F800GS 2 into 2 Headers and Exhausts

[Getcool]

Has anybody ever changed the current OEM Header and Exhaust setup on the F800GS to a 2 into 2 setup?
Does anybody know how to change the exhaust on the F800GS to give it a beat opposed to a growl?
Would the engine work with a 2 into 2 setup? Advantages/disadvanted please from anybody.
Is there anyway changing the exhausts that you could get a similar sound that you get from the KTM990? Thanks.

[DoWorkSon]

There is only one o2 sensor... It would have to be more of a 2-1-2. If you had two pipes but one sensor, it might throw off your A/F ratio. You might be able to bypass the need for o2 sensors if a company can reflash the ECU to remove the need for them.

Other than that, anything is possible. Mounting and designing a new pipe would be the hard part. You would have to run it so not to interfere with the suspension travel and other things. You could try a shotgun over/under exhaust, which would probably be easier.

[biodieselandon]

I have considered this mostly because it would be nice to get Touratech pannier mounts more symmetrical so you could run the same sized box on each side. It would look and sound pretty cool too. I'm wondering if you had a small crossover pipe (probably a good idea anyways) if you could stick the O2 sensor in there. Or does it need to be more directly in the stream? Otherwise going with 2-1-2 is probably the best option. Would like to try to fabricate with catless headers.

[LukasM]

Originally Posted by DoWorkSon

There is only one o2 sensor... It would have to be more of a 2-1-2. If you had two pipes but one sensor, it might throw off your A/F ratio. You might be able to bypass the need for o2 sensors if a company can reflash the ECU to remove the need for them.

Why do you think this would be required? It's not like the stock narrow band O2 sensor delivers much accurate info, and I think the cylinder always get the same amount of fuel anyway?

[ebrabaek]

This sounds very interesting. There are a few areas I would raise attention to. Unlike the KTM v twins, the firing order is vastly different, and I don't think you will be able to mimic that sweet sound. Many things can be said ofBMW....not all good, But I would like to think that they did a fair amount of research when specking out the engine with Rotax, regarding how the motor behaves with regards to exhaust pulses...back pressure..... and nominal flow through the exhaust. This is just a thought, and I have nothing to back this up. I think if I was/would do this, I'd make some phone calls to Dynojet....Or at the very least align myself with a reputable tuner, and rig up a twin pc5 with auto tune, each controlling each bank..... I know i know.... wishful thinking, but it sure would be nice....If this could be done. You will add some weight, but would make the muffler smaller..... That said... Just my two Kroner....

[Getcool]

Please see this thread here.
http://www.advrider.com/forums/showthread.php?t=732208
I am not too sure what research went into this conversion, but I really like the look of the bike with the 2 exhausts.
Has anyone seen this bike and that can comment on it please.

[DoWorkSon]

Originally Posted by LukasM

Why do you think this would be required? It's not like the stock narrow band O2 sensor delivers much accurate info, and I think the cylinder always get the same amount of fuel anyway?

It might, at minimum, throw a CEL or other error.... Once out of closed loop it might be ok, but not sure how bike would react with an CEL.

When I modified my Duc by modifying the intake, the super lean condition threw off the o2 sensors and caused an error... Once the sensors warmed up or bike revved up out of closed loop problem went away, but not initially... A dual setup would likely cause same thing. Poor idle/unable to maintain idle since the bike is only reading A/F for one cylinder rather than two.

I ended up re-flashing the ecu and eliminating the o2 sensors, which solved issue.

[LukasM]

Originally Posted by DoWorkSon

It might, at minimum, throw a CEL or other error.... Once out of closed loop it might be ok, but not sure how bike would react with an CEL.

When I modified my Duc by modifying the intake, the super lean condition threw off the o2 sensors and caused an error... Once the sensors warmed up or bike revved up out of closed loop problem went away, but not initially... A dual setup would likely cause same thing. Poor idle/unable to maintain idle since the bike is only reading A/F for one cylinder rather than two.

I ended up re-flashing the ecu and eliminating the o2 sensors, which solved issue.

I'm talking about your statement that you have to go 2-1-2 because you would have problems reading the A/F ratio on just one cylinder.

What difference should that make if the cylinders are not controlled individually anyway? The A/F ratio should be the same on a parallel twin, same flow of air, exhaust length etc.

[DoWorkSon]

Shouldn't be any issues running 2-2... Except the fact that you will still possibly receive an error upon startup from the o2 sensor reading only on cylinder instead of two(how it is on f800 currently since its 2-1).

But yes I agree, other than that, no issues