GSA header pipes

[Boxerfan]

Could anybody please let me know if the header pipes that I had on my '08 Gsa are suitable for fitting on the newer double overhead cam bikes from 2010?

I suspect they won't but wondered if anyone has a definitive answer.

Many thanks.

 

[Schtum]

I believe (I haven't tried it myself, although I do have a set of pre twin-cam Remus headers in the motorradhaus...) that the pipes will fit but you'd either have to remove the valve between the headers and the can or have them cut and shut to accommodate the valve.

 

[2 wheel humvee]

I believe (I haven't tried it myself, although I do have a set of pre twin-cam Remus headers in the motorradhaus...) that the pipes will fit but you'd either have to remove the valve between the headers and the can or have them cut and shut to accommodate the valve.

I could be wrong but I think the diameter of the header pipes at the outlet where they meet the flap/valve thing on the twin cam is greater than earlier versions, I've had Remus headers on previous GSA's and now have Akra headers on the twin cam, I've not measured them both but the twin cam outlet appears a larger diameter than I recall my earlier bikes

 

[Schtum]

I could be wrong but I think the diameter of the header pipes at the outlet where they meet the flap/valve thing on the twin cam is greater than earlier versions, I've had Remus headers on previous GSA's and now have Akra headers on the twin cam, I've not measured them both but the twin cam outlet appears a larger diameter than I recall my earlier bikes

Yes, I think that's correct which is why I said it'd be necessary to cut and shut earlier headers to fit the valve.

 

[Boxerfan]

Thanks for your answers gents.

I have been told by my local dealer, (who doesn't know if the header pipes fit!!) that the exhaust servo can be detached from the bike and won't have any detrimental effect, just shows a fault code when BMW plug there computer in to it.

So this weekend I'm fount to attempt to change the pipes, fingers crossed!!

 

[BrokenPaw]

Hi Boxerfan,
Bit late joining the thread, but just found it.
What sort of difference did you find replacing the header pipes on your twin cam?
I have no numbers, but I heard that the 2010 twin cam went up a bit in diameter on the header pipes; does this mean there is not as big a gain as in earlier years?
I also saw some photos of the obstruction to flow of the exhaust valve, even in the open position, not to mention the cat!
Any thoughts on how the engine is running with the change in pressures?
Have you ridden the twin cam much prior to the exhaust mod, and what did you find lacking in it?

 

[doctorsmudge]

Hybrid

Aha..... found the right thread. Any ideas on this one then.........
A 2010 gsa, with remus headers from an 08 GS. I've taken the exhaust valve off as its seized (now there's a thing) I've also got an Akro Titanium end can. So, will the headers meet up with the can without the wunderliche section of stainless to join? Will the diameters match. I'm kinda thinking the 08 headers are just a bit longer than the 2010 headers to compensate for the exhaust valve, I just need to hope the 2008 and 2010 cans are the same length??

Anyone heard of this combo before??

 

[BrokenPaw]

Hi doctorsmudge,
I will be interested to hear how your motorcycle performs compared to standard 2010 twin cam.
I am guessing the remus headers do not have a crossover pipe at the front.
Are you planning on a re-map?

 

[doctorsmudge]

Hi

No, the pipes dont have the link at the front, from all accounts from the tuners it makes little or no difference. Especially when you consider they link just before the Exhaust valve/can. I will be getting a remap, trouble is I'm in Scotland and the usual place is down at mallory park, thats a hell of day out for that.
I have a long trip to southern spain coming up though so I will be making efforts to get it done before I go as I'd be worried about going all that way with a lean mixture.

 

[Boxerfan]

Aha..... found the right thread. Any ideas on this one then.........
A 2010 gsa, with remus headers from an 08 GS. I've taken the exhaust valve off as its seized (now there's a thing) I've also got an Akro Titanium end can. So, will the headers meet up with the can without the wunderliche section of stainless to join? Will the diameters match. I'm kinda thinking the 08 headers are just a bit longer than the 2010 headers to compensate for the exhaust valve, I just need to hope the 2008 and 2010 cans are the same length??

Anyone heard of this combo before??

Hi Doctorsmudge,
I have replaced my whole twin cam exhaust for the whole remus system from my 08 GSA. You can't mix and match the headers and can from different years because the bore at the join between header and cans is bigger on the twin cam to allow for the flappy/valve thing. But the servo and valve are really easy to remove and then the whole 08 system fits no problem.

Steve

 

[Boxerfan]

Hi Boxerfan,
Bit late joining the thread, but just found it.
What sort of difference did you find replacing the header pipes on your twin cam?
I have no numbers, but I heard that the 2010 twin cam went up a bit in diameter on the header pipes; does this mean there is not as big a gain as in earlier years?
I also saw some photos of the obstruction to flow of the exhaust valve, even in the open position, not to mention the cat!
Any thoughts on how the engine is running with the change in pressures?
Have you ridden the twin cam much prior to the exhaust mod, and what did you find lacking in it?

Hi Brokenpaw,

Well the exhaust system is changed with no problems whatsoever. I took the whole system off my '13 GSA and replaced it with the Remous from my 08.
What sort of gain there is in power overall is difficult to measure but straight away the engine feels looser and pulls well from lower revs.
I have to say one of the main reasons I changed the standard exhaust was because of a really annoying drone at cruising speeds 80-85 mph. Hard to explain just annoyed me. And thankfully it is gone now.

 

[BrokenPaw]

Hi Boxerfan,
Well done and a success.
And good results without the remapping. That's good to know - I am still a littlle wary of the remapping, although everyone has nothing but good experience, so sounds the way to go.

 

[doctorsmudge]

Aha

Hi Doctorsmudge,
I have replaced my whole twin cam exhaust for the whole remus system from my 08 GSA. You can't mix and match the headers and can from different years because the bore at the join between header and cans is bigger on the twin cam to allow for the flappy/valve thing. But the servo and valve are really easy to remove and then the whole 08 system fits no problem.

Steve

There is a company that manufacturers bespoke exhausts just up the road from me. I'm hoping they can make a join slightly larger at one end that the other. I'm told they can do anything. Meercat Custon EXhausts. I'll let you know how it pans out. Once the headers and can arrive I'll offer them up and get the measurements I need.

 

[doctorsmudge]

And Finally....

To end this saga this is what I found. With the remus 08 decat downpipes being about 5 mm down on size to the 2010 plate ones, but still larger than stock I needed a link pipe with a slight bend in it to join it to the 2010 Akro tailpipe. The exhaust valve was junked. The guy from Meerkat Custon exhaust in about 15 mins cut some stainless, bent it to shape, stretched the Akro end diameter by 7mm and fitted it along with two new stainless clasps for £30. The guy is a hero.
Performance wise, it has a lot more pickup midrange, top gear acceleration from 60 to 90 is much much better, and thats the speed you need it at.
Noise wise............ Jesus... remember the Battle of Britain epic, well the noise of a formation or Heinkel bombers is the best comparison........ its feckin loud, thats with the baffles in! Pensioners diving for cover as I ride it down the street.
Next stop Hilltop in July while en route to southern Spain.
Thanks for all the help given on the thread.............