Standard de-catted headers Vs aftermarket Remus, Akrapovic etc.

[SteveM]

Can anyone tell me if there is much performance to be gained my changing my standard de-catted headers for something else like Remus headers etc. Is there some inherent design aspect that make the aftermarket ones better or is it just the elimination of the catalytic matrix that counts. I'm not concerned about any weight saving to be had or aesthetics. 2011 GSA. Cheers

 

[APE]

It certainly improved performance on the earlier single cam. In terms of design some say the version with the link pipe gives better mid range.

Less clear on the twin cam - the headers were redesigned and I'm not sure so many people have bothered with this upgrade - I haven't and am also interested to hear views with respect to the later model.

 

[Bendy toy]

I have an Akraprovic Ti shotgun cans system. I like the style. ;-)

Hilltop told me fancy headers with "race" can might make a couple of bhp on a dyno remap but to all intents there is no big difference and no top end power gain with standard map.
I certainly found a better midrange but how that compares to a decat I don't know.

The main issue is we can use any two of
- Decat/headers
- Free flow can
- Free flow air filter
All three will make the standard ECU map run harmfully lean.
He also recommends posh petrol to keep exhaust temperatures down.
My bike def runs better on posh petrol and costs me a few pence less per tankful over plain 95.


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[Pughy]

Can anyone tell me if there is much performance to be gained my changing my standard de-catted headers for something else like Remus headers etc. Is there some inherent design aspect that make the aftermarket ones better or is it just the elimination of the catalytic matrix that counts. I'm not concerned about any weight saving to be had or aesthetics. 2011 GSA. Cheers

Hi Steve. I fitted Remus headers and end can on my single cam which made an improvement but not significant. The GTR silencer & flapper valve removal on my 12 Triple Black has unleashed significantly more power (+ it sounds like a Stuka ) I am not sure that the high cost of new headers (£450'ish) is going to be worth the next step, I may try a free flow air filter instead.

 

[Bobbin-Man]

Steve, stick to what you have. The balance pipe is there for a reason and because don't have a cat now the only real gain would be to fit the Akrapovic headers which would smooth the flow a little going through the cavity where your cat was .... that's a lot of outlay for a small gain, not worth it!

 

[SteveM]

Hi Steve. I fitted Remus headers and end can on my single cam which made an improvement but not significant. The GTR silencer & flapper valve removal on my 12 Triple Black has unleashed significantly more power (+ it sounds like a Stuka ) I am not sure that the high cost of new headers (£450'ish) is going to be worth the next step, I may try a free flow air filter instead.

Good morning David, I've heard that free flowing air filters and non OEM pipes can make the bike run dangerously lean without a remap or similar. There's loads on here somewhere about it.

 

[Pughy]

Is it a big job to remove the cat out of the original headers?

 

[SteveM]

Is it a big job to remove the cat out of the original headers?

No, it's not really a big job but you can't be too shy about it. I cut my exhaust in half with a thin disc grinder then levered/smashed out the cat matrix, then got a local engineering firm to weld it back together for a tenner. The biggest benefit is having a decent securely mounted vice.
It has made a difference performance wise and coupled with the junking of the flappy valve and the addition of an accelerator module it runs really well. Would really like a different end can and a Hilltop remap though.

 

[Sgt Bilco]

Good morning David, I've heard that free flowing air filters and non OEM pipes can make the bike run dangerously lean without a remap or similar. There's loads on here somewhere about it.

If you go for a straight through system and free flowing air filter, you will need a powercommander or remap. I run keihan headers, FMF can (with baffle in) and a Power Commander 111 on my 06 GSA and the power is smooth and loads of torque. There is no gain to be had from a K&N in my opinion.

 

[NZRalphy]

No, it's not really a big job but you can't be too shy about it. I cut my exhaust in half with a thin disc grinder then levered/smashed out the cat matrix, then got a local engineering firm to weld it back together for a tenner. The biggest benefit is having a decent securely mounted vice.
It has made a difference performance wise and coupled with the junking of the flappy valve and the addition of an accelerator module it runs really well. Would really like a different end can and a Hilltop remap though.

Thanks this is good to know about the Cat. Was there a noticeable improvement in the low-mid range power? Did moving the cat change the fuel economy?
Ralph

 

[Bendy toy]

Rather than pay to have the cat case opened and welded how about getting the cat bulge replaced with a new link pipe.
I've never asked a custom exhaust specialist about this but should worth a look.


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[SteveM]

Hi Ralph, removing the cat seems to have made the engine pick up a little quicker and acellerate a little harder. As far as fuel economy goes I have no idea as I don't monitor it, sorry.