Fabricating a 2-1 exhaust

[docc]

WOW, Bjorn! That is sweeet! Can't wait to see it all together!

[68C]

I wish I had listened to my welding instructor, a thing of  beauty.

[Bjorn]

So the final part between the collector and muffler is taking it final shape. Only need to add a support to the collector to level it out and a clamping band.

 

 

Hope to build the rest this weekend

[Bjorn]

The whole exhaust is a ''joint venture'' between my little brother and me. He did most of the welding, as he is a welder. This weekend we finished most of the pipes. Only need to fine tune things like the mounting points next weekend, cant wait to try them

Ill post more pictures of the centrestand and fixations next time.

 

 

 

 

[sp838]

Awesome job! Is the muffler welded to the end of the pipe, or did you make it removable?

[Bjorn]

Yes its welded, however in theory you can remove the muffler. Its hold to the pipe by means of springs. I do know that its very tight and hard to remove.

Removing the exhaust is quite easy though, its a lot lighter than the original set-up.

[emry]

Nice, i wish you lived in my neighborhood. You clearly have more energy than me.

[docc]

 . . . I'm not that old (23)  . . .

Methinks that is the critical energy statistic right there.

[Admin Jaap]

Nice!

[68C]

So what did little brother use gas, mig or tig?

[Bjorn]

Its all TIG welded, using backing gas to prevent the material from burning on the inside.

 

I just booked a dyno session for the end of april, cant wait

[docc]

I am sorry the forum lost the last few posts of this great thread.

 

Bjorn, how about a picture of the bike now?

[Bjorn]

So, for now the fabrication is done. Here is how it looks. Its an older picture, with the temporarily bracket at the end.

 

 

made all the mounting points flexible by using a steel bush fitted with a rubber one. By this I how the pipes dont crack:

 

The RH side cleaned up nicely:

 

After a test ride i found the noise magnificent w/o the db killer. But is was also too loud. Since i want to use the bike for holidays and dont fancy discussion with the police about the noise level, i wanted to reduce the noise just a bit. The exhaust can came with a standard db killer. Due to the small diameter this really made the exhaust sound weird. We made a new killer with a much larger diameter. In this way the sound/waves do get reflected but do not affect the flow too much.

 

Here is a piece of the original one, and the new one:

 

In order to measure the deviation in the sound level I used an dB-meter. European laws state the measurement should be carried out 50 cm from the rear side of the exhaust, under an angle of 45 dgr. Every motorcycle has a specific sound level at a certain rpm. For my guzzi this is 90dB @ 4100 rpm.

 

I did a couple of measurements:

 

• Idle w/o db killer: 84,9 dB
• Idle with dB killer: 82,6 dB
• 4100 rpm w/o dB killer: 99,6 dB
• 4100 rpm with dB killer: 97 dB

To the ear is sounds much quieter and not ridiculous. In motion it sounds perfect, its there riding normally and really roars when you open the gas . Its not at the required level, but ill take my changes.

 

[68C]

So what is the other bike just in view, Laverda?

[Bjorn]

I also made a few Videos however I cant work out the whole youtube setting stuff

 

Final fact for today:

 

Total weight of the old system :  12,27 KG

Total weight of the new system:  4,5 KG

 

So i can ''gain'' some weight without a loss in performance hehe  

 

 

The bike you saw, thats my ''other project'' (XS650 scrambler)