| Author | Message | ||
     Reepicheep |
Huh. Rough rule of thumb, how many HP to hit 100 mph on fairly low to the ground naked bike? 35RWHP? Some wild guesses... from http://www.bgsoflex.com/auto.html Computed Aerodynamic Horsepower Required is 32 (with total swags put in for Cd and even frontal area...) That's CLOSE. Spec for the F8 is something like 30 HP. | ||
| Buelliedan |
and every 50 mph above 100 gets much, much, harder and the hp required goes up exponentially (SP?) | ||
| Firemanjim |
No difference for cylinder numbers or 2/4 stroke, just engine size,pushrod or not, and blown/unblown,gas/fuel--realizing that "fuel" is anything other than event supplied gasoline.Could be nitromethane or could be Shell gasoline. Good ball park is you need 200HP to go 200 with bodywork,after that get your wallet out! | ||
| Buelliedan |
Can you imagine how much it cost Bill to go 312!!! | ||
| 46champ |
Jim that sounds about right 200hp for 200 mph never quite seen it that way before. The next question is what fairing is that normal road racing a long track XRTT or the Charlie Toy stuff. I'm just courious how much better the new stuff is. | ||
| Reepicheep |
I might actually do it! Local venue, stock class, and I have the right bike in the garage and running already. I'm not sure I could get 100mph out of it, but I think it would be pretty close. It'd be silly not to do it. I'd need to borrow leathers, put in new clutch springs, get new tires, and maybe do some dyno tuning to make sure I have the jetting spot on one particular RPM. The bike appeared to have been raced (and locked up) doing flat track before I got it and got it running again. It has a pretty rare goofy fork stock as well, so I can actually set the thing up for a ton of trail and to make it ride lower. It's a two stroke, back when the Japanese were really innovating, and the rotary valve has reliability issues over time, but it sure pulls hard. Modern two strokes have broader powerbands, but I bet this thing makes as much peak HP... maybe more.  | ||
| Buelliedan |
heck yea, Go for it. Even if you do not set a record I can guarantee that you will have a great time. Just be careful as it is more addictive than crack!!! | ||
| Reepicheep |
Looks like ECTA records (if I am reading the site right) is a bit higher... 103 mph, and they do distinguish between 2 and 4 strokes. 103 is tougher, but based on how this bison pulled relative to my old KLR-250 (which would hit 85 mph as measured on GPS), this old dirt bike should be able to approach the ton. I got the bike for $100 in a barn, and couldn't bear to leave it broken, so I put another $300 to get it running again, but have no idea what to do with the thing. Blowing it up in a land speed record attempt would be great fun. | ||
| Buelliedan |
$400 now will add up to many thousands when you get hooked. You have been warned!!!  | ||
| Firemanjim |
Gut the airbox,think about porting it and getting piston coated,could run no base gasket to up compression a bit and thinner head gasket, lower it, fill tires to 45+, loosen brakes, new non o-ring chain,make sure wheel bearings are good and have no drag---can even pop seals off and fill with thin grease---lower narrower bars,read rules and see if you can get aweay with cutting down seat. What size leathers do you wear, I have 3 sets so can lend one if you are my size. (Message edited by firemanjim on December 07, 2011) | ||
| Fast1075 |
You can cut the rotary disc back to change the intake timing and gain some power. A good pipe would do wonders if you can find one or at least the spec for the cone angles and lenghts. Those rotary valve motors made good power. There were a couple of guys that ran drag races with them back in the day in IDBA. Dang if I can remember how quick they were. Dave Schultz built a record holding 250 that his then teen aged son rode. I am almost positive it ran in the 100 mph range in the quarter mile. I never built any rotary valve Kawi's so I can't really offer solid specifications on what to do. (That was after all 35 or more years ago, and my memory isn't THAT sharp)If it was a Can Am, I built engines for a local motocross Pro in the early 70's. Those things were fastashell. | ||
| Reepicheep |
Good suggestions. And being a two stroke, just jetting it precisely for whatever the conditions are that day will probably go a long way. Right now, the bottom ring isn't actually the right one. Its the right diameter, but is too thin. So I should either get a spacer, or try and get the right ring. The pistons are LONG out of production, so it's a challenge. For leathers, I run a big XL or XXL. So unless you have some sized for two of you, I probably won't fit. | ||
| Buelliedan |
If you are planning to run in production class you MUST run a stock pipe. | ||
| Slaughter |
Work through a dealer to get yourself a custom piston. Easy to do but it's going to be $300+ bucks. | ||
| Firemanjim |
Call John Noonan at Wossner Pistons--landspeed guy. | ||
| Reepicheep |
I'll try that Jim, thanks. I doubt its that hard to find a ring that will work, but you need the dimensions of all the other off the shelf rings. I just picked the cheapest old snowmobile ring set I could find at Dennis Kirk that was for the right bore diameter, which ended up pretty close. Somebody in the business may have enough stock laying around that he can just measure. $teve... la-la-la-la I can't heeeeaaarrrrr you..... | ||
| Buelliedan |
If you just want rings then you need to talk to Ed Law at Total Seal. Phone # 800-874-2753 You will need to know each rings depth, height and diameter. Noonan deals with full pistons kits | ||
| Reepicheep |
Better and better! Thanks! | ||
| Bluzm2 |
Bill, have you check with Weisco? They don't have it listed on their web site but they may be able to help anyway. | ||
| Gearhead |
With all the recent interest in Bonneville in several automotive publications a group of friends and I started planning a trip to the salt this summer to spectate. A few weeks ago one of the guys said, "Heck, since we're going we should run something there!" All eyes turned to me, "you should run your race bike." I've been looking at the rule book but can anyone give me the low down on running an XB12R just to get the opportunity to run on the salt? Yeah, I know I'm a REAL newbie to this but any thoughts, comments or suggestions will be GREATLY appreciated!! | ||
| 46champ |
Gearhead the first thing you have to decide is which event you want to go to. Speedweek which is run by the Southern California Timing Assoc. SCTA and the Utah Salt Flats Racing Association are both primarily car events about 25% of the entrants are bikes. The Bub AMA event is a bike only event. Speedweek and the USFRA use the same rule book and their classes are generally the same. The BUB AMA classes are similar to the other events, but the rule book is different in several aspects. Because you are a current racer your bike and your gear will conform to the BUB event easier and cheaper. For instance I would wager that your racing suit will be legal for the BUB event and will not be close to being legal for Speedweek. If you go to Landracing.com you will find links to all the sanctioning bodies that deal with landspeed racing. | ||
| Gearhead |
Thanks 46! We were looking to attend Speedweek so your info gets me onto the right track! | ||
| Buelliedan |
To run at Speedweek rewuire leathers that are "all cow". In other words there can be no ventilation holes or stretch panels except at the back of the knees. As said most race leathers will not be legal so unless you want to buy new leathers you might want to re-consider runing at Speedweek. Bubs however uses AMA rules so leathers that are legal for road racing are legal at Bubs. You can have vetilation holes as much as you want bt they either must be 1 piece leathers or zip togther full circumference. Plus Bubs has a run whatcha brung class that allows you to just get the Bonneville experience without going for a record. It is much cheaper to run which is the main advantage. | ||
| Gearhead |
Thanks Buelliedan, I may have to rethink the Speedweek participation. I'm far enough away from Bonneville that a second trip to Bubs probably won't happen and buying a second set of leathers for one event doesn't make much sence but I'm still anxious to go to Speedweek! | ||
| 46champ |
I can understand going to Speedweek for the spectacle. If you are still undecided I would suggest ordering a SCTA rulebook from their website. The rulebook for the BUB event will be posted on their website for download in the next month or so. | ||
| Gearhead |
Just got back from Bonneville Speed week a couple of days ago. I went as a spectator and enjoyed every minute of it! I ended up helping the gas guy for the better part of a day so I had a great opportunity to visit with a lot of racers and check out a lot of machines. Now I've got the salt bug!! | ||
| Moxnix |
Yeh, it's something else, eh? Everyone ends up helping someone doing something, and fueling vehicles is an important aspect on the route to the starting line. I was tethered to the audio equipment up in the pits for a 12 hour webcasts every day. Like being a night shift mortician, someone has to do it. And, we were parked directly across from the timing tower, so the smells, noises and view were right there. Glad you enjoyed it. | ||
| Rex |
See everyone there. Heading out tomorrow night. we set up on Saturday, and start racing on Sunday. | ||
| Moxnix |
BUB starts racing tomorrow after a long Saturday of tech inspection followed by a great display of S&S bikes for photographers. I'll have to count them in the photo. Jeff Bailey's 160 S2 is great looking bike with the new fairing. The Buell Brothers are in attendance with S2s wrapped in RR type bodywork. Should be some records this week. Man, this is the place to race LSR. Nice small crowd, great management of the venue by the BUB volunteers. Some very trick stuff on two and three wheels in attendance. Of course, I'll be audio casting the BUB FM radio channel on Meridix.com, search Landracing, the days program should come up, older programs archived. This motorcycle only meet takes me back to my sordid youth. Teams from around the world, V-twins, European bikes, and even some of our Japanese friends are riding V-twins. If there are big numbers for speeds, I expect them to be Japanese engines, Hayabusa, etc. But, an old motorcyclist is just glad to be on the salt once again amongst all types of folks, stockbrokers to guys on SS. Cool vibe. | ||
| Moxnix |
Rex Chaney is the FM radio station announcer for the BUB meet. Listen if you like. Late start tomorrow, but go to Meridix.com, search "landracing" and hit the listen live for his great coverage of the event. |
