[tslewisz]

I just read Venom's post on his 16-toofer and one thing caught my eye: The Muzzy-isms are worse after the gearing change. Seems confusing to me. I'd think lower gearing would tend to mask the irregularities.

I've been spending a lot of time on mapping for rideability lately so it's intriguing to me. My bike is a 2000, full Muzzy (LOUD baffle!), PCIII (the 'r' wasn't available when it was purchased), 17T, BMC Race filters, Bear Stacks, workmann pilot jet mod. I started w/ Cliff Randall's map since I think he devoted a lot of time to rideability issues. Doing the pilot jet mod helped a bunch in the 2500-3000 range, though it didn't help my idle. No biggie. Anyway, from that baseline I began making changes. For example there was a "hunt" @ 4000rpm/40mph. Adding 6% more fuel @ 5% throttle took care of it (Cliff was -24, I'm -18 now). Pretty much got things smoothed out from 2500-3000, too, by adding fuel (or not removing as much, as you prefer) but 2000rpm is still for shit. I wouldn't care except that dyno runs start there. Aside from that, just accellerating normally, it's hardly noticeable.

Anyway, comments about why the gearing affected Venom the way it did, or anything else, are welcome. Thanks.

tsl

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[Venom]

In short lower gearing gives the motor more levrage to turn the wheel. And any problem in power delivery is amplfied Because of it.

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[CrotchRocket]

One good thing about the gearing is that it accelerates through the Muzzyisms faster and doesnt effect low speed riding as much as the stock gearing!!!


CrotchRocket

" I just live my life a 1/4 mile at a time "</p>

 

[Guest]

.

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[Ozzy]

I installed the Cliff Randall map mods, with a full Muzzy system. Here is what I experianced.

Fuel comsumption went way up, lost 20% economy

Idle speed dropped, had to turn the idle adjuster waaaay in .

At elevation 3000'+ the bike ran poorly under 5k

Took out Cliffs mods and the bike ran far better.

Installed Yosh RS-3 Duplex system, now running 0 maps for fuel and ing. Bike has better drivability than it ever did with full Muzzy and any map below 3000 rpms.

Idle speed is set at 1150 on the PC3 screen tach. Has 100-120 rpm surge.

Have a slight flat spot with slooooow throttle roll on from 1200-2000 rpms.

2500 rpms, a small surge when hot at steady cruise under light throttle, 3rd gear mostly.






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[tslewisz]

Thanks, Venom.

zed

When adding a full Muzzy exhaust there are usually rideability issues: The idle has a lope, or surge, and there is a flat spot, or stumble at 2500-3000.

Ozzy

Thanks for input. Haven't checked my mileage lately. Hope I can do it this afternoon! I think there are better choices than Muzzy for a streetbike. I'm not giving up on it yet, though.

tsl

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[Venom]

No doubt muzzy is a great drag pipe but i ride on the street mostly.So these problems drive me nuts. All in all from what i have read on this board over time i think akro is the best choice. Even though its more expencive.

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[Guest]

the big 12 engine puts out a lot of HP
in this technological age we expect much.....
maybe too much......an engine like this on carburetors would be worse

will tell you a few things i've noticed
the 12 has some LONG duration cams
resulting in much overlap

that also will result in lope

those huge throttle bodies will also result in ait being unevenly distrubted in the box causing 2 problems
a narmonic dip & what some describe as hunt
at a particular rpm range the air is unstable....
the sensors cant keep up with the rapid changes

these same symptoms have been present on hi strung
engines with carburetors on bikes & cars...
even when switching over to a yurbo setup.....BIG HP
those flat spots... surges & lopes are still noticable

some aftermarket exhaust systems make it worse in an attempt to gain hp at the very upper reaches
blocking off the clean air....... using the bear stax....
only make it worse
if you are drag racing....it hardly matters
if you are street racing....same situ
if you are road racing.....12's are rarely road raced
the problem is very evident in street riding....
the last few yrs i roadraced some of the fllat slide carbs
really good.... could tune 4 circuits & get it right...
in fact dropping a set of carbs on the big 12 .....
disconnecting everything else..... one might see 10%
increase on the dyno.....has been done with other engines

still that flat spot you would see on the graph
& probably notice riding the bike

case & point the old z-28 with the 302ci engine
optional cams & dual point ignition.....headers
crazy car to drive......kicked much ass bk n the day
.........idled at 3000 to 3500 rpms......
below that pretty weak...... loped.... surged.... etc

part of the problem with the big 12 is not so much the
fuel injection....... mostly the sensors that are set up in
a handshake situation with the other sensors
some members on the site report problems......
others dont.......would tend to lean toward the
many different combos of modifications & then resulting what the sensors are reading & telling the ECU to do

the symptoms are the same we had with carburetors.....
we had to tune around them then....... by the seat of out pants.....sometimes good..... other times much cussing...
big headaches & instant loss of religion

thought i would share what i think i see is an old
problem in a new situation.......
a heads up to some or many on at least where
the best results may come from for all the effort
& headaches







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[ZX12richard]

The surges sounds cool actually.... I have had people ask me if it has a cam...... I say nope has two....<img src=http://www.ezboard.com/intl/aenglish/images/emoticons/laugh.gif ALT=":lol"> ....

If her eyes aren't crossed and one eye lid flapping like a hummingbird wing your not quite there yet...</p>

 

[CrotchRocket]

Ozzy...Cliffs map is set up in Canada!!!...Its cold up there so he runs rich!!!...I cant see it being anygood for anyof us here in the mid U.S. with the humidity!!!


CrotchRocket

" I just live my life a 1/4 mile at a time "</p>

 

[tslewisz]

I guess every bike's different. I put Cliff's map in mine, took it by for a quickie dyno and it was very LEAN! I'm in central Illinois. Bumping the button full rich (amounts to 8% according to the PCIII manual) added 4rwhp and it was still a little lean. I've been concentrating on changes for rideability, but I added 10% more fuel than Cliff's at 100% throttle at upper RPM. (Note to new mappers: Buttons are reset when you load a map.) I'm about due for another dyno...

I know she has BIG cams, BIG injectors, makes BIG HP and goes REALLY fast. I'm just trying to civilize her a little bit!

tsl

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[workman1000]

I have heard a lot said about Cliff Randall's map with the "fix" for the flat spot. If I understand correctly, the "fix" is to add fuel and make it rich to the point where it helps with the stumble/surge. IMHO, its a bad idea. By richening the mixture and running it too rich, maybe it will help with the stumble/surge, but at what cost? The cost is that it will gum up your valves and leave deposits which will eventually affect performance. If you don't believe me, try this. Any of you that have been running too rich at low RPMs in order to try and smooth it out, look inside the airbox. If you take the top off the airbox, you can see directly down inside the throttle bodies all the way down to the tops of the valves. Take a flashlight, open the butterflies on the TBs, and look at the tops of the valves. If you have been running too rich, in all likelyhood, you will see massive deposits sitting on top of your valves. This is bad and it will affect your performance and peak hp numbers. It is a bad idea to make your motor run anything but optimum mixtures in all circumstances. As far as tslewisz running lean of the map, I don't have a clue. Everything I read about Cliff Randall's map said it added copious amouts of fuel trying to "fix" the stumble/surge.


Zed Racer is correct in saying that this is an old problem that is inherent in high performance engines. All we can do is to try to minimize it as much as possible. Also, he was correct in saying it is the result of the input to the sensors. If you want to address the problem, then you need to address the cause. That being the erratic inputs to the sensors, namely the air pressure sensor. First get your fuel right, then do the pilot jet mod. This will all but eliminate the low RPM stumble/surge that everyone experiences with a full header. It also helps a little with the idle, but not as much as with the stumble/surge. What this does is addresses the erratic vacuum signal to the sensor rather than trying to mask the problem by adding too much fuel. A much better way to go about fixing the problem and it won't clog up your valves. The bottom line is this, you want your bike to be running the optimum fuel mixture at all times and under all circumstances. Anything else is couterproductive and can eventually lead to other problems such as valve deposits, fouled plugs, ect. All of this leads to decreased performance and ultimately, a loss of horsepower. Which we all agree is not a good thing.

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[tslewisz]

workman

First, I want to thank you for all the work you put forth that brought us your pilot jet mod. I only hope that some day I can contribute something as significant to the community. Second, I want it to be clear that I agree with what you're saying. The solution should be a "smarter" ECU/sensor arrangement. However, if adding fuel at certain places in the matrix makes the bike run better, I'm probably going to do it, within reason. My feeling is that if it's not running well, by bucking, snorting, and generally being cantankerous, it's hurting itself in the bottom end, transmission, camchain, etc., from all the "snapping" going on. In the case of changes focused on rideability, I'm going with the ass-dyno rather than what any instrumentation says. I might have to pay the piper down the road in shortened plug life, gummy valves, etc., but I'll accept it.

Thanks to everybody who's participating in this thread. I think it's great stuff. This is my first attempt at FI tuning and I appreciate ALL insight, theoretical and empirical. Plus, I only have a little carb tuning experience to fall back on. I'm definitely no expert.

tsl

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[workman1000]

Its actually probably good that you don't have much carb tuning experience because everything you know about carb tuning doesn't apply to FI. What is true for carbs can sometimes be just the opposite for FI.

That being said, I still think it is vitally important to get the right air/fuel ratio in all circumstances. I bought my Yosh RC3 race exhaust from someone who had the same problems. Low RPM drivibility issues, bucking, snorting, jecking around at low RPMs, and general shitty performance at low RPMs. He got frustrated with it and went in another direction. I put it on my bike and with a little tuning, it runs unbelievably well. My only issue is a slight bit of idle hunt when cold and that goes away as soon as the bike warms up sufficiently. But I absolutely don't have any of the low RPM drivibility issues that someone else had with the same exact pipe. A correct map is vitally important, I can't stress this enough. You usually can't rely on a supplied map to get it right. It takes dyno tuning and/or O2 sensors, EGT sensors to get it right. It is more expensive and time consuming to do it this way but it is the ONLY way to get it right. Running too rich is a vicious cycle. It may help a little temporarily but then as it leaves deposits on your valves and fouls out your plugs, and eventually, your drivibility issues will get worse. It is the inevitable conclusion if you run it rich. Just out of curiosity, EXACTLY which pipe are you using and what year is the bike? Also, which map are you using and where did you get it from?

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[tslewisz]

My pipe is a full Muzzy stainless w/ round, polished aluminum can. The previous owner said it has the "competition" baffle, but I find no such nomenclature on Muzzy's website. It IS fuggin' LOUD, though! The map I started with is from easy's site and is referred to as "Updated Cliff Randall 1270 Muzzy PCIIIr Map". I'm using a PCIII (not 'r') and no advancer. The bike is a (faster red) 2000, and, reiterating, has BMC Race filters and Bear stacks, which I'm sure do nothing to improve things on the low end. <img src=http://www.ezboard.com/intl/aenglish/images/emoticons/wink.gif ALT="">

tsl

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[VOZ]

i have a 02' with wrapped Muzzy full Ti system...and nothing else done.. I'm running the so called Muzzy "race" map..runs ok .. but the low end {approx 2-3 rpms} stuff still bothers .... Any suggestions.. I can work the DG software to a point.. I will be getting BMC filters non-race {whats the difference} and Muzzy block off plates .. before i take it to a shop for a custom map.. I was going to spend money on undertail and such to make it look good...but i rather it run GReAT!.. Hey WORKMAN dont ya wanna take a trip to NC and hook a brother up?....

Voz...

http://www.pbase.com/vozizm/zx12r</p>

 

[tslewisz]

BMC's race filters flow more air, 15% methinks, but require more diligent maintenance.

tsl

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[VOZ]

what about K&N's....

Voz...

http://www.pbase.com/vozizm/zx12r</p>

 

[tslewisz]

I've always used K&N's on all my vehicles, when I could, except the 12. There's been a lot of discussion on them on this forum. The concensus seemed to be that K&N's didn't offer any performance improvement over stock, and there is a mod that can be done to the stocker to make it flow more. Plus, their fit seemed to be rather poor, causing difficulty installing them. Their availability has been spotty, too.

tsl

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[workman1000]

Muzzy puts out a map specifically for the '00-'01 models and a different one for the '02 model. That is the map I would use as a starting point. Like I said, a starting point. Then with the use of some kind of tuning device, whether it be a dyno or an O2 sensor, fine tune the map to perfection based on the air/fuel mixture. If you get the air/fuel mixture right, then this will take care or 90% of the drivibility issues. Then the pilot jet mod will smooth out the low RPM stumble/surge almost completely.

Any map that you get that hasn't been specifically tuned to your bike(year model, pipe, fiters), is worthless. It could make the bike run worse than with no map at all. Different pipes, even the same pipe with a different baffle, with need completely different maps. And different years('01 compared to '02) will need completely different maps as well. The factory mapping is different for the different years on the same bike. Little things like filters even make a big difference.

If you hooked up an O2 sensor or did a dyno run, you might be shocked at how far off the air/fuel is a some points. And very small differences in pipes and baffles can make a HUGE difference. I will get the maps from Muzzy and post them. They have a different one for the earlier models and the later models. I believe they even have a different pipe for the earlier models compared to the later models. Look for a part number somewhere on the pipe, this is important. I see what I can find.

And BTW, I will be near NC sometime soon. After a trip to South Florida later this month, I plan on making a trip up to the area near Deals Gap sometime in October. I'll see what I can find for a map and post it later today.

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