GTO Fortification, Part 1

It's an unfortunate fact that the Australian-sourced '04 GTO hasn't topped the Billboard charts like we all hoped it would. Some say it's the milquetoast styling, others say at around $33,000 MSRP, the price is just too high. Regardless, there's no denying it's one hell of a driver's car.

Compounding the plight of the 350hp LS1 5.7-liter '04, the new and improved 400hp LS2 6.0-liter '05 GTOs are stealing what's left of the spotlight. OK, so the '04 may have "only" 350 hp to the '05's 400, but Vortech has a fix. Its new '04 GTO supercharger system, PN 4GJ218-018SQ, adds well over 100 hp at the rear wheels with a mere 7 psi of boost, it is emissions compliant in all 50 states (certification pending at press time), and it can be installed in just a day or two. With a suggested retail price of $5,950.95 (or $5,686.95 unpolished), it doesn't take a math major to realize you could put one on a used '04 LS1 GTO and have an '05 LS2 spanker for well under 30 grand.

Can this trick be performed on the 6.0-liter '05? Not at the present time, as the LS2 uses Siemens engine-management electronics while the '04 LS1 uses a Delphi system. The folks at Vortech haven't cracked the Siemens codes yet. So, for the time being, the Vortech GTO trick is applicable only to '04 models.

If you want even more Vortech power, look into the new H.O. tuner supercharger system (PN 4GJ218-020SQ satin, 4GJ218-028SQ polished). It makes more boost (8.5 psi) but does not contain fuel-system or ECU upgrades. A qualified professional is required to provide proper engine calibration. That's why Vortech calls it the "tuner" supercharger system.

For Part I of this story, we will begin the installation and learn what makes the Vortech V-2 SQ S-Trim centrifugal supercharger tick. The installation instruction book is comprehensive, so the basics of what it takes to supercharge an '04 GTO will be presented here. In Part 2 we will complete the installation and perform the dyno testing.

Well, what are you waiting for? Grab an '04 GTO and bolt on a Vortech before the word spreads.

Vortech installation begins with removal of the front bumper cover and steel skid plate. Recognize the installer? He's Vortech's Ricky Best. Maybe you've seen him install Vortech supercharger systems on TV shows like Overhaulin' and Monster Garage.	Here's a final look at the stock GTO powerplant.	The engine was stripped of items to facilitate the install. Some of the stock parts that will not be reused include the engine covers, air filtration box, coil mounts, harmonic balancer, and inlet ducting. Smart owners will stash them away for safe keeping.
After removal of unnecessary components, the engine is ready for the supercharger installation.	Fingers point to supplied passenger side coil pack spacer brackets that relocate the coils 1.5 inches for Aftercooler clearance. The driver-side coils remain in the stock location.	The corner of the plastic computer box cover must be trimmed away for supercharger duct clearance.
Though M40 automatic-equipped GTOs can skip this step, the clutch slave cylinder on our M12 six-speed-equipped GTO is repositioned via a supplied bracket in order to make way for the coolant reservoir.	This adapter sandwiches between the oil filter and the filter boss to supply pressurized engine oil to the supercharger case.	The system includes this roto-broach to cut a supercharger oil return line hole into the cast-aluminum sump. Instructions call for packing the broach with grease to attract any chips so they don't enter the sump.

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GTO Fortification, Part 2 Part 2: Completing the Installation and Dyno Testing