Power House
Holden VX SS Commodore
The new House of Power project car – a VX SS with LS1 and auto transmission – was found with exactly the right options Rob was looking for – none! The day after the car was transferred, the modifications began. First to go was the stock airbox, which was flicked in favour of an over-the-radiator (OTR) intake with a K&N filter (which is removed for track runs). To lighten the load a little, the spare tyre and jack were jettisoned. The standard wheels and tyres were put aside in favour of some front runners and M/T slicks on the rear. There is nothing more dangerous than running radial tyres on the front and crossply tyres on the rear; the difference in sidewall movement makes the rear end wiggle more than Marilyn Monroe on the President’s birthday. That is why major tyre companies have developed new lines of radial drag slicks.
The engine was then treated to an 80mm throttle body, a 25% underdrive pulley kit to save on parasitic losses and Di Fillipo long tube headers went on, along with a Magnaflow cat-back exhaust system. An HP Tuners programmer was used to improve the shift points in the automatic, up the rev limiter and delay the action of the thermo fans. After re-programming, the auto was treated to a 3600rpm high stall torque converter to really get some startline action happening. Stock springs and shocks were used, soft is good on the drag strip.
After these initial modifications were carried out, Rob tied the VX to his Dyno Dynamics dyno and made some preliminary power runs. With the OTR and 80mm throttle body fitted the car managed a best of 305rwhp and 318lbs/ft of torque. After the headers, exhaust and pulley kit were added the car improved with 329rwhp. Now it was off to the Motorplex. Straight away the car notched up a best of 12.652-seconds at 112mph – not bad for a first attempt. Not long afterwards, the torque converter and some suspension upgrades were added and the times fell to 12.355 at 114mph, the 60-foot times were 1.855 (using ET Street rubber on the rear). Switching to dedicated M/T slicks those times fell further to 12.252 with a 1.725 60-foot time.
Low 12s from such a mild street combo would make most people pretty happy – especially if it was their budget, everyday driver. But what is the point of having a project car if you are not going to try a few things?
It was camshaft time.
After sliding in a more aggressive hydraulic roller cam but retained the standard intake manifold. After a re-tune the car punched out 392rwhp on dyno. In this guise, the car returned to the dragstrip and suddenly dipped into the 11s for the first time. The official time was 11.908 at 115mph, with a 1.75 60-foot time. On a very well prepared track and with a brand new set of Hoosier drag slicks, the car ran a PB of 11.624 at 117.49mph with a 1.630 60-foot time. Once again, at the Hi Tech Titles, the car rattled of a new best ET of 11.60 at 116mph, with a 1.707 60-foot time. These results were achieved in 35-degree heat, with 25% humidity, which makes the time even more impressive given the LS1’s dislike of any heat source.
The VX is still hitting the rev limiter hard on the first to second ear shift but a new (and beefier) transmission will solve that problem. A solid roller camshaft and a set of ported cylinder heads should have the car deep into the low 11s hi 10s in the near future. However, these further upgrades will not occur until some more thorough testing has been carried out on the current combination. We will bring you an update of the car’s progress. It just shows what can be achieved on a reasonable budget using off-the-shelf performance components, combined with a good tune. Stay tuned.
The car has now done a pb of 11.38 @ 119mph at fast Friday and a string of 11.40 time and time again.
Made 414rwhp cam only auto. With n2o made 510rwhp with 100shot and ran a 1 hit wonder run with 10.70@ 127mph.
Tech Sheet
Engine/Driveline
- HOP custom grind cam
- Valve Springs upgraded
- Double Row timing chain
- Fuel system
- 3.91 Diff gears
- 4000 Hi-stall
- Fast 90mm manifold and Fast Throttle Body
- OTR Intake
- 1 7/8 inch Difillpo Headers
- 3 1/2 inch Single System
