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Trojan
| Posted on Wednesday, December 05, 2007 - 09:30 am: |
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hey trojan, where in england are you? i'm from southport originally. i'd love to get back there.its been about 27 years for me. We are in Darlington, County Durham. Trust me, you wouldn't want to come back here now. The country has changed an awful lot for the worse in 27 years I'm afraid. |
Babyhuey
| Posted on Wednesday, December 05, 2007 - 10:16 am: |
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thats what i've heard, i still have sister and an aunt and uncle over there. i'd still like to come back and visit at the least. that's the deal with pistons for the xb? that's my best options with out going over board money wise.any experience with the new s/e xl heads,i sell quite a few of them but only on 883 conversions and never put any on an xb. if thats a good choice they would be cheaper than having my stock heads redone.-andrew |
Reepicheep
| Posted on Wednesday, December 05, 2007 - 12:07 pm: |
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Blake, now you have me thinking about goofy but interesting ideas... Could you take a stock XB, rework the cams, intake, and exhaust path, and convert it into a supercharged single? The idea would be that the rear cylinder is a compressor, and the front cylinder is the engine. Maybe build a bolt on supercharger kit that replaces the whole rear jug. I'm not sure why you would do it, except maybe as a cheap way for a wide open singles racing class. Or just to say it could be done. Or maybe to race on pike peak |
Blake
| Posted on Wednesday, December 05, 2007 - 06:58 pm: |
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I don't see how you could get the rear cylinder/piston/etc assembly to act as a supercharger, but removing it and bolting on a blower sure would seem doable. That Roger Goldammer fella has done a few customs with blown Big-Twin-based single cylinder engines. Very cool stuff! Sure sounds like a fun project, which is one big reason I like the idea. Come over this weekend and we'll work out the plans. |
Knickers
| Posted on Wednesday, December 05, 2007 - 10:00 pm: |
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Using one cylinder as an air pump for forced induction for the other cylinder is a fascinating idea. You route the exhaust port of the pump cylinder into an intake manifold for the firing cylinder. But you have to think about reworking the cam drive for the pump cylinder to turn at crank speed rather than 1/2 that so you get a 2 stroke air pump. That's the way you get the manifold pressure up - two gulps of air from the pump for every intake stroke of the firing cylinder. If you run the pump cylinder as a 4 stroke you're just wasting energy cycling the same air charge from one cylinder to the other. I suppose you could keep the pump cam drive at 1/2 speed but put two bumps on each cam to make it a 2 cycle pump as well. Matt - I'd be interested to know how you get 407 lbs. My xb9 with full fairing, chain conversion (520) and stock battery weighs 440 lbs with a full tank. Is that weight with stock wheels? I can't seem to find much more than another pound or two of stuff to take off. I keep reading the HP & weight stats of the racing buells in Roadracing World and they all seem to be just over 400 lbs - I figured they had no starter and super light batteries or something. Kurt (Message edited by knickers on December 05, 2007) |
Reepicheep
| Posted on Wednesday, December 05, 2007 - 10:23 pm: |
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I was thinking just run the 2nd cylinder as a simple compressor, that builds up a small pressure tank (cant spell resivour). This tank feeds the intake (fuel injected). You could regulate the pressure to be whatever is needed, so your fuel injection system could meter in not just fueling rates, but "airing" rates as well. Makes more sense to just replace the second jug though, and tie right onto the crank like a normal cylinder would. That would make that cool goldhammer thing look even more organic and reliable... no exposed belts. Though again, at the end of the day, you would probably be no better then had you just left the other cylinder, unless you are riding at 35,000 feet |
Diablobrian
| Posted on Wednesday, December 05, 2007 - 10:36 pm: |
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sure sounds like it'd be a cool fire-blast (blast motor in a firebolt chassis) project to me! |
Diablobrian
| Posted on Wednesday, December 05, 2007 - 10:48 pm: |
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There isn't a whole lot to be gained in thunderbike below 400lbs if (as almost all are) your motor is putting out close to 100hp. You don't want to cut power:weight (1hp:4lb) too close and get burned by the dyno after the race. Getting an XB significantly below 400lbs can get VERY expensive very quickly... We were/are around the 405 mark according to the ASRA scales and that was with no starter, smaller battery, all excess threads cut off of fasteners, lightened crank and reciprocating parts, and everything excess we could find removed. then again Matt is talking about British pounds, and those are feeling pretty heavy versus the American equivalent these days eh?
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Blake
| Posted on Wednesday, December 05, 2007 - 11:30 pm: |
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Kurt, Matt stated that weight was for a half tank of fuel. Now remove all the street stuff, including kickstand, headlights, tail lights, passenger pegs and bracketry, switch-gear, mirrors, heavy padded seat, heavy muffler, license plate and holder and turn signals... then put on a lightweight muffler. Swap the steel front sprocket for a nice aluminum alloy one. Mount up some racing tires in place of the heavier street going variety. It all ads up. |
Knickers
| Posted on Wednesday, December 05, 2007 - 11:47 pm: |
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Blake, Yup I've done all that. I figure half a tank of fuel is around 15 lbs which puts me at 425. No kickstand, lights, passenger pegs, switchgear, mirrors etc. Running a micron full exhaust which I realize isn't the lightest option out there. I also got AL sprockets, Michelin Pilot Race skins and a fiberglass solo tail. Oh and a Hoban Bros. Dark Horse lightened crank. I must have 15lbs of shot in the fuel tank or something.
Maybe I need helium in my tires. :-) |
Blake
| Posted on Thursday, December 06, 2007 - 12:43 am: |
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The full fairing and chain conversion would add some weight back, but I think your scale may be off. |
Diablobrian
| Posted on Thursday, December 06, 2007 - 03:22 am: |
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Matt had a full fairing on his race bike too. Gotta have space for the sponsor's logos y'know! Do you have the starter, full size battery, lighter rear subframe (shortened and made of lighter tubing), all the excess wiring in the harness (it adds up) and starter ring on the clutch? Of course removing all that stuff will put you into a position where you will need rollers or a start cart to get the bike fired up. If you go even further by getting rid of the entire alternator assembly and running total loss a very small battery will give you enough power to run a sprint race, and will recharge very quickly between races, but these are pretty extreme mods that can end your race if the bike dies on the course. The rider has a very hard time push starting the bike (even with corner worker help) on the more radical high compression motors. However, the gamble is that it won't die and the lighter weight will be an advantage in the corners and accelerating where lack mass counts the most. (Message edited by diablobrian on December 06, 2007) |
Gearhead
| Posted on Thursday, December 06, 2007 - 06:37 am: |
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Swap the steel front sprocket for a nice aluminum alloy one. Blake, I'm running the belt on my race bike yet, where can I find the above mentioned aluminum sprocket? |
Gearhead
| Posted on Sunday, December 30, 2007 - 03:25 pm: |
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Race bike only questions... Is anyone using a quick racing throttle like the one's sold by Yoyodyne? I'm also curious if anyone is using any of the easy pull clutch assist products like the Muller Power Clutch kit? What are your impressions and suppliers? Thanks in advance!! |
Blake
| Posted on Sunday, December 30, 2007 - 06:43 pm: |
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"where can I find the above mentioned aluminum sprocket?" I got mine from American Sport Bike. |
Gearhead
| Posted on Sunday, December 30, 2007 - 08:22 pm: |
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Thanks, Blake, but I found what I was looking for, an aluminum transmission belt drive gear, at Evolution Industries. Unfortunately, they are out of stock but will hopefully be machining up a batch within the next month or so. |
Truckstop
| Posted on Thursday, July 10, 2008 - 12:39 pm: |
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I'm baaaack. Ok, so I'm doing more research again and getting more serious about this, trying to put together a budget for next year. (Still don't know what, if anything I'll be riding next year. The ULWSB rule change was postponed until '09 so I'm still on the Hawk this year. Latest news is that SVs will be restricted to 650cc's but otherwise get SuperBike rules.) 1.) Best options for Chain conversion, (please provide links where possible, I'm doing searches, but would like to know what you guys have used and liked) what have you guys used and what do you like best. I want to do this because the two tracks I'd be running at, BHF and RA are *completely* different in that BHF is tight and twisty, whereas RA is a dragstrip with some turns. The swingarm kit from Hal's looks cool, but it's too much $$ for me. 2.) How many tires do you go through? I'm spoiled in that I can make one set of tires last a whole season of races, practices and trackdays since I'm on a bike with no horsepower. Y'all go through a rear each weekend I'm guessing? (I run Michelin Pilot Race and will stick with that due to the discount I get.) Thanks! |
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