Eliminating the exhaust valve on Camheads.

[Nick V]

As per subject line. I've done a cursory search, but can't find any indication (so far) that anyone has yet done this.

To save a(nother) duplicate thread, can anyone share a link to any other threads where a procedure for doing this is described?

I have a spare set of de-catted Remus headers and a Tornado Developments race exhaust I'd like to use on my new '10 GSA. And I am NOT using that waste-of-space exhaust valve.
So, the objective here is to get rid of the valve and as much of the servo-motor gubbins as possible, whilst not getting the bike to register any fault codes.

Any ideas, anyone?

 

[GSA PEK]

Exhaust valve

Hi
Just fitted my full Akropovic to my GSA 90th aniversary
I have taken the exhaust flap out and fitted a link piece. To disconnect the workings of the flap, I took the controller off and removed the cables. Then fitted the controller back to the bike and plugged the connector back into it
With no fault codes

 

[ghost-rider]

yep ive done this, and ive been running it for over twelve months, no problems, ive got an akrapovic and a set of de-cat headers, looks a lot neater, and sounds so much better, as said though you've got to leave the servo motor plugged in otherwise that will bring up a fault code, when I removed the cables from the servo box, I also found two perfect black grommets to plug up the holes where the cables used to come out again looks a lot neater and just stops water getting in

just do it mate, don't listen to all the shite on ere about "not" removing it, it has one purpose only, and that's to control noise pollution, fook that

 

[Bendy toy]

My Mk2 has an Akraprovic shotgun system wouldn't know a flapper valve if it hit one and sounds stunning especially when wound right up.

The same system will also fit the Mk3.
Just disconnect the cables and leave the motor in place.

 

[GedJack]

yep ive done this, and ive been running it for over twelve months, no problems, ive got an akrapovic and a set of de-cat headers, looks a lot neater, and sounds so much better, as said though you've got to leave the servo motor plugged in otherwise that will bring up a fault code, when I removed the cables from the servo box, I also found two perfect black grommets to plug up the holes where the cables used to come out again looks a lot neater and just stops water getting in

just do it mate, don't listen to all the shite on ere about "not" removing it, it has one purpose only, and that's to control noise pollution, fook that

What he said, been running like that for two years, no issues. Looks great.

 

[karlp]

As per subject line. I've done a cursory search, but can't find any indication (so far) that anyone has yet done this.

To save a(nother) duplicate thread, can anyone share a link to any other threads where a procedure for doing this is described?

I have a spare set of de-catted Remus headers and a Tornado Developments race exhaust I'd like to use on my new '10 GSA. And I am NOT using that waste-of-space exhaust valve.
So, the objective here is to get rid of the valve and as much of the servo-motor gubbins as possible, whilst not getting the bike to register any fault codes.

Any ideas, anyone?

Please explain why the exhaust valve is a waste of space

 

[Bendy toy]

The closed exhaust valve gives a higher back pressure that makes better use of header resonance at mid range. It opens to give free flow at high revs.

But the Mk3 boxer valve is behind the catalyst and the header makes little pretence towards resonance (the sides are not equal length and catalyst bulb kills any resonance.

It's there to meet noise regs but opens to allow full power for a market that buys on numbers. (how fast, how many bhp, how many torques, etc)

If it was reliable and didn't look like the afterthought it really is then why not keep it. But otherwise it's just weight and cost for no benefit.

That said my Akra shotgun exhaust is perfectly adequate for lower revs/power on one muffler with a minimal baffle. A valve on the other muffler would allow full power at high revs without losing the sound.

 

[BrokenPaw]

Dyno run comparison.

I've looked at dumping the flap, but mine is not broken, is still under warranty and the TC is really quite nice to ride.
However, I am curious; has anyone done a back to back run on a dyno?
Same bike, same day, only difference, flap operating, and then in default position fully open? The numbers would tell the tale. Maybe a job for someone who is taking out the flap and doing a re-map.
I agree it does look ugly and almost says "I am about to breaK"!

 

[ghost-rider]

I've looked at dumping the flap, but mine is not broken, is still under warranty and the TC is really quite nice to ride.
However, I am curious; has anyone done a back to back run on a dyno?
Same bike, same day, only difference, flap operating, and then in default position fully open? The numbers would tell the tale. Maybe a job for someone who is taking out the flap and doing a re-map.
I agree it does look ugly and almost says "I am about to breaK"!

aint bein funny, but its a noise valve for fooks sake, "back to back run on a dyno"??, this has been covered a few times on here regarding the flap valve, and every time the issue seems to get over investigated if thats the right word to use, either take it out or don't, simple as that, I had no issues with my valve, but simply preffered the neater look once me headers and akra can were fitted, and also one theory I have regarding the 1200 twin cam "stalling issues" is the valve, the valve in my opinion acts as a choking device if it snaps shut too quickly possibly, and in my opinion would just stall the engine, but I could be barking up the the wrong tree with that one but as for the warranty, mines been in a couple of times, service warranty etc., never been an issue

 

[Bendy toy]

The Mk 3 will happily take exhaust systems intended for the earlier models. The only difference is the flapper valve.

 

[BrokenPaw]

Oops,
Sorry folks, I did not realise my dopey dyno idea had already been aired - underestimated you people.
Will do a bit more searching next time.

 

[Nick V]

The closed exhaust valve gives a higher back pressure that makes better use of header resonance at mid range. It opens to give free flow at high revs.

So my hunch was right... in theory, it would exploit the same principles as Yamaha's EXUP valve?

It's there to meet noise regs but opens to allow full power for a market that buys on numbers. (how fast, how many bhp, how many torques, etc)

If it was reliable and didn't look like the afterthought it really is then why not keep it. But otherwise it's just weight and cost for no benefit.

You mean, aside from being present to keep the Politically Correct (tm) happy?

This has been getting stupid for a long time now. Catalytic convertors follow the same argument: in theory, they reduce the amount of unburned hydrocarbons and carbon monoxide.
But they have negligible effect until they've reached operating temperature, and the increased back-pressure they present means that the engine must burn more fuel to do the same amount of work.
So while the percentage of harmful emissions may be reduced somewhat under certain limited circumstances, the volume of overall emissions is actually greater.

As was pointed out to me many years ago: useless measures can only serve as alibis for politicians as long as their uselessness has not become evident.

 

[Nick V]

I haven't been on the site all weekend (internet access from my place is spotty at best) - but amongst other things, I did manage to eliminate the valve from the exhaust.

As per the other posts I've just read, relevant steps were as follows:

1. I dismantled the rear half of the exhaust, and removed the valve body.
2. Standard silencer was placed in the 'Useful Spares' bin.
3. Valve servo controller unplugged, removed and inspected.
4. Actuation cables disconnected and valve joined silencer in bin.
5. Quick inspection of valve servo controller. Much annoyance to discover that the housing is integrally-moulded and cannot be opened except by brute force.
6. Replacement and re-plugging of valve servo controller.

I installed my spare Tornado Developments exhaust, using a link pipe originally made for my previous '09 hexhead GSA. Some creativity was needed to mate the link pipe to the camhead headers, but I managed.
It's strictly an interim solution, as the standard headers will eventually be replaced by a set of Remus headers I have. (They need to be repaired - the left-hand header pipe took a bad knock at some stage. But I got the complete header pipe for R400, so who's complaining? )


What I have in mind next is something more ambitious - eliminating the valve servo controller by 'fooling' the ECU into believing it's still there... when it is not.
This will require knowledge of the relevant pin-outs (with my limited knowledge of electronics, I presume that two of the pins handle motor-control current, and two are for valve-position limit switches, but without breaking into the black box, it's going to be very hard to tell...
Can anyone help?)

 

[ghost-rider]

What I have in mind next is something more ambitious - eliminating the valve servo controller by 'fooling' the ECU into believing it's still there... when it is not.
This will require knowledge of the relevant pin-outs (with my limited knowledge of electronics, I presume that two of the pins handle motor-control current, and two are for valve-position limit switches, but without breaking into the black box, it's going to be very hard to tell...
Can anyone help?)[/QUOTE]


honestly mate don't bother, each to there own an all that, but it honestly aint worth it, just leave it plugged in and forget about it

the reason for leaving it plugged in, is because like the Yamaha exup valves, on turning on the ignition, the ecu does a cable tension cycle of the valve, which is why you hear it to start with, if the box ay there, it then registers a fault, but as for what pin does what, somebody else will have to chime in with that one, but like I said, I honestly wouldn't waste time on it, just keep it simple

 

[Nick V]

honestly mate don't bother, each to there own an all that, but it honestly aint worth it, just leave it plugged in and forget about it

the reason for leaving it plugged in, is because like the Yamaha exup valves, on turning on the ignition, the ecu does a cable tension cycle of the valve, which is why you hear it to start with, if the box ay there, it then registers a fault, but as for what pin does what, somebody else will have to chime in with that one, but like I said, I honestly wouldn't waste time on it, just keep it simple[/quote]

I hear you. And if I'm completely honest with myself, you're dead right.
It would be nice to have if it were a bit easier to get that box open, but since it isn't, no one except a race bike builder would ever notice the weight difference.

Me being obsessive me, though, I can't stand the thought of a component that does nothing to earn it's keep taking up space on my bike.

 

[Bendy toy]

+1 to keep it simple as possible.

The ECU will measure valve motor current to gauge cable tension. How would you fool that one without even more logic circuits? Leave it connected and spend the cost of fooling the ECU on a remap.

 

[Nick V]

...spend the cost of fooling the ECU on a remap.

Speaking of that...
I've seen much mention of an ECU re-map by a UK shop called Hilltop Motorcycles.

How do they accomplish this? Does the ECU use EPROMs which can be re-flashed? Or do Hilltop use a piggyback module like a Power Commander?

 

[birdseye]

So my hunch was right... in theory, it would exploit the same principles as Yamaha's EXUP valve?



You mean, aside from being present to keep the Politically Correct (tm) happy?

This has been getting stupid for a long time now. Catalytic convertors follow the same argument: in theory, they reduce the amount of unburned hydrocarbons and carbon monoxide.
But they have negligible effect until they've reached operating temperature, and the increased back-pressure they present means that the engine must burn more fuel to do the same amount of work.
So while the percentage of harmful emissions may be reduced somewhat under certain limited circumstances, the volume of overall emissions is actually greater.

I'd like to see your evidence for this. Catalytic converters work once their temperature gets above 200C and that happens typically when the engine itself gets to temperature. So on a 30 minute journey you might have 5 mins of emissions and 25 mins of clean air. No way would it take 15 mins to get to operating temperature. In short removing the cat is like removing baffles or the flapper valve - an antisocial modification done because you want to be awkward and to irritate non bikers with extra noise.

I live between two biker roads and every weekend in summer out come the warriors , usually on sports bikes but nowadays on GSs as well, deliberately loud exhausts messing up everyone else's weekend peace and quiet. So the locals moan to plod and out come plod with their radar guns and then of course bikers complain about being targetted. Is it surprising we get targetted? Put up two fingers to the rest of the population and then act surprised at the result? Stupid.

To avoid attracting attention and yet more restrictions, keep a low profile.

 

[ghost-rider]

I'd like to see your evidence for this. Catalytic converters work once their temperature gets above 200C and that happens typically when the engine itself gets to temperature. So on a 30 minute journey you might have 5 mins of emissions and 25 mins of clean air. No way would it take 15 mins to get to operating temperature. In short removing the cat is like removing baffles or the flapper valve - an antisocial modification done because you want to be awkward and to irritate non bikers with extra noise.

I live between two biker roads and every weekend in summer out come the warriors , usually on sports bikes but nowadays on GSs as well, deliberately loud exhausts messing up everyone else's weekend peace and quiet. So the locals moan to plod and out come plod with their radar guns and then of course bikers complain about being targetted. Is it surprising we get targetted? Put up two fingers to the rest of the population and then act surprised at the result? Stupid.

To avoid attracting attention and yet more restrictions, keep a low profile.

is there any fookin point to this, other than just

 

[Alan R]

+1 to keep it simple as possible.

The ECU will measure valve motor current to gauge cable tension.

It seems unlikely that the software is that sophisticated - when the valve seizes up, all that seems to happen is that the servo constantly tries to cycle the valve - They seize in the open position and seizure does not seem to affect performance. No fault codes are registered, no yellow triangle and no faults available to view via GS911.
Alan R