The Australian Power Porting process involves forcing an abrasive medium through a manifold, resulting in enlarged passageways and the removal of power robbing, roughcast surface contours. The procedure removes and polishes metals only where air flows, an ability that traditional methods of porting can't see - let alone reach. While this sounds very similar to Extrude Hone (the American system), the Power Porting system differs in that the 'product' forced through the passages has a design and form that are very different.
A Bit Of History
Two or so years ago Sally and Andrew Sanders, and good friend Albert Lamb, decided to look outside the normal ways of extracting performance from a combustion engine. "We wanted to make our cars faster, something where we could develop it to not only work for us, but also offer financial rewards," Andrew explained.
The problem is that totally new ideas don't grow on trees. Fortunately, Andrew and Albert's experience mix was such that they were able to open each other's eyes to new and exciting possibilities. With Albert running a successful country Victorian automotive repair shop, he could offer an open view to how mechanical improvements should be made. On the other hand, Andrew had only enough automotive experience to get him by, yet thanks to 17 years in the quarry and mining industry in an engineering role, he offered some refreshing concepts.
"Almost my entire working career in the mining industry has revolved around working out how not to wear equipment. In other words, my job was developing product to reduce equipment wear - in particular, looking for ways to stop abrasives from doing what abrasives do."
Looking more closely at the concept of Power Porting, it is effectively the delivery of an abrasive medium through the runners of an inlet manifold or other 'portable' components.
It works like this; as the abrasive is forced through a runner, it works to abrade any restrictive points or areas. For example, when run through a 90-degree bend, this selectivity or natural occurrence sees virtually no metal being removed from the long radius, which allows for greater air flow velocity in the bend. While the amount of airflow is quite important, also significant is the way in which the Power Porting process can be used to balance airflow. Manifolds and other parts are flow tested and the 'weakest' runners treated to a greater degree of Power Porting in order that a better air flow balance between each cylinder is achieved.
In a turbocharger, the surfaces of the standard compressor housing are made as smooth as is economically practical, as any roughness may cause some of the air to detach itself from the surface, causing eddy currents and reducing the overall efficiency. "After Power Porting, our testing has shown a significant increase in flow and a reduction in temperature, especially in hi-flowed turbos".
The Real Deal
Satisfied of the promise, work commenced on an otherwise stock VL Commodore. "We tuned it to the best of our ability for a baseline, then removed and ported the manifold. The result was an engine that ran very rich, however once tuned it revealed a reasonable gain in power while transforming the drivability", Albert enthused. "The engine was so much better, more responsive, smoother and more powerful."
Satisfied they were on the right track, the crew built themselves a crude dyno test rig based on a chassis equipped with a steerable front end, solid-mounted Ford nine inch diff and a VL turbo engine (RB30ET) backed with a stock five-speed manual transmission. The engine was run at a maximum of 15 psi boost, with power figure taken at 4500 rpm to ensure the engine lasted. The engine was improved in that the turbo was fitted with a slightly larger comp wheel, it had an extra injector and the fuel reg was adjusted to deliver a higher fuel pressure, and it was equipped with a free flowing three inch exhaust system. (So what about that second turbo you can see? Read on!)
Albert and Andrew then decided, "We wanted to see what engine and turbo efficiency would be like if we retained the stock turbo in its normal position, while adding a secondary large capacity Holset turbo (with airflow meter mounted on the side). The Holset compressor side would deliver flow to the inlet side of the stock turbo while the exhaust side of the VL turbocharger would deliver flow into the exhaust of the Holset. With this system in place we've seen an incredible 70 horsepower increase at low rpm and with massive torque."
At this point, the Centerforce clutch cried enough, so further testing awaits clutch replacement.
Power Porting is still in its infancy, due to the boys deciding to initially restrict sales to local punters whose vehicles were, in effect, guinea pigs. Examples include a G180 1.8 litre Isuzu twin cam engine in a local rally car. Power Porting of the exhaust ports resulted in improved drivability, an increased rate of acceleration, an 8 rwhp increase and around 200 flywheel horsepower (thanks to other mods of course).
How about a WRX rally car. Yep, simple turbocharger and exhaust manifold Power Porting resulted in an apparently radical improvement in acceleration, improved drivability and 12 extra kilowatts at the wheels. It even sounds like a different engine.
Where Do You Get It?
Andrew and Albert have appointed a number of Melbourne-based agents, and the results here have also been significant. Blue Chip Tuning has, as an example, played with a VN Commodore 5.0-litre engine whereby in stock trim the engine delivered 193 rwhp, however with ECU recalibration, twin cat exhaust system and Power Ported inlet manifold it developed 235 rwhp! Developments continue and are gaining pace. A Power Ported Tickford XR8 inlet manifold resulted in an average 53 cfm per runner increase.
But prices are on the high side, that's for sure. For example, Power Porting a Holden or Ford EFI manifold will set you back around $1100! Prices of between $500 and $800 apply to four cylinder and six cylinder manifolds, while turbo compressor housings are set at around $300.
Howe Automotive - Bacchus March
C.O.M.E - Melbourne
Blue Chip Tuning - Melbourne
A.T.S - Melbourne
Racecraft - Melbourne
Motivator Race Engines - Bendigo
Andrew and Albert wanted to thanks Rod Rainsford of Motivator Race Engines for his assistance in helping them set up their flow benches while offering his porting expertise.