READY TO LAUNCH
> POR440 GETS ITS ARSE INTO GEAR AHEAD OF USA MARATHON
THE decision to take POR440 to Hot Rod Drag Week in the USA was a big one. I’ve been down this road before, and there’s a whole bunch of stuff that can derail the best-laid plans – EPA declarations, shipping delays, finances, not to mention the obvious one: tearing up junk on the car. But if ever there was a set of wheels that suited the event, this old Val is it. It’s pretty quick, cheap to run, reliable, looks cool, and now with a/c fitted it’s even comfortable to drive. The driveline is solid, the engine is cheap to fix, with parts readily available, and if the paintwork gains a few extra scratches along the way, big deal!
Confident that this tatty hardtop has all the attributes necessary to power through Drag Week, we spent the final weeks before it was packed into the shipping container working towards an eight-second pass. The car’s best so far is a 9.1@150mph at
Drag Challenge, so, despite its size and weight, we know eights are gettable. The little stock-bottom-end 327ci combination was making plenty of steam, but there was much room for improvement in the first 60 feet. The suspension was a long way from being junk, with Competition Engineering adjustable front shocks and Calvert nine-way adjustables in the rear, with Gazzard Brothers split mono-leaf rear springs and tractions bars.
Sure, it was working okay – we were throwing 16 pounds of boost at in on the two-step at 3600rpm and it still didn’t turn the tyres off the startline – but with a small engine and big 80mm turbo with 1.08 rear housing, the motor wasn’t making massive torque and the body wasn’t transferring the weight. The rear springs weren’t separating properly on the launch – in a leaf-sprung car you need the rear leaf to separate from the body on the launch rather than compress.
Given the timeframe for shipping the car, there was only one solution, and that was to get it back to Paul and Scotty Cortina (aka the Gazzard Brothers) in Queensland. These guys are the leafspring kings in Australia, with their nitrous bigblock Holden running a staggering 1.17 seconds in the 60-foot on a 275mm radial!
It didn’t take long for the boys to identify a couple of issues: too much positive pinion angle (which was causing an ongoing driveline vibration on light cruise) and insufficient rebound control on the shocks. They also shortened the back half of the split mono springs to allow them to work better in the custom rear sliders (which replace the factory shackles and bushes). Spring selection was critical for a car fixing to rack up 8000 kays on a USA trip with three guys on board and the same weight in luggage and parts.
Further investigation revealed that the traction bars had been hitting so hard that the pin had sheared through the front bush, further unsettling the car.
After a week of late nights, they got it all sorted
and we headed to the track. We narrowed our focus to the crucial areas of the launch and the first 60 feet – the big end will take care of itself. Knowing that the car would plant the little 235 radials even harder, we lifted the two-step from 3600 to 4000rpm. Paul immediately noted we needed to increase the tyre pressure from the 18psi we had been running to 20, as it wrinkled up the radials on the launch, a clear sign of insufficient pressure.
Next pass, the car left on 14psi at 4000 and unloaded the tyres at the 60-foot. While this can often mean insufficient rebound adjustment, trackside video captured by Paul showed that the car would launch and when the front shocks ran out of adjustment it unsettled the rear and unloaded the tyres. While these sound like simple problems, they are almost impossible to diagnose from the driver’s seat, and this is why it’s always a good idea to get people involved who know their stuff.
Unfortunately, on the next pass it threw the serpentine belt. Seems the new Corvette belt tensioners on the a/c system were not coping with the super-long belt.
So the Comp Engineering shocks went in the bin with the Calvert rears and Scotty and Paul custom-made a set of coil-over-style shocks similar to the rears and ran them on their shock machine before fitting them to the front end, paying special attention to ensure the compression and rebound adjusters were not too close to the exhaust turbo plumbing.
After that it was a quick trip to Fireball Custom Fabrication, where Andy Mcconnell ran a laser over the belts. They were all true, but as an added precaution he replaced the smooth belt tensioners with a set of custom-mades with a machined shoulder to keep the belt running dead true.
Andy also did an awesome job of mounting a removable race seat in the rear between the rollcage tubing – one that can be easily changed over at the track to the driver’s position to make the car comply with race tech – as well as a bunch of other last-minute finishing touches. His workmanship is faultless.
Back at the track, the change to the car was immediate. On the first pass it left the line on 14lb but just didn’t hit hard enough at 4000rpm, so the next run, with Scotty at the wheel, it left on 20lb at 4000rpm.
“It was a wild ride,” Scotty said. “We were only testing so I didn’t drive it out the back door, but it pinned me in the seat on the launch, the glovebox flew open and it was outta there.
“Paul’s car runs a bottom 1.5 in the 60-foot and that thing just nailed it. It’s clear that we need to throw a shitload more power at it now because even with an extra 100hp at the treads on the launch, it hooks and goes but still hasn’t blown the tyres off on the startline.
“We are really happy with the way the car is leaving now and wouldn’t change a thing.”
So now we head to Drag Week knowing that an eight is on the cards, hopefully one each day of the five days. With the car now at maximum boost on the startline, trying to add more boost and gluing it to the two-step does nothing but fry the transmission and heat up the engine bay. From this point we’ll need to raise the two-step even higher to get it to hit harder. The downside of that is it brings the first-to-second shift closer and requires more rpm at the top end of the track. As it is we are crossing the finishing line at 6900-7000rpm, so the stock rods are getting a workout.
The trans is getting hotter on the startline as we beef up the tune, so we’ve had to reassess the oils and fluids we are running. Getting the transmission really hot by holding it on the twostep with big boost sends the trans temps through the roof and makes it harder next pass to cool the car down and get it up onto boost. It also preheats the engine bay so the intake temps creep from the low to high 30s.
This has a flow-on effect to the engine, where getting it glowing on the startline means slightly lower oil pressure overall (as reported by the datalogger). So we have made the change from a mineral oil to Castrol EDGE 0W-40 full-synthetic for the engine, and also swapped from a Type F fluid and hydraulic oil in the transmission to Castrol Transmax. The engine seems to like it as it will come up on the transbrake faster, keeping the heat out of the oil.
Interestingly, we had fitted a converter drain (activated by opening a 12-volt solenoid plumbed into the converter circuit of the valvebody that would bypass the oil going to the converter and send it back to the sump) to allow the motor to come up on boost faster when the transbrake was activated, but since changing to Transmax, we have not needed to use it. While these solenoids do only give you gains in the vicinity of 200400rpm, every little bit helps.
So at this point we’re done. The car is finished and with only a handful of spares (plugs, a set of head gaskets, top and bottom radiator hoses, serpentine belt and enough oil for an oil change), it’s off to the docks. We will collect the car in Long Beach at the end of August for our 4000km cruise across the USA, via Mo-kan Dragway for the Fuel Altered Labor Day Weekend meeting prior to Drag Week.
Big thanks to all who have helped so far: Haltech, Sumofab, Castrol, Gazzard Brothers and Fireball Custom Fabrication.