KZScott
Needs a life
high on speed
Posts: 7235
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posted August 01, 2008 02:07 PM
Excellent information Marc. thank you
I was aware that advanced or retarded ignition timing affected AFR, but thats about it. no idea how much. is there a general rule for this type of thing? advancing shows up leaner and retarded shows richer correct? i guess im asking if a set amount of degrees will show a set amount of AFR change?
thx, this stuff is great! 
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01 ZX-12R 8.84 @ 156.3 no bars, DOT tires. Pump Gas, NA.... turbo 8.47 @ 164.
00 ZX-12R 8.62 @ 165.2 no bars, slicks, Pump Gas, 55 shot.... turbo 8.32 @173
00 ZX-12R Fastest NA Kawasaki in the world 1: 222.046 1.5: 226.390 Loring AFB
00 ZX-12R street turbo 1: 227.9 1.5: 234.1 Loring AFB
00 ZX-12R LSR turbo 1: 263.1 1.5: 266.5 Loring AFB Worlds fastest ZX-12R
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TRNorBRN6001
Needs a job
Posts: 2021
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posted August 01, 2008 03:35 PM
I think that would be CO2 gas.
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TRNorBRN6001
Needs a job
Posts: 2021
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posted August 01, 2008 03:38 PM
Most of the dyno guys I have been around (but I have not been around many) don't tune to a specific AF, but tune to the customers driving/racing perameters, while trying to extract the best smoothness and most power. There is no doubt that there are advantages to having extra gasses available to tune with and the lower Inertia drum. However, I believe so much more rests on the operators shoulders.
Just my idiots two cents again.
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marc salvisberg
Parking Attendant
Posts: 21
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posted August 01, 2008 04:34 PM
quote:
Excellent information Marc. thank you
I was aware that advanced or retarded ignition timing affected AFR, but thats about it. no idea how much. is there a general rule for this type of thing? advancing shows up leaner and retarded shows richer correct? i guess im asking if a set amount of degrees will show a set amount of AFR change?
thx, this stuff is great!
Thanks!
If the fueling is already "best" - Retarded timing leaves extra O2 and less CO2.
There wasn't enough heat or time to join the O2 to the CO2, before the exhaust valve opened.
On the other hand, changing the ignition timing will slightly change the "right" amount of fuel required (again) for best power.
And - there will always be exceptions on different engines - That's why the default tuning method is always "Best Power (under load, as opposed to sweep).
M
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Marc Salvisberg
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TRNorBRN6001
Needs a job
Posts: 2021
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posted August 01, 2008 06:31 PM
The couple of (Non-FP) people I know do both constant load and sweeps for tuning. From what I have seen the majority of "constant load/steady state type" tuning was used for street, cruiser, V-twin, road race applications with a comparatively small percent of sweep tuning. The drag bikes were load tuned similarly, but with a slightly higher percentage of sweep type tuning.
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tcchin
Zone Head
Posts: 867
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posted August 02, 2008 08:15 PM
I've never seen a non-FP dyno used to do step tests, and I don't know how you tune for smoothness with a high-inertia drum and heavy smoothing filters.
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TRNorBRN6001
Needs a job
Posts: 2021
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posted August 03, 2008 12:01 PM
 Edited By: TRNorBRN6001 on 3 Aug 2008 13:05
Unfortunately that's probably true. Most probably tune to a specific AF, down load a map, or just use the power link, instead of seeing what the motor needs. An electro magnet is used for the constant load/steady type state tuning. I believe it may even be very similar to the load system used on the FP Dynos.
I'll assume most tuners will tune for more than just 100% throttle (sweep type), with that said how else would a Non-FP tuner tune different throttle openings and positions? For example: a Harley cruising at 60-70mph at a low percentage of throttle, would be tuned by using a constant load/steady type state tuning instead of open throttle sweep type.
As far as smoothness, there are no doubt many degrees of smoothness. My smoothness may be very different from yours, I do not know. I am not familiar with every aspect of the way Factory Pro Dyno operators tune. I would bet though, not every FP operator would get the exact same tune on a bike as compared to another Factory Pro operator. With that said (and I could be very wrong with this next point as well), but I do not think every bike that goes to a Factory Pro Dyno has each individual cylinder sniffed and tuned/mapped....so in that some smoothness may have actually been lost as well. Back in the old days a guy would ride the bike on the road and use his 5 senses to tune a bike, it is amazing how smooth they were able to get those bikes. It is also very amazing how those (usually) older people are able to listen to a bike and tell you what and where it is out of tune as it is running down the track. Truly an art most modern dyno operators have lost.
My disclaimer: Ultimately whether Factory Pro or Non-Factory Pro dynos are tools for tuning and not for HP bragging rights. As I said before there are advantages to reading extra gasses and having a low inertia drum. I still believe the operator is the most important factor in the equation!
With all that said I guess I have been spoiled in that the Non-FP Dyno guy does load/step type tuning, and gets that bike running real smooth without a low inertia drum or heavy smoothing filters.........................plus, he just does it on the side as a hobby!
Just an idiots extra two cents,
Gary
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