rtbain
Expert Class
old, fat and slow
Posts: 244
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posted August 07, 2010 05:10 AM
Airspeed vs. ground speed
Aircraft: 1:1 if direct rear vector
If you are traveling in a hot air balloon that has no drag (theoretical) your air speed will be zero. Your ground speed will be equal to wind speed at that altitude.
Land vehicles that have hit the aerodynamic wall:
With direct rear vector not an exact correlation, but it will help.
The problem is one of how you are traveling through the air. When directly connected to the ground by the vehicle things like friction, gearing and max attainable RPM come into play negating a direct 1:1 correlation.
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Randy
   
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Shane661
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posted August 07, 2010 06:15 AM
 Edited By: Shane661 on 7 Aug 2010 17:57
quote:
Snane , look at the run log form loring last year , sorted by speed
your run on saturday was 197.001..... a few mph faster than you have ever run at maxon. And sunday magically you ran 211.... 14 mph faster .... and the with a tailwind that was very close to that ...
i went 187.4 on saturday and 202.8 on sunday .... 15.4 mph faster
ali went 220 on saturday and 229 on sunday ... only 9mph faster
greg neal went 179 on saturday and 190 on sunday ... 11 mph faster
looks like records were set with 9- 15 mph tail winds..... or maybe we should conclude that big riders benefit more ?
Roy
Roy, did you not see the part where I missed 3 shifts and there was a head/crosswind on my Saturday pass?
Saturday's angular head/crosswinds were gusting as high as 13 mph. In addition, the tailwinds were gusting as high as 29 mph on Sunday. Compared to normal conditions it was close to the weather that landed Dorothy in OZ. Not just a 9-15 mph steady wind as you imply.
When you pick and choose your data, it is easy to land at the conclusions that you want. As I said before, you have to look at all of the data to draw a clear conclusion. I think it has been fairly clearly stated in this thread that there are several reasons why you will not see the theoretical 1:1 benefit.
Aside from that, several people have provided real-world examples, explanation, and opinion based on years of actual racing experience. None of them seem to be supporting a 1:1 correlation on a land-based vehicle.
All that aside, we can probably put this to rest now...if we can agree to disagree. 
Shane
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Shane661
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posted August 07, 2010 06:41 AM
Edited By: Shane661 on 7 Aug 2010 15:10
Massive threadjack aside, I do have a quesiton for Jim regarding his 14:
Do you think it will turn a wheel again this season??
I'm sure we are all anxious to see where this project is headed!
Shane
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Phantom13
Zone Head
Posts: 736
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posted August 07, 2010 07:27 AM
Wow, way too much BS being thrown on the floor and I don't have my boots on.
Jim, Doug, Roy..... Good luck with that theory, I hope you all continue getting this magical 1:1 gain.
P.S.- I DARE any of you to ask this question on suzuki hayabusa.org or landracing.com... I bet it goes nuclear. Better yet, maybe someone should bring them here by posting a link and asking for input from the entire LSR community.
Maybe then we can get to the bottom of all this?
Sound good?
____________
"The only place Success comes
before Work is inside the Dictionary."
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Phantom13
Zone Head
Posts: 736
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posted August 07, 2010 07:50 AM
Oh and while we have the attention of the entire class, perhaps Jim and Doug would like to discuss their other theories like,
- big bore stroker engines do not produce any more heat riding around town than a stock bike.
Or my personal favorite...
- Doug's claim that there's NO tire slippage at 200mph. (Remember the 199mph Muzzy 12 run thread where you said that?)
This way we can add even more credibility to their theory.
$5 says this thread gets deleted or locked by Karl.
Any takers?
____________
"The only place Success comes
before Work is inside the Dictionary."
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CraigChrist
Pro
BAWLS
Posts: 1043
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posted August 07, 2010 08:07 AM
how about you focus more on that 2x2 build that everyone is so excited to see the results of (this time around) and less on being a complete douche? That would probably work out a lot better for everyone.
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60ft-------1.42
1/8th------5.97
mph-------119
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Phantom13
Zone Head
Posts: 736
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posted August 07, 2010 08:28 AM
The 2x2 build is in the oven, its not my fault the first build owner wanted to keep it hush hush.
As for the douche comment. Since when did trying to get the facts straight become a complete douche move?
This is about giving due CREDIT to EVERYONE in LSR for their speeds. By saying you get a 1:1 gain, it makes everyone look slower than they really are... But makes Jim look faster.
Look who's defending Jim... TFA and nobody else.
Let's see how people OUTSIDE of Jim's personal interests feel about the issue. Is that really a douche move or do you think it's for the benefit of everyone reading to know the TRUTH?
If you raced LSR, you too would be offended by someone propping up their performance by playing down those of EVERYONE ELSE.
THAT my friend is what I consider a complete douche move.
____________
"The only place Success comes
before Work is inside the Dictionary."
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dougmeyer
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posted August 07, 2010 11:07 AM
Edited By: dougmeyer on 7 Aug 2010 19:21
Somehow I knew this was going to head in this direction. first of all this isn't a "theory". This is all settled science, easily provable physics. It is the way the world works. Consider the following without regard to the comments in my previous post referring to bank angle and effective tire diameter. These are real effects but what we're talking about is the pure effects of the wind.
First "tail wind", Crosswind", and "headwind" needs definition. Many of the statements being thrown around do not differentiate between a direct wind component and some other force. If the head or tail wind is constant and its direction aligns EXACTLY with the heading of a bike that has stopped accelerating due to the balance of power and the opposing drag, the effect is going to be very nearly 1:1. This is obviously because a given power will be required to overcome a given aero drag and the drag force is the result of the velocity of the air against the bike (airspeed). The bike will attain a specific speed over the ground when the balance of power required matches the force against the bike. Reduce the drag force 5% with a tail wind and the GROUND SPEED where the balance occurs is 5% higher at the same maximum airspeed as before the change. The same occurs with a head wind. Now look at a crosswind, let's say a 10mph wind. Start with this as a direct tailwind and you have 10 mph on the tail, and for every degree you move this wind, around to a 90 deg crosswind, you reduce the tailwind "component" and increase the side (cross)wind component until, at a 90 degree angle you have a pure crosswind of 10 mph, continuing around to a 10 mph headwind. At the angles in between, you have a resultant wind composed of the portion still a head or tail wind and and the part that is a side or crosswind. at a 45 degree angle to the heading of the bike, these are equally split, making our 10 mph tailwind quartering crosswind and giving you a 5mph crosswind component and a 5 mph tailwind component.
So, real world: You almost never have a constant wind and almost never one with a direction exactly the same as the heading of the bike. So it's always a guesstimate. It's the guesstimate that is the theory, not the science. If you were able to know what the relative wind was at every foot of the run you could compute your resultant EXACT ground speed at everyone of those same feet.
I would be perfectly comfortable predicting that, in a constant, known wind situation, that if I had a bike the consistently ran 200 mph in a no wind situation that I would run 202.5 with a 45 degree 5 mph quartering tailwind.
For those interested, here's how this works in an airplane with the most advanced GPS based avionics ((EFIS or electronic flight control system) like the one I fly almost daily. At a given power setting the True Air Speed (TAS is corrected for altitude and temperature) at a given altitude is constant and I mean exactly constant. The GPS knows this airspeed and also knows the flight path over the ground (actually, through space, but this is geo-referenced to positions on the earth's surface.) If the aircraft heading (where the nose is pointed) coincides with the track over the ground, the EFIS knows there is no cross wind. If the heading differs, something is causing the airplane to need to correct into the wind to stay over the desired ground track and the EFIS computes what wind direction must be present to cause that mismatch. If the True Air Speed differs from the speed over the ground, the EFIS then makes a computation as to what wind velocity would be required to cause that mismatch. The EFIS then combines these measurements to present to me on the "glass" panel that I have cross wind of x speed from y degrees. It also takes that computation and tells me pretty much to the second when I will be arriving at a certain point in space in the future. If these functions were not mathematically perfect, none of this would be possible.
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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dougmeyer
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moderated
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posted August 07, 2010 11:22 AM
Edited By: dougmeyer on 7 Aug 2010 19:47
A picture might help:
This is the Primary Flight Display in the Garmin G900x EFIS equipped Lancair Evolution that I fly.
The little box at the bottom of the vertical tape on the left is the true airspeed TAS shown at 296 Knots. The vertical tape on the right is the altimiter showing me at 22,000 feet.
The rectangle at the top of the square box to the lower left shows an arrow and 53KT. This is the actual crosswind velocity and direction. The rectangle to the right shows that this wind results in 20 KT headwind and a 50 KT crosswind component. Why do I want to know that? well it tells me that the 53KT crosswind is only effecting my forward speed by about 20KT. I say about because this fluctuates as a result of very small correction in heading and average wind.
Now, this is the other screen in the panel, the MultiFunction Display or MFD
You can again see the 53KT vector in the upper right corner, and also the Groundspeed (GS) of 279 KT in Magenta at the top left. The magenta line across the screen is the path of the plane across the ground and you'll notice the difference in the angle of the little airplane symbol and that line, the result of the crosswind (this is known as the Wind Correction Angle).
Cool Stuff, no?
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
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DahMurf
Expert Class
2006 Hayabusa - Black
Posts: 132
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posted August 07, 2010 11:24 AM
quote:
Snane , look at the run log form loring last year , sorted by speed
your run on saturday was 197.001..... a few mph faster than you have ever run at maxon. And sunday magically you ran 211.... 14 mph faster .... and the with a tailwind that was very close to that ...
i went 187.4 on saturday and 202.8 on sunday .... 15.4 mph faster
ali went 220 on saturday and 229 on sunday ... only 9mph faster
greg neal went 179 on saturday and 190 on sunday ... 11 mph faster
looks like records were set with 9- 15 mph tail winds..... or maybe we should conclude that big riders benefit more ?
Roy
Not that I really want in on this pissing match but I would like to point out that most people were undergeared for last years event. Are all of these runs with only the addition of the tail wind or might that have included other tuning or gearing changes in between?
If you add my bike to the list we had a 218 run & then a 228 run but we had to change the gearing because the 218 run ran out of gear at the 1 1/4 mile. You could say it was tail wind but that wouldn't be accurate as they weren't identical back to back runs. We didn't have enough time to run it again with the same configuration/pilot this year. We did hope to find out for ourselves & our set up how much the 1/2 mile without the tail wind helped.
Debbie
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Miss you my friend - #1302 Twin Jugs Racing
ECTA 200 MPH club@202 / Texas 200 MPH club@209 / Loring 200 MPH club@218
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Shane661
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Posts: 11494
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posted August 07, 2010 11:36 AM
Edited By: Shane661 on 7 Aug 2010 19:39
quote:
So, real world: You almost never have a constant wind and almost never one with a direction exactly the same as the heading of the bike.
Ok, Doug, so to condense things: Basically the theory is sound, but in practice it rarely if ever precisely aligns with the results. So, in essense, even if you have what seems to be a perfect tailwind, it likely will not align perfectly. Thus, you can pretty much forget about the 1:1 ratio in practice. And even if it did align perfectly...it could very nearly, but not exactly, be 1:1.
I am not surprised by this explanation. I do feel that there are perhaps additional issues related to the way the motorcycle reacts to the wind, and perhaps ground-level effects to consider. But my theories are just that, and only based on my real-world experience.
Once again, as I stated earlier: real world race results trump theory every time.
Shane
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dougmeyer
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posted August 07, 2010 11:55 AM
Edited By: dougmeyer on 7 Aug 2010 19:57
You're right Shane. but yet again your use of the word theory really bugs me. What is going on here is not a theory, it is proven science. but you have a theory as to why your results do not usually match what would be expected to happen given the facts.
Debbie
The wind causing your need to go taller on the gear is exactly accurate. This is because the reduced drag at a given wheel speed provided by the tail wind enabled your bike to pull to a higher RPM. The power/drag balance then occurred at a higher wheel speed, causing you to run out of available RPM.
OK It's Saturday and I'm going for a ride. See ya' later....
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
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Shane661
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posted August 07, 2010 12:03 PM
Edited By: Shane661 on 7 Aug 2010 20:06
quote:
You're right Shane. but yet again your use of the word theory really bugs me. What is going on here is not a theory, it is proven science. but you have a theory as to why your results do not usually match what would be expected to happen given the facts.
I can deal with you not agreeing with or understanding my choice of words, the semantics....after all, this is the internet. When you say "You're right Shane" that is good enough for me. 
I am simply calling the book-science the "theory" of what some people "think" should happen under typical race conditions. The "practice" is what I call the real-world results. I am not disputing the truth of the science at all.
Shane
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Phantom13
Zone Head
Posts: 736
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posted August 07, 2010 12:12 PM
Doug, are you saying your 222mph run on Karl's bike would have been a 202mph run in 1.5mi in calm conditions?
Or Shane would have ran 192mph in the 1.5 mile?
Or Jim's 12 would have ran 199mph in 1.5miles?
those are more like their 1 mile speeds in calm conditions.
And since we already know the extra distance is worth at least 6-8mph... Well.... You get the point.
Again I ask. Would you like to see what everyone else thinks about what you're saying?
Maybe I'm the idiot here, I'll gladly eat crow to learn something new.
I'm pretty confident in my position, are you?
____________
"The only place Success comes
before Work is inside the Dictionary."
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Y2KZX12R
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CompetitionCNC.com
Posts: 3762
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posted August 07, 2010 01:46 PM
Edited By: Y2KZX12R on 7 Aug 2010 21:49
quote:
Oh and while we have the attention of the entire class, perhaps Jim and Doug would like to discuss their other theories like,
- big bore stroker engines do not produce any more heat riding around town than a stock bike.
Or my personal favorite...
- Doug's claim that there's NO tire slippage at 200mph. (Remember the 199mph Muzzy 12 run thread where you said that?)
This way we can add even more credibility to their theory.
$5 says this thread gets deleted or locked by Karl.
Any takers?
This is about giving due CREDIT to EVERYONE in LSR for their speeds. By saying you get a 1:1 gain, it makes everyone look slower than they really are... But makes Jim look faster.
Look who's defending Jim... TFA and nobody else.
Let's see how people OUTSIDE of Jim's personal interests feel about the issue. Is that really a douche move or do you think it's for the benefit of everyone reading to know the TRUTH?
If you raced LSR, you too would be offended by someone propping up their performance by playing down those of EVERYONE ELSE.
THAT my friend is what I consider a complete douche move.
Wow, Your way off base here. Good luck. Oh and last year just for the reccord, I had zero (unmeasureable) tire slip at 218 mph. This year I had about 3% with the longer arm.
Shane, I'm going to do the rest of the engine development on the DTS engine dyno. We can work much faster and do far more testing in a lot less time. So we may not put the engine back in the bike this year.
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Y2KZX12R
CompetitionCNC.com
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dougmeyer
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moderated
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posted August 07, 2010 01:52 PM
Phantom,
What I'm saying is, if I ran a bike set up for the 1.5 and ran 222 with the bike no longer accelerating at the lights with a direct 20 mph tail wind and got back to the line immediately and made a run with NO wind, the run likely would be a 202, assuming of course identical shift points, tuck etc.
I'll gladly (and have) defend my other observations as they are usually rooted in actual collected data, seat of the pants impressions and suppositions.
Sure I can take it. I pride myself on staying away from bullshit but don't mind reading what others have to say and will gladly listen and debate, especially if it's backed up with fact. Otherwise it's just somebody's opinion.
____________
It's not that I think you're dumb, it's just that so much of what you know isn't true....
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Shane661
Needs a life
Posts: 11494
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posted August 07, 2010 01:59 PM
Edited By: Shane661 on 7 Aug 2010 22:04
quote:
Oh and last year just for the reccord, I had zero (unmeasureable) tire slip at 218 mph. This year I had about 3% with the longer arm.
Shane, I'm going to do the rest of the engine development on the DTS engine dyno. We can work much faster and do far more testing in a lot less time. So we may not put the engine back in the bike this year.
Jim, what did you log in order to determine tire slip? I would like to log that on my bike as well.
On a related note...I wonder why gearing charts never agree with actual results? I mean, it always seems to be a few percent less speed than the gearing chart suggests (with measured tire circumference, of course). One would think that you would gain speed with no slip, due to tire growth.?
I am unfamiliar with the DTS dyno...is this the system?:
http://www.dtsdyno.com/
Good luck, looking forward to seeing the results. 
Shane
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Shane661
Needs a life
Posts: 11494
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posted August 07, 2010 02:20 PM
Edited By: Shane661 on 7 Aug 2010 22:39
quote:
Phantom,
What I'm saying is, if I ran a bike set up for the 1.5 and ran 222 with the bike no longer accelerating at the lights with a direct 20 mph tail wind and got back to the line immediately and made a run with NO wind, the run likely would be a 202, assuming of course identical shift points, tuck etc.
Doug, you did mention that a near 1:1 gain could only be achieved under "perfect" conditions. You also mentioned that due to some factors relating to ground based vehicles, you will not quite get a 1:1 relationship...even with said perfect condtions. You also said that it is very unlikely to achieve those best-case condtions.
Let's cut to the point. Nobody got a 1:1 gain in mph vs. wind speed last year at Loring. In fact, it would be extremely rare (mythical?) for a near 1:1 instance to occur.
This information is also based on collected data.
Shane
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brendasue555
Expert Class
Posts: 436
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posted August 07, 2010 04:43 PM
Wow, you guys need to simmer down, this is starting to sound like road rage. Can't we all just get along. As far as Rickey riding my bike, here is what happened. I rode it and ran out of gearing or whatever makes it keep going faster at around the mile mark. I ran a 185.291mph. Rickey said he thought it would do 190, I said no it wouldnt go any faster without a different sprocket. I did another run and went 185.819 and was sure that was all there was with that gearing. Ricky asked to ride my bike so of course I said yes. His first run he went 185.869 so yes he did go .05 mph faster than me but he now agreed with me on the fact that it was all I was going to get on that gearing. He then went down the track about 5 to 7 tenths of a mile and then got on it. That run he went through the traps at 185.154. I dont know much about any of this crap but learning to trust my judgement concerning my bike was priceless and I thank Rickey for teaching me to trust what I know. (something Doug has been trying to convince me of for a while now) I learned so much at this event. One of the things that I learned from Rickey is that without Doug none of us may have ever gotten to know who Rickey Gadson is. He told us about how he got his start and how Doug Meyer was the one who believed in him and hooked him up with Muzzy's and then later with Kawasaki. I love Kawasaki's and I give them credit for snatching up Doug to ride motorcycles for them and then for snatching up Rickey. My bike being serial # 20 is no fluke. Thanks Doug for all you have done to help me learn to go fast and for building me such a good strong motor. Jim, don't forget that you are poking around on my future husband. It is hard to know that his guts (rods) and such are trashed. Please rebuild him before the wedding. I always new I would marry a zx14 but now I know exactly which zx14 it will be. Thanks Jim, Oh and I will definately take Phantom up on that $5.00 bet. NOW PAY ME!
____________
Brenda
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dougmeyer
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moderated
Posts: 2713
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posted August 07, 2010 04:57 PM
Shane,
Again, you are right! But the relationship is not mythical or incorrect. It is absolutely correct but extremely rare to occur. Over time, as you build a database you can get extremely good at predicting performance.
Look at the NHRA fuel guys, they look at ALL the conditions before a given run and compare these to their database. They then tune for a run, expecting to run within a few hundredths of a specific ET. If the run is "good" but the performance is different than what the data told them to expect, they know to look for what was wrong.
But, without knowing what is correct you are unlikely to ever be able to determine where you are or "how "far off" you may be.
Thanks, Brenda Sue
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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shiphteey
Needs a job
Posts: 2529
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posted August 07, 2010 05:14 PM
Some good info here.
I'd like to address Roy's summation of Loring 09 runs:
your run on saturday was 197.001..... a few mph faster than you have ever run at maxon. And sunday magically you ran 211.... 14 mph faster .... and the with a tailwind that was very close to that ...
i went 187.4 on saturday and 202.8 on sunday .... 15.4 mph faster
ali went 220 on saturday and 229 on sunday ... only 9mph faster
greg neal went 179 on saturday and 190 on sunday ... 11 mph faster
looks like records were set with 9- 15 mph tail winds..... or maybe we should conclude that big riders benefit more ?
-----Me picking up 9 mph and concluding that it was due to my size isn't necessarily the cause for that relative to everyone elses's gain. Having run 227 mph on the rev limiter for 10 seconds I knew the bike needed a smaller rear sprocket on the back. Last run of the day and I was pressed for time so I got in line with 800 psi in the line. I knew I didn't have enough time to get them up to optimum pressure without risking not making a final pass so I ran knowing full well that I'd go a little faster but probably not be able to pull the top of 6th to the rev limiter. I was right. I was about 300 rpms from the rev limiter and I could feel it just hang. Do I believe the bike would have gone 232 or so? Based on the previous run of 227 mph for 10 seconds I don't think thats very far fetched. I was essentially down on power on my final run, right when I needed the power the most given such tall gearing.
Just wanted to throw that out there. As many know the repeatability of nitrous can be tricky (pressure and weight of bottles) vs na motors and turbos. But hey, its cheap.
On a side note, I remember having a pretty stiff headwind at Bonneville and going 199 on GPS into the headwind. Unfortunately the return run being a tailwind had me on the rev limiter very early and I had to keep getting off the spray, yielding a 208. The way the bike was pulling gave no indication that it was running out of umph with the tailwind...who knows, maybe it was a 215 run if i had the right sprockets on.
Figured I'd throw this in since its somewhat relevant to the topic.
A.
____________
Gemini Motorcycles
Topping out everything from Ninja 250s to nitrous ZX-14s.
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Shane661
Needs a life
Posts: 11494
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posted August 08, 2010 02:05 AM
Edited By: Shane661 on 8 Aug 2010 10:28
quote:
Wow, you guys need to simmer down, this is starting to sound like road rage. Can't we all just get along. As far as Rickey riding my bike, here is what happened. I rode it and ran out of gearing or whatever makes it keep going faster at around the mile mark. I ran a 185.291mph. Rickey said he thought it would do 190, I said no it wouldnt go any faster without a different sprocket. I did another run and went 185.819 and was sure that was all there was with that gearing. Ricky asked to ride my bike so of course I said yes. His first run he went 185.869 so yes he did go .05 mph faster than me but he now agreed with me on the fact that it was all I was going to get on that gearing. He then went down the track about 5 to 7 tenths of a mile and then got on it. That run he went through the traps at 185.154. I dont know much about any of this crap but learning to trust my judgement concerning my bike was priceless and I thank Rickey for teaching me to trust what I know. (something Doug has been trying to convince me of for a while now) I learned so much at this event. One of the things that I learned from Rickey is that without Doug none of us may have ever gotten to know who Rickey Gadson is. He told us about how he got his start and how Doug Meyer was the one who believed in him and hooked him up with Muzzy's and then later with Kawasaki. I love Kawasaki's and I give them credit for snatching up Doug to ride motorcycles for them and then for snatching up Rickey. My bike being serial # 20 is no fluke. Thanks Doug for all you have done to help me learn to go fast and for building me such a good strong motor. Jim, don't forget that you are poking around on my future husband. It is hard to know that his guts (rods) and such are trashed. Please rebuild him before the wedding. I always new I would marry a zx14 but now I know exactly which zx14 it will be. Thanks Jim, Oh and I will definately take Phantom up on that $5.00 bet. NOW PAY ME!
Brendasue...to further add to the festivities:
Just because Rickey didn't go any faster than you, it doesn't mean that the bike didn't have more mph in it with a seasoned LSR rider on it, or perhaps some tweaks to your setup.
No question that if Rickey ran your ZX-11 at the dragstrip, you would probably see the limits of the machine at his hands. That is his profession. LSR, not so much.
I am only telling you this to encourage you....you may very well be able to go faster than Rickey someday. Sometimes we need to be very careful how we measure our performance.
Shane
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brendasue555
Expert Class
Posts: 436
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posted August 08, 2010 02:36 AM
Shane, with respect to your knowledge ..... neither Rickey nor myself are "seasoned " land speed racers. I doubt a very spicey racer could go much faster. Maybe a rookie like Scott Guthrie is wrong too, but I think that he agreed that there wasn't much left with that gearing. I could be wrong but don't think so. The only way to increase your mph at that gearing would be with a lighter weight rider or better tuck or better aerodynamics of the plastics. I would not dare to argue with you as I know this for sure, you have been doing this bike thing a while and I am so new at it. But, I am confident in this. I know my bike and us rookies rode the piss out of it You might know something I don't know but I love a challenge, wanna see what you can do on her in a mile or a mile and a half with the sprockets I had on. I will even put my 5 bucks that Phantom owes me on the line if you can go more than 2mph faster in similar conditions......no wind to speak of. So until you show me different I have to stick by what I know. Seasoned rider or not I bet I wouldn't lose the 5 dollars. And if I did it would be worth 20 to know I was wrong and get schooled. I told you I learned to be confident in what I know about my bike. It isnt going to matter if you go a mile or a mile and a half. the mph will be the same. As long as you dont lose to much in the last half mile trying to stay out of the red.
____________
Brenda
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Shane661
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posted August 08, 2010 02:55 AM
Edited By: Shane661 on 8 Aug 2010 11:06
quote:
Shane, with respect to your knowledge ..... neither Rickey nor myself are "seasoned " land speed racers. I doubt a very spicey racer could go much faster. Maybe a rookie like Scott Guthrie is wrong too, but I think that he agreed that there wasn't much left with that gearing. I could be wrong but don't think so. The only way to increase your mph at that gearing would be with a lighter weight rider or better tuck or better aerodynamics of the plastics. I would not dare to argue with you as I know this for sure, you have been doing this bike thing a while and I am so new at it. But, I am confident in this. I know my bike and us rookies rode the piss out of it You might know something I don't know but I love a challenge, wanna see what you can do on her in a mile or a mile and a half with the sprockets I had on. I will even put my 5 bucks that Phantom owes me on the line if you can go more than 2mph faster in similar conditions......no wind to speak of. So until you show me different I have to stick by what I know. Seasoned rider or not I bet I wouldn't lose the 5 dollars. And if I did it would be worth 20 to know I was wrong and get schooled. I told you I learned to be confident in what I know about my bike. It isnt going to matter if you go a mile or a mile and a half. the mph will be the same. As long as you dont lose to much in the last half mile trying to stay out of the red.
Well, Brenda, it wasn't very clear to me that you didn't make a gearing change. If that is the case you could have easily been gearing limited. I am confident that there is more speed left in that bike, if you look hard enough.
I would love to take you up on your offer someday, as long as you don't mind the bike setup being adjusted a little. I too love a challenge. 
That being said, there are a lot of LSR jockeys out there who are closer to your size, and could better illustrate my point. As I'm sure you are aware, when it comes to racing, size DOES matter.
Shane
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posted August 08, 2010 04:09 AM
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Oh and last year just for the record, I had zero (unmeasurable) tire slip at 218 mph. This year I had about 3% with the longer arm.
Shane, I'm going to do the rest of the engine development on the DTS engine dyno. We can work much faster and do far more testing in a lot less time. So we may not put the engine back in the bike this year.
Jim, what did you log in order to determine tire slip? I would like to log that on my bike as well.
On a related note...I wonder why gearing charts never agree with actual results? I mean, it always seems to be a few percent less speed than the gearing chart suggests (with measured tire circumference, of course). One would think that you would gain speed with no slip, due to tire growth.?
I am unfamiliar with the DTS dyno...is this the system?:
http://www.dtsdyno.com/
Good luck, looking forward to seeing the results.
Shane
I was logging RPM and using a software program where tire slippage can be factored in. I can send you the program if you like. Its a nice windows based program and its not huge. This program is extremely accurate as long as you use safety wire to measure the tire circumference. you cant use a rope or string etc. or you get a bigger number due to the center line of the rope being out from the tire surface. The numbers are usually within .1 or .2 mph.
The DTS dyno is a water brake engine dyno. Its the same dyno the cup shops use.Penske has three of them. We can do sweep pulls at different acceleration rates or hole it at any rpm or even pull the engine down etc. Also we can monitor many aspects of the engines performance on a cylinder by cylinder basis. Without the engine in a bike its very easy to work on as you could imagine.
I really am looking forward to having the same tunability that we had on the zx12r. The hacked zx12r ECU was awesome. Were just waiting for the guys to release it. hopefully soon.
At this point I know now that the cam timing wasn't optimal for peak HP. but we didn't know the scavenging rate of the relationship of the huge valves we had in the head. We shot for under scavenging rather than over scavenge.
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