Rod Penrose’s world record holding VW Beetle drag car.

On the 3^rd November 2001, Rod Penrose driving his chop-top VW Beetle drag car broke a long-standing Hot VW’s “A Sedan” world record at Heathcote Park Raceway in Bendigo Victoria.

Two days earlier Rod had the car on chassis dyno for the first time and after 8 dyno runs, the car had produced 297 kW (398.3 horsepower) and 628 nm of torque at the rear wheels. This reading was taken at 7,632 RPM at 185 kph with 31-psi boost. This was calculated to be 512 horsepower at the flywheel.

 Rod loaded the car onto the trailer and headed for Bendigo. First run off the trailer the car misfired, backfired, farted and ran lean enough to melt a spark plug. The time was 11.46 @ 98.1 mph.

Rod then richened the fuel mixture, wound up the boost to 24 psi, with the wheelie bars set very low so as not to wheel-stand, the car spun the wheels all the way down the ¼ mile. The time was 10.06 @ 143.1 mph. The next run, Rod lifted the wheelie bars a little, richened up the mixture and again increased the boost to 31 psi. The car ran very straight and very fast, clocking a 9.27 second pass with no mph recording on this run.

Rod was feeling good at this stage, so he decided to richen up the fuel mixture again and reset the boost at 31 psi, as according to the onboard data logger the boost was only 24 psi, the car ran 9.26 @151.6 mph.

After downloading the data, Rod found that he was only getting 24 psi from the turbo. After closer inspection, Rod found an adjusting bolt from one of the wastegates had vibrated out and was missing. After replacing the bolt the car ran a 9.56 2 152.8 mph.

Rod downloaded the data from this run and found he was still only making 24 psi of boost. This time he found that the dial-a-boost on top of one wastegate was winding itself shut and therefore one wastegate was operating at 31 psi and the other wastegate was operating at only 13 psi which is why it was producing only 24 psi of boost. Racetape was used to hold the offending dial-a-boost open. The next run the car lifted the front wheels in all four gears and went as straight as an arrow. The time at half-track was 5.82 @ 124.58 mph and the 60 foot time was 1.41 seconds. The time was good enough to set both ET and mph for the “A sedan” record for the ¼ mile.

“A sedan” class is unlimited VW style engine configuration, steel body; fibreglass hood, doors, decklid and fenders are allowed. Wheelbase must remain + or – ¾ inch for body used.

Some statistics about Rods car.

Start line launch at 5575 rpm
1^st gear is gone in 1.26 seconds at 8518 rpm.
2^nd gear is gone in 2.46 seconds at 8961 rpm.
3^rd gear is gone in 4.25 seconds at 9180 rpm.
End of ¼ mile run 8.96 @ 155.87 mph at 9035 rpm.
Gear change from 1^st – 2^nd takes 11/100 second
Gear change from 2^nd – 3^rd takes 14/100 second
Gear change from 3^rd – 4^th takes 14/100 second
Acceleration, 0 – 100 kph = 1.92 seconds. 0 – 200 kph = 5.4 seconds
Boost temp at start of run 80 degrees Celsius and 188 degrees Celsius at the finish.
Maximum fuel pressure = 55 psi.
Maximum boost pressure = 31 psi.
Engine displacement 2810 cc
Case – Autocraft, dry sumped
Crank – Scat 86 mm, Type 4 mains and flanged for flywheel
Rods – Carrillo, Porsche journal
Heads - Autocraft pro series, 50.5 x 40.5 Del-Nest titanium, K 800 springs, ported by Rod.
Cam – Autocraft 925, steel billet
Piston and cylinders – Autocraft 102 mm forged pistons and ductile steel cylinders.
Rings - Dykes top and Autocraft 2^nd and oil scraper
Oil pump – Autocraft 3 stage dry sump
Rockers – Autocraft pro series 1.25:1 ratio
Pushrods – Autocraft dual tapered chrome molly
Compression – 8.72:1
Intake – 65 mm mild steel tube tubing, HPC coated with chassis shop blow off valve.
Induction – T72 turbo, dual turbonetics wastegates with dial-a- boost controllers
Exhaust – 2 inch primary tubes 22 inches long, HPC coated, 3 ½ turbo outlet HPC coated
Ignition – Compufire dual coil packs with Auto meter pro control rev limiter
Clutch – Dual disc with floater plate and custom pressure plate
Transmission – 75 Kombi casing
1^st 3.55
2^nd 2.06
3^rd 1.44
4^th 1.04
Ring & pinion - Richmond 4.60:1
Differential – Dave Folts aluminium spool
Axles – Dave Folts 5 inch shorter swing axle conversion.
Special mods – Gene Berg intermediate housing and hi torque starter
Car – 1968 Beetle, 125 mm chop on roof, fibreglass one piece front & rear guards, 2 mm aluminium floor, 0.8 mm aluminium firewall, interior panels, air scoop and engine lid. 1.2 mm aluminium rear wing, steel doors, roof and ¼ panels.
Chassis - Mild steel & chrome moly tubing weighing 110 kgs.
Front suspension – 8 inch narrowed VW king & link pin. Willwood disc brakes with 4 piston callipers.
Rear suspension – 32-inch long chrome moly trailing arms with Spax adjustable shocks, 920 pound springs, Willwood 5 lug hubs, 13 ¼ semi floating discs with 4 piston callipers
Wheels rear - 15 x 8 spun aluminium, 28 x 9 Mickey Thompson slicks
Wheels front – 15 x 3 ½ spun aluminium, 23 x 4.5 Formula Vee tyres
Car weighs – 1428 lbs without driver and 1656 lbs with driver.