675 EXUP Testing

hordboy · May 7, 2009

An oft-debated subject, I decided to do some EXUP testing today. I've done it in the past, but wanted to re-visit my findings to confirm them. So I present to you two graphs. The bike in question belongs to a forum member. It is all stock except a TOR muffler. I plugged in my new replacement ECU, which among a dizzying array of options, lets me choose the EXUP opening. (Tuneboy also allows you to mess with this, but this bike did not have a Tuneboy flashload in the stock ECU)

Graph #1- 40% throttle, 15% eddy load. Run 40 is the stock EXUP opening curve, run 42 is the EXUP opened 100% all the time. I was trying to be at 40% throttle by 2k rpm, and pretty much succeeded in hitting the marks.

Graph #2- 100% throttle by 2k rpm, 0% eddy load. Run 36 is the stock EXUP opening curve, run 38 is the EXUP 100% open all the time. Yes, there are two curves there.

I will let you draw your own conclusions. The only difference I could tell was the bike was noticeably quieter at lower rpm's with the stock EXUP curve programmed in.

shaunthesoundguy · May 7, 2009

Woah.
So it is confirmed, the valve IS in fact the most annoying thing on the planet.

tehfastar · May 7, 2009

Pretty much confirms what my butt-dyno said about removing the valve... no difference in power delivery.

[FLUX] · May 7, 2009

Thanks for doing the "MythBuster" testing. The one other thing that will silence any remaining dissension would be to remove just the EXUP valve entirely, while leaving everything else stock. That's a fair amount of work though.

burn675 · May 7, 2009

It has been quoted by Simon Warburton of triumph many times that the exup value in the daytona and in a lot of other none triumph bikes is there to help the bike pass static & Drive by noise tests and has nothing to do with creating a better performance curve, without the exup value and well set up tunes you would end up with a large mid range hole in the talk curve just to enable the bike to get through the mid range drive by noise tests.

mb66l79 · May 7, 2009

After seeing that maybe I will unhook the exup so it's open all the time. Once again, nice work hordboy.

canyondancer · May 8, 2009

All stock except a TOR muffler means nothing. Of course your results would be nearly the same. The only difference would be noise.
The debate here on the forum was not to compare the percentage of EXUP settings. The debate was the HP and torque curve WITH and WITHOUT an EXUP valve.

Load the TOR tune {1st edition 06 tune} on your customers bike. Do a full throttle dyno run and print the torque and hp curve.
Then REMOVE the EXUP valve only. Just take out the butterfly and nothing else.
Now post the HP and Torque curve WITHOUT the EXUP.
If you do that...you'll see a huge torque curve DIP.

THAT is the real debate. Losing torque down low when the EXUP is removed. Try it....please.

mb66l79 · May 8, 2009

canyondancer said:
All stock except a TOR muffler means nothing. Of course your results would be nearly the same. The only difference would be noise.
The debate here on the forum was not to compare the percentage of EXUP settings. The debate was the HP and torque curve WITH and WITHOUT an EXUP valve.

Load the TOR tune {1st edition 06 tune} on your customers bike. Do a full throttle dyno run and print the torque and hp curve.
Then REMOVE the EXUP valve only. Just take out the butterfly and nothing else.
Now post the HP and Torque curve WITHOUT the EXUP.
If you do that...you'll see a huge torque curve DIP.

THAT is the real debate. Losing torque down low when the EXUP is removed. Try it....please.

Maybe I'm confused, but the way I understand it is that he had the exup connected for one run and then disconnected it for the second run so it was open the whole time. He did this for 40% throttle and 100% throttle.

So what difference would it make whether or not he had the stock tune or the TOR tune?

I'm especially interested in this as I have the TOR can and tune with cat gutted and am considering unhooking the exup valve (so it is open all the time) if the only measurable difference is that it's louder at low rpm's. I'm not willing to give up any low end torque though.

MGFChapin · May 8, 2009

WOW 109 hp?? Is that on an 09 Daytona or does the TOR really add that much?

jwong1024 · May 8, 2009

Very interesting... I too believe that it does not alter any performance, but the cat deff needs to be removed!!!

EvilSteve · May 8, 2009

So, if the bike makes the same power with the EXUP open all the time, why not just leave it alone?

I have a mechanic friend who removed the valve entirely, got a while new section of pipe inserted in its place.

tehfastar · May 8, 2009

Because it's a common failure point. Plus if you want to be anal about removing all unnecessary weight the stepper motor and cables weigh a couple of pounds.

IanRR · May 8, 2009

OK, is it possible just to take the valve out or leave it open position but also get the light on the dash to go out. If so, how?

ton · May 8, 2009

Hey J.D.

i'm sure canyondancer would be willing to pay you for the dyno time to do the exact experiment he describes to put this debate to rest permanently. prolly better to use his bike though, just so that the variability in dynos is taken into account.

-mark

YamRZ350 · May 8, 2009

From what I can tell, there's only one guy here going on about the merits of the exhaust valve and power delivery.

No matter what you show him, or tell him, he will just continue to argue his version of reality.

mb66l79 · May 8, 2009

hordboy - would it be possible to run the same test on the same bike with the TOR tune instead of the stock tune (that is assuming it had the stock tune in the first place). I would think that should settle this, unless the cat would really affect it that much which I'm afraid it would. Just thinking out loud here.

hordboy · May 8, 2009

Why? That would be a test of the tunes and not of the valve. All I am interested in is the valve's effect on power delivery, and that's the only variable I tested in this case.

mb66l79 · May 8, 2009

hordboy said:
Why? That would be a test of the tunes and not of the valve. All I am interested in is the valve's effect on power delivery, and that's the only variable I tested in this case.

Based on what CD was saying, the only thing I could think of is if removal of the valve affects (or lack thereof) different tunes in different ways. I wouldn't think that it would, but I'm no expert on this subject.

Either way, nice work on your testing, I think you convinced me to unhook my valve. I have the TOR can and tune with the cat gutted, I'll have to see what my butt dyno says on the difference.

hordboy · May 8, 2009

Well, I'm sure CD would be right, removal of the valve would have a different result with different tunes. That's why I removed the variable of the tune, and made sure the mapping was roughly optimized for each testing condition of the valve. I guess I'm assuming everybody realizes that, and I shouldn't be. Again, simply running the bike with one tune and the valve hooked/unhooked, doesn't give you any meaningful data on the valve. The same way modifying your engine and running the stock tune wouldn't give you any meaningful data on the engine mods.

And, for the record, I'm not saying everybody should go out and disable their EXUP valves. I just wanted to find out if the valve itself provides power enhancement. It seems not to.

mb66l79 · May 13, 2009

hordboy said:
That's why I removed the variable of the tune, and made sure the mapping was roughly optimized for each testing condition of the valve.

canyondancer said:
So what did the butt dyno tell you? Let me guess....loss of torque under 5k....right?

I haven't had a chance to test it yet, but hopefully this weekend. I'll post up my thoughts after I actually do it.

If I understand hordboy correctly, the tune was different for the runs with and without the valve. My conclusions from this are that the valve is worthless if you dyno tune the bike, which is nice to see some hard evidence behind this. :thumbsup:

From what I've read on this subject in other threads, I understand the main question as whether or not removing/unhooking the valve without changing the tune has any effects on low end torque. For myself, and I would assume the majority of other people, this is what I would like to know as I'm not ready to spend the money on dyno tuning. I've read lots of people arguing this both ways but haven't seen any definitive evidence like hordboy's test, unless I missed it. I'm afraid that until someone shows evidence solving this question one way or the other, like hordboy did with his test, this topic will never die.

carpel21 · May 9, 2009

I'm likely taking the exhaust off to the fabricators next week but still undecided whether to remove just the cat or cat and EXBV. Mine has never seized even with riding in the UK spring/autumn and being stood up through the winter. If I leave the EXBV on, then no need to remap (20109 +3 degrees ignition for standard can) and I could always just cut the cables and leave it open if it does seize. The cover bolts are mush though so I'd need to drill them to set a seized valve open. If I do remove both, then how much will the fuelling be off under 7K? I have Tuneboy so could trim it up but would it run richer or leaner without the valve?

shaunthesoundguy · May 13, 2009

With the stock tune and removing the exup, the bike will undoubtably suffer in the RPM ranges that the valve was meant to be functioning.
Hordboy proved that the exup itself provides no power gains, but a retune is necessary if you remove it, as our stock tune obviously is mapped to have it there. And essentially after removing it the only gains are losing 1.5 pounds and no more fussing with it.

mb66l79 · May 17, 2009

Well I did some testing of my own today. I have an 06 with the early TOR tune, TOR can, and gutted cat.

By unchecking the exbv box in tuneedit, the exbv no longer functioned. I made sure it was in the wide open position for the test. The first thing I noticed was the much improved sound of the exhaust at low rpm's, it was much louder too, I fell in love with it immediately. According to my butt dyno, I feel like there was less torque in low rpm's. I feel confident enough in that result that I am leaving the exbv hooked up as I prefer the increased performance over the improved exhaust melody. I am disappointed as I wish I could have it both ways.

Since I was already doing testing with tuneboy I decided to try out the madas tune with my setup to see how it compared to the TOR tune. My butt dyno was not calibrated well enough to notice a difference between the two, which surprised me. I will continue to run the TOR tune however.

I may at some point this summer try out some of the other more popular tunes that can be found in the massive tuneboy tune thread, just to see if I can find one that will be better with my setup. I think canyondancer has the exact same setup as me, and I would think there are others as well, so if/when I do, I'll post up my thoughts.

It would be nice to run these tests on a dyno, but until I have that much extra money, I have no evidence for my results. I think I answered the question for myself, but I don't expect anybody else to accept any of this as fact.

canyondancer · May 17, 2009

mb66l79 said:
Well I did some testing of my own today. I have an 06 with the early TOR tune, TOR can, and gutted cat.

By unchecking the exbv box in tuneedit, the exbv no longer functioned. I made sure it was in the wide open position for the test. The first thing I noticed was the much improved sound of the exhaust at low rpm's, it was much louder too, I fell in love with it immediately. According to my butt dyno, I feel like there was less torque in low rpm's. I feel confident enough in that result that I am leaving the exbv hooked up as I prefer the increased performance over the improved exhaust melody. I am disappointed as I wish I could have it both ways.

Since I was already doing testing with tuneboy I decided to try out the madas tune with my setup to see how it compared to the TOR tune. My butt dyno was not calibrated well enough to notice a difference between the two, which surprised me. I will continue to run the TOR tune however.

I may at some point this summer try out some of the other more popular tunes that can be found in the massive tuneboy tune thread, just to see if I can find one that will be better with my setup. I think canyondancer has the exact same setup as me, and I would think there are others as well, so if/when I do, I'll post up my thoughts.

It would be nice to run these tests on a dyno, but until I have that much extra money, I have no evidence for my results. I think I answered the question for myself, but I don't expect anybody else to accept any of this as fact.

Yep we both have the same year bike...same setup. It would be great if you could afford the dyno run and see if it puts out the same power and torque as mine. I know dynos are different...but it would at least show two of us with nearly the exact HP and torque curve. I don't think there is any need for a dyno run with EXUP disconnected. We both know the noise is louder and the torque is less. I'm kinda suprised no one has made a map specific for our setups yet. I think with a disconnected EXUP valve....you could recover a little of that lost torque down low with a custom map....but i'm pretty certain that big dip in the torque curve would remain. That's why i havn't pursued it. I love that flat torque curve.

carpel21 · May 17, 2009

How is it that Hordboy's dyno graph is conflicting with your butt? I tried this also and noticed no power loss but fueling felt a little off. There must be an explanation that will satisfy all. Is it possible that the valve, under high pressure (WOT) could be held further open than it's intended angle? This would give the noise reduction and slightly higher torque at smaller throttle openings, but tie in with Hordboy's full throttle graph that shows near identical power curves?

(my post in another thread):-
I want to get shot of it, but not at the expense of grunt up to 7k so I decided to do a bit of home testing. Got to thinking that Tuneboy has a check box "exhaust valve fitted" in the tune constants so I unchecked it, downloaded, turned off/on and voila, no squeek on startup tests! Exhaust note had changed for the better too though not as much as I thought it would. Took it for a very short blat out of town and back again and my feelings were this:

Not noticably weaker in the lower rpm, but the response was a little fluffy, like it was running rich, though not to the extent of pausing before pickup.
Where off/on throttle transitions at around 3k used to make the bike "kick", it was now noticably smoother and easier to navigate in city, like small roundabouts, junctions and slow moving traffic.
My setup by the way, is standard can, BMC raod filter, and 20109 final dyno tune by Tuneboy.
This was a very preliminary test (around 20 mins) and when the weather settles down I'm going to do some roll on runs in 6th gear from 3-7k, and time them with the onboard lap timer, then activate the EXBV again and repeat.
So far, while I completely agree with Canyondancer in theory on this, my personal opinion is leaning towards the torque curve not being affected to any noticable degree, even without a remap as Hordboy's dyno results implied also. Sorry CD:itsok:

canyondancer · May 17, 2009

Sorry for what? Put it on the dyno and see how much torque you lost under 5k. When you do...you'll see a huge dip in the torque curve under 5k too. I've seen a few charts with the EXUP removed and they all have a huge dip. It gets worse with a full system.

kellito · May 19, 2009

you did say "huge" though.

J.D. tested and saw no huge dip, I know he mapped to roughly optimize fueling for both configurations, but don't you remap for any change to the exhaust? To my knowledge he is the only person to put data up before and after removal of valve, and there is plenty of people who don't have the valve and make good flat torque.

canyondancer · May 19, 2009

kellito said:
you did say "huge" though.

J.D. tested and saw no huge dip, what do you call that dip at 5500 and at 7k? I know he mapped to roughly optimize fueling for both configurations, but don't you remap for any change to the exhaust? To my knowledge he is the only person to put data up before and after removal of valve, and there is plenty of people who don't have the valve and make good flat torque.

Show me a flat torque curve with the EXUP removed.

[FLUX] · May 19, 2009

I simply don't understand what the fuss is about.

People change exhaust systems all the time. It's pretty much common knowledge that any time you change any part of your exhaust system that it needs to be remapped to get the best results out of it. Isn't that common knowledge by now?

I simply don't understand why we're fighting over whether or not removal of the EXUP valve from a stock system without a remap results in a non-optimal torque curve. I would have thought that would have drawn a collective: "Well DU-U-UH!", from almost everyone with a semblence of a clue.

hordboy's tests show that removal of the valve and a subsequent remap to suit results in no torque/power loss, and it's run on the exact same dyno to remove dyno specific variables from the equation. Don't give a rats arse if someone ran a test on the same type of dyno, each dyno is different. Period. Can't compare them. Don't even bother. Don't even try. It's utterly and totally pointless, irrelevant, and confusing to even attempt do so. Once again, I thought that would have drawn a collective: "Well DU-U-UH!" from everyone with half a clue.

So what, pray tell, are we all arguing about here? I haven't the faintest idea. The EXUP valve is noise-control only. The proof is right there in the OP. It should be obvious to all but the most stubborn that if Triumph UK could have done without the EXUP valve, they would have, because it's clearly not there for any performance reasons. They simply would've ditched the valve and released the bike with the correct map instead, or are we arguing here that they wouldn't have supplied the correct map? That seems to me to be about what it boils down to, and by golly that's a pretty silly point.

carpel21 · May 19, 2009

Ha ha, in a nutshell FLUX! The fresh perspective is usually the clearest. Yes I was originally under the impression that he hadn't remapped until someone pointed it out in a later post. Playing with the mapping a bit now to see if I can get it back but the weather is shite.

canyondancer · May 19, 2009

Here is Hordboys claimed dyno run with a mapped EXUP valve....and a another dyno run that is mapped without the EXUP valve. >

canyondancer · May 19, 2009

Now here is my dyno run WITH an EXUP valve and the TOR map...TOR can.

canyondancer · May 19, 2009

Now i ask you...does Hordboys dyno chart look ANYTHING like mine does? Hell no. Different dynos or not....the steepness of the hp curve and the flat torque curve on mine are completly different. In fact...Hordboys dyno chart doesn't even look like a stock Triumph 675 chart. Why is that?

In BOTH of Hordboys dyno charts....the SAME dips in the torque curve appear. That is NOT possible to acheive when disabling the EXUP valve. I repeat...not possible. Stock 675 Daytonas do NOT have those dips in them. The chart that Hordboy produced appears to be a 675 Daytona with a full system on it and all he got with a custom map that he made is 109 hp.

Just in case anybody thinks i'm fulla shit....the shop name of where my dyno run was made is right on the chart. Call them and ask if the chart is real.

Take a real close look at Hordboys torque numbers. On his chart...he gets 39 to 49 pounds torque between 7 and 12 grand. On my chart i'm getting between 49 and 51 pounds between 7 and 12 grand.
That is 10 pounds of torque difference....and i have 5 more pounds of torque at 12 k tahn he does.

So i don't know where or how Hordboy came up with that chart....but it's certainly NOT with and without the EXUP valve.

[FLUX] · May 19, 2009

canyondancer said:
In fact...Hordboys dyno chart doesn't even look like a stock Triumph 675 chart. Why is that?

Here's a dyno graph of my second '07 675, absolutely bone stock intake/engine/exhaust wise as it was meant to be out of the factory. The only thing different about this bike from a stock factory bike was that I had fitted the black painted fairings to it from my BotY bike.

I'm seeing a heck of a lot of similarities between hordboy's and my graphs.

So i don't know where or how Hordboy came up with that chart....but it's certainly NOT with and without the EXUP valve.

How would you know? Do you even have a stock 675 dyno graph to compare the shapes of? You only have a single graph of a modified exhaust system from your bike, and you're the one calling other people liars because their stock graphs don't mimic yours. FFS, that's taking it too far.

675 EXUP Testing

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