Cycle News - Archive Issues - 1990's

the ru le book are good eno ugh for Italy, it'll work okay Down Under, too ! I The cha nce to ride the 750-V8 racer at 'the scenic, sw itchbac k Broa dford ra ce ra ck o u t in th e bu sh n or th of M el bourne provid ed a hands-on u pdate on two yea rs of Dry sd a le d evel opment. P lus , I have to admit, it w as a personal ben chma rk in track testing: I never rod e a racebike wi th mor e than six cylinders ;u ntil ·now . . l At first I was all set to wea r earp lugs to ride the Drysd ale, but then I realized J'd ha ve bought tickets to th e co nce rt, but not have heard the music play! Liste ni n g to the hau n tin g h o wl issu in g fro m the V8's twin und ersea t exha us ts as Drys d al e wa rmed it up n ot o n ly mad e the flesh ting le, it also p rovid ed a window on the wo rld that Grand Prix racin g m ay ye t become once aga in, if p romi s ed p lan s to pus h th r ou gh a . .1000cc fou r-s tro ke form ula against the ' vested interests of the two-stroke ma fia d o in fact ach ieve real it y. We ll, if tha t means m usica l multis like th e Aussie V8, bu t bu ilt by major ma nu fac turer s lik e Hond a o r Kawasaki or even MV Agusta, then sign me up for season tickets! One reaso n why World Superbike sco res with spectators over GP racing anywhe re exce p t Spain or Japa n is the sound of the m usic - and the V8 Drvsdale is the same, only mu ch more so: it's the closest thi ng there is today to riding a 195O/60s wo rks GP racer. Even mor e so tha n a 15,000 rpm Honda or Kawasa. ki Su pe rbike, u nderlining th at the d ay the music died wit h the introd uctio n of n oi se re stri cti ons ba ck in 1976, co mpounded by the restri ction on the nu mbe r of cylinders imposed in'1 970, was a very sad one. Listen to the Drysdale V8 being warmed up on the company' s Web site (h ttp :/ / werp le.net.au/ - iw d) and then tell me I'm wro ng! Mind you, yo u hav e to rid e the Drysdale V8 like a two-st roke racer off the line or ou t of s low turns, winding it up on the d u tch to coax it into the po werband and ove rcome the lack of in erti a fro m the milled-from-solid cranksha ft, weighing just ove r 12 p ound s, which starts life as a solid billet of metal scaling a massive 97 pounds! Rather incongruous ly, the V8 starts on the button in pit lane, thou gh the Kawasaki ZZ-R250 starter motor has to wor k prett y hard at sp inni ng twice as man y cylinders as it' s us ed to coping with normall y, before t he engine finally fires up a nd se ttles down to a trademark V8 burble a t low rev s. Bu t the n, as yo u blip the throttle to ma ke it sing, yo u realize the eight 32mm Keihin ra cin g flats lides Drysda le has now fitted on the racer, compared to the ~V Mikunis on th e street protot ype I tri ed two years ago, ha ve quite a stiff combined action. And the twistgri p isn' t a very fast-action one - it could really do with being speed ed up. "W e' v e tri ed se ve ra l a lte rna tive return springs, and the lightest ones that w ou ld overcome the suc tio n effect and ac tua lly close th e throttle s till ha ve a stiff action," Drysd ale says. "We've also tried larger cable wheels, for more leverage , bu t these slow th e throttl e actio n down too much . There' s ju s t no way aro und the fact that eight separa te th ro ttle slides have to be opened at once, and that takes a lot of effort - making d evelopmen t of a com pa tible fu el in ject io n system a priority, for the streetbikes as well as the racer." True to his word, Drysdale has been wo rking on his own EFI system for the past six months, usin g his own d esign of F1-type rota tin g-barrel throttle bodies, coupled wi th Bosch in jecto r s and a n AustralDrysdale-made Motec ECU with (Below) Exotic simplicity: The "otto carb" Drysdale VBengine is capable of produc ing in the neighborhood of 115 bhp at the rea r wheel at 13,200 rpm. Elect ronic fuel injection will be the next step in increasi ng performance. Despite the des ign, the engine utilizes many over-the-counter Yamaha parts for eas y se rviceab lility. (Right) American supertuners Vance & Hines have played a role In the deve lopment of the Drysdale, as a made-to-order V&H Powerpak ignition co ntrols the fire, replacing the Yamaha CDI black boxes formerly used on the mach ine. so ftw are sp ecially d eveloped to co pe wi th the high revs - as much as 17,000 rpm - of the V8 engine. It' s this w hich will be fitted to the str eet V8s (thus also reducing emissions and improving fuel consu m p tion, two cri tical fac to rs on a bike with so many cylinders), after first bein g R&D'd on the racer. But once yo u ge t used to the heavy, rath er slow thrott le actio n, the flats lides cu rrently fitted to the bike give s tro ng pickup, with quite a bit more power on tap th a n o n th e CV-s h od pro totype I r ode t wo yea rs a g o . The mu s cu la r , lu m py V8 m oto r p icking up revs s o e ffo r tlessly b ef ore smoothi n g ou t at higher rp m to delive r its haunting. hig hpitched howl. Get the V8 turning above 9000 rpm and the Drysdale sings sweetly as th e read in g o n th e m ulti- programme PI di gital tac ho rushes effo rtless ly towards the revlim iter. orrnally d ialed in at 16,000 rpm on the racer, it was lowered tojust 14,000 revs for this ou ting. with the engine being fresh off a rebu ild and needing to be run in . But even tapp in g th e gea rleve r a t 13,500 rpm to hit a h igh er ra tio on the ex tra cta bl e, ca s se tte- ty pe, s ix-s peed cl u ster, wh ich u ses Yamaha YZF 750 gea rs and o il- ba th clutch, lea ves th e e ngi ne still s qu arely in the m e aty powerba nd abo ve 11,000 rpm and running as sm oo th as silk, yet s trong as s teel, back to the red line. The level of performance is on par with a well set-up Du cati 916SP or Suzuki TLlOOOR. That me ans around 115 bhp at th e b ack wh eel at 13,200 rpm - in line with Drysd ale's claims for 140 bhp at the crank, with added music! It has unexpectedl y good midrange punch, which on a bike The unusual chassis configuration mounts the Ohlins rear s hock perpendicular to the rear wheel. like this means anywhere fro m the fivefigure rev mark upward, though it will pull cleanly ou t of a tum as low as six gra nd . Th e o n ly downsi de to th e p erforman ce was a pretty big flat spo t arou nd 8000 rpm, which w as a bit d ifficult to wo rk arou nd on a tight track like Broad ford wit h so many slow turns, wh ere on the gearing fitted I could only just grab fou rth gea r on th e top s tra ig ht. Thi rd wo uld have been all that was possible if I' d been ab le to re v it right ou t to 16 gra nd . It' s not reall y fa ir to criticize a bike like this for being a bit of a handful aro u nd a track it' s not at all built for ; it's rather like testing Mi ck Dooh an ' s NSR500 at the Sachsenring. And I'll bet that at big tracks like Assen or Mon za or Phillip Island, keeping the V8 racer on the pipe would be mu ch easier. In fact, it' s a cre d it to Drysdale and hi s crew tha t the bik e beh aved as well as it did as a fish out of w ater at Broadford. But thou gh I got quite adept at keeping the r evs up a n d /o r coa xin g it through the flat spot, this is an area the team d oes need to wo rk on in conjunction with the fuel in ject io n, b ecause Drysd ale says he has an extra 8 bh p on tap just-b y sho rteni ng the int ake stubs and bellmouths to the maximum. This is just as Du cati has don e on its '99 Works superbike - but on the V8 it comes at the expense of an eve n bigg er hole in th e powerban d . "Thi s is exh aus t-re la ted, " Dr ysdal e sa ys, "and part of the engine management ·R&D we' re d oing Is.to d evelop a fully-mapped ER package wi th compa tible in take len gt hs and exhaus t system, w hich w ill make th e bi ke 'ca rbu ra te' properly. We kn ow wha t has to be don e, and mapping the fuel injection correctly will be a big factor in ge tting it to run cleanly, as well as stro ngly," Getting t h e r a cebik e to ru n co o l en ou gh with th e ex t ra power on tap entailed junking the underseat radiator of the street prototype - the V8 en gine's bulky architectu re preven ted a sufficien t volume of high pressure flow of cooling ai r from reaching it - an d replacing it with a pair of fro nt -mo u nted radi ato rs. en en en - > CI :::> < 25

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