Landracing Forum
Bonneville Motorcycle Speed Trials => Bville Motorcycle Speed Trials Rules Questions => Topic started by: blackdog on April 25, 2010, 02:13:52 PM
-
hello to the all the bub folks.
A Friend called me to see if I was interested in a Yamaha xj650.
"Naw... I don't need another project."
"but it's got a *TURBO*"
"and it's *FREE*"
pick up the SCTA rule book from 2007 and hey no record for 650 production blower! wooo hooo!
Fast forward 6 months and.....
Rude Awakening #1, it's not a 650, it's 653cc now in the 750 class, where there is a record run over 200mph.
RA #2. the tires must have a speed rating for the record in your class.
RA #3. The only speed rated tires that will fit the rims are too wide for the rims and to fit between the forks and swing arm.
The top speed for this bike (with the shaft drive gearing) should be 121-127mph. the tires on it are good for 130.
Now I've given up on setting a record, but after the time and money, I just want to run.
I've looked through the "Run What-cha Brung" regs on this site, and the AMA regs.
Do I understand that if the bike passes technical inspection, I don't have to "class" the entry?
-
I have a Yamaha XJ650 too. They are great reliable bikes and part of the short-lived production Japanese turbo bikes of the early '80s. Run Whatcha Brung at BUB is just for fun only and there are no classes because you are not going for a record. You just need to pass scrutineering and pay the fee. You will get an official timing slip though.
BUT you can enter the bike at BUB in the competition side as a 750 P-PB. That record is open. Go for it.
Don
-
Don,
this is too good.
the records are not the same for SCTA?
do I join AMA first?
The bike looks like a fun bike for the street, although My habits are more of the duel-sport (Transalp), touring-cruiser type(gl1500).
but after sitting out under a tarp for ten years, not likely to see the street again.
I am also in the Seattle area. (north beach) where do you do speed testing at?
-
Bonneville willie buchta
-
No, the records for SCTA/USFRA and AMA/Bub's are in no way related, and yes, you must join the AMA to be allowed to run at Bub's.
-
Speed testing? What speed testing? You just build the machine to the rules and cross your fingers whatever you did made it go fast.
But at BUB, the WWYB line is shorter, so if you want to pay that fee too, you can get in some test runs. About the max runs per day in the competition line is two and maybe NONE.
Just make sure you read the rules and modify your bike to pass tech.
Don
-
well, the AMA it is.
Thanks for the input, I can read the rule book five times and not get the details.
HI HO
-
Cool. You sound inspired again!
Do you have the body work for it? Or will you run it naked this year?
-
You should be able to find tires,I did for my sons bike back in 2006,ran a Turbo Seca at SCTA event. Good fun.Plugged line to wastegate so it made 15 psi,made a shorty exhaust so no muffler,IRC he went 127/128
Last couple years Bubs lines have been extremely short, we were getting multiple runs every day.
-
Cool. You sound inspired again!
I always intended to find out how fast this basket case could go, even if it meant sticking a gps on it and running down the street in front of my house.
but.....
the donor/sponsor wanted to go to the salt as a participant (not a spectator)
Do you have the body work for it? Or will you run it naked this year?
I'll use the bodywork even though it might be designed more to keep the mud off polyester on the way to the disco than for max speed.
Without the fairing the computer/gauge cluster is so big it might count as streamlining.
firemanjim..... Ive got tires for the speed the bike can go,(130) but will they let me run in a class that has a higher record (200+)?
on mine the wastegate muffler rusted off so I made a vented plug. Is the popoff valve enough to keep it from going postal?
Do you guys do both events?
-
Pretty sure I found V rated,and you could shave those.
Sorry about the 200+ records--those would be mine and my partners. LOL.
Thinking of Bubs and WOS this year with our 750.
You can always do RWYB or 130 club.
-
Dog, jet your bike on a dyno in Seattle running on a good grade of premium gas without ethanol. Use ERC 110K at Bonneville. Your jetting should be close and you will not need to test ride it at full speed on the street. It would be a good idea to take a plug reading at B-ville to make sure everything is OK.
Go for the open record. These records do not stay open for long.
-
The BUB rules do not specify any particular tire rating. It just says it is up to the rider to determine if their tires are safe. So for the 120-130 mph your bike will go, I would not worry too much about a speed rating or shaving them. Just get new or used, recently manufactured, good condition stock sized and rated tires and you will be good.
Don
-
firemanjim..... I don't think your sorry at all (HA HA)
wobbly........thanks for the tip on not using ethanol, what happens if you do?
On my last trip to the salt, my 250 that tested out to 80+ at sea level only hit 64.338 at Bonneville, hope the turbo will handle the altitude difference.
Don....tire shaving is new to me; who shaves them?
why does a shaved tire handle speed better?
The tires I have are new, better to shave them anyway?
-
The benefit of shaved tires is so that the profile can have better traction on the salt surface. Additionally the less rubber on the tire the less likely it is that the tread will peel off. Shaving is only is good for real high speed bikes. At about 180 mph tires start slipping because the drag exceeds the traction. So the lower speeds don't need any special conditioning.
One season I thought I was really smart and brought a Shinko utra soft drag race tire to Bonneville. It lasted about 3 miles and was shredded. The heat and friction of slipping on the salt just ate it. The carcass held air, but the tread was hanging off in big shredded chunks. Live and learn.
Don
-
"...tire shaving is new to me; who shaves them?"
Nate Jones Company -- see ad in the rulebook. He's in the Los Angeles area -- has supplied Bonneville racers with tires for years - and has been known to visit customers' pits to check up on his product.
-
Save yourself a lot of problems .....AND READ the BUB RULES, regarding tires......(the rules are on the BUB web-site)
-
Don.........thanks for a explanation I can digest, IE: shaved tires are of no benefit for my power/speed range.
Seldom Seen.......that explains why the local tire shop had no idea what I was asking about, must be something unique to the salt?
Bak189.......I've only been a 99%er since sunday, but I looked over the supplemental regulations on the FIM-BUB-RWB site.
2.N. tires tells me that the tires are "rated for the appropriate speed" and "use is at the Sole discretion of the participant" *Bingo* this is just right for my setup.
The only other differences I've seen are the oil plug safety wire and zip tie the kickstand.
they don't need the 15deg. limit on the steering? after all the midnight oil..........
-
The jetting method I use works with summer blend premium unleaded ethanol free gas and I have not retried it with ethanol gas. It may work with ethanol gas but I do not know. I can get ethanol free gas so I use it for the jetting. The bike runs OK on ethanol gas in normal street use.
The ethanol gasoline does not age well and it is inconsistent in quality. Also, the ethanol does not produce the power of straight gasoline. It will not hurt the engine but it might hurt the carbs. The stuff ate up the floats and gaskets on my 1986 Yamaha.
-
wobbly..... thanks, I'm learning a lot on this forum
-
Blackdog--not too sorry,you are correct! Turbos love Bonneville,not affected by altitude to the extent the naturally aspirated guys are!See ya at Bubs.
-
Firemanjim......... that was my first thought when I heard the word "turbo" in connection with this bike. The altitude difference seems to be a two edged sword, It might be a little easier to move through thinner air, but harder to get torque out of the motor, just like airplanes. The solution there was to supercharge. should work here too.
I haven't worked with a turbo before, but I like the idea of using waste energy to boost power.
-
to the folks who helped with advice and the the thousand (+) viewers who might be curious about how it turned out:
I entered the bike as - 750cc - "modified partial streamlining - production blown" this was OK.
the safety inspection went well but I had to wire more stuff and wrap the gas lines (misunderstood difference between "fuel line- gas line) in the rules.
1st run fuel problem 84 mph (too embarrassed to pick up timing slip)
2ND run 120.848
3rd run kill switch malfunction dnf (but limped back to pits)
4Th run 121.405
5Th run 125.345 (12mph tail wind)
6Th run 122.080
7Th run 104.621
8Th run 120.691 (down run for the record)
9Th run 116.440 (return run)
too lazy to pull the head off to prove my 653cc didn't exceed the 750cc class so no record in the book.
I got my moneys worth and my sponsor is happy.
thanks for the help/advice
-
Blackdog, it looks to me like you had a very successful first trip to BUB and Bonneville. Putting 9 runs in makes from some great experiences to log into memory.
Will you be back next year to up your times and log it into the record books?
-
Cole222- haven't decided yet, there might be 5-10 mph more in the ol' scooter if a new rev limit can be set. but then the gearing, tires, and fuel injection or carb, it just goes on and on.......
I'm not in very deep on this bike so if I want to see life at 130-150 range, might be better to look for new wheels.