2004 Pontiac GTO Vortech Intercooler Install - Back In Black Part IV

The front-mounted heat exchanger's function is to cool the warm liquid that has come from the charge cooler box (and subsequently, the water reservoir). Another advantage to Vortech's air-to-water-to-air system is that this heat exchanger can be much smaller than a traditional air-to-air intercooler thanks in part to the larger heat transfer coefficient afforded by liquid than air. This law of heat transfer helps allow the charge cooler mounted atop the engine to be compact in size as well.

The front-mounted heat exchanger's function is to cool the warm liquid that has come from the charge cooler box (and subsequently, the water reservoir). Another advantage to Vortech's air-to-water-to-air system is that this heat exchanger can be much smaller than a traditional air-to-air intercooler thanks in part to the larger heat transfer coefficient afforded by liquid than air. This law of heat transfer helps allow the charge cooler mounted atop the engine to be compact in size as well.

The lower mounting bracket for the aftercooler water reservoir shares a hole drilled in the frame with the cooler. It can be a bit of a challenge to get these two to line up properly with this previously drilled hole.

Marking and drilling yet another hole in the framerail, the driver-side end of the cooler can be tightened down. The cooler is just the right height so that it gets blasted with outside air that comes through the grille and under the bumper bar. In this view it looks like the power-steering cooler is going to take a bashing underneath the car, but we'll see later on that it is safe.

Vortech supplies some specially shaped aluminum tubing for the more complex twists and turns of the aftercooler plumbing. One such tube runs around the upper passenger side of the radiator to the brass fitting atop the aftercooler water reservoir. Warm liquid travels through this tube.

It's time to start the wiring for the aftercooler water pump, and Vortech supplies a relay that we found mounted nicely at the front of the fuse box on the passenger-side fenderwell. This makes wiring into the box behind it, as well as attaching the black ground wire to the battery ground terminal ahead of it, an easy task.

The completed fuse box wiring is as shown here with the red wire (inline fuse included) going to the fuse box power supply and the yellow wire tapping into a terminal on the stock fuel-pump relay. Vortech didn't say which terminal to use, so we picked one and turned out to have guessed correctly; you should be able to tell from the photo which one it is. Some custom bending of the Vortech-supplied terminal tap is required to get it to fit in there just right.

Only one wire needs to be run to the location of the aftercooler water pump, and we found the best routing for it was atop the upper crossmember in front of the radiator, past the hood latch assembly, and then down to the pump. This way the wire would be hidden nicely beneath the plastic radiator cover and had several locations where it could be zip-tied in place.

The aftercooler water pump mounts in front of the radiator next to the cooler using a couple of Adel clamps and self-tapping screws. Because it runs off of a signal from the fuel pump relay, this pump will run whenever the fuel pump is running, i.e., whenever the car is running. We connected the pump's ground wire to one of the self-tapping screws holding the Adel clamps. To check that the wiring is correct, simply turn the ignition to "on" and the pump will cycle; it is very audible.

The bottom fitting of the water reservoir connects to the inlet of the aftercooler water pump using a 23-inch length of 3/4-inch rubber hose. At this point we were getting really worried about refitting the plastic shroud that channels air from the GTO's lower grille to the radiator; this hose traveled right through where that piece needed to be.

Liquid that has already passed through the cooler is run up to the charge cooler through a maze of tubing that runs through the passenger-side fender, behind the battery, and around the neck of the washer fluid reservoir. It is much easier to install this tubing if one first loosens the battery mount.

Attached to the water inlet end of the aluminum tubing that runs behind the battery is a 50-inch piece of rubber hose that must be run just beneath the passenger-side headlight and across to the fitting atop the passenger side of the cooler. Here, we snake this hose behind the bumper bar and over to the cooler.

The path from the charge cooler to the aftercooler water reservoir is completed by yet another piece of rubber hose that starts at the straight brass fitting on the charge cooler, runs in front of the battery, and connects to the already-installed aluminum tubing that passes over the upper passenger side of the radiator.

To complete the aftercooler system tubing, one last section of rubber hose is run from the fitting atop the driver side of the cooler to the outlet of the aftercooler water pump. We had to get a bit creative here since the brass fitting in the cooler wouldn't fully tighten at the correct angle (90 degrees counter-clockwise from what you see here), otherwise, we could have used the one-piece molded hose Vortech provided and not have had to hodgepodge two hoses together.

After all of the plumbing has been hooked up, one final loose end remains: getting the stock plastic shroud to fit back on. Here we contemplate all the notching that will be required, as the reservoir, cooler, pump, water hose, and power-steering lines all interfere with the shroud going back on there.

After marking all the appropriate areas to be notched, a Dremel tool or similar instrument can be used to cut the plastic shroud. Remove only as much material as is necessary since unneeded holes in the shroud will allow air to escape through them, depriving the cooler and vehicle radiator of necessary airflow. This is especially true at high speeds, when the area in front of the radiator becomes pressurized.

After several trial fitments, the shroud is finally ready to be reinstalled. We impressed ourselves with how well we got this piece of plastic to fit, but at the same time, we realized that, had we exhibited less patience in notching it, the job would not have come out nearly as well. Note that one of the aftercooler lines must pass through the shroud, so it is not a good idea to add water to the system until this step is complete.

With all of the aftercooler plumbing hooked up, the system is ready for some fluid, which is poured through a cap on the charge cooler. Vortech recommends a 25 percent antifreeze and 75 percent water mix; we also went ahead and added some Water Wetter to further improve heat transfer in hopes of dropping the temperature of the intake charge even more. Note that the cap on the charge cooler must be very tight or it will leak.

Speaking of leaks, we found one when we began adding liquid to the aftercooler system. It turns out what we thought was an unused, blind hole in the side of the water reservoir was in fact a through hole. We had to run out and buy a 1/2-inch NPT pipe plug to seal it. This was especially strange because a similar hole on the opposite side of the reservoir did not leak.

Finally, the bumper cover can be reinstalled and our GTO can look like a real car again. Those pesky snaps under the headlights go on much easier than they come off, with only a swift whack of the fist needed to seat them. But first make sure they are lined up correctly or you risk breaking some snaps--it appears we did just that in taking the cover off, as evident by the missing gray plastic below the rearmost portion of the headlight.

With the bumper cover back on, a peek underneath calms all fears about the power-steering cooler hanging in harm's way. In reality, it is tucked neatly behind the lowermost portion of the bodywork and is invisible from the front of the car. The scraped underside of the bumper cover (chock it up to careless driveway entry by the owner) is evidence that the only contact that occurs under here is much further ahead of the power-steering cooler.

Back under the hood, a small clearance notch must be cut in the plastic radiator cover for one of the aluminum aftercooler tubes to pass beneath it. With this done, the cover can be reinstalled using the factory plastic clips--and the Vortech supercharger system installation is complete!

Vortech's custom tuning is provided in the form of a DiabloSport Predator unit that simply hooks to the OBD-II diagnostics port below the dash and reflashes the computer. The Predator is a handy tool with a lot of functions, including, but not limited to: checking and clearing engine codes, real-time data gathering from the vehicle's sensors, and adjustment to the vehicle's tune if desired (though we have left Vortech's tune untouched).

While other manufacturer's blower kits can boast a "clean" install by keeping those plastic GTO engine covers, Vortech's system looks mean, mechanical, and ready to kick some serious Blue Oval behind. A turn of the key rewarded us with the familiar rasp of our SLP exhaust, along with a new aural sensation: the slight but noticeable whine of the Vortech V-2 SQ SC-trim supercharger. We put the tranny in "D," pulled out onto the road, and-well, you'll just have to wait until the next issue of GMHTP to find out!