FZ1 exup motor and cables

[gel]

I am looking at an 09 FZ1 it has an after market can but also has the original can as well. I have asked if the bike still has the exup cables and they can't see any. If the exup motor has been removed would this not throw an ECU error. I saw no error when I road it. And it seamed to ride fine. Should I be worried?

[slappy]

No.
The exup on the FZ1 is for emissions only, it does nòt  affect running or performance.

[gel]

Great news, I'll stop flapping now. Dealer has confirmed the exup motor is there but no cables.

[Seabass]

According to the tuner that did my ECU reflash he reckons they are more than an emissions thing. Im no expert but he talked about exhaust back pressure and resonance etc. Heres a link to another FZ forum I'm a member of You'll see my power graphs and just to point out to you after the remap youll notice a hike on power/torque between just below 4k and up towards 6k. This is apparently where the exup operates. You'll read loads of different opinions online, my opinion is that its there for a reason and not just to regulate noise. 

Heres the link bud:

[Seabass]

http://www.998cc.org/forum/gen-ii-tech/17072-ecu-re-map-hilltop-motorcycles-3.html

[slappy]

I have had 3 different aftermarket  end cans on my FZ1 since I got it. I have not noticed any difference in performance of any kind with the exup removed and when I first bought it it still had the original exhaust and exup on.
Most people on this forum with a FZ1 have put an aftermarket can on and I cannot remember anyone saying it affected performance.
Something might show up  on a dyno but on the road there is nothing.

[Seabass]

Personally i respectfully disagree with you. Since the ECU remap the kick in the lower rev range is definitely noticeable, maybe its just a coincidence that there is a noticeable improvement on my bike in the area where the exup operates, although i think not. I have the benefit of riding the FZ before and after the remap with the exup in operation on both counts. I'll be keeping my cables attached. I don't wish to start yet another debate on the exup as its been done to death over the years, i just want the OP to be aware of the different experiences we've, with my personal advice being to retain the exup and if possible, get the ECU remap.

[slappy]

You had your ecu remapped and you can notice the diference in performance, well that is what you paid for, I imagine you would be disapointed if there was no significant improvement.
But if you ride a stock bike with stock exhaust and exup, then dump the exup and fit an aftermarket end can, you will not notice any difference in performance nor will you damage your engine or ecu which I think the OP was worried about when he posted his question.
To be honest with you I have been considering an ECU reflash myself  so I can dump my Juicebox Pro.
The place is local  to me and has been recomended by two workmates, £180 for reflash and a couple of dyno runs and when I have spoken to them they said the ECU reflash will totally eliminate  the ned for the exup.

[JoeRock]

Personally i respectfully disagree with you. Since the ECU remap the kick in the lower rev range is definitely noticeable, maybe its just a coincidence that there is a noticeable improvement on my bike in the area where the exup operates, although i think not. I have the benefit of riding the FZ before and after the remap with the exup in operation on both counts. I'll be keeping my cables attached. I don't wish to start yet another debate on the exup as its been done to death over the years, i just want the OP to be aware of the different experiences we've, with my personal advice being to retain the exup and if possible, get the ECU remap.

Couple points here fella - no. 1 is that this region of the revs is one at which emissions readings are taken, so the bike is flattened off here - lot of modern bikes have a problem with a flat spot at this area of the revs. That's why you'll be feeling the kick up the ass so much at these revs, remapping it here makes the biggest difference as compared to the original power if you get me.
Your tuner is right on the older Exup valves - they were to help boost low end performance. From everything I've read though the newer valves are just noise reducing.

[Seabass]

Between reading what are a lot of opinions on the web, and what Hilltop have recommended (just google them to see what people have to say about him) I went with his expert advice. I guess the only way to see if the exup would make a difference would have been to run the bike with and without the cables attached on their dyno. That wasnt done as the tuner said ideally to have the exup in operation. Thats what o have and should you care to check the results on the link i posted above you'll see the before and after of graph 4 (i think). Massive improvement which can be felt when riding the bike. Each to there own and its something for the OP to think about. Personally I'll keep my cables attached as it rides beautifully now.

[noggythenog]

I think at the end of the day this thread shows that you can still get good power gains even with the exup fitted.


Like you say Seabass it's a tricky one to prove whether the exup being there has improved the bike or whether the remap has done it regardless of the exup as you didnt have it dynod without the Exup plus the tuner tuned the bike to the spec of having the exup fitted.


I think you're right to listen to the tuner......even if he is or isnt correct about the exup because if you approach a tuner and pay the dosh for their advice and expertise then youve gotta accept what they're saying or walk away and clearly you're happy with the service.


But power gains aside i think it's fair to say that you can run the bikes without the exup without any significant differences and maybe because these bikes are so bloody powerful anyway then if there is a difference with/without exup then it maybe needs test conditions to notice it.


Being smooth is another matter, my bike got smoother just from blocking off the AIS alone, i dont have a power commander yet and it isnt remapped and it is still a stonking engine......little snatchy on the throttle but certainly not lacking in the power department from what i can feel anyway.

[Fazafou]

When I took my cables off and fitted a fuel silencer, I think it's lost a little mid range but gained at the top.

It's not enough to know if this is real or just maybe me perceiving it differently, but the effect is minimal even if real.

On the other hand the bike now sounds amazing

[Seabass]

Here what your saying noggy, to play devils advocate with the guys that have removed the exup and not ridden a bike with the ECU and exup attached, they may be surprised and feel more of a difference. I'd even go as far as to say if i ever meet up with any of you for a foccer rideout I'd be happy to swap FZs for a short period to gauge the difference.

I haven't got a problem with other peoples theories on the exup, its healthy discussions like this that make a forum decent, with everyone sharing their views and experiences. The OP can then make an informed decision based on that! Based on Geoff at Hill tops advice (tuned Chris Walkers ZX10R shortly before mine) he appears to know what he's doing.

So back to the OP... decisions decisions!

[slappy]

If you remove the cat from the downpipes would this not have more effect on back pressure than removing the exup?
The exup is open or partially open in most of the rev range but the cat is like a honeycomb that has quite small holes in.

[noggythenog]

Seems to me that even by the time the Gen2 was created that the Exup had started to have its day with Yamaha....perhaps because they sound so bloody annoying to keep clean and working well and well i dont see exups being used on any of the new range of bikes so obviously they've figured out other ways of improving exhaust flow throughout the rev range.

[Fazafou]

If you remove the cat from the downpipes would this not have more effect on back pressure than removing the exup?
The exup is open or partially open in most of the rev range but the cat is like a honeycomb that has quite small holes in.

Removing back pressure is a good thing, it's exhaust velocity you don't want to lose, which the exup can help with.

The idea of 'back pressure' is a bit of a misconception http://www.gomog.com/allmorgan/exhaustbackpressure.html

Getting rid of the cat will help, going to a huge wide pipe can be detrimental though if velocity is compromised, so the exup can add a restriction to increase the velocity again. This all needs to be tuned though.

As long as the aftermarket pipes aren't too wide they should be ok, but I've noticed in the past on some bikes I've taken the baffle out of, the sound improves but power is down.