BONNEVILLE SALT FLATS — Drivers and crew refer to it as "salt fever." It's the reason, they say with a smile, they keep coming back to the salt year after year after year.

Just one day on the salt often times turns into a lifelong quest.

And the only relief comes in August when they are lured back to the famous raceway for just one purpose — to go faster than they did the year before.

So each year, they pack up the trailer with their race cars, spare parts and tools and take whatever highways lead them to Bonneville. Once there, they pitch canopies, take out the folding chairs, ice the coolers, smear on sunscreen and race.

This year there were more than 400 entries in the 56th edition of Bonneville Speed Week. Each and every one came to tack on more miles at top end and, if the salty track is cooperative, set a new land-speed record.

This year, consensus is, the salt is in great shape for racing. Already, more than 50 records have fallen to higher speeds.

Top honors go to Mike Nish, who set an unlimited record of 373 mph. Also, an electric car, with 10,000 D-cell batteries, set a speed record of 308 mph.

Jeff Shipley, who jokingly admits he has a bad case of "salt fever," has been running on the salt since 1958. He proudly calls himself "crew chief" of the extended streamliner owned and driven by Dave Haas. But, he's also quick to note that he is the owner/driver of a similar streamliner.

Both vehicles have two engines — one powering the front wheels and one the back. The one difference is that in Shipley's car, the engines are mounted sideways and are belt-drive.

His plans were to run only the front engine in each car until it was dialed in, then run with both engines. He was hoping to hit speeds around 250 mph in the Haas car, then kick in both engines and "with the two engines the car has the potential of 450 mph." Which would, if he's successful, set a new high-speed record for a wheel-driven car with blown engines.

His car, he projected, has the potential of speeds slightly more than 400 mph.

Gary Calver, of Auburn, Wash., has been coming each year to Bonneville since 1989. It was, he remembers, "Something I always dreamt about as a boy. Now I'm here and hope to set a record." Top speed for his car, which resembles a mini-sub with pointed nose and tail, is 199 mph. He's shooting for a record of 209 mph.

Brothers Ed and Glen Carter, from the Southern California area, have been coming to the salt for 35 years. For 17 of those years they took turns driving a 1981 Camaro. Four years ago they introduced their new car, a 1993 Corvette. Last year, between them, they set three records. Top speed was 240 mph.