Visible is the turbo's exhaust routing. Hidden are the chain-driven camshafts that actuate the engine's 16 valves and also drive a mechanical fuel pump--which, in conjunction with a tank-mounted electric pump, helps achieve the stratospheric fuel pressures needed for SIDI.
Aftermarket Possibilities
Many of you are probably thinking: OK, great engine, but it's still a little inline four! The image of four-bangers being less-than-durable is not without truth. Yeah, we've seen some four-cylinder imports make amazing power, but that power comes at a price: literally and figuratively. The amount of dough that must be pumped into your typical four-cylinder to get it to withstand large amounts of horsepower is very high, and even then, they're still a ticking time bomb of blown head gaskets, bent rods, and catastrophic block failures.
But the Ecotec is different. This particular four-banger really will withstand the abuse true enthusiasts will throw at it. But don't just take GM's--and our --word for it. We had a conversation with someone who knows firsthand: Mr. Bill Hahn Jr. Since the 1970s, this man has been turbocharging everything he can get his hands on, from V-twin motorcycles to airplanes. His company, Hahn Racecraft, was founded in 1988 and provides turbo systems for vehicles ranging from T-Types to Vipers, Miatas to GTOs. But it's GM's Ecotec platform that has really gotten his heart thumping in recent years. "This second-gen Ecotec architecture is really something. Several years back, GM made a promise that they were going to go after the Ecotecs with a vengeance, and I'd have to say they were not exaggerating in the least!" Hahn has worked extensively with this engine platform in all its applications, and already produces turbocharger systems for the LE5-equipped Sky and Solstice.
Looking more closely at the Borg-Warner dual-scroll turbo, we see where it gets its name: two separate exhaust passages leading from the exhaust manifold to the turbine inlet. "Combined with the VVT on both the intake and exhaust, this is a key element in getting good low-end torque and power at the same time," says GM's Ed Groff. "Typically, if you put a turbocharger on that's large enough to get the power that you want, you would suffer at the bottom end. We have a variety of technologies--the SIDI, the cam phasers, and the dual scroll--that all help the bottom end," says Groff. Thanks to the engineers' efforts, turbo lag is allegedly cut to imperceptible levels, furthered by a lightweight turbine design.
"I'm excited enough about this new Gen II Ecotec engine that I believe in stock form I will be able to push it further--safely and durably--than any engine from any manufacturer that came before. With the Gen II, we're working with an engine that is brutally durable as far as its bottom end design. With a casing that splits in half like a racing or motorcycle engine, these things are just amazingly capable of higher horsepower. It's really encouraging because while other manufacturers have some pretty powerful four-cylinders on the market, a lot of them are working with 10- or 20-year-old technology compared to the all-alloy Ecotec. You have to be really selective with engines these days, and I can honestly say that the Ecotec, which we have been working with for years, has an incredibly durable track record compared to anything else we've ever worked with. I can honestly say that there's nothing out there from any manufacturer that surpasses it."
Exactly how the aftermarket will address the challenges that direct injection, high fuel pressures, and a brand-new, advanced E69 ECM bring is hard to say. But we can tell you that support is already out there for the Ecotec engine line, and these new technologies only add to the possibilities; though in the spirit of a capitalist market, nobody is saying just how such challenges will be addressed. "At this time, I'm not at liberty to discuss the methods we're planning on using on the LNF in any type of detail, but I already have some pretty solid methods planned out," says Hahn. "I do want to emphasize that we are going to be all over this vehicle. We are excited as can be especially because it's turbocharged, and we may be able to push the envelope even further with this engine than any previous Ecotec just because of the strength of the direct injection system."
Other than the altogether different engine that, in factory guise, gives a whopping 83 hp and 94 lb-ft increase over the standard Sky, the Red Line sports chassis upgrades as well. Beside Red Line-specific coil springs, this new go-fast Saturn model also gets thicker anti-roll bars. However, according to GM's press material, these suspension upgrades yield no improvement in skidpad holding, as the Red Line pulls the same maximum of 0.90 g as its non-turbo bro. This is most likely due to tire size being identical for the two cars: 245/45-18s all around. The Red Line does get Goodyear Eagle F1s instead of Eagle RSAs, but we still would like to see some fatter meats to match the Red Line's vastly-increased potential for speed. Fortunately for less experienced drivers, standard on the Red Line is the latest StabiliTrak electronic handling control system, helping keep such folks from using all this power to inadvertently put their gorgeous Saturn roadster into the woods.
Pictured are the new E69 ECM, cam-driven mechanical fuel pump, high-pressure fuel rail and fuel injectors. These comprise pretty much everything needed for the Red Line's gasoline direct injection system, which GM refers to as SIDI (Spark Ignition Direct Injection, which stands in opposition to spark-less diesel engines, which have featured direct injection for some time).
But the question remains whether the Kappa platform's chassis is really up to the challenge of handling the LNF's current 260 hp, not to mention the power increases sure to come not only from the aftermarket, but from GM itself in the years to come. Indications are that the answer to this interrogatory is a resounding yes. Bill Hahn Jr., who has been testing the Sky/Solstice platform since its debut last year, explains. "In terms of chassis and driveline, it's already an outstanding piece in terms of architecture. Here you have a four-cylinder, two-seat car, but the reason it weighs as much as it does is because the chassis is so strong. It's a true performance-bred piece, with unequal length A-arms at all four corners and coil-over shocks; this isn't just some warmed-over, parts-bin car with a pretty body on it. The Sky is a real performance car. There's a lot to be said for that, because while there have been similar cars brought to market previously, there has been nothing quite as brutally capable."
"Our testing with our turbo vehicles has shown that the car's ability to put down extra power is actually pretty awesome," states Hahn. "We are not experiencing excessive wheelspin or wheelhop, or some of the other things we see with some vehicles as we turn up the power. This car's dynamics put power down extremely well and without a lot of drama." And even if super-high power levels were to overwhelm this current chassis structure and driveline, rest assured that the aftermarket will step in to take up the slack. For example, extreme-duty axles are in the works, and Hahn Racecraft has already come up with a higher-capacity clutch. So if you've got a hankering to turn up the wick way past GM's design intentions, fear not: all indications point to the aftermarket addressing any problem areas as they become apparent.
Will it Succeed?
The Saturn Sky is a niche vehicle, and the Red Line version appeals to an even narrower range of buyers. As a two-seater with limited trunk space, practicality is far from optimal; but that's beside the point. The current 2.4L Sky is being bought by open-air aficionados on a relative budget who want to drive one heck of a cool-looking car. The Red Line will appeal to the rarer few of these same folks who care not just about looking good and a tight driving experience, but who want to blow the doors off of Miatas and S2000s--not to mention a lot of other so-called sports cars on the road. And many of these buyers will probably want to mod up their Red Lines to take full advantage of this amazing car's as-yet-untapped potential in both powertrain and chassis.
At an estimated base MSRP of under $30,000, the Sky Red Line is still quite affordable for a large percentage of us enthusiasts. The only problem we foresee is Saturn dealerships starting to charge a markup for these limited-edition cars. After all, a big reason the buying public has been attracted to Saturn dealerships since the brand was introduced is the pay-what's-on-the-sticker, no-harassment-from-salesmen policy. Word is that Saturn has issued an advisory letter to all dealerships asking them not to charge extra for the Sky Red Line when it arrives, but apparently the no-haggle pricing situation at Saturn is more of a policy than any sort of contractual agreement between GM and its independent franchisees. We can only hope dealerships don't hurt sales of this car the same way Pontiac dealers did grave damage at the introduction of the 2004 GTO, creating some very upset enthusiasts and setting themselves up for the car's eventual cancellation.
Though the 2.4L Sky is only able to traverse the standing quarter in a ho-hum 15.7 seconds at 89 mph, GM is saying the 2,990-pound, manual-equipped Red Line will pull a 13.9 at 100 mph. Expect to get to 60 mph in only 5.5 seconds (versus the standard Sky's 7.2).
Conclusion
There's a lot more to talk about with respect to this vehicle, but needless to say, GM has the potential here for a sales and image slam-dunk.With the turbo Sky, GM further solidifies its commitment to not just performance, but advanced, responsible performance technology that simultaneously improves power production, fuel efficiency, and tailpipe emissions. With more SIDI applications in the coming years--the first being a 2008 3.6L V-6 for an as-yet-unnamed vehicle--things will only continue to get more exciting with GM. In fact, by 2010, GM says 1 out of every 6 cars the company sells will feature direct injection. How many of those cars will feature kickass turbocharger systems like the one seen on the Red Line is anyone's guess, but we're hoping it's at least a few.
Though there haven't been many whispers about future rear-drive Saturns to come, we'd be shocked if the Red Line emblem didn't grace more than a couple worth-drooling-over vehicles in the future--regardless of drivetrain layout. If nothing else, the Sky and the soon-to-be-released Aura demonstrate designers' intentions that Saturn cars look the part of a very sophisticated automobile brand, even if it turns out that the Sky Red Line is the only car of theirs that truly walks the walk. And with insiders strongly hinting that 260 hp is only the beginning for this 2.0L motor, things will only get better for the Sky Red Line.
Until now, admitting that you owned a Saturn in front of other performance enthusiasts was a bad move for your social popularity. Let me be the first to declare those days are over.
A look at the combustion chamber shows a fairly standard four-valve setup with centrally-mounted spark plug, but peeking through on the left is the tip of the SIDI system's fuel injector: a breakthrough in more than one way. "SIDI is effective in cooling the charge because the energy to evaporate the fuel comes from the gas phase in the cylinder. With port fuel injection, the energy to evaporate the fuel is coming from the port walls, so the heat is coming out of the metal. But with SIDI, we are injecting during the intake stroke into the gas phase so we are taking the heat out of the air. This helps cool the charge, which lets you up the compression ratio roughly 1 unit. A PFI engine at this level of boost would normally be in the 8s for compression," says GM's Groff. | 
Here we can see the function of the oil jet and the specially-machined oil galley in the piston at which it is aimed. "The jet-spray oil cooling system brought us well below our engineering piston temperature targets for the 260 hp output of this engine, ensuring durability," says GM's Ed Groff, who continues with even more interesting information: "At the same time, this will enable us to take the power up even higher. Knowing that this engine has got to continually grow and improve to maintain its image for GM, we made sure we had a lot of margin for improvement on the current horsepower level of 260. The oil jet cooling system, coupled with other technology, gives us the capability to increase power density further. So its power is not, in effect, done!" | 
A front-mounted, single-pass air-to-air intercooler drops charge temps by a claimed 212 degrees F. Ed Groff explains, "It's an internally finned, high-efficiency design. The platform did a very nice job of meeting the needs passed down by GM Powertrain, and it effectively cools the charge at the flow rates we are dealing with." Assuming this illustration shows the correct routing of the intercooler ducting, we can see that designers did a very good job of keeping it fairly straight and well-routed. |
A look at the LNF's piston shows its specially-shaped crown, which directs the air/fuel mix toward the spark plug, furthering the cause of efficiency. As any avid GMHTP reader knows, more efficiency means more power! Lower emissions aren't a bad thing, either. | | |