Just a couple of things from the memory banks. In the early eighties I worked at Chivo's tyres and Neil Chivas rode Suzukis in production racing.
GSX-1100E and GSX-1100S models both came out in wire wheel models which were used as the race bikes because the wheels were a little lighter and the rear was an 18" on the wire models and a larger range of tyres was available.
There is a lot of rumours about the so-called "Bathurst Specials", and many believe this included the Katana. The fact is no Katana bikes were ever built as "Bathurst Specials" by the factory.
We used to get a new bike for every endurance race (Calder 2 hr, Hub 300 km, Castrol 6hr, Arai 500km etc) and after one meeting we would put it back to standard, sell it off and get a new one. (I used to get to run them in...about 6 a year). If Neil did any local racing or tyre testing he used whatever bike he had in his possession at the time.Everything on the wire and mag wheel bikes was the same. (except, of course, the wheels and tyres).
In about 1983 the upper limit for racing in all Australian classes was set at 1000cc so Suzuki Australia imported some bikes that would comply. The bikes that were available that suited our design rules were the GSX-1000S Canadian model which were the only katanas I ever saw with the smooth bore carbs as standard. Unfortunately they all broke pistons at Bathurst within about 100kms of each other. They were ridden there in the Arai 500 by Neil Chivas, Rod Cox and Rob Toomey from NZ.
The 1000 katanas were all imported with mag wheels. When we went to the track with them they were fitted with wire wheels as the 17" rear was unsuitable for the Pirelli tyres we were using. However, the scrutineers were awake to us and made us run with the mags.
Due to his long association with the Suzuki factory, the NZ importer was able to get a slightly better bike than we could. They had (even back to the GSX-1100E's) different cams and exhausts. These were known as the E-27's (after the cams) or the "Black Pipers" (after the exhausts). With the introduction of the "D" models in Australia all the bikes GSX-1100ED, GSX-1100ESD and GSX-1100SD and GSX-1100SE were running in what we would have called "Black Piper" spec.
There were two racing models worthy of note. The GSX1000 (circa 1981) is a now very rare model with more aggressive camshafts, flat-slide carburettors and wire wheels homologated for then international superbike racing rules. The GSX1100SXZ, also from 1981 and with wire wheels, more aggressive camshafts but with CV carburettors in Australia. New Zealand models were fitted with oval bore slide carbs. An extra air inlet hole adjacent to the standard one in the air box and large bore mufflers (same as fitted to the previous Castrol 6 Hour special the GSX100ET). This model was designed for production racing in a number of countries, including Australia and South Africa.
Stories tell there were some 500 made, though it may be as high as 800 this is still unconfirmed. The chassis numbers began with GS110X-100388. The 1100s were raced with mixed success in Australia in 1981, and with the rule changes for 1982 Castrol 6-Hour production race, saw teams scrambling to find 1000cc versions.
The wire wheels were preferred in 1981 because they were lighter than the then cast wheels with slightly wider rims, and the rear tyre width was limited by the rear brake caliper stay bar. There was also a better choice of tyres with the wired wheels being 18-inch, as opposed to the (at the time for production racing) alloy 19-inch alloy front rim.