ZX10R Exhaust Valve

[JayGates_SP1]

Ok few questions......
1. What the hells it for? Noise? Emitions? Power?
2. What will it do if I rip it out?
3. Has anyone ever done this?
4. Why is belly button fluff always blue? :laugh1

[Gixxer-TeZ]

Ok few questions......
1. What the hells it for? Noise? Emitions? Power?
2. What will it do if I rip it out?
3. Has anyone ever done this?
4. Why is belly button fluff always blue? :laugh1


Not sure on the ZX10 but heres a bit of info on the R1 Exup Valve. I suppose they basically do the same thing. When I had my 2006 FZ1, I had a race can fitted which removed the exup altogether. The control cables (if still attached to the CDI) were tucked neatly behind the seat plastics so the CDI thought the EXUP was still attached and working so not hindering the CDI's performance.

http://biketransplant.tripod.com/exup_replacement.htm

[RaceMeNSee]

the Exup valve is supposta help something to do with low down revs or something!? i have/had one on my c1h 636 ninja...but when you replace the standered can you have to disconnect it! i had to make like a little disk thing to trick it into thinking it was still there....otherwise the FI light stayed on all the time!

[kasandrich]

4 stroke engines like backpressure in the exhaust, it improves something called scavenging, and thus gives more torque.

However, it is a balancing act in that at high revs, that backpressure stops the engine breathing freely, giving that nice free revv'ing feeling we all love, and try to improve with race cans, which are straight through rather than baffled.

The exhaust valve gives you the best of both worlds, it it controlled by the CDI/ECU unit, when the engine is at low revs it closes the valve, thus giving backpressure, when the revs rise, and from memory I think its around 6-8,000rpm on my Fazer 1000, the CDI/ECU sends a signal to operate a little motor to open the valve, this leaves the exhaust unrestricted so that it can breath freely at high revs, thus giving you the best of both worlds. More torque at low revs, a freely breathing engine at high revs.

Thus giving the best of both worlds:)

EXUP stands for EXhaust Ultimate Power

[JayGates_SP1]

The bloke from racefit said to loose the valve as its only for noise and emissions.... He would say that tho!

Im concerned that removing its going to cause more hassle then its worth.

Hmmmm LATESHIIIIFT or MICKTLS lol I need your inifinate knowledges ha ha

[Lateshift]

The geezer is right, these days the exhaust valve in their different designs is more for noise and emmissions control, earlier bikes used the valve system as Kas said for controlling the scavenge on the exhaust system.

On my R1 i have disconnected the cables and left the servo motor on which stops the bike showing a fault, on most other bikes by disconnecting the cables it can cause an FI fault on the clocks, if you can live with that then fine, just disconnect the cables completely from the servo, if the fault light annoys you then there are companies that produce a plug that will loop the signal to fool the ECU into thinking everything is working fine.

But to answer the question, yes you can ditch it, but dont expect the bike to run perfect as most fuel injected bikes when they have their valves removed to fit anything other than a full "tuned length" system tend to then need some fueling adjustment, but its not always the case so try it and see :)

http://www.areapnolimits.com/products/Servo-Override-FI-Light-Fix.php

http://www.ivansperformanceproducts.com/other.htm

Most who are using these bikes as race/track day bikes tend to just ignore the fault, it wont affect the running if the servo is completely removed, my advice would be to disconnect the cables at both the valve and the servo and leave them fitted, leave the servo connected too and see how it goes from there :)



For reference ;)

Kawasaki Integrated Powervalve System (KIPS)
Honda V-TACS
Suzuki AETC & Super AETC
Yamaha previously YPVS but now EXUP

:)

[Dal]

Belly button fluff is nearly always blue because most garments we wear have a large concentration of blue in them.

It has been proved that the fluff can even be caused by underwear. ;)

[Lateshift]

I reckon there has to be a more supernatural answer to that one though, you could spend a week bollock naked on a beach and expect to find sand under the hood and in the hole, and yet still find blue fluff in a bellybutton! :D

[kasandrich]

I may be able to shed some light on this!

Contrary to popular belief, we are not full of blood and guts! :o

Just as teddy bears are stuffed with a white stuffing, we are full of blue stuffing :o

Blue belly button fluff is just a slight leakage of this stuffing and nothing at all to worry about, unless you start to pull it and it keeps coming, and you can feel a slight tugging sensation, if this happens, you MUST stop pulling or you will entirely deflate yourself.

HTH

BTW, this hopefully explains that I am NOT fat because I am a pie muncher, merely that someone was over exhuberant with the blue stuffing

[Lateshift]

well that shatters the mystique and blows my theory about intrepid 'blue belly button fluff monsters' right out of the water then :D

last time i watch the sodding smurfs then! :mad: :D

[JayGates_SP1]

wow, some good answers them! :)

Well tonight i took all the exhaust valve bits off only to find that the valve itself is held to the pivot by two screws that wouldnt be out of place in an electric plug. The are deep in the pipe and round off rediculously easy. I found that by disconecting the two cables and hiding them in the seat unit the spring in the valve is strong enough to hold it open.... But id rather have it out. So anyways took it for a lap..... Hmmm pulling away needs another 1000rpm.....not alot of action til 5000rpm then the exhaust gets loud and back wheel spins up on wet surface.... Conclusion. Im leaving the bloody valve in til I get someone who knows what the hell they are doing can pull the bitch out! And that the valve does give back pressure enough so to help you pull away withoput reving its nuts off!

[MICKTLS]

Ben .....Lateshift is correct in his answers for the later valves and as for blue belly button fluff .....we all evolved from smurfs and not monkeys its just the way our forefathers remind us of our origins :laugh2