Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/126245
. Bast Bros. to test E ne~est All-American ~ engine ~ , (j) 1"""'4 "scra tc h ," , bu t ' m o re like a h ig h pitc he d, a lmost too high to hea r , J ripping , teari ng, squea ling as layers of I soft rubber peel off the frantically 1 turning tire, 4 The start is nothing. It's the shift , int o third gear when the turbo really kicks in . The front wheel leaves the ground again , th e bike straining and settling back against th e wheelie bar , my spine being for ced hack into th e step in th e sca t. 10 ,500 rpm is rea ched instantly in th ird , again in fourth , and ,aga in in fifth . The pow,'r never sto ps. It's like comi ng on the ca m and neve r fa lling off th e po wer. T he curve is , straig ht line , incr easin g with rpm , j ust \(Tl0re a nd m ore a nd more horsepower as th e revs clim b , turning faster a nd goi ng fast er , accelerating even hard er, all th e pow er and sp eed and accelerat ion multiplying a nd growing at an unreal rate . . The boost gauge hovers around 20 pou nds of boost. The ET lights flash past , and wh en th e Suzuki flies ~h roug h th e termina l speed lig hts, the tach indicates 11,500 rpm , still pulling fas ter and harder than evcr. The bike ~ pe rfect ly sm oo th and stable'. a nd moving very , very fas t. ,." Back in t he pi ts . H ahn tells m e t ha t .the m oto rcycle has accelerated fro m z~ro to 131.57 m iles per ho u r in one quarter m il e . tearing dow n the pavement distance in 10.56 seconds. I Wha t Hahn does no t have to tell me is t hat ridi ng the American Turbo- Pak GS7 50 at the d rags is a very heavy-duty rush . " I didn't get a chance to ri de the bik e on the street, but on the return roads it seemed to run like a sto cker when the turbocharger was not kic king in. Turbochargers are peculiar mechanisms. For instance. if yo u' re riding a turbocharged motorcycle at 5 miles per hour in third gear , ~ownshi ft i ng to second and gassing it will not cause the tu r bocha rger to provide boost or more power than a tock motor. The turbocharger re all y boosts erformance in the upper gears . orking under load. The bike has to e moving very fast a lready before t he u rboch arger has much affect. To be used safely with more than bout five pounds of boost , an engine ust ha ve fo rged pistons, T he forged isron kit in t his Suzu k i upped isp laceme n t to 870cc . T he ur boch a rger kit cost $995 , p lus 120 .65 for raci ng parts (larger turbo n it , fuel pu mp , la rge diameter tai l ipe ). plus $212 for th e MTC p isto n it (pistons , ri ngs , wrist pins , clips , opper head gasket, O-rings) , plus $38 or a heavy-duty cylinder stud kit , Ius S34 .95 for a heavy duty valve pring kit. The total retail cost for the ngine, and. \!1r~ ,?ci},\rgn p.aF~~ n rhe ' (Above) Bill Hahn, (Below) start of a rush. Suzuki is SI .4 0lJ.6 0 , plus tax for Californ ia resid en ts, The basic turbocharger kit incl ud es: Turbo cha rger, ca pa ble of turning 100 ,000 rpm , but probably turning a maximum of 60 ,000 rpm in actual use . Shaft bearings are pressure-fed oil from the engin e lubrication system . . Carburetor /intake ma nifold , a 38mm Bendix with accelerator pump mounted on a ba lanced- Flow inta ke ma nifo ld . Bo ost ga uge, m a d e i n W est German y. ind ica ting u p to 30 pou nds per sq uare in c h (psi) , g lyceri ne da mped . K&N a ir filter. Exhaust header, tail pipe. a nd was te gate . the waste gate a llowi ng the amount of boost to be dailed in with an allen head wre nch. Rich horsepower freaks can ge t all this st uff fro m American T ur bo- Pak , 2127 S. Hathaway , Sa nta Ana . CA ' 9 2 7 05 . ( 7 14 ) 557 -7004 . B ut be forwarned . Once you sa il thro ug h the lights a t 131.57 , just about anything slower is go ing to seem very tame. The first 1.7 runs # I. 2. 3, 4. 5, 6. 7. 8. 9. 10, I I. 12 . 13 . 14 . ,15. 16. 17. l ~ Elapsed ti m e T erminal speed (seco nds) (miles per hou r) 97, 93 14 .22 110,4 2 13. 09 1 0 9 . ~9 13 ,0 I 119 .24 12.28 11.84 122 .62 122 ,44 II. 78 12.05 . 120. 64 123 .62 IU 6 125.69 11. 09 124 .4 8 11.1 5 127 ,29 I l.I 4 10.72 129.31 129 .31 10.79 128 .93 Il.l3 ~ 1 0 , 86 131.57 131.57 10 .62 . JO ,56 ... J 131 ,57• ,. ' I H • • ' Mike Bast. catching the enthusiasm that runs high at the Maely ranch, has been working day and night with the rest of the crew on final assembly and testing of Ken Maely's four-valve OHC speedway engine. It's a race with the calendar as Mike and brother Steve are scheduled to debut the complete Maely spaedway bike at the Houston Astrodome January 30. The first shakedown runs started during the January 22-23 weekend. The unsinkable " Shoeman" is selling a complete package to racers: motorcycle, spares, and a complete racing/maintenance training course for $2.500.•The entire first Droduction run of 2S and 20 out of the second production run are already sold, More details next week. Next week in ....._.I". . . . ~lt Read all about Houston Who did what, when, and why in the Camel Pro Series season opener Newest All-American engine Inside Ken Maeley's speedway four-valve The Hurt report, Part I A Safety study by riders, for riders 7