exhaust pipe size? pics of 2 into1 exhausts

[Guest]

i currently have a 1981 gs450L. the previous owner hacked the mufflers off the pipes. my plan is to make new head pipes and a colector to make my own 2 into one exhaust and then insert a baffle into the end of the pipe. i was wondering what size pipes i should use for the head pipes and what size pipe should i use after the collector? the bike currently has k&n pods and the carbs have been rejetted. it runs good for a 450, but i want to de L the bike and quiet it down. can anyone share their pics of their 2 into 1 exhausts?

[koolaid_kid]

Look at pete's exhaust. Absolute art.

[telemaster]

I have this one on my 450. Mac 2-1 in all black.

http://www.motorcycle-exhaust.com/product/PU8030103.html

The fit is sloppy and it has a few leaks out of the box. If you don't mind tinkering, it's works and is inexpensive (I paid $150 for mine, the link above is for reference and has a more expensive price tag). That was 6 or 7 years ago too.

Don't know about the others, but I can still drain oil and change filter without removing the pipes.... a major plus for me.

[pete]

Aww shucks George... but yeah the Tranzac dude did an awesome job on it...

If I remember I'll try to get some outside diameter measurements tomorrow while I'm giving her the next service.

[telemaster]

Aww shucks George... but yeah the Tranzac dude did an awesome job on it...

If I remember I'll try to get some outside diameter measurements tomorrow while I'm giving her the next service.

I like the looks of the mid-mount exhaust, and yours looks really good. I see there is a heat shield where your leg sits, but doesn't it still get hot?

[pete]

I like the looks of the mid-mount exhaust, and yours looks really good. I see there is a heat shield where your leg sits, but doesn't it still get hot?

Thanks mate, yeah I love it... the guy did an awesome job of making what I envisioned reality.

It's ceramic coated which makes a huge difference to the outside temperature and generally I don't notice it. Occasionally my leg will brush it when I'm stopped at a traffic light and when that happens I know it's there, but it's not burning through my pants or anything...

[telemaster]

Thanks mate, yeah I love it... the guy did an awesome job of making what I envisioned reality.

It's ceramic coated which makes a huge difference to the outside temperature and generally I don't notice it. Occasionally my leg will brush it when I'm stopped at a traffic light and when that happens I know it's there, but it's not burning through my pants or anything...

Cool. Never thought it would have a ceramic coating. Makes sense and saves your pants!

[pete]

Cool. Never thought it would have a ceramic coating. Makes sense and saves your pants!

The ceramic coating is fantastic! Not only does it save my pants but it cools down really quickly after you stop as well which is really handy if you need to get into the carbs or anything reasonably soon after you turn it off.

There's supposed to be performance benefits as well by helping the exhaust gases get out quicker by keeping the outside temperature cooler, but I've got no way to really verify that for myself...

[pete]

I did remember to do some measuring too... in the photos below there looks to be rust on the exhaust... it's not, the flash makes it look really bad and it's in desperate need of a clean and polish and all those marks will come out...

Anyway, header diameter is around 37.5mm:



The diameter at the collector is 49.6mm:



Left header length is about 760mm:



The right header is a bit longer and is about 890mm:



And from the collector to the end of the reverse megaphone is about 720mm:



And this is how it routes:



Sorry it's so filthy, due for a clean and polish tomorrow if I get time...

[81gs450l]

pete i love the way your pipes look. one day i hope to have my L model cleaned up and de L it. thanks for taking the time to measure your pipes for me. i am still looking for an exhaust shop here in colorado that is willing to do the pipes the way i want them to look. the first shop i took it to basically said they could do it, but why waste my money on an old bike. the guy told me i should save up for a newer bike.

[pete]

pete i love the way your pipes look. one day i hope to have my L model cleaned up and de L it. thanks for taking the time to measure your pipes for me. i am still looking for an exhaust shop here in colorado that is willing to do the pipes the way i want them to look. the first shop i took it to basically said they could do it, but why waste my money on an old bike. the guy told me i should save up for a newer bike.

Good stuff, and yeah you need to find a different exhaust shop

The guy I took it to here was keen, just gave me a good idea of price and I said go for it.

I left my cardboard mock up at home as well as the work iPhone so I couldn't show him what I wanted, but from my description he took it on board and got it absolutely perfect...