The final run lifted Hay's personal best terminal speed to 208.07mp/h.
"We're so close now. It's not even the blink of an eye," said Hay.
A number of changes to the car have found the extra performance.
"The fuel system has been improved and we've been getting some good advice on tune-ups.
"The lighter body has helped and so has going back to smaller rear tyres. We tried bigger tyres on the car but switching back to the smaller tyres and moving to running the right lane seems to have worked well."
The team has some extra motivation in recent weeks after long-time crew member "Shorty" Stinson suffered a fatal heart attack.
"We lost "Shorty" nine weeks ago but he was there helping us at the weekend. Winning the Nationals is for him," said Hay.
There are two more chances to better Grant's record this season - at the Bay Rodders Nostalgia Drags meeting on Easter Sunday and at the rescheduled Drag Masters event on April 21, which was rained out earlier in the season.
Frost looks ahead
Sloan Frost's campaign for Tauranga's M1 Motorsport team experienced some mixed fortunes at NZ Superbike Champs at Hampton Downs on Sunday.
After qualifying third fastest on his BMW S1000RR, Frost was a second lap retirement in the opening 15-lap race with a broken throttle cable.
But the 20-lap NZ Tourist Trophy race later in the day saw Frost battling with defending champion Andrew Stroud (Suzuki), with the lead changing on several occasions before Stroud won by a 0.469s margin.
"It was a good race - we passed and re-passed each other about five times," said Frost.
In the process, Stroud set a new Superbike lap record of 1m 04.109s with Frost close behind with a 1m 04.221s effort, also under the previous record.
By winning both races at Hampton Downs, Stroud closed up dramatically on series leader Robbie Bugden (Suzuki) who was a retirement in race two with a broken chain.
This weekend the final round of the championship brings a new challenge with Taupo hosting a round of the national series for the first time since the 1980s - and for the first time on the extended circuit.
"I set the lap record at Taupo at a club meeting a few weeks ago and I've done a lot of laps around Taupo so I'm really looking forward to this weekend," said Frost.
Bugden leads the Superbike title race with 132.5 points from Stroud on 122. Frost is third on 97.5 points who edged out his margin over fourth placed Nick Cole to six points.
Super stock
Saturday night brings the eagerly anticipated return of super stock racing to Baypark Speedway.
The Pollock and Sons Crane Hire-sponsored Super Stock Invitation is expected to attract a field of drivers mainly from the Rotorua, Huntly and Kihikihi tracks, including former national champ Kyle Fraser (Rotorua).
Tauranga's Mark Decke is part of a Rotorua-based contingent that also includes Bryce Steiner and Ashton Fleming.
Entries already confirmed from further afield include Hawke's Bay Shane Penn and Sam Bartholomew plus Palmerston North racers Shane Melssop and Chad Ace.
Ross takes final
Tauranga saloon car racers Chris Cowling and Brent McClymont finished on the podium at the North Island Champs raced at Upper Hutt's Te Marua Speedway on Saturday night.
Cowling continued his strong season and finished second to Auckland driver Nigel Ross in the final while McClymont was third, completing a season where he's finished on the podium in all of the Speedway NZ sanctioned titles - second in the NZ title and the NZ Grand Prix and third at the North Island Champs.
Waihi racing
There's racing this Saturday at the Waihi Beach Dirt Track Club with the 11th round of the club points series for the 2011-12 season. Racing starts at 11am and the track is located at 597 Beach Rd, Waihi Beach.
On Sunday, the BOP Kart Club is running the third round of its points series at Fagans Valley Raceway near Te Puke.