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Can We Reduce Engine Braking?


Guest ohlarikd

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Guest ohlarikd

Good to know my videos are still out there helping folks even though I've moved onto BMWs...

Anyway, the engine braking was one of my FAVOURITE things about my VFR. I used to love slamming it down a gear from high revs and just letting the bike slow me down while roaring its head off. *Especially* in traffic! The sound of a VFR with aftermarket pipes on the overrun is something I will miss forever.

Even after ten years, my 2002 VFR800 still turned heads with its fat baby-eight exhaust note. If only the fuel injection wasn't so wonky...

Also worth pointing out that I believe Ducati controls engine braking in the new Panigale motor by keeping the valves open on the overrun (I think it was exhaust valves). Doesn't help with the VFR of course, but people have solutions to the problem out there.

Ah, thought you were on here! Yes, those videos are FANTASTIC! Really opened my eyes. All the parts about 'don't adjust this', well I adjusted :) Since I moved the supposedly non-adjustable reference valve, I put it back to where my photos say it was. Also, the locknut on my wax post was much higher stock than yours in the video. I wonder how that is set at the factory. I put it back to where I had it, but may try it in your position. First, must get valves synced, then I can mess with the other adjustments.

Throttle-by-Wire is so helpful in so many ways... I can see why it was done. Too bad no one makes anything for the poor ol' VFR.

PS: The idle thing that would open and close by itself is part of the wax idle unit. Read up on it.

There are at least a couple threads about how to make your own manometer for under $20, and a few threads on how to do a sync.

I watched the Wax Unit video and understand it. Sounds like 1930s technology... That thing should be computer controlled. If it was, it could be opened up on engine braking to control it. If someone could get a servo and plug it into the Power Commander, which is aware of the RPMs, it could detect someone downshifting and open those valves up...

Edited by ohlarikd
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You can save a few $/£'s by using a dual vacuum gauge. I do, just connect one to whichever is the non adjustable one on the 6th gen, get the bike to running temperature, then check the measurement, now attach the other gauge to the same source & compare the reading to give you a +/- factor. Return the 1st gauge to the static source, then add the 2nd gauge to each of the other ports & adjust. Remember that everytiem you make an adjustment, check & correct the idle, then recheck all the other ports.

I find on my 5th gen when you hit the sweet spot, when you rev the engine, you will hear & feel the smoothness & the engine revs up much quicker & smoother. Feels much nicer to ride once setup correctly. Loses much of the snatch in the throttle & is smoother everywhere.

One other thing to check, is to set the throttle free play to ZERO, be careful when adjusting it, swing the bars through there full range, you may need just a smidge of free play, this makes adjusting the throttle at small openings much smoother.

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Guest ohlarikd

You can save a few $/£'s by using a dual vacuum gauge. I do, just connect one to whichever is the non adjustable one on the 6th gen, get the bike to running temperature, then check the measurement, now attach the other gauge to the same source & compare the reading to give you a +/- factor. Return the 1st gauge to the static source, then add the 2nd gauge to each of the other ports & adjust. Remember that everytiem you make an adjustment, check & correct the idle, then recheck all the other ports.

I find on my 5th gen when you hit the sweet spot, when you rev the engine, you will hear & feel the smoothness & the engine revs up much quicker & smoother. Feels much nicer to ride once setup correctly. Loses much of the snatch in the throttle & is smoother everywhere.

One other thing to check, is to set the throttle free play to ZERO, be careful when adjusting it, swing the bars through there full range, you may need just a smidge of free play, this makes adjusting the throttle at small openings much smoother.

Thanks for the response Mohawk. I ened up buying the 4 gauge unit, it was only $85 shipped. I've always wnated one anyway when I had carbed bikes (still looking for a 1995 CBR 900rr...) I think I will be able to get this running better - I sort of assumed that it was designed this way. We shall see what I can do.

I have adjusted my throttle to zero play last year. Along with the G2 throttle, the PCV, and the maps provided on this site, I don't really think much about it anymore. The one thing I did notice when I reduced the engine braking a few days ago was that the bike was much easier to ride. It was not snapping my head forward when I closed the throttle and then snapping it back when I slightly opened it. Made things MUCH smoother. Of course I did it all wrong, but it proved that things could be better if I do it right.

Edited by ohlarikd
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TBH I haven't read all 8 pages of this post because it is 6thgen related and my answer was posted by Yoshi on the first page (just pull in the clutch) but as I giggled at my intellect (and then thought how smart Yoshi has become with his advanced education) I also thought of the VTec...

Perhaps you can map some magic that opens the closed valves on a closed throttle decel situation just as the VTec opens them when you hit 6,200 rpm (or 6,800 for 2006 and newer I think).

just a thought, Yoshi can chime in anytime with a smarter answer.

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The engine brake is something else that I like on VFR. But sometime I wish it not to be so strong and to get a little fuel economy on slow/downhill decelerations. I compare it with the car which cuts off the fuel but is not making hard deceleration because the ECU keeps some air path still open in the engine. Like somebody else said it before, a stepper motor for the butterfly valves or another mechanism to keep at least one valve open all the time during deceleration might have helped ...

Still I can live & enjoy the bike the way it is (pity I was to late to get the money in time for a torocharger).

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You should try the engine braking on an Aprilia RSV4 - its like throwing a frigging anchor out and deploying a drag chute :blink: Mind you I actually like engine braking :fing02:

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You should try the engine braking on an Aprilia RSV4 - its like throwing a frigging anchor out and deploying a drag chute :blink: Mind you I actually like engine braking :fing02:

:1: and when I don't want it i either slip the clutch a bit or just stay up a gear or two longer, then fan the clutch with a double tap downshift prior to setting up for corner exit...

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Guest ohlarikd

You should try the engine braking on an Aprilia RSV4 - its like throwing a frigging anchor out and deploying a drag chute :blink: Mind you I actually like engine braking :fing02:

I believe the Aprilia Race ECU allows you to change the engine braking. Also Bazzaz and ECU Unleashed so I read. All thanks to ride by wire.

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I think the Ape has close to 14:1 compression (and needs high test gasoline) as opposed to our pedestrian regular fuel burning, low compression VFRs

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Guest ohlarikd

You should try the engine braking on an Aprilia RSV4 - its like throwing a frigging anchor out and deploying a drag chute :blink: Mind you I actually like engine braking :fing02:

:1: and when I don't want it i either slip the clutch a bit or just stay up a gear or two longer, then fan the clutch with a double tap downshift prior to setting up for corner exit...

Yes, understood. But in day to day commuting and traffic, I find the excessiveness a bit tiresome and unnecessary. Then again - if my TB sync gauges ever show up, I will re-adjust then re-assess the situation. I think some of you out there are feeling different levels of engine braking for whatever reason, so opinions are varying widely. The way mine is now, based on my experience on all my other bikes, it is RELATIVELY excessive.

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Engine braking is just running an air compressor with the momentum of the bike and mostly unrelated to sucking on the closed throttle butterflies. Keeping a mildly higher idle, like 1500-1800 will take a lot out of the apparent braking. Learning to slowly slip out the clutch on downshifting is very useful on VFR's, as Jason Pridmore used to demonstrate. Those two simple things will make you more pleased than thrashing around with ECU and imbalanced throttle bodies. Just sayin'

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I like engine braking. Let me ask this how many folks here do clutchless up and down shifts...Friend showed me how and haven't looked back. I'm sure some will hate on this, but my 03 runs fine in my opinion.

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You should try the engine braking on an Aprilia RSV4 - its like throwing a frigging anchor out and deploying a drag chute :blink: Mind you I actually like engine braking :fing02:

As you have both, how does the engine braking compare to your 6th gen ?

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Guest ohlarikd

I like engine braking. Let me ask this how many folks here do clutchless up and down shifts...Friend showed me how and haven't looked back. I'm sure some will hate on this, but my 03 runs fine in my opinion.

I clutchless UPshift a lot when having a little fun. But I don't know how to clutchless downshift and I haven't found a reason to yet.

Engine braking is just running an air compressor with the momentum of the bike and mostly unrelated to sucking on the closed throttle butterflies. Keeping a mildly higher idle, like 1500-1800 will take a lot out of the apparent braking. Learning to slowly slip out the clutch on downshifting is very useful on VFR's, as Jason Pridmore used to demonstrate. Those two simple things will make you more pleased than thrashing around with ECU and imbalanced throttle bodies. Just sayin'

The compression happens anyway, but the intake stroke would normally have the butterflies open, so that is a difference. So yes its a compressor, but engine braking can be reduced by opening up the intake tract on the intake stroke and reducing vacuum. There isn't any easy way to open the intake valves during compression since the cam keeps them shut.

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Engine braking is just running an air compressor with the momentum of the bike and mostly unrelated to sucking on the closed throttle butterflies. Keeping a mildly higher idle, like 1500-1800 will take a lot out of the apparent braking. Learning to slowly slip out the clutch on downshifting is very useful on VFR's, as Jason Pridmore used to demonstrate. Those two simple things will make you more pleased than thrashing around with ECU and imbalanced throttle bodies. Just sayin'

Here's a test for you then, which will prove the point that its the throttle being closed causing the issue. Find an empty bit of road, accelerate to which ever speed you choose in whatever gear you choose then close throttle & measure the roll down distance to a low speed or stop. Now repeat the exercise exactly as the first trial, but instead of closing the throttle, just hit the kill switch & leave the throttle open ! You will find the retardation is much reduced & you should roll a lot further.

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Engine braking is just running an air compressor with the momentum of the bike and mostly unrelated to sucking on the closed throttle butterflies. Keeping a mildly higher idle, like 1500-1800 will take a lot out of the apparent braking. Learning to slowly slip out the clutch on downshifting is very useful on VFR's, as Jason Pridmore used to demonstrate. Those two simple things will make you more pleased than thrashing around with ECU and imbalanced throttle bodies. Just sayin'

Here's a test for you then, which will prove the point that its the throttle being closed causing the issue. Find an empty bit of road, accelerate to which ever speed you choose in whatever gear you choose then close throttle & measure the roll down distance to a low speed or stop. Now repeat the exercise exactly as the first trial, but instead of closing the throttle, just hit the kill switch & leave the throttle open ! You will find the retardation is much reduced & you should roll a lot further.

I think it would be an appropriate comparison if he shut the engine off both times, once coasting down with the throttle closed and once with the throttle opened as you suggest.

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Somehow you are feeling the back torque that normally occurs with a v-4. I'm not sure why it affects you so much, but the standard answers are there in throttle management, idle RPM setting, clutch release, and if available, the use of slipper clutches. Reprogramming to reconfigure off-throttle RPM roll back could theoretically retard engine braking. One would have that deceleration rate to live with in all circumstances, so I can imagine it would not suit all downshifting circumstances. The main purpose of downshifting is to be in the best RPM range in the power band to use for acceleration out of the apex in any case. As some wag has said, "The engine is not a brake", although it can become an expensive one.

I have tried killing the motor at speed and rolling throttle open or closed. There is a small perceptible difference in retardation, but not strongly so, not near enough to warrant all the fuss over it as a passive device. Opening a live throttle, on the other hand, has an enormous effect on deceleration. I'd shop there.

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+1 your talking about a lot of money for something you could just change your riding technique .... It's interesting reading and we definitely have some very capable personal .....

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I have heard people say that a V-4 has more low end torque than an inline 4 of the same displacement due to the V-4 firing order. Aren't two cylinders firing at once whereas with in I4 only one fires at once or have I got that wrong? Anyway I agree the VFR is limp in first gear but I thought that was due to gearing.

I recently tested an R1 crossplane, looking for a vfr replacement. It was at the top of the list, it may have more peak power but really I didnt see alot of differnce, except the unstability once the r1 was hard on the throttle though 100 mph(acceleration headshake), but that might be weeded out through suspension adjustment. End result, defrintely not worth giving up the VFR. Lets hope the Cbr is alot better, Im wanting to cop a ride off one of those. Some of these guys should have rode, 80'100's and 125's of the 70's, then they'd have a better idea of what no lowend actually is.

Edited by spud786
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Guest bhawk191

I tend to agree with the guys that suggest adjusting your riding style. It seems the problem is yours alone, therefore, it is caused by you. As for all your tinkering, I called Honda Techline yesterday at work (Im a Honda tech)..They recommend you throw your tools away.

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Guest ohlarikd

I think some of you guys are misunderstanding me. I know I can adjust my riding technique. Its no big deal. I merely asked in the beginning if we could reduce engine braking more to MY liking. I like less engine braking. Is that so horrible? Some of you are quick to pass judgement like I don't know what I am doing. Everyone has preferences in how a bike feels. I like less, you may like it just the way it is. Why is this such a debate?

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I think some of you guys are misunderstanding me. I know I can adjust my riding technique. Its no big deal. I merely asked in the beginning if we could reduce engine braking more to MY liking. I like less engine braking. Is that so horrible? Some of you are quick to pass judgement like I don't know what I am doing. Everyone has preferences in how a bike feels. I like less, you may like it just the way it is. Why is this such a debate?

If I may....... There will always be some that stick to the question and try to come up with a solution....... But, there are the rest that will use a thread to express their thoughts on a subject that may not even be close to the subject(guilty)....... And, once the problem is solved, the thread can keep going on for days, just because it's an interesting subject and no longer related to you, but just the variances of thought which can bring in some fun/dumb/etc. comments.

Of course their are some that might attack you personally(which is not tolerated on this forum), And you handled that one well !

Just remember that all comments are coming from ppl that know what they're talking about, and of course there are also going to be ones that not only don't know what they're talking about, but didn't even bother to read the thread, but just chimed in on one post.

But with most forums, this is one of the highest caliber forums available..... So far we're at 10 pages on how to change engine braking, pretty darn good.

Thx for the thread.

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