Project Aerio Part III

Boosting the 2.0-Liter-How We Did It

After the initial introduction to our Project Aerio, and one "Power Page" session, it's time to turn up the wick and unload some fuel for more horsepower. We're getting boosted, baby! All-motor power was fun, but we're used to it by now and we're itching to make more. Just as vampires thirst for blood, tech editors fiend for horsepower. There's currently zero turbo kits available on the market for the Aerio, so we had to take matters into our own hands. With the help of Burn's Stainless, Turbonetics and Alan Viado of Design Craft, we were able to design our own kit worthy of extra power, as well as additional show points. Now we're going to show you how we did it.

The cost of materials to build a turbo kit from scratch can run into the thousands. Therefore, we decided if we're going to pimp out the Aerio as a worthy show/street car we'd have to go all out. We are talking 321 stainless-steel manifold, 6061 aluminum intercooler piping and some of the best components Turbonetics has to offer. The Turbonetics part was easy; we simply filled out Turbonetics' spec sheet with our vehicle's engine specs, and the turbo was in the mail. We opted to also use a Turbonetics Racegate, blow-off valve, silicone connectors and a Spearco intercooler with A'PEXi end tanks.

The Manifold
Manifold construction plays a vital part in the turbo system's performance. Next to only the turbo itself in importance, the manifold could be called the system's backbone. To many, building a turbo kit from the ground up would be considered rocket science, but to the gang at Import Tuner and Design Craft Fabrication it's a mere Lego project. While the key parts were in the hands of Turbonetics, the main fabrication side of things were in handled by Alan Viado of Design Craft and me, Gary Castillo. After examining the engine bay, we found there was plenty of room for mounting the turbo on the driver's side, but this also meant our system would not be standard compared to your typical turbo kit. However, it would give us the ability to utilize the Burn's Stainless header design program for maximum horsepower. We decided to sacrifice a few ponies to accommodate the size of the overall turbo kit. Now the only decision was whether to mount the turbo above or below the exhaust manifold. Mounting it above would allow us to maintain all the factory catalytic converters. The factory exhaust manifold mounts to the primary cat, while the secondary cat is located beneath the floorboard.

First we had to build a temporary manifold jig. This required getting a head flange laser cut exactly like the O.E. exhaust manifold flange. Turbonetics has plenty of turbo flanges, as well as downpipe and wastegate flanges. Besides the Suzuki head flange, all other flanges are off-the-shelf Turbonetics stainless flanges. Once we set the turbo in place, we had plenty of downpipe and intercooler piping mounting room. Once the stationary jig was complete, exhaust manifold construction began. One part we did not incorporate from the factory manifold was the EGR valve, which happens to be an emissions-related part. However, our head flange does include the port for the EGR, so we simply tapped the hole to a 3/4 NPT thread in case we ever chose to apply it to the turbo system. For now it's just tapped and plugged.

The manifold itself is constructed of 16-gauge, 321 stainless-steel U-bends. Sizing came in 1.625 in. with a 3-in. radius. Our first option was to use a Burn's stainless collector to bolt to the turbo, but due to the limited spacing between the engine and radiator we elected to construct our own. The manifold was completed in two days' time and was then sent out to a local machine shop to be resurfaced to ensure there would be no exhaust leaks.

Downpipe
The downpipe was next on our list, and as the building started we decided to make a few changes from our initial plans. Rather than plug the downpipe into the O.E. primary catalytic converter we decided to remove it and build the whole downpipe from the turbo back to the secondary cat. This meant two O2 sensor bungs needed to be mounted to the downpipe, as well as an exhaust doughnut with springs. The main purpose of the exhaust doughnut is to compensate for the flex from the engine to the downpipe; the springs provide tension between the exhaust piping and doughnut. Our downpipe is made of Burn's Stainless 304 16-gauge stainless steel, sized 2-1/2 in. in diameter.

Intercooler
The factory bumper was removed to unveil a very large bumper support, but the handy part was that it was a bolt-on affair. Keep in mind that removing this support may hinder structural rigidity in front-end collisions, but man, you can fit a huge-ass intercooler inside this bumper. We chose to stick with a decent-sized cooler, not too big. The new core is a Spearco tube-and-fin design, sized 22 x 7.8 x 2.87 in. Setting up the inlet and outlet was a difficult maneuver; not only did we have to position the tanks to work around the chassis, we had to make sure the engine bay was adequately spaced to clear all the piping. Since we still wanted to use the bumper support, we decided to remove the driving lights for intercooler pipe spacing. Our only other choice to save the driving lights would be to get rid of the bumper support and route the piping in its place. Our piping was 2-1/4 in. in diameter, but rather than painting our plumbing, we decided to use 6061 aluminum and send it out for polishing. Once the routing of the piping was decided, it was on to making the end tanks. We came up with a pair of A'PEXi end tanks designed for a Sylvia core that just needed to be sized down slightly. Our modifications were minimal and it was much easier than making them from scratch.

The piping was a snap since there was no cutting of the car involved, with the exception of the driving lights bumper mounts. Routing from the throttle body to the intercooler end tank on the passenger's side was simple since we removed the O.E. intake box and resonator. The driver's side piping was a little more difficult since the coolant reservoir was in the way. Its placement was directly in the path of a clean shot through the driver's side fender down to the intercooler. Rather than bend the intercooler piping to go around the reservoir, we relocated it to the opposite side of the battery. This allowed the piping to form a perfect U shape from the turbo to the intercooler inlet.

Air Intake
One thing that must be noted is the way the factory engine management system works. This system uses a mass air sensor, but unlike most cars its sensor is mounted on the throttle body rather than the intake pipe. This left us two choices: We either had to relocate the mass air sensor to the turbo intake side or leave it where it was and see if an A'PEXi S-AFC could handle the duty of controlling the sensor's voltage. For the time being, we left it in its O.E. position while we ran it in low boost. The way we looked at it, we could always mount it on the intake pipe later. Our intake is constructed of 2 1/2-in. 6061 aluminum piping connected to a Turbonetics/K&N open-element air filter. With the way the turbo is placed we have the option to either run it ram-air style or use a filter on the turbo if the weather is wet.

Oil Feed and Return
Just like any turbo system on the street, oiling the turbo is an absolute must. How important is it? I've seen idiots out there get so happy about their turbo systems, they fire up the engine without plumbing the oil to the turbo, just to hear the car fire up. Boom, there goes the turbo! Believe it or not, I saw one guy even try and drive his car without oiling the turbo just for a quick once-around the block. The car didn't even make it past first gear.

What people need to understand is at full throttle your standard turbocharger turns at 80,000 rpm or higher. This is why oiling is important, especially on initial start up. Luckily for our project Aerio, our factory oil pressure sensor is located about 1 ft away from the turbo. Most cars run a factory oil pressure switch and, in most cases, this is to turn on a dash light that signals the driver in case of an emergency: "Hey stupid ass, your engine is low on oil!" This sensor is the perfect spot to tap a tee for our turbo oil supply. Another critical area for oiling the turbo is in the return line. This line needs to travel back down to the oil pan, which requires adding a hole in the oil pan and either welding a fitting or using a bulkhead connector to the pan. It's usually best to mount the fitting as high on the oil pan as you can. Mounting the fitting on the sump of the pan can sometimes cause a backup of oil in the line on deceleration. Backing up the line will cause the turbo bearings to leak oil into the exhaust and intake stream. Using a -10 line also aided us in keeping the oil from backing up.

With the fabrication side of the turbo kit complete, we'll get into the next issue of fooling the fuel system and extra timing devices that will help us along the way. Will the Aerio's fuel system hold up to 7 psi of boost on the dyno? Check an upcoming issue and find out if we make some useable horsepower-or blow the engine.

This is the complete manifold... read full caption This is the complete manifold on the car with the turbo. Notice how tight the turbo's surroundings are without making contact.
		It was now time to finish... read full caption It was now time to finish off the downpipe's connection to the exhaust. For this, we had 15-year exhaust tech, Rick Perry, from Exhaust Systems Hawaii lay some TIG booger welds to the last piece.