Top team: Ricky May in the speed sulky behind Monkey King after his brilliant second-round heat win at Newcastle.

IT MAY be Monkey King's superior speed that bags him tonight's $A1 million Interdominion Grand Final, but his rivals are taking no chances that it's his American-designed cart that's giving him an edge.

The best pacers in New Zealand and Australia have been left in the wake of owner Robert Famularo's flashy white sulky all season, chasing home Monkey King in the New Zealand Cup, New Zealand Free-for-all, the Miracle Mile and both his Interdominion heats.

But five of the 10 horses who will line up at Menangle, outside Sydney, at 7pm this evening will be hitched to the new speed sulkies sporting an array of colours akin to greyhound vests: blue, yellow, white and black.

Joining Monkey King, in his white cart, and stablemate Baileys Dream, in his black version, will be reigning Interdom hero Mr Feelgood (blue) and ex-Kiwis Smoken Up (yellow) and Washakie (blue).

Comments by former American trainer Brett Pelling that the cart gives horses a huge advantage – he likened it to the body-hugging suits which took swimming by storm – sparked a frenzy of orders to American manufacturer Tom Harmer and will see every Evolution cart in Australia in action tonight.

Smoken Up's trainer-driver Lance Justice said where millimetres can mean a difference of hundreds of thousands of dollars, it was a no-brainer that he should seek out the best cart possible.

It was all the more important given Smoken Up had been completely undone in the second round of heats by a new, conventional sulky which, with wider tyres, caused him to strike the wheels and refuse to stride out. "I rang top professionals in the US and Canada and they all told me if I didn't have one of these carts, which track and ride better, I'd be behind the eight-ball.

"They're talking about a gain of one second over a mile – Monkey King beat us a neck in the Miracle Mile and you wonder whether I'd have beaten him if I had one."

A cart Justice had already ordered was delayed in shipment so he has borrowed the yellow sulky of Queensland trainer Darrell Graham.

"I congratulate Monkey King's owner for getting the new cart and it's now up to the rest of us to step up to the plate. I'm sure that in years to come if you haven't got one, you'll be at a real disadvantage."

Trainer Tim Butt tried the new design for the first time behind Mr Feelgood last week at Newcastle, when the horse finished a game second to Blacks A Fake in record time.

"He actually hit the wheels, so we'll have to push the cart out further. He certainly went great – it was his best run for a while – but how do you measure how much of that was down to the cart?

"But we don't want to have any excuses – and Kevin [part owner Kevin Seymour] was keen to use it."

Butt, however, said he had no plans to buy the new cart because at $8500 it was too expensive. It made more sense to try to build them in New Zealand for $4000 to $5000.

Famularo said when the first version of the cart arrived from the United States 18 months ago, he wondered if he'd made a big mistake. Thinking it would be made out of carbon fibre or some similar space-age material, he was alarmed when he tried to lift it and discovered it weighed 8kg more than conventional carts. "It's aircraft steel alloy and is very rigid."

Famularo, in consultation with Harmer, then had to rebuild the sulkies to adhere to New Zealand standards, making them narrower and longer, a change which he believes might have reduced much of their perceived advantage.

"Monkey's cart is about eight to 12 inches longer and Bailey's cart is even longer than that because he's a much bigger horse. But the whole unit is very well balanced, it has a lot less flex in the shafts, and is a very good ride."

Harmer, former trainer of New Zealand stallion Falcon Seelster, actually started his search for a better ride by enlisting the help of a bicycle wheel manufacturer, Aerospoke, to design a better wheel.

"He looks at our plastic wheels with the holes and laughs," Famularo said. "Aerodynamically, they're a disaster." Famularo, who has never been afraid to think outside the square and embrace high tech, says it's all part of being as professional as you can.

Trainer Brendon Hill "puts up with" his tinkering, he says, but is adamant it's what's between the shafts and who sits in the seat that counts.

Laidback driver Ricky May was too busy at home last week harvesting wheat, barley and oats to worry about the sulky debate.

While he acknowledged the heavier cart did not move around so much, tracking truer, he believed it was more the fact Monkey King had strengthened this season that explained his dominance.

"There's no doubt he's stepped up another level. I think it goes back to the cup two years ago when he went no good and we found out he was crook and turned him out.

"From the time he came back into work he's never looked back and has felt like a different horse.

"He's been going phenomenal – he looks a million dollars and is racing like a million dollars." The Monkey has banked $1.17m in his last seven starts, winning six times. May said he was surprised how fast Monkey King ran his last quarter in the second round at Newcastle – officially clocked at 26.6sec, he had plenty of petrol left.

And while many might have been surprised Genuwine crossed him out of the gate, May said he quickly realised how fast his rival was going and took hold to let him past, before launching for the front.

"I haven't slaughtered him out of the gate yet," said May, who realises it would be folly to attempt an early lead in the final with several fast gate-runners drawn inside him, including ex-stable rep Washakie, drawn to lead from one.

Famularo can see the irony if Washakie, whom he sold in late 2007, denies him an Interdom win.

"He had super gate speed when we had him and I'd be surprised if he had a problem holding the front."

Famularo, surprisingly, won't be at Menangle today. While he prefers not to fly, Famularo says he will have just as much fun, and be a lot more relaxed, watching on TV.

Besides, he's got a bit superstitious and will be inviting the same people round who've shared the excitement of the Miracle Mile and other Australian wins – "every time I'm with them, Monkey wins". Famularo admits he's a bit different in that regard and doesn't miss the atmosphere – "The horse, driver and trainer are the real heroes. I find it a bit embarrassing as an owner, it's like you don't deserve it."

Besides, Famularo has work to do – there's the little matter of that new sulky sitting out in the barn.

His rivals might think they're catching up, but Famularo has another version on the go. Named the Safe-T model by Harmer, it is even more radical and does away with the fork outside the wheel.

"The harness racing executive has looked at it and are happy," says Famularo. "We'll trial it at the workouts when Brendon gets back. But we still have a couple of modifications to do. It could be 12 months before we're ready."

May and Famularo's other drivers shouldn't breathe too easy either on the demise of those lycra suits. The Famularo designed one-piece suits used last year didn't flatter the boys, showing up their their skinny legs, and other bits.

"They were a failure as a fashion statement," admits Famularo. "The guys are entitled to look decent when they're not in their carts.

"But when I have time, I want to work on a two-piece..."