OK, so maybe the title is a bit of a stretch. We'll be leaving out some turbo-oriented stuff, like diesel truck applications and other junk you couldn't care less about. And there will be no A&E-style The Life biography on Galen Tomlinson, otherwise known as Turbo on American Gladiators. But if you're thinking about adding a turbocharger to your engine, or upgrading your car's factory turbo, we've got some good information here, culled from a number of experts in the turbocharging industry. They shared their thoughts and opinions about how to choose the right turbocharger, engine upgrades you should consider in addition to the turbo, and some highly recommended accessories that'll help you get the most from your new boost levels.
Choosing a Turbo
Our hands-down favorite quote about turbo selection came from Tyler Tanaka, marketing manager for Turbonetics. "It's like buying shoes," Tanaka explained. "You don't just go to the store and order a pair of shoes that are too big for your feet. The turbocharger has to be the right size for your application." (Tanaka has also been known to say, "I like buying shoes...women's shoes." But that doesn't seem too relevant to the topic at hand.)
So, as sexy as that huge snail would look under the hood, it may not be right for the kind of driving you do. It's true that a bigger turbo will produce more air volume, which translates to higher levels of peak power. But the bigger turbo takes a lot of exhaust pressure to make that boost, which translates to a ton of turbo lag.
Now, lag isn't necessarily a bad thing, if you're a drag racer. "On a front-drive car, turbo lag is your friend," said Jensen Oda of A'PEXi. "You sacrifice power in first gear, but in second through fifth you will always have power when shifting the gears. The last thing you want is a turbo that spools up too quickly in first gear, 'cause the tires will just go up in smoke, which usually ends up smoking second, and finally bogging in third."
But that's racing. "Bigger is not always better if you aren't going to race," said "White" Mike Liao of Blitz. On a street car, when you're not always at wide-open throttle (at least, we assume you're not all the time), drivability is more important than peak power. For that extra power punch at the midrange, go with a smaller turbo that'll spool up quicker.
Heard the term "ball-bearing turbo"? That means the center shaft between the turbine and c
For a lot of you, choosing a turbo will be as simple as opening a catalog or going online and picking the right kit for the kind of car you drive and the way you drive it. Almost all of the turbo companies we talked to offered complete turbo kits, which have been assembled after lots of R&D time. "Leave it up to the experts," said A'PEXi's Oda. "The last thing you want to do is experiment on your daily driver."
But what if there's no kit for your car? Where do you begin? "Do all the basic stuff first: headers, plumbing, fuel, ignition, so the car is as good as it can be," said Turbonetics' Tanaka. "Then sit down with one of the turbo manufacturers and go through the engine's parameters."
Questions to ask the turbo maker include how much horsepower are you interested in? How much boost? At what rpm do you want peak power? What kind of transmission are you using, what kind of torque converter or clutch? Also discuss non-engine related stuff, like what sort of conditions you drive the car in. If you're in Denver's thin air, you're going to need a different setup than a guy in LA or Long Island.
With that kind of information, said Tanaka, "a company will choose a turbo unit that's personalized for your car and how you drive."