt, writing is on top. I just made that up. Don’t think there is a difference. If the EV is new to you, then check the air box cover. Two years ago , I decided to drill 1”” holes so more air could enter. The sound would make a Harley owner with straight pipes cry uncle. I had to replasticize the lid, it was that loud thru my earplugs.
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When in doubt, writing is on top. I just made that up. Don’t think there is a difference. If the EV is new to you, then check the air box cover. Two years ago , I decided to drill 1”” holes so more air could enter. The sound would make a Harley owner with straight pipes cry uncle. I had to replasticize the lid, it was that loud thru my earplugs.
EV not new to me. Airbox is stock original.
Noise is exhaust note.
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Put the dirty side down. Isn't one side dirtier? That would be road grime unless it's new.
My airbox has 2 2 1/2 inch holes in it, intake roar is almost the same as exhaust. It gets loud in the airbox, pods or K&N's are quieter.
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Put the dirty side down. Isn't one side dirtier? That would be road grime unless it's new.
My airbox has 2 2 1/2 inch holes in it, intake roar is almost the same as exhaust. It gets loud in the airbox, pods or K&N's are quieter.
Did the forensics. Unit probably swapped for H Pipe early on. Both sides look equally clean. No scratching more obvious on one side than the other.
On a later unit with O2 sensor installed the O2 sensor is on the side opposite the stamped Moto Guzzi part number. Significant?
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If you look at it from the side, if there is a slight angle between the inlet and outlet pipe, the outlet should angle slightly up. It has been a while since I looked at one.
If the in and our are straight with each other then, like others already said, I don't think it matters.
John Henry
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Looked at the one I have and Zoom Zoom is correct that there is a slight upward angle on the exit pipes.
That puts the engraving on the unit facing down on mine.
Also the front pipes have slits that fit over the header pipes while your mufflers will have slits that fit over the exit pipes. Hope that makes sense.
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Sounds like the info I needed.
Thanks
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Just curious, many of us who bought these bikes new replaced the canister with an H pipe mostly to save weight which is significant. Why did you opt for the canister?
Pete
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Thought everyone dumped the canister to clear the transmission drain plug.
I am told the canister makes the exhaust much quieter.
I like long rides and wish to have as little engine noise as possible.
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Thought everyone dumped the canister to clear the transmission drain plug.
I am told the canister makes the exhaust much quieter.
I like long rides and wish to have as little engine noise as possible.
The H pipe might increase exhaust level by 1db at best. The canister is fairly efficient at eliminating back pressure so the H pipe didn't help much performance wise either. It was mostly about weight savings. Had forgotten about the drain plug issue I had the H pipe on before the first oil change.
Pete
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A number of responders stated that the canister offered "significant" noise reduction. I kind of believed them. Hope they are more correct than your 1 db number. Oh well it's only $40 and a bit of time.
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I removed the tumor from the 90 Cal III and took the cover from the SP II and put it on the Cal. The tumor outlets are longer and are smaller and as others said angle upwards.
Has a bit throatier sound but lets the engine rev up a bit quicker probably due to less restriction.
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As sort of a summary:
The goal was apparent noise reduction.
I put a phone app decibel meter a measured distance behind the bike on the center line and averaged 85 db.
I replaced the crossover with the tumor and repeated the test and read 84 db.
At the measuring point my ears did not notice a difference.
Took the bike through a hundred mile loop. Sitting behind the Plexifairing 3 with my open face helmet the difference was phenomenal! The harsh high frequencies were gone! Difference of night versus day! I can now hear a number of other engine sounds (none bad) that were masked by the crack of the exhaust. As an added bonus deceleration does not produce the popping uneven exhaust note it previously did. I'd swear it's a bit smoother too.
So, the experiment is pronounced a success. There is an exponential increase in pleasure derived riding this bike. Wish I had done it before last year's cross country.
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glad it worked out for you. it's a very big difference with a full face for the worse and the windshield makes it even louder.
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Are you running the stock mufflers after the canister?
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(https://i.ibb.co/K2HqWmW/20190827-163835.jpg) (https://ibb.co/K2HqWmW)
Are you running the stock mufflers after the canister?
I'm pretty sure they are. Picture of exit end of muffler above. Got them off this board. But the EPA cert doesn't list my frame. "EPA approbed GUZKCA1064 and GUZKDA1064." My bike is V11EV GUZDBK. The mufflers are also stamped Lafranconi at the inlet end. So, do I have the stock mufflers?
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Still happy with the ride? As I had said I was doing much the same.. I had stock mufflers lined up, but with all my cars breaking down, funds kinda dried up.. But I did get a chance to get a center muffler, and you know.. I expected it to be much more heavy hearing how people talk about them. Its really only a few pounds more then the H pipe.. and being that Im too fat anyways... weight would be better off me then the bike. :) Anyways... its still got a nice growl from the aftermerket piped.. but about 90% of the popping on decel is gone. Much less "busy" sounding at mid range RPM's so I dont find myself short shifting all the time around town. All in all I like it. Still has the mean almost V8 sound at high rpms, and a good grumble at idle, but much more enjoyable to ride! I still plan to get stock mufflers when funds clear up, but till then Im going to keep riding, and might find this did the trick.
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375 miles of country and highway yesterday and still happy with the ride.
My dyno is only seat of the pants but cruising 70 in the 4K range the bike seems to accelerate far better than it did with the H Pipe. Don't like tractor trailers in adjacent lanes. I've had two explode tires that hit me with debris (I was in a car). Getting out of the shrapnel zone seems to happen more quickly than before the H-Ectomy.
Maybe it's like the old BMW K100RS. Testers dynoed a bunch of aftermarket performance exhausts that were all noisier than the factory unit. Their conclusion was that all the aftermarket units caused a loss of power. The manufacturer got it right when they mated a their components.
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I only put a few miles on mine, but it does seem to pull a bit better from low to mid range. I didnt do any high RPM blasts to see top end yet... But I so rarely go there so no big deal.
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+1
I have too agree....my 03 Hydro EV pulls stronger all thru the range with the factory center muffler, H-pipe is coming off tomorrow. Now I recall this is the same reason I pulled the pipe off my Jackal...that mid range pull/sound is addictive!