• Ciao Guest - You’ve landed at the ultimate Guzzi site. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER - Use the CONTACT above if you need help. New to the forum? For all new members, we require ONE post in the Introductions section at the bottom, in order to post in most of the other sections. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have, have likely been already answered. DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back in and reply within 24 hours, or your post will be deleted. Note there's decades of heavily experienced Guzzi professionals on this site, all whom happily give endless amounts of their VALUABLE time for free; BE COURTEOUS AND RESPECTFUL!
  • There is ZERO tolerance on personal attacks and ANY HYPERLINKS to PRODUCT(S) or other competing website(s), including personal pages, social media or other Forums. This ALSO INCLUDES ECU DIAGnostic software, questions and mapping. We work very hard to offer commercially supported products and to keep info relevant here. First offense is a note, second is a warning, third time will get you banned from the site. We don't have the time to chase repeat (and ignorant) offenders. This is NOT a social media platform; It's an ad-free, privately funded website, in small help with user donations. Be sure to see the GTM STORE link above; ALL product purchases help support the site, or you can upgrade your Forum profile or DONATE via the link above.
  • Be sure to see the GTM STORE link also above for our 700+ product inventory, including OEM parts and many of our 100% Made-in-SoCal-USA GTM products and engine kits. In SoCal? Click the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work, and don't miss our GT MotoCycles® (not) art on the BUILDS tab above. WE'RE HERE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED - DO NOT EMAIL AND ASK QUESTIONS OR ASK TO CALL YOU.
  • Like the new V100, GuzziTech is full throttle into the future! We're now running on an all-new server and we've updated our Forum software. The visual differences are obvious, but hopefully you'll notice the super-fast speed. If you notice any glitches or have any issues, please post on the Site Support section at the bottom. If you haven't yet, please upgrade your account which is covered in the Site Support section or via the DONATE tab above, which gives you full site access including the DOWNLOADS section. We really appreciate every $ and your support to keep this site ad-free. Create an account, sign in, upgrade your account, and enjoy. See you on the road in 2024.

Exhaust pipe diameter

N

Novusuhu

Just got it firing!
Joined
Jul 3, 2024
Messages
3
Location
Boortmeerbeek, Flanders, Belgium
Hi everyone

I have a Moto Guzzi V9 Bobber and I'm customising the exhaust.
I removed the catalytic converters and replaced the original mufflers with high flow 'Highway Hawk megaton' mufflers.

I love the sound I get from these new mufflers, but I want them a bit further away. So I have to put on some extra piping.

What pipe diameter should I use best for this application?

*I will keep the rest of the original piping of the exhaust (so no cutting on the original pipes).
*The original exhaust pipe starts at 51mm ->38mm ->41mm (end)
*The new mufflers have a 45mm sleeve.


(The small adapter pieces that I use now to go from the pipe to the muffler have a lot of leakage. I want to make something leak free. )
 

Attachments

  • 1719990287875.jpg
    1719990287875.jpg
    133.1 KB · Views: 13
  • 1719990287904.jpg
    1719990287904.jpg
    91.3 KB · Views: 12
  • 1719990287890.jpg
    1719990287890.jpg
    109.8 KB · Views: 11
  • 1719990287862.jpg
    1719990287862.jpg
    102.9 KB · Views: 12
It looks to me like you have taken all the measurements needed. If there are automotive exhaust shops in Belgium they may be able to fix you up. Automotive pipes will need to be coated to prevent rust. Also with all the changes you have and will make a remap of the ECU is needed. See the Store tab for fueling options.
 
john zibell said:
It looks to me like you have taken all the measurements needed. If there are automotive exhaust shops in Belgium they may be able to fix you up. Automotive pipes will need to be coated to prevent rust. Also with all the changes you have and will make a remap of the ECU is needed. See the Store tab for fueling options.
Click to expand...
Thanks you for the reply, John.

I forgot to say I can do the welding myself.
I just need to know what diameter I use best.

Looked at some exhaust online stores and it seems there are three mayor pipe diameters I can choose:
38 mm, 45 mm or 51 mm. 🤔

Do you know what would be the best?

When I got the right pipe size I can start to weld.
 
You have the bike in front of you and know what you are trying to do. Exhaust work requires pipe expanding tools and so on. By you getting the correct size for where you make a connection is something you can do. If you want slip fit vs welded. Personally I prefer slip fit with clamp. You are modifying your bike from stock, so whatever you do, is your responsibility. I will make no further comment on this question.
 
As John was saying, you would do best with on of these,
1720097207168

Measure the pipe you have, find the closest you can to that size and « customize » it for the perfect fit !
I was amazed at the precision of the Slip on mufflers from GTech.
A perfect snug fit , no clamps, no leaks GREAT sound :inlove:


Thé pocket phone doesn’t quite do them justice, the tone is deeper in person.
 
You must log in or register to reply here.
Back
Top