YZF
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posted February 19, 2009 09:32 AM
 Edited By: YZF on 19 Feb 2009 17:32
Question to kbryant and other dyno operators
When you tune bike on dyno, do you try to set AF ratio to the same fixed number (e.g. 14.7:1) over the whole powerband, or there is also times when you set different AF ratios at different rpm ranges? E.g. from 3k rpm to 6k rpm more rich and later more lean or whatever... ?
Thanks for reply
  
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K Bryant
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posted February 19, 2009 04:57 PM
Edited By: K Bryant on 20 Feb 2009 01:06
It really depends on so many things. A reasonable statement would be that whatever the target goal of A/F is for a given tuning session, the goal would commonly be to have as flat a graph as possible. But yes, there have been cases I've made minor adjustments during certain parts of the rpm or throttle position depending on what we are trying to accomplish. But every tuner may have a different opinion and that's what makes tuning so challenging.
Since I'm on a short "Red Bull" break ..... To expand on that -
It is not uncommon to deviate on A/F numbers , depending on what the project is. Are we tuning for this area? Street or Track? This throttle position or this rpm? This altitude/humidity? Engine stock or modified? Is it on squeeze or blown? Safe tune/max tune? MPG or Top End? This fuel/that fuel? You set the agenda for a given session, and try to attain and keep that goal at that particular moment in time, on that particular vehicle. It can vary greatly. That's why the best tune is always a custom tune by an experienced tuner (not necessarily the same as a dyno operator). Tuning is all about having a certain amount of base logic or understanding, then making adjustments from there. The best tuners are tweakers (no pun intended  ) who aren't affraid to experiment; and unfortunetly sometimes compromise. At times, that's all tuning is about; compromise! Some of the best "dyno tunes" on the dyno, do not directly correlate to best performance on the track (or street). It's simply another tool. A great tool though! 
With my background being more related to roadracing, I''ve had some absolutely killer dyno sessions with power numbers and maps that make your eyes bleed. But once the rider gets on it, on the race track, he may very well ruin your "god complex" with their feedback. Of course we can always lay the blame on the tires, suspension, the girl friend, etc... Though it's simple to say , it can be very hard to attain what we call "direck link" (throttle input to rear wheel). That's what most riders want. Whether they fully understand the concept, is a constant "tuning session" in itself.... So.... is the best tune actually a system that is always in an ever changing state of "auto-tune"?
Opinions from those that seek that one less tenth in the quarter mile, or one extra mph at Bonneville are always welcome.
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Johnnycheese
Pro
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posted February 19, 2009 07:48 PM
you give the motor what it want and forget target numbers
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fish_antlers
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posted February 19, 2009 07:51 PM
like what if it want wimen?
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What business is it of yours where I'm from, Friendo?
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fish_antlers
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posted February 19, 2009 07:51 PM
Edited By: fish_antlers on 20 Feb 2009 03:52
okay... that was a joke... I'll go stand i the corner now
sorry 
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What business is it of yours where I'm from, Friendo?
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smokehouse4444
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posted February 19, 2009 08:49 PM
LOL 
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thekaz
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posted February 19, 2009 08:54 PM
quote:
like what if it want wimen?
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YZF
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posted February 20, 2009 12:05 AM
Edited By: YZF on 20 Feb 2009 08:09
quote:
It really depends on so many things. A reasonable statement would be that whatever the target goal of A/F is for a given tuning session, the goal would commonly be to have as flat a graph as possible. But yes, there have been cases I've made minor adjustments during certain parts of the rpm or throttle position depending on what we are trying to accomplish. But every tuner may have a different opinion and that's what makes tuning so challenging.
Since I'm on a short "Red Bull" break ..... To expand on that -
It is not uncommon to deviate on A/F numbers , depending on what the project is. Are we tuning for this area? Street or Track? This throttle position or this rpm? This altitude/humidity? Engine stock or modified? Is it on squeeze or blown? Safe tune/max tune? MPG or Top End? This fuel/that fuel? You set the agenda for a given session, and try to attain and keep that goal at that particular moment in time, on that particular vehicle. It can vary greatly. That's why the best tune is always a custom tune by an experienced tuner (not necessarily the same as a dyno operator). Tuning is all about having a certain amount of base logic or understanding, then making adjustments from there. The best tuners are tweakers (no pun intended ) who aren't affraid to experiment; and unfortunetly sometimes compromise. At times, that's all tuning is about; compromise! Some of the best "dyno tunes" on the dyno, do not directly correlate to best performance on the track (or street). It's simply another tool. A great tool though!
With my background being more related to roadracing, I''ve had some absolutely killer dyno sessions with power numbers and maps that make your eyes bleed. But once the rider gets on it, on the race track, he may very well ruin your "god complex" with their feedback. Of course we can always lay the blame on the tires, suspension, the girl friend, etc... Though it's simple to say , it can be very hard to attain what we call "direck link" (throttle input to rear wheel). That's what most riders want. Whether they fully understand the concept, is a constant "tuning session" in itself.... So.... is the best tune actually a system that is always in an ever changing state of "auto-tune"?
Opinions from those that seek that one less tenth in the quarter mile, or one extra mph at Bonneville are always welcome.
Thanks for reply. I understand about different goals and needs and what you as tuner want to achieve, etc... but gerenally, is it "safe" to change AF ratio in the rpm range, as rule of thumb?
If you make lets say 13:1 from 2k to 13k and then you see that somewhere in the middle there are some dips, how you try to make them flat?
I was just wondering, in theory, if constant af ratio over the whole rpm range is the "best safe" thing to have, or if it is common practice to make af ratio changes somewhere in the middle inorder to smooth power curve.
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BobC
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posted February 20, 2009 02:00 AM
There's more to dyno mapping than getting a constant A/F ratio across the board. We noticed on my ZX-14 that peak power could be raised a little by leaning off the mixture a bit. It depends on your application whether that's the way to go. If the motor spends a lot of time at max rpm the life could be shortened. There was also quite a lot of work done to the map between 3 and 4 thousand rpm to get the best power curve after removing the secondary butterflies. Eventually we found another 10bhp at 3,500.
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K Bryant
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posted February 20, 2009 09:35 AM
YZF - I'm not sure what you mean by "safe" ? At your example of 13:1, we're not talking about numbers that would be "un-safe". The "theory" is if you have a "safe" A/F number across the board, then all things being equal, it would be safe. Of course it's common practice to make A/F changes somewhere/anywhere in order to smooth the power curve. When tuning, "safe and smooth" don't necessarily go hand in hand.....
As BobC points out, there is much more to mapping than getting a constant A/F ratio. Even after all these years of dyno testing & tuning, I'm still constantly amazed at what a small change or adjustment can do, that makes a significant difference. When you are close, and really starting to zone in to your target area, and are suddenly rewarded with one more hp or smoothing out a little blip, man is it satisfying. As indicated, it can be a compromise as well, depending on where your motor is going to spend most of its time.
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YZF
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posted February 20, 2009 11:12 AM
Edited By: YZF on 20 Feb 2009 19:15
By safe I mean - motor lasts longer with that particular adjustment. I am asking, because we have a local dyno tuner here and i noticed in various different graphs (before and after), that all they do is change stock "bad" af ratio line into constant 13:1 over the whole rpm range. Well, at least thats seems to be so, because different bikes have different stock AF curves and they just smooth AF ratio to 13:1 in all their dyno sheets over the whole rpm range.
So i was wondering if they just "set ratio to 13:1, job done, take money, see you" or is it the way it should be done, even if after such adjustments HP line becomes even more unsmooth.....
P.S. Their target, almost always, is for non-racing riding (street, highway, etc). For "normal guys" not racers.
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2000redrocket
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posted February 20, 2009 01:09 PM
i found out that for real street riding and 1/4 mi twards 13.0 to 1 is better than 13.5 to 13.7 to 1. but the leaner will dyno higher numbers. but leaner will not work as well wide open under load racing.
for me having the bike at 14.0 to 13.7 under 4200 rpms is what i tuned my ecu for. i now get 39 mpg om my zx12 with 1 down in front gearing and muzzy pipe normal riding.
i guess what type of dyno you go to can depend what you are able to tune for.
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K Bryant
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posted February 20, 2009 02:33 PM
quote:
By safe I mean - motor lasts longer with that particular adjustment. I am asking, because we have a local dyno tuner here and i noticed in various different graphs (before and after), that all they do is change stock "bad" af ratio line into constant 13:1 over the whole rpm range. Well, at least thats seems to be so, because different bikes have different stock AF curves and they just smooth AF ratio to 13:1 in all their dyno sheets over the whole rpm range.
So i was wondering if they just "set ratio to 13:1, job done, take money, see you" or is it the way it should be done, even if after such adjustments HP line becomes even more unsmooth.....
P.S. Their target, almost always, is for non-racing riding (street, highway, etc). For "normal guys" not racers.
I don't think I would go so far as to say they are doing anything wrong or bad at all. For "normal guys not racers", that probably works fine. I don't set every bike at 13:1. But tuners will have different thoughts on this.
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Bad in Black
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posted February 21, 2009 02:25 AM
Kerry thanks for taking the time to respond and share a bit of your knowledge with us 
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YZF
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Posts: 144
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posted February 21, 2009 03:19 AM
quote:
quote:
By safe I mean - motor lasts longer with that particular adjustment. I am asking, because we have a local dyno tuner here and i noticed in various different graphs (before and after), that all they do is change stock "bad" af ratio line into constant 13:1 over the whole rpm range. Well, at least thats seems to be so, because different bikes have different stock AF curves and they just smooth AF ratio to 13:1 in all their dyno sheets over the whole rpm range.
So i was wondering if they just "set ratio to 13:1, job done, take money, see you" or is it the way it should be done, even if after such adjustments HP line becomes even more unsmooth.....
P.S. Their target, almost always, is for non-racing riding (street, highway, etc). For "normal guys" not racers.
I don't think I would go so far as to say they are doing anything wrong or bad at all. For "normal guys not racers", that probably works fine. I don't set every bike at 13:1. But tuners will have different thoughts on this.
Yes, i bielieve that they do nothing wrong, I was just curious to see one of their graphs when after such another "flat af ratio", power curves and dips were bigger than before.... so i thought "why they didn't add or remove fuel in those dips" but it seems that they just set constant af ratio (13:1, 14:1, whatever) and don't change it in the middle of rpm range because as they say "changing af ratio in the middle is bad" ... :/
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Johnnycheese
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posted February 21, 2009 05:30 AM
just remember this..........
you are looking at WOT.
A real tuner can do more with other than the WOT pull you are looking at.
and like I said before you give a motor what it wants not some magic number.
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oncourse
Expert Class
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posted February 21, 2009 08:28 AM
I have read this whole thread and have learned from it. The pc3 is not the ultimate solution, as mentioned before, it is a piggy back system that is based on throttle position. In no way can it "totally do what the motor wants at any given instant" it is a cheap compromise, but does have it's advantages.
Since modern bikes (still lagging in electronic technology compared to cars) use map sensors to sense loads compared to a lot of cars which use Maf (air volume) and o2 sensors we are somewhat limited as to what can be done in the aftermarket world as we know it now.
I do not know how the pc5 actually works, except for the fact that it does use wideband o2, there were some cars in the late 80's early 90's that relied heavily on o2 input in closed loop. I do like the fact that the pc5 is self mapping, but do not know what it is based on also, and YES ignition timing does play into the whole equasion.
Truly the real KEY to the ultimate performance is a custom program for the ecu, though I do wish it had input from an o2 sensor, we can live with map vs maf, it has been done succesfully for a long time but feedback would be nice.
The ultimate solution "Use obd II, just like cars, make the computer flashable (eprom) so that custom maps can be easily flashed into the ecu". Heck I can do it with my truck, why can't I do it with my bike??
There are, in my belief, tremenous gains to be had, real world gains in proper fuel and ignition management, probably more than any exhaust system could ever deliver, though it would help.
Just my .02
Rob
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fish_antlers
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posted February 21, 2009 08:33 AM
I was also going to ask about the PC5... I have a bunch of info on it from the dealer show.. wondering if anyone here has tried it?
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What business is it of yours where I'm from, Friendo?
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SteveWFL
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posted February 22, 2009 06:57 PM
quote:
I was also going to ask about the PC5... I have a bunch of info on it from the dealer show.. wondering if anyone here has tried it?
I'd like to see a comparison of the PC5 against the Bazazz, I can't seem to find one anywhere
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billeason
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posted February 22, 2009 08:12 PM
Im working on it now,but only on the dyno. Its 20 degrees plus40 mph NW winds here in the mid atlantic and no tracks are open until next weekend weather permitting. As Oncourse stated above there is no self tuning with these bikes,not in the true since. There has to be a target a/f programed or by riding the bike and letting the box guess at how you will be riding with some perimeters being monitered tps.iac,map and 02. I still get by with the wb and lcd harnessed to the pc. Its the easiest way i found to tune for 1/4 passes anyway. Its just as accurite has any of the piggy backs and until we get the smart stuff maf truely closed loop tuneable ecu's its really just what you like to play with when it comes to which is better...........Bill
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bill eason
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