| Author | Message | ||
     Blake |
Very cool stuff. Thanks for taking time to share it all with us.  | ||
| Moxnix |
A little heresy here: The Hayabusa fairing has some bikes pushing 260 mph. Whilst the RR1000/KRTT fairings are a well proven road racing design for under 200 mph, at about 215-220 mph (per my cheap super computer) there begins a "lifting moment" due to drag on the dolphin nose. The Hayabusa offers downward pressure at speed. Do gobs of testing with the Toy design before opening the throttle. It needs to be "right" to avoid getting the wobblies. Your Paughco frame will put you into Special Construction. In which class do you intend running? 1350 A-PF, special construction "naked," or 1350 APS-PF, special construction partial streamlining? I suggest not buying a fairing this year, just an LSR front fender from AirTech and run against that softish 1350 A-PF record. Then go for the 197mph record when you see what fairings work for the people setting records. You really need a rulebook. No, really. | ||
| Isiahstites |
Moxnix, I could not agree with your post more! Most of what you said is what is what I plan on doing. This year I am going to run A-PG 1350 and possibly A-PF and as I learn maybe next year I will do other things in the APS classes. Thanks, Scott | ||
| Moxnix |
Take that A-PF record and I'll send you a C-note along with a small decal from my R&D company for 2008 sponsorship. If you want to see the big show and wait in line to run, go to Speedweek. Or enjoy BUBs while it lasts and get an AMA record. If you want to set Bonneville National Motorcycle Records, you may consider attending the Utah based USFRA Utah Salt Flats Racing Association "World of Speed" where you get the chance for more runs, weather permitting; $40 membership, same SCTA $10 rulebook, your record still gets into the SCTA records. <www.saltflats.com> And have a good time. | ||
| Isiahstites |
Moxnix, So I am clear on this, you are saying if I break the A-PF record you will send me a c-note and then sponsor me in the 2008 season? Does El Mirage count? I forgot to mention in my last post I already got a rulebook. I picked one up at the El Mirage meet last weekend. I also picked up my logbook. And early this week I picked my number.........1877. The only Bonneville trip I can see myself making is the Bub meet due to my boss retiring from work four days prior to the meet so he can go to Bonneville, however I do plan on racing El Mirage July 15th as my first race and I plan on racing there the rest of the year. Scott | ||
| Moxnix |
Ooooops, I am sorry for any misunderstanding in the way I wrote that. If you bump that SCTA record, I'll pay $100 to put my small decal on your bike for the 2008 season. I do a lot of "non-profit" work with the R&D, so I am sorry I can't fully sponsor a racer's season. It's just there are a few records that need to be upped. In the long run, with the special construction class, you may want to make note of Section 7.A.4 on page 95 in the Motorcycle Rules: "strongly recommending" all new special construction class vehicles be submitted for a pre-event inspection by the Tech Committee. I "think" this also means passing an inspection at the dry lakes will help you pass scrutiny on the salt. But, for BUB, who knows. I've heard odd stories on scrutineering there. Sorry for the lack of clarity regarding sponsorship. There is a whole thread on landracing.com on the subject. Best to have a rich uncle or large discretionary slush fund. | ||
| Isiahstites |
Moxnix, Thank you for the clarification! I am greatfull for your offer and I look forward to potentially taking $100 from you. I am greatfull for any type of sponsorship, so thank you for that!I have read some of the "sponsorship" thread on landracing.com. As far as inspection of my bike once complete I have several people in my area who are known LS racers and I will have them look over the bike prior to attending a race. Scott (Message edited by isiahstites on May 13, 2007) | ||
| Firemanjim |
Bub's scrutineering no better/worse than SCTA, my best experiences have been with USFRA folks. The first year they instituted the "all leather" rule the tech folks disallowed my partners leathers -- he had sewed leather patches inside his leathers to cover ventilation holes.This was done after talking to tech folks on the phone.Later at the starting line we saw a guy with duct tape over his vent holes and when I asked how it passed tech he replied that tech told him to do it(duct tape must really be fireproof!!)--the really annoying part was I had been standing at tech with Terry with a roll of duct tape in hand as were were covering up numbers on his bike. And to really piss us off we watched a HD rider take off on his bike with leathers that did not even zip together--HTF did they pass??? | ||
| Moxnix |
This should be an interesting year all around. | ||
| Firemanjim |
Most of the Hayabusas going really fast have little or no "stock" bodywork anymore. Fenders and fairings massaged,gastanks lowered,tailsections lengthened and lowered. Aaron's RR has been running at the speeds you mentioned and I never heard him or Timbo talk of the bike being unstable. We'll see when I get mine together as I now have some "massaged" RR bodywork. Joe Amo has the Toy bodywork and has been 240+. | ||
| Moxnix |
Not unstable, just lifting. Here's my cut and paste view: Aerodynamic lift, particularly over the front wheel is potentially dangerous, because it reduces the hold of the tires on the surface. It is not always realized that, even with a body shape that produces no net lifting force there is still a tendency for weight transfer off the front wheel and onto the rear due entirely to the effect of the drag force. The drag force, Fd, can be considered to act through a single point, at a finite distance above the ground. This produces a torque trying to rotate the bike about its rear wheel, thus lifting the front. So, all else being equal, anything that reduces drag and/or the effective height at which it acts, will help reduce this weight transfer. In addition to just reducing drag the ideal situation would be for the body shape to create a down force at the front and a lifting force at the rear to exactly balance the above effect. John Britten's early AeroZero fairing comes to mind. I suspect a Toy rear section might do well behind modified RR front bodywork. (Message edited by moxnix on May 13, 2007) | ||
| Court |
>>>>I never heard him or Timbo talk of the bike being unstable. Just the opposite. Timbo reported, following the last record run, that the RR/RS was "rock solid". Aaron took if for a run and posted a 213+ and reported the same observation. I was under the impression, mostly hearsay, that stock Hayabusa bodywork is not that slipperly. I have no data on it. The RR is the result of extensive wind tunnel testing and Bantz has made significant changes based on observations during the old 202.989 days. Fun stuff. | ||
| Moxnix |
Thrust, drag and weight on the one hand. Lift or downforce on the other. RR1000 CdA 2.71 GSX-R1300 2.91 A turbocharged Hayabusa make gobs of power to get to 250+ mph. Pushrod V-Twins are not currently matching that output. I'd never say never. | ||
| Rocketman |
As I recall, the Hayabusa was launched with a much publicised campaign touting its superior to other motorcycles aerodynamic bodywork. Much research in wind tunnel testing was claimed, as was the design of the front hugger and area under the nose of the fairing, which allegedly addressed exactly the point Max mentioned about downward pressure at 200mph or thereabouts. I'm no authority but I don't remember any motorcycle passing more than 210mph when running an RR type fairing, or copy of. Though I'm sure there are speeds recorded by the likes of Richard, Tim, or others, that may be fractions quicker, if not record runs. I mention this in no way as a put down. It is the opposite. Just such is a remarkable achievement on many levels. Even more so when one considers the age of the RR design, and what technology wasn't available back then, as it is now. What would be a shame is if the Hayabusa were seen as any less remarkable a design just because it's a product of the technological advancements available today in motorcycle design. Neither design deserves criticism in my opinion, but I am of the opinion the Hayabusa design should be capable of speeds in excess of 250mph, whilst the RR design may (should?) not be. I believe that is what Max was referring to if I have understood him right. Rocket | ||
| Moxnix |
The KRTT wind tunnel time Dick O'Brien got the boys at Cal Poly to do was back in the 1960s. So, I give credit to those who make the descendants of that self same shape go so fast today. Were I willing to put my money where my mouth is, and with deadlines coming up I am not, then I'd send a Buell to Bonneville with a Hayabusa fairing. And maybe a Charlie Toy rear section. Perhaps when I get done with my aircraft design obligations by this time in 2008, as feeding the wife and spawn comes first. | ||
| Diablobrian |
The right way to compare would be to do multiple runs with the same bike with each of the body work styles on it and average the runs for each style. That is as close to a scientific comparison as anyone can get without a wind tunnel, and negates the factor of the different HP levels and characteristics of the motors. | ||
| Moxnix |
COSMOSFloworks embedded in Solidworks; no waiting in line in the heat. | ||
| Firemanjim |
Your right in the amount of HP it takes to push the Hayabusas up to the 250 mph area while it take considerably less to push the RR body to the 220 area Aaron has seen. John has to turn his tune down to around 495 so it does not spin the whole run--and you should see the amount of lead on his swingarM. When Aaron's bike first went over 200 that meet had nunerous Hayabusas there with hp numbers in the 190-200 range and only 2 went 200. IIRC the bike was down on hp from those bikes. | ||
| Moxnix |
Here is my theoretical fix for the lift problem no one has experienced on the KR/XR/RR fairing: A "parakeet beak" sticking out from the lower portion of the nose over the front wheel. Nothing extravagant, just something like the little beak/fenders the Italians used on some small GP bikes in the early 1950s. How to make the bike go 230 mph is another matter. | ||
| Court |
Still the classic . . . the time Richard Nallin pulled inot line to wait for a run. . . the guy on the Zoomabusa next to him gives his a snotty look and says "I did a 189MPH, how fast did that Buell go? . . to which Richard plitely told him "I'm backing up a 202+". Ya gotta love racing. By the way . . that year the bike was experiencing SIGNIFICANT lift. Richard was reporting the front end waving left and right as he passed 200MPH. The fact that Richard dealt with the oscillations is a credit to his abilities and experience. At the time a theoretical solution was researched, refined and converted to a practical solution by the capable hands of JB2. Apparently in worked. Lat year Timbo reported the bike to be "rock solid" at 213+ and subsequent 210+ runs by other riders were reported to be "a piece of cake". I think the lift thing, at least for that bodywork is sorted out. Aerodynamics is king. (Message edited by court on May 15, 2007) | ||
| Rocketman |
How aerodynamic is 172.9 mph, and what would be the effects of significant lift at this speed ? Rocket | ||
| Moxnix |
See my post above: "In addition to just reducing drag the ideal situation would be for the body shape to create a down force at the front and a lifting force at the rear to exactly balance the above effect." And the later: "that year the bike was experiencing SIGNIFICANT lift." So, there was a lifting moment. And a fix. And another record for Buell. Not bad. Re: 172.9 mph, it appears there were no reports of lift below 200 over the years. | ||
| Diablobrian |
I'm fairly certain a specific speed (172.9mph)can't be more or less aerodynamic....... unless I missed something pretty darned important along the way.  I'm guessing I misunderstood the question from Rocket :} "How aerodynamic is 172.9 mph, and what would be the effects of significant lift at this speed ? " Maybe he meant : How stable is the RR bodywork at 172.9mph....  I'm not trying to be a knob, I'm trying to follow, learn from, and contribute (very little) to a thread that has really been interesting so far. | ||
| Rocketman |
I'll explain. There are those it seems that assume the Hayabusa isn't as slippery as it should be. Hence, they struggle to make 200 mph with 190-200 bhp, when the RR had no trouble at all. Such comparative analysis is bollocks in the real world. There are so many differences between why which bike ran what speed on that day, such as weight, power delivery, fuel, not to mention who was riding what................you get the picture. Fact is, 172.9 mph is the current world wheelie record, set last year on a GSXR1000 with its front wheel airborne for a flying kilometer. The pop-up wheelie record stands way over 200mph. What does this say about aerodynamics? Rocket | ||
| Diablobrian |
Ok, I understand, kind of what I was getting at with my previous post about running the same bike with each of the bodywork styles to eliminate differences in power characteristics, hp, weight etc. so we are on the same page. I agree with the point I think you are trying to make. That point being: You can model things to the end of time on a computer but that only gets you so far. The real world has surprised more than one engineer when the variables he encountered in the real world didn't match his theoretical tests. If that wasn't the case wind tunnel testing, and real world shake downs would be a thing of the past wouldn't they? Going out to the salt would be redundant in that scenario. Thank God that computer modeling hasn't replaced real world racing....yet. | ||
| Court |
>>>>Thank God that computer modeling hasn't replaced real world racing....yet. That remains true, but becomes less true by the day. Many folks, I'd wager, have little appreciation for how accurately things may now be modeled. One key element, without saying too much, is validating and adjusting models with empirical data. The old "garbage in, garbage out" caveats continue to apply. Constantly challenging the model is essential. I also have a fear of the word "anomaly". I hear folks, as failures are studied or testing occur, sometimes refer to a frequency of "1" as an anomaly. Everything, I submit, occurs for a reason. An "anomaly" is sufficient reason to cast doubt on a model. Court | ||
| Rocketman |
I wasn't making a point. I was showing that it is capable for a GSXR1000, a less aerodynamic Suzuki than its big brother Hayabusa, to hold its front end in mid air at 172 mph for a distance of 1 kilometer. Such a feat tells me that if a few 190-200 bhp Busa's struggled to reach 200 mph on the same course on the same day as an RR1000 broke 200 mph with apparent ease, then I'd have a hard time assuming the Hayabusa's aerodynamics were to blame. Given the wheelie record speed and the GSXR1000 relationship in design to the Hayabusa, such would suggest to me that other factors beside aerodynamics were responsible for the seemingly poor performance from the Busa's. Because I see it as so, I could not conclude the RR1000 beat the Busa's because of its fairing and body shape / design. That would be an incorrect assumption to make, and as such needs pointing out when others here are trying to imply otherwise. Let's keep it real. Rocket | ||
| Scott_in_nh |
I was showing that it is capable for a GSXR1000, a less aerodynamic Suzuki than its big brother Hayabusa, to hold its front end in mid air at 172 mph for a distance of 1 kilometer. ok so it did the wheelie - do you know that the GSXR is or isn't more aero in the wheelie position than the 'Busa? Such a feat tells me that if a few 190-200 bhp Busa's struggled to reach 200 mph on the same course on the same day as an RR1000 broke 200 mph with apparent ease, then I'd have a hard time assuming the Hayabusa's aerodynamics were to blame. Given the wheelie record speed and the GSXR1000 relationship in design to the Hayabusa, such would suggest to me that other factors beside aerodynamics were responsible for the seemingly poor performance from the Busa's. Please expound on how it tells you that. sorry, but you logic is weak here. If I take two bikes down the 1/4 mile on the same day, if I know the weight of each and their elapsed time, I can calculate the horsepower made. the HP some other slower bike made while doing a wheelie is irrelevant. If 2 bikes went down the salt on the same day under the same conditions you can either calculate the drag created if you know the HP and speed or you can calculate the HP if you know the drag and speed. With ALL else being equal, if one bike went faster - it either had more HP, had less drag or both. Of course things are rarely ALL equal so variables in weather can take place within minutes, riders skill/courage varies and even the traction available 1 foot to the left or right could play into it as well, so I am not saying that one bike is definitively more aero than the other, just that your wheelie analogy doesn't work. Because I see it as so, I could not conclude the RR1000 beat the Busa's because of its fairing and body shape / design. That would be an incorrect assumption to make, and as such needs pointing out when others here are trying to imply otherwise. Let's keep it real. Agreed! (Message edited by scott_in_nh on May 16, 2007) | ||
| Court |
Please Lord . . . I don't understand these equations but do me this one favor and don't let contact patch be a variable! | ||
| Diablobrian |
Too late Court! Contact patch is a huge factor in available traction  |
