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Building Horsepower for World-Record Speed

HE QUEST FOR A 200-mph record might not be on the top of most peoples’ bucket list, but for Rob Phillips and his ’69 C-10, known as the ZR10, this dream is starting to take shape.

Want to go 200 mph and make it count? The Southern California Timing Association hosts two events that currently recognize those who go 200 mph, El Mirage and Bonneville. While some racers choose to compete officially in only one of these events, most racers try to participate in both. Many of the vehicles also run multiple classes within each event.

As of 2016, there is no current record at El Mirage for the Blown Modified Pickup Engine B class (BMP/B). For Modified Pickup Engine B class (MP/B), the current record is 168.671 mph. This means that Phillips can make a pass in BMP/B, remove the blower and make another pass in MP/B, possibly setting two records.

Bonneville is a little more complicated than El Mirage. If Phillips decides to participate at Bonneville, he must run over 200 mph in order to set a record in either class. In the BMP/B class, the record currently stands at 238.517 mph. In the MP/B class, the record isn’t far behind with 225.246 mph.

Receiving the famous red 200 mph hat given to drivers who run 200 mph or faster at either El Mirage or Bonneville is also a lure to compete.

 THE KEY TO RECORD SPEED

So how does one go about reaching 200 mph at one of these two events? There are several components that come together when building the right vehicle, and some are more complicated than others. The motor was first.

INCREASING THE HEARTBEAT

The platform starts with an ATK Performance LQ9 6.0L iron block. With longevity in mind, Phillips chose an iron block to handle the stress of the boost. With a 4.030- inch bore, the 408-ci LS motor should be a sufficient foundation to get the job done.

Phillips and ATK Performance worked together to build the bottom end. ATK outfitted the LS motor with Wiseco forged pistons, Manley rods and a Manley 4-inch stroker crank. By the time the bottom end was complete, every part had been upgraded to withstand the 1,000 hp that would be required to set a record.

Next, a Straub Technologies custom-grind camshaft was installed. The custom-grind shaft allows Phillips to tailor the power band, which is essential for big horsepower numbers.

Known as one of the best roller lifters to withstand high rpm and stress, Phillips used a set of Morel lifters. Cometic head gaskets were also installed to provide better sealing for high-boost applications.

Cylinder heads were next on the list. Trickflow 255cc LS3 aluminum heads were the best fit for the upgraded LS motor. This Trickflow cylinder head is for a 4-inch or larger bore engine. The piston-to-valve angle was also increased for a larger camshaft.

ARP bolts were used throughout the entire motor. Though it might seem to be an especially pricey alternative, these bolts were the best choice for a high-boost application. Not only is the hardware tested for strength, the ARP facility also tests how much the bolt will expand within certain applications.

Manton Stage 5 push rods and an LS3 rocker arm trunion upgrade were next on Phillips’ list of engine parts. The trunion upgrade consists of a bronze bushing and hardened shaft to eliminate all of the roller bearings. This essentially reduces the amount of moving parts in the motor and makes the rocker arm more accurate, eliminating play in the valve train.

The blower was key to creating enough boost to go over 200 mph. The Magnuson Heartbeat 2300 was chosen because of its internal heat exchanger design, which keeps boost temperatures lower and promotes better performance.

The Heartbeat was previously bench tested at the Magnuson facility at 10,000 rpm for five minutes without any problems. Phillips was reassured that the amount of boost needed to go 200 mph would be possible.

The fuel is fed to the motor with Injector Dynamics’ ID 850 injectors. Unfortunately, after the engine dyno test, Phillips learned that these injectors were not big enough for the amount of boost and fuel needed to pull 1,000 hp. A bigger injector is a must if Phillips wants to go 200 mph.

A Holley HP EFI system acts as the brain. This system is an LS-specific kit that
allows custom tuning. This was necessary since Phillips plans to do more than land speed race his ’69 C-10. Custom tuning the truck for road course, autocross and streetability were also at the top of Phillips’ list when considering the rebuild of his C-10.

The Holley HP EFI system is extremely easy to use, which is essential if Phillips wants to run in more than one class. If Phillips decides to remove the blower and run in the MP/B class, it would take all of about five minutes to load a new tune and be on his way to the staging lanes.

An engine dyno test was scheduled at Westech Performance Group. Lucas break-in oil was used for the first 20 minutes of the initial dyno break-in phase. The oil’s high zinc content is good for the bearings, helping them seat without premature wear. Additives are also included in this oil that help when first firing up a motor.

 CHECKING THE NUMBERS

The engine dyno test was necessary before the motor was installed into the ’69 and taken to El Mirage. This test would give Phillips a better idea of whether or not everything was in order and could reach 200 mph.

Phillips had high hopes for the build and the dyno test. The goal was to break into the four-digit horsepower numbers, with at least 1,000 hp at the fl ywheel, which would make a pass at 200 mph possible.

The engine dyno test concluded that the 408-ci LS motor would not hold up to the 1,000-hp expectations. After approximately a dozen pulls, including breakin, the boosted ATK Performance Magnuson motor capped out at 803 hp with 787 ft-lbs of torque.

After assessing the dyno pull and discussing options for obtaining more horsepower, a couple of changes were suggested. One thousand horsepower would be possible with the current motor, but two components were holding it back from making a full pass.

 WHERE TO GO FROM HERE

First, Phillips needed to change from a six-rib to an eight-rib beltdrive to prevent the belt from slipping. The belt started slipping at 11 psi of boost, which was causing boost loss at higher rpm. Switching to a larger ribbed belt provided a larger contact patch on the pulley, giving it better grip and making it less likely to slip.

Belt slippage is a common problem in high-boost applications. When the belt first started slipping, everyone thought that the dyno session was over. Fortunately, Phillips used a COMP Cams belt tensioner. Tightening it down before each pull helped squeeze a few more aggressive pulls from the motor before the boost became too much for the pulley and the belt lost all mechanical grip.

Another limiting factor was the size of the fuel injectors. Even if the maximum boost numbers were obtained on the engine dyno, the motor would have run out of fuel at the top end. The injectors currently on the motor were not capable of flowing enough fuel to make a 1,000-hp pull. On the pull that recorded 803 hp, the injectors were at 85% capacity. It is possible to run an injector at 100% duty cycle, but it will not run as long or be as efficient.

With these two changes, Steve and Eric from Westech were confident that Phillips could achieve his four-digit horsepower numbers. Though Phillips does not have any plans to return for another engine dyno test, the changes to the motor will be made and the ’69 C-10 will be taken to Westech Performance Group at a later date for a chassis dyno test.

Though the dyno test might have seemed like a failure, Phillips was thrilled with the
results. The test proved that the motor was solid and nothing catastrophic happened under boost. Making changes to achieve more horsepower is simple compared to replacing a motor that fails on the dyno.

THE QUEST CONTINUES

As Phillips checks off the first component in his quest for 200 mph, he still has quite a few obstacles to overcome, including aerodynamics, suspension and safety. As Phillips has said before,it is not easy trying to make a brick go fast.

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