Help double check my Snorkel/Shim/Slipon logic

[BRad704]

So I did a GSXR muffler on my Ninjette, basically making it a high-flow slipon.

From reading here, I should have needed to shim needles when doing a slip-on, and that would result in better low-mid torque due to more fuel in those intervals.

Now, suppose I had already done the exhaust and shimming, and then removed the snorkel. I am having a hell of a time understanding what effect the snorkel removal would have on this system. I think I would benefit by adding 1 more washer, because now I have more air IN and more air OUT and need even more fuel down low.

Should I shim more? Would I remove the shims? Do I just ride it and forget about all this?

I've already done all 3 btw.

[choneofakind]

You'd have to test ride it to be sure. Likely you'd end up with either 2 or 3 shims, but only you will know for certain which works best because you're the one who rides the bike.

[Lychee]

What is your butt dyno telling you about how it is running?
Every engine is slightly different. Listen to what your bike is telling you. No internet formula will be exactly correct for every ride.

Originally Posted by BRad704

So I did a GSXR muffler on my Ninjette, basically making it a high-flow slipon.

From reading here, I should have needed to shim needles when doing a slip-on, and that would result in better low-mid torque due to more fuel in those intervals.

Now, suppose I had already done the exhaust and shimming, and then removed the snorkel. I am having a hell of a time understanding what effect the snorkel removal would have on this system. I think I would benefit by adding 1 more washer, because now I have more air IN and more air OUT and need even more fuel down low.

Should I shim more? Would I remove the shims? Do I just ride it and forget about all this?

I've already done all 3 btw.

[BRad704]

Yeah, I know each is different, but the net effect of each operation should be the same... either making the bike more lean or more rich. I guess that's what I'm looking for help with.

Slip on => make the bike more Rich or Lean? (in theory)
Shimming => Allows more fuel at lower RPM before WOT
Snorkel Out => Allows more air IN, so it makes the bike more lean?

I currently have 2 shims (#4 metal washers from Lowe's) on each carb.
Still have some popping when closing the throttle, I'm hoping all this will eliminate that too...

[choneofakind]

Slip-on = flows more = leaner
snorkel delete = flows more = leaner
shimming = more fuel in mid-throttle openings = richer


If you have not removed the Kleen-air system, that is more than likely the cause of your popping. From my experience, if your needles are so low that the exhaust cracks and pops, you'll notice it from the lean performance (surging) before you notice cracking and popping. Only time I've been able to reproduce cracks and pops was when i had 1 washer with stock mains and required 3 washers with a size larger main.

[BRad704]

Originally Posted by choneofakind

Slip-on = flows more = leaner
snorkel delete = flows more = leaner
shimming = more fuel in mid-throttle openings = richer

Thanks Chris. That's exactly what I needed to see in writing.

[choneofakind]

NP Brad, I also edited that post when I re-read yours and saw that you had popping.

[BRad704]

Originally Posted by choneofakind

NP Brad, I also edited that post when I re-read yours and saw that you had popping.

I was just reading up on some racing forums about the popping and it seems like it could also be related to a retarded-ingition timing and some unburnt fuel in the cylinder when the exhaust value opens.

That sounds right, because it ONLY started with the much-less-restrictive exhaust. Without doing a full tune, I think the only thing I could do to help is to make an obstructive plate on the muffler entrance to increase some back pressure. I've already added in a mesh & fiberglass baffle.

[Lychee]

Originally Posted by BRad704

I was just reading up on some racing forums about the popping and it seems like it could also be related to a retarded-ingition timing and some unburnt fuel in the cylinder when the exhaust value opens.

That sounds right, because it ONLY started with the much-less-restrictive exhaust. Without doing a full tune, I think the only thing I could do to help is to make an obstructive plate on the muffler entrance to increase some back pressure. I've already added in a mesh & fiberglass baffle.

Sounds like that would cause a backfire... much louder than a "pop"

[BRad704]

Originally Posted by Lychee

Sounds like that would cause a backfire... much louder than a "pop"

I'd have to set up a camera and ride past it to really capture the sound. To me, it is popping/crackling. Not just one big backfire...

[DaBlue1]

Originally Posted by BRad704

I was just reading up on some racing forums about the popping and it seems like it could also be related to a retarded-ingition timing and some unburnt fuel in the cylinder when the exhaust value opens.

That sounds right, because it ONLY started with the much-less-restrictive exhaust. Without doing a full tune, I think the only thing I could do to help is to make an obstructive plate on the muffler entrance to increase some back pressure. I've already added in a mesh & fiberglass baffle.

Yours is not a timing issue. The popping on decel comes when you quickly and completely close the throttle, doing so causes a lean condition. Ease the throttle closed.

One reason you hear it (crackling & popping) so well is because you have an empty / hollow tin can instead of a heavily baffled steel drum. The popping noise can be reduced by doing the kleen air delete mod (which you already know about), which stops the extra air entering into the already lean and hot exhaust or installing a baffle made for the slip-on.

The kleen air system is used to help pass EPA requirements. It adds a tiny amount of fresh air to the exhaust manifold so the exhaust gas does not appear to be to rich and contain too many contaminants. The system is designed to clean up the exhaust gases. Sort of a way to trick the system, but it also makes noise.

Believe it or not, there's popping that goes on in most stock exhaust, you just can't hear it.

[BRad704]

Well I'll be... thanks Blue. I have noticed that I can give just a tiny bit of throttle and it quits, and also doesn't do it when downshifting sans-clutch. All of that lines up with what you've said.

[Lychee]

Originally Posted by DaBlue1

Believe it or not, there's popping that goes on in most stock exhaust, you just can't hear it.

but if a tree falls no one can hear it... did it really occur???

[DaBlue1]

Originally Posted by Lychee

but if a tree falls no one can hear it... did it really occur???

Chances are it did, the noise was probably drowned out by human activity, wind noise or engine buzz.

[choneofakind]

I can always count on Blue to back me up

[BRad704]

Originally Posted by DaBlue1

Chances are it did, the noise was probably drowned out by human activity, wind noise or engine buzz.

The NSA still heard it...

[DaBlue1]

Originally Posted by BRad704

The NSA still heard it...

China did too.

[BRad704]

Should we be having this conversation?

[DaBlue1]

Should be good as long as you don't use terms like terrorist, bomb, Iran, Taliban, Al-Qaeda, Airplane, WTC, martyr, Boston, D.C., July 4th or U.S. plot. You know the same terminology the MSM uses.

Also never say Independent. You'll have a bunch of asses and elephants at your door within hours

[BRad704]

Libertarian?

I saw a list of "codewords" that were supposedly used to narrow down "questionable" conversations. It was everything from Bomb and Terrorist, to cloud or flight.

[BRad704]

Butt Dyno has approved my current setup of exhaust, no snorkel and 2 washers per carb.

[DaBlue1]

Originally Posted by BRad704

Libertarian?

I saw a list of "codewords" that were supposedly used to narrow down "questionable" conversations. It was everything from Bomb and Terrorist, to cloud or flight.

Hush yo mouf! Dis herr is a motorcycle forum. All we talks bout herr iz detunation, spark, fire, gas, kerosene and combustion. Gone way from herr wit all dat crazy talk. You know dem NSA folks is on herrr.

[dino74]

Originally Posted by DaBlue1

The kleen air system is used to help pass EPA requirements. It adds a tiny amount of fresh air to the exhaust manifold so the exhaust gas does not appear to be to rich and contain too many contaminants. The system is designed to clean up the exhaust gases. Sort of a way to trick the system

Its more to aid to the exhaust emission system, than to dilute the exhaust emissions.

https://en.wikipedia.org/wiki/Secondary_air_injection

[choneofakind]

If the butt-dyno is happy, I think it's time to declare this experiment a success!

[Lychee]

Independant!Independant!Independant!Independant!Independant!Independant!Independ ant!Independant!Independant!Independant!Independant!