De-Snorkle?? - SV650.org

11-05-05, 02:28 AM

I just installed a full Vance and Hines S4 exhaust system and the bike sounds great... i also bought a dynojet jet kit and am planning on rejetting it to get the full performance gain oout of my exhaust.. I am debating on whether or not to just go ahead and de-snorkle the filter before i rejett, but i am skeptical on whether or not it is going to be good for the bike? Any advice on whether or not i should desnorkle it?

by the way, i have a 2000 Sv650 with no other mods except the exhaust.

johnnyrod · 11-05-05, 11:25 AM

Don't bother desnorkelling, as far as I know there is no evidence that it helps. Get a decent filter like BMC/Pipercross/K&N instead then get it set up on a dyno.

northwind · 11-05-05, 10:33 PM

Well, lots of anecdotal evidence that it does work, but AFAIK nobody on here's made it work. My bike's supposed to be going back to the dyno on saturday if my leg's working, and if they have time we're going to copare my Race RS with a desnorkelled stock filter, see how it compares for flow purposes.

11-05-05, 11:26 PM

I de-snorkeled my stock filter before jetting and it ran very lean and made so many vibes I was gonna rent it out to the local convent.
With dynojet kit it in it was better but the vibes were still there. K&N, later version, runs better with stage I dynojet kit than de-snorkeled OE filter...

northwind · 12-05-05, 07:02 PM

It would do, the Stage 1 DJ kit was designed for the original model K&N

Doesn't go anything like big enough for a Race RS or desnorkel. I really want the desnorkel to not work when I try it, simply because I paid money for the BMC

18-02-06, 09:39 AM

My experience of desnorkelling an otherwise stock (engine/exhaust/airbox/filter) SV650 K4.

It's not worth it.

The induction noise is nice and gunning the engine with the clutch in sounds fantastic. The power lower down seems marginally better too.

However, aside from an irritating whistle at around 80-85mph, there is also a noticeable dip in power from around 6.5-7.25K revs. The dip is fairly dramatic and really scuppered my overtaking. Normally I get to about 6K revs, then as I'm about to pull out, wind on the throttle, so I am using the powerband for the duration of the overtake. I also found my fuel economy was a bit worse, because I was riding higher up the rev range, in a lower gear, to avoid the afformentioned dip.

All in all, it was in for 48hrs/200 miles before I removed it.

NB: These comments are specific to my bike which as mentioned, has the standard exhaust, stock airfilter, no tank risers, stock non-remapped ECU, no powercommander, etc. etc.

northwind · 18-02-06, 01:41 PM

Holy old thread Batman!

Since this one, i actually did run with a desnorkelled filter for a while. It's less good than the BMC Race RS- runs slightly rich all over compared to the RS. This is pretty much what I'd expected- it's considerably freeer flowing than the K&N, but not as good as the RS.

Could be a good mod if you're doing it on the cheap and you're happy to do the jetting yourself. Up a notch or half a notch on the needles, and probably DJ160s, 165s or thereabouts with a full system, 150s with a slipon (total, total guesswork!)

18-02-06, 05:30 PM

Quote:

Originally Posted by Ceri JC

It's not worth it.

...there is also a noticeable dip in power from around 6.5-7.25K revs. The dip is fairly dramatic and really scuppered my overtaking. Normally I get to about 6K revs, then as I'm about to pull out, wind on the throttle, so I am using the powerband for the duration of the overtake. I also found my fuel economy was a bit worse, because I was riding higher up the rev range, in a lower gear, to avoid the afformentioned dip.[/size]

I totally agree. I ran with a de-snorkled and had exactly the same experience.
It's not worth it.
Now I'm running a Renegade exhaust, K&N 2nd gen filter and moved the needles one notch. Result; smooth power curve with NO DIP in the middle, more power and economy (if I can resist not reving it to hear the music that is).
They say BMC is better and most racers in the states went for it but my layout works fine and the trottle is super sweet.

northwind · 18-02-06, 07:23 PM

Zunkus, did you rejet to suit the desnorkelled filter? Because it does need it, because if flows so much better than the K&N you cna't get away with stock jets, and you can't tune out the flat spot by adjusting the needles. Mine was already set up for the Race RS, which (on my bike, with a full system) means 175 DJ mains, and the desnorkelled filter worked perfectly adequately.

19-02-06, 06:55 PM

Northwind, what you're saying about rejeting for the increased flow is correct. No I didn't rejet when I de-snorkeled the stock filter. Using K&N filter and moving the needle one stop the throttle response and burn on sparkplugs shows the fueling is right. I could have left the desnorkled filter and increased the jet and most probably would have gained a bit more with that setup but in the real world I don't need more than what I've got. In my mind a good smooth power band all the way is much better than a notchy, peaky one which I was afraid of ending up with. So I'm leaving mine as is. Best not disturb what's working fine. However, your setup makes good sense too.

11-05-05, 02:28 AM	#1
DoctorJ Guest Posts: n/a	De-Snorkle?? I just installed a full Vance and Hines S4 exhaust system and the bike sounds great... i also bought a dynojet jet kit and am planning on rejetting it to get the full performance gain oout of my exhaust.. I am debating on whether or not to just go ahead and de-snorkle the filter before i rejett, but i am skeptical on whether or not it is going to be good for the bike? Any advice on whether or not i should desnorkle it? by the way, i have a 2000 Sv650 with no other mods except the exhaust.

11-05-05, 10:33 PM	#3
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Well, lots of anecdotal evidence that it does work, but AFAIK nobody on here's made it work. My bike's supposed to be going back to the dyno on saturday if my leg's working, and if they have time we're going to copare my Race RS with a desnorkelled stock filter, see how it compares for flow purposes. __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

12-05-05, 07:02 PM	#5
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	It would do, the Stage 1 DJ kit was designed for the original model K&N Doesn't go anything like big enough for a Race RS or desnorkel. I really want the desnorkel to not work when I try it, simply because I paid money for the BMC __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

18-02-06, 01:41 PM	#7
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Holy old thread Batman! Since this one, i actually did run with a desnorkelled filter for a while. It's less good than the BMC Race RS- runs slightly rich all over compared to the RS. This is pretty much what I'd expected- it's considerably freeer flowing than the K&N, but not as good as the RS. Could be a good mod if you're doing it on the cheap and you're happy to do the jetting yourself. Up a notch or half a notch on the needles, and probably DJ160s, 165s or thereabouts with a full system, 150s with a slipon (total, total guesswork!) __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

18-02-06, 07:23 PM	#9
northwind Moderator Mega Poster Join Date: Jan 2004 Location: In the garage where I belong Posts: 17,083	Zunkus, did you rejet to suit the desnorkelled filter? Because it does need it, because if flows so much better than the K&N you cna't get away with stock jets, and you can't tune out the flat spot by adjusting the needles. Mine was already set up for the Race RS, which (on my bike, with a full system) means 175 DJ mains, and the desnorkelled filter worked perfectly adequately. __________________ "We are the angry mob, we read the papers every day We like what we like, we hate what we hate But we're oh so easily swayed"

11-05-05, 11:25 AM	#2
johnnyrod Member Mega Poster Join Date: Jul 2003 Location: Doncaster, oop norf Posts: 2,128	Don't bother desnorkelling, as far as I know there is no evidence that it helps. Get a decent filter like BMC/Pipercross/K&N instead then get it set up on a dyno.

11-05-05, 11:26 PM	#4
BURNER Guest Posts: n/a	I de-snorkeled my stock filter before jetting and it ran very lean and made so many vibes I was gonna rent it out to the local convent. With dynojet kit it in it was better but the vibes were still there. K&N, later version, runs better with stage I dynojet kit than de-snorkeled OE filter...

18-02-06, 09:39 AM	#6
Ceri JC Guest Posts: n/a	My experience of desnorkelling an otherwise stock (engine/exhaust/airbox/filter) SV650 K4. It's not worth it. The induction noise is nice and gunning the engine with the clutch in sounds fantastic. The power lower down seems marginally better too. However, aside from an irritating whistle at around 80-85mph, there is also a noticeable dip in power from around 6.5-7.25K revs. The dip is fairly dramatic and really scuppered my overtaking. Normally I get to about 6K revs, then as I'm about to pull out, wind on the throttle, so I am using the powerband for the duration of the overtake. I also found my fuel economy was a bit worse, because I was riding higher up the rev range, in a lower gear, to avoid the afformentioned dip. All in all, it was in for 48hrs/200 miles before I removed it. NB: These comments are specific to my bike which as mentioned, has the standard exhaust, stock airfilter, no tank risers, stock non-remapped ECU, no powercommander, etc. etc.

19-02-06, 06:55 PM	#10
zunkus Guest Posts: n/a	Northwind, what you're saying about rejeting for the increased flow is correct. No I didn't rejet when I de-snorkeled the stock filter. Using K&N filter and moving the needle one stop the throttle response and burn on sparkplugs shows the fueling is right. I could have left the desnorkled filter and increased the jet and most probably would have gained a bit more with that setup but in the real world I don't need more than what I've got. In my mind a good smooth power band all the way is much better than a notchy, peaky one which I was afraid of ending up with. So I'm leaving mine as is. Best not disturb what's working fine. However, your setup makes good sense too.