Trackside chores are normally...
Trackside chores are normally the typical icing and computer download items, but the Accufab team has just as often hightailed it from Las Vegas to their Ontario shop and back to Las Vegas in one night just to make and replace a broken part. Such is the effort required to win championships.
Behind the 4.6 is a now-four-speed Lenco transmission: a five-speed that John eventually fitted with a dummy shaft in place of Fifth as the car is faster with fewer gears. The rearend is a hand-fabricated, Don Ness titanium housing with 4.56 gears in a 9-inch final drive.
John leaves at 6,400-6,500 rpm; shifts at 9,400 rpm; and goes through the lights at 9,100 rpm. A Race Pak data acquisition system gathers the numbers, while a Koni shock controller with Lamb programming stiffens the shocks once it's in Second gear. A move to larger slicks and the wider tubs to accommodate them was required in 2008 to get the power to the ground.
Asked if he'd benefit from a newer chassis, John replied "not really." He certainly doesn't subscribe to the new metal chassis theory. He says there is certainly new technology available today, mainly in triangulation, to make a more rigid chassis, but all things considered, he's not convinced that it's automatically better.
"It depends on the track," says John. "It's a pretty flexible car, maybe more than it should be, but there is a place for a flexible car, depending on the track."
 This is the first thing we...  This is the first thing we think of when putting high compression and 52 pounds of boost in the same sentence. But what's really important here is the impressive connecting rod--a Manley tool steel, A-beam, Pro Series 300M Lightweight measuring 5.933 inches and weighing a muscular 650 grams--and the bearing, which is still in ready-to-run condition. Fred attributes the lack of bearing damage to the 6.0-liter oiling mod. John had Manley develop this tough-as-nails rod for him; its main claim is its extremely hard material. Fred says it's so tough that it tears up the production tooling, but it's proven bulletproof, even after abuse such as this. In fact, although the piston pin is frozen, the rod and bearing are otherwise usable. |  Another view shows the preignition...  Another view shows the preignition violence. There were two such catastrophic failures in 2008, and they're distressingly easy when the engine is as highly tuned as John's. This failure was attributed to the small grooves above the top ring; Fred thinks they overheated and glowed. They've been removed in subsequent engines. |  Thick is the word here. The...  Thick is the word here. The JE piston-skirt wall measures an amazing 0.196-inch thick, yet Fred says they still collapse when worked hard. No one knows the crown thickness, but it's like a bunker. Piston weight is in the 400-plus gram league, which is meaty for a modular forging. The pin is a thumping 0.220-inch thick. It looks and feels more like an extreme-durability pin (think bulldozer) rather than a 9,400-rpm part. Again, Fred says these ultra-beefy pins will bend if the engine detonates. Yikes! |
"It's pretty forgiving--goes down the track anywhere--but the really stiff cars tend to be more loose down track; it takes more wing to keep them planted."
"I'd like to have a new car, but I can make this one work. [This] one 60-foots as good as any car at that weight and power in the country. So there is no trouble." In fact, the modular Cougar 60-foots in the 1.0-second range, "really happy for a turbo engine. The nitrous guys are happy to have 1.0-second 60-foots. We get the same and the nitrous guys burn down trying to keep up."
John does admit to huge turbos: He has to watch his porting and valve sizes or the turbos are lazy to spool. This is important as John's advantage is quickness out of the hole and in the first half of the track. The disadvantage is that with only 281 ci, John can't give up his quick starts as the little engine--it's half the size of his competition--just can't make the raw power for the big numbers at the far end of the track. Hence future tuning requires careful turbo sizing and head porting, and ultimately, John could move to a 5.4-liter program if the need arises.
Here's another look at the connecting rod, as well as the custom-fit Total Seal rings. They are bought at 3.552-inch, file-fit, and measure a thin 1.2-, 1.5-, 3.0-mm thick; they sit well down from the piston crown. The dark piston pin is Casidiam-coated, as run in the drag car. Casidiam is a super-tough, diamond-like carbon coating useful in oil-dry environments, which describes John's highly evacuated, dry-sumped crankcase. Diamond Pistons supplies the Casidim under the Trend name. The piston is moly-coated on the skirt and features two small valve pockets on the crown.
 The small notch in the top...  The small notch in the top ring groove is a gas port to aid ring sealing. Often such ports are drilled vertically from the crown, but Accufab prefers this horizontal arrangement. |  There are few tricks on the...  There are few tricks on the piston bottom. The main points are the super-thick piston walls and beefed piston-pin bosses in these Accufab-specific JE forgings. Like everything else in the engine, the pistons benefit from hand detailing, with all the edges smoothed. |  Yes, this is an old-school...  Yes, this is an old-school "B" cylinder head and not the latest single-intake-port GT casting. And yes, it is identical to the heads run on the race car (this one is off of a customer's Lightning truck engine). Fred says it takes 120 hours to race-prep these heads, including both CNC- and hand-porting, full deburring, guide and seat work, plus assembly. Accufab has built the later single-intake-runner GT heads and says they're the ultimate solution (run a bit better and require less prep thanks to only four intake ports per head), but that they stuck with the old head for 2008 as it was a known quantity. |