Supercharged BKing


Allthough it's not a real issue, it's something i wanted to improve or at least give it a try. The charger's been driven by a 7 rib v belt and i noticed when i speed up the pully ratio, it needs more tension to avoid slipping, especcially at higher revs acceleration at 100% tps. So i machined a pair of aluminum cog pulleys , fit a 25mm HTD 5M belt. Guiding plates are on the tensioner to keep the belt in place.View attachment 1577676
Will this void any warranties with Rotrex?


About warranties i don't know and don't see a problem. A multi v belt well tensioned so there's no more slip will do the same as a cogbelt. The HTD belt is not a chain, so there's some stretch possible . In advantage , i don't have to put so much tension on the belt , and so less stress on the bearings. A 80-80mm pulley ratio needs less tension as a 85:70mm ratio, because off the size off the small pulley and more force because off the increasing Rpm off the small pulley vs engine Rpm. I give it a try and see what happens, it's 30min. to put back the v belt pulleys.

The supercharger is on the bike from 2012 till now. Since a couple off years i put on the intercooler, that's the only big modification. I drove it for over 20k. now, cruising , but also many times German highway and hollydays . Till now it's very reliable, no problems at all. I never it the rpm limiter or get over 10200rpm, simply because it's almost impossible to ride it without flip over or burn the rear tire at low gears , or risk very high speed wheely's at 4- 5th gear . I use EcuEditor and WoolichRacing datalogger to set fuel and check data every now and then. It doesnt have the best milage on boost, 6 to 8km/ltr is easy done, but when you take care 12-14km/ltr is also possible IF you care about it.
It would be nice to get the oppertunity once to ride a turbo King/Busa to compare . It's around 300rwhp now on stock conrods which i think is the limit. Would be better to put in stronger rods immediately but at that time i thought 250hp would be enough... it's never enough i guess but it will do the job.


Hey I found an old pic of my old GSXR1276cc with blower , that old bike had every engine and suspension and axle bolts all custom made in titanium and gun drilled , as well as rear top engine mounts and suspension dog bones custom made , this is early 90's . Yoyodyne was only selling limited stuff to OZ then . That old bike had Moriwaki Kayaba forks , Brembo billet P4 's and Franks custom 320mm ductile iron floating rotors , Brembo radial pumps ( clutch and brake ) with kevlar lines , Marvic magnesium 3 spoke deltas 17" x 3.5" and rear 6.25 ". Had Ohlins rear shock and offset adjustable Franks triple clamps and rearsets . Ran an extra oil cooler in place of one headlight , and had a modified GSXR750 RR fairing mount and Stack memory tachometer . The swingarm was braced before any real performance testing , and in the end , the supercharger was an expensive unsuccessful experience in all . That bike was rebuilt 1340cc , flatslide Mikuni's and was then very light and capable wheelie and rolling burnout machine . My old mate from Darwin , he actually blew the blown version up , cornering at 250 ish kph , managed to save himself and the rest of the bike from any further disaster . He had a GSXR1186 kitted L model at the time , and he regularly ran 9.6 in street trim on his bike and felt that my 2nd reborn version 1340 was a lot stronger and had a low 9 in it . I blew that one up , and didn't get it to drags for try out . This is why I shake my head in sheer joy and wonderment , at the very fact I now own a reliable , do absolutely everything asked of it and more , 180bhp + super streetbike !! I sure love my Busa . :beerchug:


Sorry Vampire for cutting in , got sent the above pic today , only 1 of 2 pics still around of this bike and I got a bit excited about it all :rolleyes: . Cant seem to post own titles today also .
Anyway , taking nothing away from your absolutely hot as weapon , which I love by the way . :beerchug:
Cheers :thumbsup:


No problem, must be a great time with a bike like that. At that time without the www. as it is now it was a lot more difficult to build something like that. Good memories!
Thanks Vampire , yes if only it had injection like today ... but even then the blower weighed a ton ! It sure as got some looks though when cops saw that belt on the other side . Got to say you , and Bigdev setup's are truly awesome !!:thumbsup:


Took the bike for a ride with the new pulleys and belt. Every thing seems fine. Datalog showed 11psi @ 8000rpm ,exactly the same as before with the v-belt which is a bit more boost then expected because pully ratio now is reduced to 1 to 1.09 , before it was 1 to 1.21.



Finally i got back to the Multi V rib belt. With the cogbelt i had to adjust belt slack more requently and aligment gave some problems under max. load. The belt was pushed to the outside of the pulley's against the guides. Guiding on the pulley might be better, maybe i give it a try next year. For all the supercharger critics, there's no need to do so...


Just passend the 30k mark with the supercharger conversion and still no problem at all. Bike runs like 20k before. The Rotrex is a real good unit with almost no maintance, just checking the belt slack once in a while and changing oil every 5 years . I doubt if it s really needed but better be safe on this. But most important, far more power then you can handel on the street so always exciting.

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