Tech Feature: Boosting Performance – Nitrous, Superchargers and Turbochargers – UnderhoodService

Tech Feature: Boosting Performance – Nitrous, Superchargers and Turbochargers

Today's new cars offer so much performance directly from the factory that there's no reason anyone could need any more, right?

“It’s amazing, the horsepower potential that these cars are coming with off the factory floor,” says Frank Beck of Beck Racing Engines in Phoenix, AZ. “The ZR1 is very underrated and has so much more potential. The factories are using forced induction on Mustangs and trucks and just about everything, it seems. It’s what the people want.”

You can buy 600 hp fresh from the factory that can be a real handful on the street. So, with all that OE power, no one should want for more, right? Oh, c’mon.
beck racing engine's pro kill has all the goodies: chrome, efi and a big honkin' blower. when building such a motor, be sure your internals are up to snuff.
“The first thing these guys are doing after buying these $100,000 cars is putting more money into them,” Beck says. “They’ve just got to beat the next guy.”

OE performance may satisfy some of the customers, Beck says, but it motivates others. “It gets them thinking of ways they can beat that ZR1. ‘I may not be able to afford a new $100,000 car, but with what I have now and another $10,000-20,000, I can build something that can beat it. It just puts a new target or bullseye out there to go after.”

And that target can be pretty broad, say experts in the power adder industry. Your customers may be looking to add incredible amounts of horsepower or they may just be looking for a performance boost now and then. Chances are, they’re looking to you for advice.

“If someone with an LS1 engine is looking to gain about 100 hp, it’s not economical for him to put $6,000-10,000 into a turbo system when he can go out and spend less than a thousand for nitrous and know it’s going to be fine,” says Dwight Baldwin from Jacksonville, FL’s Stage 6 Motorsports.  

“On that car with that engine it’s going to last a long time. Now, if he wants to jump up to 800 hp at the tires, it’s going to get expensive for him on nitrous, just because it’s going to be so hard on parts. While the initial buildup on a turbo system will be expensive, but after that it will balance back out.”

Baldwin believes we’ll continue to see demand for smaller, more powerful engines because of economics and fuel pricing woes. “I’ve got a 496 in a Chevy pickup,” he explains. “It’s fun to drive but it’s outrageous to feed. When you’re getting 6 miles to the gallon and you’re making 500 hp to the wheels, it’s kind of hard to justify when you can drive a lot of cars that will make the same horsepower and on the highway get 28 mpg. It’s hard to compete with that.”

The choices available to performance enthusiasts are as varied as the range of vehicles using them. Lumped under one heading – “power adders” – you’ll find an array of options and questions to ask and answer.

Nitrous Oxide – The supercooling of the evaporating nitrous oxide increases the density of the air entering the cylinder. Although it has had an unwarranted reputation as a “dangerous gas,” nitrous can be a safe reliable horsepower booster, say experts. Of all the power adders available, nitrous is the easiest and quickest to install. Many entry-level kits can be added by a do-it-yourselfer in a few hours.

“It’s always been a ‘cheap trick,’” says Steve Johnson of Induction Solutions, in Brooksville, FL. “It’s a lot more affordable than the other options. A guy can go to a race, see a nitrous system and kind of visualize what it will look like on his car. When they see a turbo or blower system, with all the piping and think EFI and laptops, for some guys their heads start to swim.”

And so, says Johnson, does their checkbook. “The cost goes up exponentially with the other systems. Nitrous will hold its own because of its cost.”
this is a custom 427ci custom
Superchargers – basically, a supercharger is a mechanical pump that can force more air into an engine than would be sucked in by the pistons themselves on the intake stroke in a normally aspirated engine.

“A twin screw (or Roots-style supercharger) is considered a positive displacement supercharger, meaning it pumps a specified amount of air in one direction for each revolution. Positive displacement superchargers do not have to turn high rpm to create boost and make full boost starting at just off idle,” explains Sean Roe, Roe Racing, Jacksonville. “A centrifugal supercharger is basically a belt driven turbo, which uses an impeller to move the air. It relies on rpm to create airflow and therefore needs to spool up. The higher rpm centrifugal superchargers produce more heat than the lower rpm twin screw style.”

Roe says the twin-screw style can make more low rpm power than the centrifugal type because of how quickly the boost comes on. A centrifugal supercharger actually causes drag and decreases power slightly in lower rpm ranges, but can make more peak hp at higher revs.

Another positive displacement type of supercharger is the “screw-type” known as the Lysholm screw. Several manufacturers offer this style of blower. They have similar performance and operation characteristics to the Roots-type superchargers, but are claimed to be more efficient.

“I define a blown application as having a Roots-style blower,” says Beck. “To me, a supercharger is the bolt-on centrifugal kind. Roots-type blowers are the ultimate at producing torque: they do it right there, right now. Where a turbocharger and supercharger has a more linear torque curve, a blown application spikes up hard then it’s a pretty flat torque curve. The benefit of that is the instant power – the drawback is you blow the tires off.”

Turbochargers – Turbocharging is yet another option. As Beck points out, they can offer more power than a supercharger, and give a wider torque range. “They’re making a resurgence,” he says. “They’re hard to beat with their power potential.”

The problem, as Baldwin points out, is the initial cost. Do turbos make sense to the engine builder looking to add performance to his mix? It depends on the customer and the application. The initial expense on the turbo is the biggest problem, customer-wise.

“There are a lot of kits available on the supercharger side and nitrous is the most economical, period,” Baldwin explains.
“The only problem with nitrous is it’s the most violent on the motor. It fatigues the motor a lot sooner than a blower or turbos. If you have somebody doing rock crawling or off-road stuff they’re going to want instant power so most of the time they’ll go with the supercharger. In street applications and more and more often in drag racing turbos are a choice because they’re easier on the motor and they make a lot more power.”

Customers, Baldwin says, recognize that getting the power won’t be inexpensive, at least at first. “Most of my customers are aware that it won’t be cheap by any stretch. There are economical ways of doing it, certainly, based on what they’re looking to do. The biggest thing I try to stress to the customer is ‘figure out your long-term goal so you don’t have to keep replacing parts. If you want to make 600 hp in a Supra, don’t spend a lot of money on parts now that will only make 400 hp at 100 percent.  And we try never to run the turbos at 100 percent continuously – just like anything else, if you run it at 100 percent all the time it’ll wear out faster. Oversize it just a little bit and it’ll usually last a lot longer.”
This Ford GT twin kit has two Garrett GT35R turbos on it and on pump gas it made 904whp and on race gas 1080whp. This GT now has over 30,000 miles on it with no problems, says Dwight Baldwin.
Internal component upgrades? Baldwin says of course it’s an important consideration. “Turbos tend to be a lot easier on parts. It doesn’t kill bearings as bad, it’s the simple fact that you can make a lot more power but it doesn’t seem to be working as hard. We can take a stock S2000, put a turbo on it and with a little race gas make around 600 hp on the stock engine.”

The big challenge, Baldwin reiterates, is the up front expense. “It balances out long term but in the short term it can be hard to justify for the typical consumer.”

Points To Consider
Frank Beck believes experience is the best teacher. While his stock in trade is the Chevrolet engine (both Big and Small Blocks) the basics of what to take into consideration when building for any engine that will use air induction still apply.

“The number one thing people need to do is look at the big picture. Let’s say you’ve got a 700 hp normally aspirated engine. You want to run a 300 shot of boost, whether you get it from nitrous, turbo or a blower.  You now have a 1,000 hp motor. You need to make sure your components can handle that much power.”

Beck says pistons take the brunt of the beatings. Cast and hypereutectic pistons can have limitations when it comes to adding power. But even being forged doesn’t mean they’re impervious to damage. “We had a case where we pushed the envelope too far with a forged piston. There wasn’t enough material for the top ring land. You have to make sure that the parts are proper for the application.”

Beck cautions about skimping on quality. “Sometimes you need a custom piston even if there is a forged shelf stock piston that fits the application as far as physical size and dish volumes  – we’ve found even they sometimes have limitations. It may not be right for that application – it may not be rated for the horsepower level you’re trying to achieve.”

The ring package is important, says Beck.” What we’ve discovered over the years is that moly-coated rings have a tendency to – the first time it rattles ever so slightly – blow the moly off the rings. Then you’re worse off than having a standard ring. I use stainless on top for its endurance capabilities…it’s pretty bulletproof.”

Head studs give a better clamping ability than head bolts, Beck says. Chevy big blocks have two cylinders on each bank that are missing a head bolt by design. Some of the aftermarket blocks and heads have the provision to add those into the lifter valleys. “This gives you that extra clamping effect,” he says. LS engines have four bolts per cylinder, with aftermarket heads and blocks are going to 6 bolts per cylinder. Small block Chevys are pretty good all around with studs and MLS gaskets – you can throw a bunch of stuff at those.

However, everything has its limitations, Beck points out. “Again, everything will be fine up to certain point until you push the envelope and you’ll find the next weak link. The key is knowing what those boundaries are – and they’re tough to find out without pushing it and finding out the hard way.”

Also, when combined with turbos and blowers I believe that any type of endurance engine needs Inconel exhaust valves. They’re standard on all our blown engines, our marine engines and forced induction sand car engines. Anytime the end user will be running it pretty hard for a long time, beryllium-copper exhaust seats help dissipate the heat off the valve faster to extend the life. We also run piston oilers to help the pistons live under those conditions.”

Beck says another of his tricks is to use a reverse welding process called EDM to drill a small hole from the big end of the rod to small end to force oil up to the wrist pin. “If they’re running a dry sump application or vacuum pumps they’re creating a negative crankcase pressure. It produces a lot of horsepower because it helps in sealing the rings, but they’re literally sucking so much oil down, scavenging it, that it’s drying the wrist pins and they’re having problems.”

Sean Roe says when he got involved in building and racing Dodge Vipers he immediately saw easy ways to make it faster, cool better, stop quicker and sound better because the car had a lot left in it.

“Vipers are not built for high rpm. They’re a low rpm motor with big main bearings and not the greatest oiling system,” he says, “so we build a positive displacement supercharger kit. Between the cars and trucks with that motor we’ve done close to 600 of them in the past 7 years.”

Dodge started putting cast pistons in the Vipers in 2000, so when Roe sells a supercharger kit model year is an important consideration. “If a guy’s got a 1992-99 viper we tell him he can run up to about 10 pounds of boost on street gas on street compression without a problem. But a lot of guys with newer cars, because they want to modify them even more, are on cast pistons, so we see a real opportunity to upgrade them to forged pistons and premium rods – have the engine built so they can run what they want in their car. We refer a lot of work to engine builders so they can run what we offer. We supply the parts and the engine builders do the actual machine time, the bearings, the ring filing. That way it works for everybody.”

Race engine builder Pat Musi says engine builders need to help customers understand at what power level damage is possible.

“The consumer is getting smarter. With the Internet and the forums if one of them finds out something the rest will soon too, says Musi. “Unfortunately, with online retailing, you never really know what you’re getting. You see a Web site and think it’s a legitimate business only to find out it’s some fly-by-night in his garage. So you need to know whom you’re dealing with. Engine builders must make the effort to keep up with the consumer.  We have to, but I’m not sure if some of the small guys are.”

Many resources for researching performance capabilities are out there at your fingertips, from chat rooms and forums to online calculators that can help make decisions clearer – or more difficult. Frank Beck cautions that just because something is said to bolt instantly into place doesn’t mean it will be that simple.

Steve Johnson concurs, and says education is as important in the information age as ever. “That’s one of the things I try to work on with all my customers and tell other people as well: is the guy you’re looking to buy from knowledgeable? Will he be able to offer educated answers and tech information and help point you in the right direction rather than just say, ‘Here’s your kit.’”

Johnson says the popularity of the movie “The Fast and the Furious” did some real injustices to the industry. “That movie, while it made nitrous incredibly popular, helped taint our market in many ways.”

He says, “It seems to go in waves, and crowds. Nitrous was always looked at as a voodoo black science – you needed to be a witch doctor to understand it or install it. But the kits available these days have gotten a lot more reliable, the tuning information has gotten better. Still, a lot of the youth have grown up on forced induction – a lot of them grew up around the turbos and blowers. They like dealing with the electronic fuel injection and so on.”

Pat Musi says the future is anything but clear for performance. “It’s becoming more mainstream, but who knows what the government will allow in the future?  With them bailing out the car companies will they keep making Camaros and other OE performance cars?”

Johnson says “Last year, during the height of the recession and the election, we were definitely slow, but this year we’ve been busy as ever. Part of that is our reputation keeps growing thanks to our exposure at races and online as well as just being a small business – we’re still able to continue to grow even in hard times.”

Dwight Baldwin recognizes that this is an accessory, not a necessity. “It’s a luxury, and as far as the street guys or the guys looking to just add a little performance, that’s died off pretty heavily right now. The serious enthusiasts are still doing it, and a lot more guys are turning to competing at the track, which is much safer, but they just seem to be more conservative now, doing more research before they make a purchase.”

The solution to determining whether a particular power adder is right for your customer lies ultimately in his hands. What is it he or she wants to achieve? Sometimes when you’ll want to play salesman, you’ll instead need to play counselor, talking them out of what they THINK they want and helping them instead to realize another system might be better for their application.

The most important factor to remember, say our experts, is that the engine components need to be capable of handling the additional power.

But don’t stop at the engine, caution these experts. If you’re building a vehicle that will accelerate like a rocket, your customer needs to be aware of his needs at the other end too.

“It’s not just engine components you need to upgrade,” says Baldwin.  “We’ve got a Supra in the shop now that makes 900 hp. The owner is still running OEM brakes on it.  I’ve told him ‘You’re running 300 hp brakes with a 900 hp car.’  Unfortunately, that’s one of the hardest things to sell – everybody wants to go fast: they’ll put a lot of money in the car, with power adders of all kinds – but trying to sell them brake and driveline upgrades is tough. ‘Why do I need a $2,000 clutch?’ You just spent $15,000 on a motor and turbo set up…what are you going to put behind it?

“I always have to tell them ‘You know, this your life you’re messing with if there’s an accident,” says Baldwin.

Beck says when you’re building for the maximum combined horsepower potential, put some cushion factor in there. “The air/fuel ratio should be much richer than a normally aspirated application, timing is more conservative, watch your compression ratio, static and combined for the boost.”

“It’s not so much the racers,” says Frank Beck, “because they seem to do the maintenance, have the knowledge and the respect for the components and understand what they’re pushing. It’s the guys who just have the money, that we need to educate. You might have the beer factor at the lake and the sand dunes and they’re just tying to beat their buddy and they never lift until they run out of lake. Then they turn around and do it again. They don’t let the parts cool down – you’ve gotta give them all the help you can.”

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