Triple Downpipe Diameter?

  • Thread starter Thread starter Harry Lime
  • Start date Start date
H

Harry Lime

Guest
I have 3 sets of triple downpipes (exhaust pipes)

Two sets are for a standard triple 3-1-2 setup. Set 3 is part of a 3-1 system.

Set 1 has a downpipe ID of 32mm
Set 2 has a downpipe ID of 36mm
Set 3 has a downpipe ID of 38mm (3-1 system)

Sets 1 and 2 would be set up with "Jota" type silencers and appropriate collector boxes.

Engine is 1200 (1116)cc and has 4C cams, i.e. Slater Mirage setup.

Bike is running fine on the 3-1 setup at the moment, but I'd like a "standard" setup as well.

So which set should I use for a road bike? Looking for sporty road performance rather than outright flat-on-the-tank speed.

I like the more delicate look of Set 1, but don't want to strangle the poor thing.

My literature says that "Jota" and "Mirage" specifications included larger collector boxes and baffle free silencers, but says nothing about downpipe diameters.

Any advice welcome.
 
Bigger ID downpipes need bigger ID collectors.

The 'large bore' collector of Slater bikes is now the norm.
Originally the early triples came with a ridiculously narrow diameter collector box (the '1' part of the 3:1:2 system)
The Slater system is I think 50mm diameter (ovalled out)

The only 180 ( I think) with larger ID downpipes was the 1980 Jota, and they were only larger ID at the cylinder head end, reducing to normal diameter about an inch or two  after the header clamp.
 
Yes, the bigger headers, flared at the front and then tapering down, were fitted to series 1 Jotas in 1980 and perhaps to the later series 2 bikes as well.   

They are also fitted to later 1200s, including the TS Mirage, well they are to mine, anyway.
 
You must log in or register to reply here.
Back
Top