Cycle News - Archive Issues - 1980's

~ .- -, e (.0 00 Q') ...... C(j c-r ..... .... ...- '0.. ~ * .. ,.. . .... • .. The contestants, ready for a dragstrip shootout: Honda VFR750F, Suzuki GSXR750. Yamaha FZ750. They're all high-performance 750s. Dragsfrip comparison: Honda VFR750F vs. Suzuki GSXR750 vs. Yamaha FZ750 Sueefbikeshowdown By John Ulrich There are n ow three J ap an ese manu factur ers in the high-performance, sporting 750cc sweepstakes. In m odified Sup erbike tri m, th e H onda VFR 750F, the Su zuki G SXR750 a n d the Yamah a FZ750 are close, although Edd ie Lawson 's Ya maha and Wayne Ra iney's H onda had some top speed and 22 taller-gear acceleration on Kevin Sch wa n tz's Yosh im ura Suzuk i in th e 1986 Daytona 200. In Stock Pro ducti on-class road racin g . Suzu ki GSXR750s are clea n ing up , lar gely due to th e fac t that most of the best ride rs ride GSXRs so th ey can win th e serious co nt ingency mon ey p osted by Suzu ki. T he re are st ill a few ri de rs re m a ini ng co m petitive o n FZ750s in d iffere nt pa rts of the co u n try, but th ey' re at a di sad vantage. T he H o nda ha sn ' t been read ily a vaila ble lo n g en ough to judge its impact. And th e winni ng Stock P roduction race bikes typ ica lly have a ftermarket shock absorbers. re-jeued carb uretors, ad va nced ig ni tion tim in g , engi nes bored I m m oversize with raci ng va lve jobs ' a n d ba sic bl uep rint in g ; they are , si mp ly. tun ed to th e limit of the ru lebook. T hen there' s th e dragstrip . Yamaha and Honda ha ve bot h hi red Ja y Glea so n a nd m ade forays to th e co untry' s fastest dra gstrip , Baylands Raceway Park in Fremont , Ca liforn ia, in searc h o f num bers ent itlin g first the FZ750. a nd now the VFR 750F,to be billed as " the fast est and q uickes t 750cc street bi ke." When Yam aha did it , G leason 's best run on the FZ750 was 10.87 second elapsed tim e wi th a termina l speed o f 124.13. When H onda did it months later, G lea son went 10.84 sec. a t 125.17 mph. (G leason hasn ' t r idden a Suzu ki G SXR750 a t Frem ont). Wh en Yamaha or Honda go to th e dragst rip with G leason, th ey a ren' t foo lin g a ro u nd . T he bikes are as good as th ey can be. Mech ani cs are in attendance. G leason is the quickest a nd fa stest stock -bike pi lo t in the known world , an d he's al so rela tively light, weighing 130 pou nds .in stree t clo tlies. And it's difficult to mak e a direct co m parison because dragstrip co nditio n s ca n vary from day-to-da y, a n d co ndi tions such as ava ila ble tractio n a n d air den sity affect time a nd term in al spe ed . Bu t wh at a bo u t stock mo to rcycles, as in the kind sitt in g o n deal ersh ip floors arou nd th e co u nt ry, wi thou t specia l prepara tion , wit ho u t a sq ua d o f m echani cs hover in g abo u t, ridden by a 145-po u nd p ilot , each a t th e same dragstri p on th e sa me day ? T hat's wha t we wa nted to kn ow w hen we wen t to Los Angel es Co unty Raceway near Pal mda le, Ca li forn ia with one eac h 1986 H onda VFR750F, Yam ah a FZ750and Suzuki GSX R750. T he track, loca ted in th e hi gh desert , is at 2500 'fee t eleva tio n. It typ icall y ha s excell ent tra ction, but th e a ir is thi n ner th an the air a t sea level. For that reaso n , the NH RA has developed co rrectio n facto rs for ,use in determ ining o fficia l reco rd s. According to th eory, m u lti p lying ela psed ti me and term in al speed fro m LACR by th e co rrec tio n facto rs (.9679 for elapsed time, 1.0339 fo r te rmi na l speed) brin g the figu res into line, wit h figures achi eved a t d ragstrips a t sea level. T h e bik es we used were stoc k prod uctio n m o torcycles. withou t special set- up or a tte ntio n . We ra n th em with stock air pressu re in th e tires, wi th the rea rvi ew mi rro rs a ttac hed, with , th e sus pension sett ings a t th e sta nd a rd p ositions. All th ree bikes carried a bo u t two gallons of gaso line when we sta rte d o u r run s. For backg round in forma tion , we weigh ed eac h mac h ine on a cert ified sca le, with a fu ll tan k of gas. T he Honda VFR750F weigh ed 508 po u nds! co m p a red to 469 fo r the Su zukt GS X R750 a nd 529 po unds for the Yamaha FZ750. T he Honda is a four-va lves-percylinder, DOHC, water-coo led V-fo u r in an a lu m in u m fra me. T he Suzuki is a four-va lves-per-cyl in der , DOHC , oi l-coo led in line-four in an alum inum frame. T he Yama ha is a fivevalves-pe r-cylinde r, DOHC, wa tercooled inline-four in a steel frame. I started with th e Honda , and it im mediately beca me a pparent that th e H onda m ak es a lo t of power an d ha s a very narrow clu tch engageme nt p o int , ma kin g it difficult to leave the lin e smooth ly. T he cl utc h is basi call y in or o u t during ha rd lau nches; typ ica lly, th e engine bogged or the bik e hook ed up and wh eelied as the cl u tch sna pped into fu ll engageme n t despill' my bes t effort s to avoi d th at. T h is is no thing new. T he 1984 Honda VFIOOOFmad e a lo t of p ow er and had a n on /off cl utc h, a lso, and it wa s ha rd to launch a t the d rag strip , too . Now, th e 1986 Honda VFR750 is th e same way . In 12 passes (made in sets of th ree with cool-off time in between sets), the Honda' s best u ncorrec ted run (as seen on th e dragstrip tim ing eq u ipme nt ) was 11.46 sec. a t 119.36 mph, o n the n inth run . T he H o nd a mad e si x o f th e 12 runs at 119 mph a nd reached 120 o n onepass , The rest o f the passes were 118s a nd a single 116 wh en I m issed a shi ft. I never co u ld ach ieve th e ideal lau nch - fu ll th ro ttl e, a t redl in e, smoo th ly and q u ickly engaging th e cl u tch - with th e Honda . Its gra bby cl u tch rem a ined an irrita nt to th e en d . The Yama ha's clutch is m uch bet ter, bu t the Yamaha obvio usly doesn 't make as m uch p ower as th e H onda , a nd it's a lso hea vier. I go t severa l ' close-to- pe rfec t passes o ut of th e Yamaha , the best unco rrected run being 11 .51 sec. at 117.49 on th e ni nth p ass. Most of th e Ya maha 's ru ns produced terminal speed of 11 6 m ph , with on ly two passes in th e 117s; two wer e 115s a n d one was II I wi th a missed shift. T he Suzuki's cl u tch is sligh tly better than the Yam aha 's, a nd th e co m bina tion of th e excelle nt, co ntroll a b le clu tch ac tio n a nd the ligh test weight o f th e th ree mad e it easy for me to co nsis tent ly launch a t full thrott le at redline: th e bi ke left th e line ha rd a nd stayed fla t with out a ny whee lie problem . T he Suzuki's best u ncorrected time was 11.44 sec. a t 117. 18, on th e sixth pa ss. T he Suzuki made four o f 12 pa sses a t 117 m ph, with two passes eac h at 116, 115 and 114. T he fastest pa sses came in th e 'm idd le ru ns, six, seven, eigh t a nd n in e. In th e last set , th e Suzuki ran slo wer , incdi ca tin g tha t it was ge tting h ot and wasn 't cooling off as q ui ckly as th e o ther two mach in es. Applyin g th e N H RA correctio n factors gives us 11.09 sec. a t 123.41 for th e Honda , 11.14 sec. a t 121.47 forth e Yamaha, and 11.07 sec. a t 121.15 mph fo r th e Suzuki. L ooking a t term in al speeds, th e H onda ma kes th e most pow er , bu t its elapsed , time is hurt by a grabby clutch. T he Yamaha and th e Suzu ki mak e abou t th e same p ower , bu t th e Suzu ki ha s th e adva ntage du e to lighter weig h t. ' In stoc k -cl a ss roa d racin g , th e Honda shou ld ha ve a power a nd acce lera tio n advantage, but tha t advantage ma y be offset by th e Suzuki's lig h ter weig ht and o ther handling factors. Riders of Yamaha FZ750s shou ld, th eoret ica ll y, ha ve to rid e harder to co m pe te with eq ua l rid ers o n H o n d a s 'a n d S u zu kis . Bu t to know fo r sure, it will ta ke a race track test , and th a t's a noth er story. Obvio us ly, n one of thi s takes in to acco u n t streetabil ity, co m fort, gas m ilea ge. etc. For th at , stay tu ned .

• Cover