Exup....

[anutz]

So the EXUP valve on my bike when i got it was showing issues, 7K code at start, so cleaned it up and greased it all up, all is well now aside from a broken bolt ( not me! )


Reason i post is who runs without it, and what impact does it have...


I have read it kills performance and low down torque, yet i see after market exhausts from certain manufacturers that have no EXUP...


Would a dyno against a standard EXUP versus a set of pipes with no EXUP show big differences....

[Falcon 269]

There has only ever been one aftermarket header system that eliminated the EXUP without causing some kind of flat spot around 3.5 - 4.5k rpm.  That was the Muzzy 4-1 with horizontal merge plate in the collector.  No longer on the market and rare as hen's teeth in the UK.

Even the best 4-2-1 systems, such as Akrapovic, suffer a little in that rev range in order to deliver better power from around 5k rpm upwards.  I would describe it as slightly softer power delivery rather than a flat spot. 

The flat spot from the cheaper EXUP-less replacement systems is very noticeable and impossible to tune out.

[anutz]

OK, not looking to change mine, but shame its such an important part that on my bike in any case has been neglected ( with lots of other stuff!!!! )


When i looked at mine the top left bolt that holds the bracket in place the servo cables locate into had no bolt, but it still works as with the cover on it jams the bracket in place, just would be nice if the last owner had sorted it out!


I will have to have the pipes off to fix, and i am not sure its even worth it...


I got ride of the 7K code, but i know one cable is really tight and one is loose so need to do some more work on it, the exhaust seems very burbly, there is no baffle so that might be it

[Falcon 269]

I got ride of the 7K code, but i know one cable is really tight and one is loose so need to do some more work on it, the exhaust seems very burbly, there is no baffle so that might be it

The freeplay should be identical in both cables - around 1.5mm

See Pat's Site for info on how to set EXUP correctly: http://www.cartestsoftware.com/fz1/

[Reaper]

The flat spot from the cheaper EXUP-less replacement systems is very noticeable and impossible to tune out.

I'd disagree with that I'm afraid. I have a straight through set of stainless downpipes on my Gen1 which I bought off of another Forum member and don't have any issues.
Granted my bike has been Ivanized and has a performance filter, etc but the acceleration is smooth througout the rev range. In my experiance the Gen 1 can work perfectly well without an Exup Valve but it needs to be set up properly.

[anutz]

So i just checked my EXUP cable tension, way out, adjusted it properly and it does seem less rough at low RPMs, still need to change spark plugs, and other bits to look at...


Anyway, would be interested in others comments on systems with no EXUP and downsides...

[Falcon 269]

I have a straight through set of stainless downpipes on my Gen1 which I bought off of another Forum member and don't have any issues.

What make?

[turbo-steve]

my exup was damaged when i got the bike.( i know i should of checked it.) Had a very small flat spot at 6500rpm
that made me have a look at the exup.Thats when i found out the exup was damaged and one of the cables removed.
So i removed the exup and put a bolt in. Runs fine now no flat spot at all. Been on my m8s bike with exup in and there may
be a little extra below 4000 but was useing the ass dyno.
Will be putting a ivans kit in over winter so we will see.

[grim168]

Had mine around 18 months and exup been seized all that time. Never ridden another so didnt know any different. Only recently got 7000 fault when revving hard rev counter would drop to zero then back up to seven. Was seized closed. What a difference now. Top pulls much harder and easier to wheelie

[Reaper]

I have a straight through set of stainless downpipes on my Gen1 which I bought off of another Forum member and don't have any issues.

What make?

Don't know for sure I'm afraid as it was bought second hand but it looks like a Black Widow System to me

[Falcon 269]

Be interesting to see what the dyno reveals.  I have dyno charts from a Fazer with those headers and the dip in the power curve is very noticeable.  I'm happy that you don't feel anything amiss with yours but I would never claim that Ivanising would overcome inherent faults in the design of a header system.

[Reaper]

Be interesting to see what the dyno reveals.  I have dyno charts from a Fazer with those headers and the dip in the power curve is very noticeable.  I'm happy that you don't feel anything amiss with yours but I would never claim that Ivanising would overcome inherent faults in the design of a header system.

Thats not what I said at all so please show a little courtesy to others and step away from the condescending remarks.

I never claimed that Ivanising would resolve anything, I simply stated what set up I was running and that MY bike was set up properly without any negative impact upon performance.
The OP asked for comments on peoples experiance with removal of the EXUP system. I provided detail of my experiance, the fact it might differ from yours is simply something that the OP could, if they wished, use to consider their options and make an informed desicion.
I'm making no sweeping claims just commenting on my experiance so why don't you try a similar approach rather than the "this is my opinion and I'm therefore right" approach ?

[Falcon 269]

Nothing discourteous or condescending in my reply, I think.  I read your post to mean that Ivanising and fitting a performance air filter had contributed to 'properly setting up' your bike to work with the headers you've got fitted. 

I offered my opinion (and that's all it ever is - my opinion, nothing more) because I've been asked in the past whether Ivanising would cure flat spots caused by poor header design.  I put the same question to Ivan himself and the answer was a definite 'no'.  Perhaps I should have made that clear earlier.  It's not a sweeping claim from me, it's based on the experience of a guy who helped design the best aftermarket header system ever built for the Fazer 1000, and who also reworked his Akrapovic headers to improve their low-end scavenging.

You didn't enlarge on what else you've done set-up wise but out of genuine interest, is there anything in addition to the carb work?  If there's a way to make the Sandy Spares/Black Widow headers work well, it would be very helpful to us all to know how.

[Exupnut]

Nothing discourteous or condescending in my reply, I think.

Agree

[teecee90]

Nothing discourteous or condescending in my reply, I think. 

Also agree. Mike is a top bloke who knows his onions. Dismiss his experience and opinions at your peril.