Aftermarket exhausts

[Bendy toy]

I've just bought a headers and collector system (thanks Julian). My question is, why do some systems have a cross pipe linking the headers near the front while others (like mine) do not.

 

[cocker]

i wondered this too

 

[Robbo1200ADV]

Remus don't Akro do , doesn't seem to make much difference My Full Akro has a cross pipe but the previous pre twin cam unit did not . Take the baffle out and enjoy broardcasting when you go to / come back from work

 

[Deleted account 190920001]

just different ideas on how to get best performance. Remus without the link pipe has slightly bigger pipes than the OEM and akro. There doesn't seem to be much to choose between them performance wise.

 

[(RIP) Miff]

It's all to do with back pressure waves and cylinder scavenging

 

[Bendy toy]

That was my thoughts so why do BMW (who would surely want to minimise manaufacturing costs) have a system with 2 extra welds and a joint when others such as Remus have fatter pipes with no link.

 

[Deleted account 211025001]

just different ideas on how to get best performance. Remus without the link pipe has slightly bigger pipes than the OEM and akro. There doesn't seem to be much to choose between them performance wise.

A link pipe with a small diameter header should give better bottom end/mid-range and no link pipe and fatter headers better top end. At least that was supposed to be true of the older Guzzis/MBW's. I think it's less of a noticeable issue with FI and more powerful engines

Andres

 

[Bendy toy]

Lets hope my system doesn't mess up the bikes low speed pull.

 

[Deleted account 190920001]

Maybe the link pipe makes more of a difference with the cat in place and akro just followed on? Either way I don't think k there is much in it, just itching then cat is the really important part.

 

[Deleted account 211025001]

Lets hope my system doesn't mess up the bikes low speed pull.

It won't

I've a full BOS, fatter headers and no link - better 'go' at all revs

Andres

 

[Deleted account 190920001]

I have the remus headers and the low end pull is noticeable better than stock

 

[Bendy toy]

I'm going for stacked twin cans. Will send pix when done.

 

[Sgt Bilco]

Lets hope my system doesn't mess up the bikes low speed pull.

It will improve low down torque so you'll notice a difference.

Keihan and Akra use the balance pipe because it evens up exhaust gas flow as I'm led to believe. When we first did the Keihans, we decided to make them the same diameter and design as the OEM but without the CAT.

Some clever kraut boffin deep in the basement of the factory obviously decided a balance pipe was beneficial so who are we to argue