Twin-Turbo Engine

What it fits
The Banks Twin-Turbo SBC product line is not based upon a specific vehicle fitment. It is based upon a Chevy small block or a comparable Dart small block engine with an aftermarket EFI fuel and ignition system. Give us a call, tell us what you're looking to do with your engine project, and we'll tell you exactly what you can expect from Banks Power!

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Engine Block
The 4.125" bore custom block is built to Banks' specs by Dart. It is cast from a high nickel alloy and is equipped with splayed main caps and ARP head studs for superior strength.

Cylinder Heads
The head design evolved after many hours of research on the part of the Banks Race Shop. The result is the optimum 23° aluminum head for use with the Banks Twin-Turbo System. It features custom CNC ported intake and exhaust ports as well as a unique combustion chamber. The heads house 2.080"/1.600" Severe Duty Valves, Banks 1.470" double valve springs and 10° Chrome-moly retainers. This unique combination promotes maximum power output while providing optimum durability.

A 3.5" stroke crankshaft is the heart of the 6.15L/375ci Turbo engine. Cut from a non-twisted 4340 forging and precision balanced to our specs, it is designed for power levels well in excess of 1100HP. Chosen for its superior quality, strength and durability, it will provide a lifetime of trouble-free use even in the most extreme environments. A Fluidampr Harmonic Balancer controls torsional vibrations.

Pistons and Rods
Years of race engine building experience has resulted in the optimum performance design for turbocharged applications. The Banks forged pistons are custom machined to provide the 8.5–1 Compression Ratio needed to optimize street and strip performance as well as the necessary valve clearance. They feature a 1/16, 1/16, 3/16" ring pack, which is uniquely located for better sealing and longer ring life. Connecting rods are 4340 Forged H-beam rods with ARP 7/16" rod bolts, chosen for their remarkable strength, light weight and durability.

Camshaft and Rockers
The Banks turbo engine uses a solid roller Comp Cam with a Banks custom lobe design. The lightweight lifters actuate custom length 5/16 " pushrods as well as the Jesel Shaft-mounted Roller Rockers. The camshaft is custom ground to maximize cylinder head design.

The massive amount of air needed to make 800HP is fed to the engine via a Banks-designed pressure chamber with an integral shuttle valve and a billet throttle body. Both sit atop an Accel Pro-Ram manifold, which is CNC port matched to fit our heads. The high port runners optimize air movement and help broaden the torque curve.

Fuel and Spark
Fuel Injection and spark management is provided by Accel DFI. Their proven system, combined with the thousands of hours logged on the Banks dynamometers plus on-the-road testing, has resulted in a truly solid calibration, which works equally well with manual or automatic transmissions. Idle quality, drivability, mileage, and wide-open throttle have all been addressed with this sealed calibration. The calibration is designed to provide safe fuel and spark management with a minimum of 91 octane fuel for everyday driving, and 100 octane fuel for maximum boost situations.

click for largerExhaust Manifolds
These compact, high-flow manifolds were designed by Banks for the ultimate in fit and long-term durability. Their unique design resists cracking and distortion while providing the best turbo and wastegate placement for ease of installation.

click for largerThe Banks BigHead® Wastegates are designed for a flat boost curve resulting in an awesome power transition. The high-gain actuator allows for quicker spool-up and less boost creep. The stainless steel body withstands the high temperatures, ensuring a long and reliable service life.

click for largerTurbochargers
The high-flow turbochargers, built by Banks to our own strict specifications for optimum performance, deliver outstanding power from their compact frames. With our precision-balanced inconel turbine wheel and shaft assembly, the assurance of durability and reliability is never in question. Driving is a smooth, pulse-pounding power fest that gives you the "nailed back in your seat" thrill you'd expect from Banks. The efficiency of our compressor design helps to reduce inlet air temperatures to acceptable levels, eliminating the need for an intercooler.

Front Accessory Drive
click for largerThe compact design of the CNC’d billet aluminum front accessory drive aids with the installation of the Banks Twin-Turbo engine into many vehicles. A single serpentine belt drives a high output alternator, AC compressor, high-volume water pump and power steering pump. Billet pulleys complement the high-tech look of this system. The CNC-machined aluminum front accessory drive assembly is both attractive and compact, minimizing overall engine length. A single serpentine belt drives all the accessories. It is also available fully polished. (PLEASE NOTE: The power steering pump, alternator and air conditioning shown are available separately.)

Final Testing
Each Banks Twin-Turbo Engine is tested in our dyno cell for one hour, following a proven automated break-in procedure. After valve lash checks, leak-down and compression tests are taken, the engine is given a number of full throttle power runs to verify performance. This assures that each engine is performing to the high standards of excellence set by Gale Banks Engineering.

When customers receive the Banks Twin-Turbo Engine, it includes an engine wiring harness, which they can customize to their application. Included with the engine are exhaust flanges, wastegate flanges, pressure regulator, and fuel pump. An owner’s manual, installation instructions, and dyno sheets are also supplied with the package. Gale Banks Engineering will also work with the customer to create that perfect look for their application. Polishing, chrome plating, anodizing and color coordination can all be worked out to create the desired finished product.


Banks Twin-Turbo Systems are also available

Complete Twin-Turbo systems are also available! (click to enlarge)

If you are a do-it-yourselfer, Gale Banks Engineering offers the complete Twin-Turbo kit to fit a GM small-block V-8 engines. Installation by a competent mechanic can be completed in one weekend. The Banks Twin-Turbo system offers tremendous performance and economy in a classic package from the company that never compromises.

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Get All the Facts on Banks Twin-Turbo Technology (including comparisons to
supercharging and nitrous, insights on boost and intercooling, oiling systems, and much more) in our Free PDF Download (1.7 MB)



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Few People Have Ever Experienced Really High Horsepower.
Read about it in the Twin-Turbo V8 "Facts of Life" tech article.



POWER GALLERY: Here's just a few notable rides that are powered by a Banks twin-turbo engine:

Banks twin-turbo Thunderbird Banks twin-turbo Gaylord truck Banks twin-turbo trike Banks twin-turbo T-bucket Banks twin-turbo Pikes Peak
Peace Thunderbird
< read about it >
Gaylord's '52 Chevy
Las Vegas Trikes
< read about it >
Lee Sklar's T-bucket
Pikes Peak
< read about it >

Do you have a Chevy small block project in the works? Give us a call and we can help you take it to a higher level! Let's chat about it: (800) 601-8072

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The accompanying graphs show the results of dyno tests on a 366-cubic-inch Banks prototype Twin-Turbo engine. The tests were conducted with and without intercooling on 91- and 100-octane gasoline. As the tests show, you can run higher boost when proper intercooling is installed, thus achieving higher horsepower and torque. To reach power levels above 1000 hp, turbocharger boost increased to just over 20 psi, and larger fuel injectors had to be installed along with an equivalent fuel pump. The fuel injection and engine management system was recalibrated for the octane of the gasoline being used. These graphs indicated just how flexible the Banks Twin-Turbo packages can be to meet your performance needs.

Dwayne Peace's Ridler-winning '55 Thunderbird

1955 Thunderbird with Banks twin-turbo engine

Check out the Ridler award-winning 1955 Thunderbird with a Banks twin-turbo engine in these two magazines:

Street Rodder Premium


ApplicationYear RangePart #
Twin-Turbo engine
Small-block Chevy V-8, 800-1100 hp
Twin-Turbo system
Stock block | Standard port heads | Low-pressure wastegates
Twin-Turbo system
Stock block | Raised port heads | Low-pressure wastegates
Twin-Turbo system
Aftermarket block | Standard port heads | Low-pressure wastegates
Twin-Turbo system
Aftermarket block | Raised port heads | Low-pressure wastegates
Twin-Turbo system
Stock block | Standard port heads | High-pressure wastegates
Twin-Turbo system
Stock block | Raised port heads | High-pressure wastegates
Twin-Turbo system
Aftermarket block | Standard port heads | High-pressure wastegates
Twin-Turbo system
Aftermarket block | Raised port heads | High-pressure wastegates

Banks Twin-Turbos reviewed in Super Chevy magazine


When people achieve power, they often want more. For extreme examples, think of history's many tyrants. For less extreme examples, think about hot rodders. While it's true that we hot rodders are slightly less deviant that the Napoleons of the world, we are fairly consumed with increasing our power - horsepower that is.

A little power under the hood leads to ambitions of more, much more, (insert evil laugh here.) After the first grab and taste for horsepower, there's no choice but to become a local tyrant at the dragstrip or on the street.

For those who lust for domination, Gale Banks Engineering has taken the small-block Chevy and given it more power than any reasonable person could want. Perfect! When it comes to musclecars, are any of us horsepower junkies truly reasonable? Banks' twin turbo-powered small-block Chevys have the capability of producing up to 1100 horses at the flywheel. Click below to see the rest of the article!

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 Be sure to check out the Super Chevy website »

Twin-Turbo engine dyno'd at 1100 hp

Gale Banks Engineering built a Twin-Turbo engine for a customer's '69 Camaro in Australia, and this is it being tested on a dynamometer. The results: 1100 hp. That'll be one happy Aussie!

Twin-Turbo & Diesel Engine Programs

At the 2006 SEMA show, interviewed Peter Treydte of Gale Banks Engineering about twin-turbo and diesel projects.

Twin-Turbo engines & kits

Banks Power twin-turbo Chevy small-block engines and kits are available to the public, and here on HorsePowerTV, Gale covers the turbo basics, plus how he creates staggering power gains.

Twin-Turbo on a Trike

For the first time (that we're aware of), a Banks Twin Turbo engine finds a home in a motorcycle, and not just any motorcycle, a three-wheeled one at that!

Free Test Report

Featured Video:

Pikes Peak 2011 pt2


Gale Banks, an old (and I mean that in a positive way) hot rodder … is a bit of a perfectionist, always trying to outdo even himself.

Four Wheeler