STAGE WRITE

IT’S BEEN a while since I visited the upgraded Palmyra drag strip. It’s the oldest privately owned track in Australia, but the facilities are now first-class, with a concrete startline and shade covers on the mound for spectators. The club has done a great job in renovating the track.

One car that stood out during my recent visit was David Sheehy’s stock-headed, stockbottom-end 5.0L Coyote-powered Mustang. The CPV Tuning naturally aspirated streeter ran 10.2@136mph, a new terminal speed PB for David’s Blue Oval two-door – and that was with the transmission left in Drive. At a previous meeting, David has manually paddle-shifted the E85 pump-fuelled Mustang to a world-record 10.08@134.7mph.

According to the Moroso calculator, 136mph is good for a 9.85 if the car’s suspension is sorted out. David’s Mustang is knocking on the ninesecond door with minimal chassis development, a 3500rpm stall converter, no transbrake and pretty small street-legal MT radial slicks.

Stock Mustangs weigh 3700lb, and around 3900lb with the driver. But David’s ’Stang is much lighter; there’s no spare tyre, jack, tools, back seats, passenger seat, carpet, underlay, door panels, air conditioner or condenser. The stock exhaust system weighed 35kg, so has been replaced by lightweight speedway mufflers that weigh only 10kg. The tailshaft is carbonfibre, the crossmember is chrome-moly, there are lightweight wheels all ’round and the stock giant front discs and calipers have been replaced by lighter brakes. But according to David, there’s still another 200lb that can come out.

Asked how much power the almost-stock 5.0L is making, David quoted a very conservative 600hp. If you plug 136mph and 600hp into the Moroso calculator, the car and driver would have to weigh 3100lb max. Personally, I’d be astonished if the Mustang is that light, and think 660hp is more realistic.

Very little has been done to the Coyote engine. Comp stage III naturally aspirated cams have been fitted, with stock valve springs. A Cobra Jet manifold has been port-matched to the stock heads, and the twin throttlebody has been converted into a large single-blade. The headers are stock 1/ 78 in Xforce items. That’s it.

One of the key reasons the engine is making so much power is that it’s tuned and rev-limited to 9000rpm. David told me the power is almost dead-flat from 7000 to 9000rpm. This suggests that there’s a restriction holding the combination back, like the intake ports’ maximum cfm has been reached. I’d love to see the heads ported, and think the Mustang has the potential to dip way into the nines naturally aspirated. I don’t think an Andra-approved chrome-moly rollcage will be far away.

One thing I noticed during my Palmyra visit was the lack of street racers on race day. Friday night is the Keep The Speed Off The Street night, plus a test and tune for racers, which is $50 entry. There’s no competition, just mate racing mate in their hot streeters, and it’s well supported. Saturday, on the other hand, is $100 entry, and a lot of street racers seem a bit gun-shy of the competition aspect. They’re missing out on good traction, as there’s often dew on a Friday night that can make the startline a little slippery. On Saturday the track is well-prepped and sticky; this is when a car will run its quickest times. One racer I spoke to suggested the club charge $50 for Friday night, but half-price entry for street racers on Saturday. This might encourage more of the street racers to participate in competition.

A couple of other racers informed me there are street cars that can’t race because they’re too quick. For instance, one of the local racers threw a big-block into his Kingswood. First time out the old Holden went 10.50, backing off at the 1000ft mark. After his one and only run, the racer was told not to bring the car back until it has a ’cage. It hasn’t been back to the track since.

I’ve mentioned this before, but ANDRA really needs to look at implementing eighth-mile racing for quick street cars without rollcages. The cutoff for ’cage-less cars over the quarter is 11.0 seconds, which is around 120mph terminal speed. To me speed is the main risk factor, and I think 120mph at the eighth-mile would make sense as the governing limit before a rollcage is mandated. If there are any ANDRA officials reading this, can you see if you can get it implemented, please?

DAVID SHEEHY’S STOCKBOTTOM-END COYOTEPOWERED MUSTANG RAN 10.2@136MPH, A NEW TERMINAL SPEED PB FOR THE CAR

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