Joe: And here is the turbo guru himself, who
just happened to bring along his new Sidewinder crate engine, get this, twin turbo Chevy small
block. Man, this is going to be cool and before I drool on it too much, Gale, I thought it’d
be a good idea, just for the newcomers, to give us a little turbo basics. Gale Banks: Well, a turbocharger is a compressor
driven by a turbine. So turbo charger: exhaust flows through the turbine, in here on the
rear, up to about 100,000 rpm shaft speed is produced and sometimes well over that.
It drives a compressor that’s on the front of the turbocharger. Air flows in, is compressed
and boosts pressure and runs in through this plenum, through the throttle body, and in
to the engine. This particular setup has direct-port fuel injection. Now, the turbocharger I found back when I
started messing with them in the late ’50s, early ’60s, compared to blown engines I was
building at the time, at the same boost, I’d have a horsepower advantage with a turbocharger.
It could be as much as 200 horsepower. Same boost level, same engine, same fuel. Well,
the reason for that is, that when you have a blower sitting up here, it’s parasitically
drawing horsepower through a belt off the crankshaft. The turbo runs on wasted exhaust
energy. Yeah, it makes a little back pressure, but it doesn’t use as much shaft horsepower,
so you get more out of the flywheel with a turbo than with a blower. There’s some other advantages. With a turbocharger,
using the waste gate, I can control the amount of exhaust flowing through the turbine and
I can change the speed of the turbocharger relative to the speed of the engine. Which
means I can make boost, I can paint a torque curve, like you could only image with a blower.
As far as throttle response, turbo lag is gone. That’s history. We have tire problems,
we don’t have power problems. So, you can also vary the octane by changing the boost
level with a waste gate. This thing’ll run on 87, all the way up to 100 or more. But
at 100 octane, clear, no lead, this thing makes 1,115 horsepower. Joe: Wow. Gale: So, there you go. Joe: Why did you want to come up with this
new concept of twin turbo for the small block Chevy? Gale: Well, this is when something gets old
enough, it gets to be new again. Back in the ’70s and the early ’80s, I built a lot of
twin turbo 700 horse Firebirds and Cameros and Corvettes. We had the first magazine tested
over 200 miles an hour with a street machine. Then I got into diesel, and I’ve done a couple
decades of doing diesel. Of course there’s turbos on those too, but no one stepped up.
No one came out with a bolt-on, ready to go, 100,000 mile-capable twin turbo setup. So,
we built the engines as an example. Guy doesn’t have to buy the engine. He just needs a turbocharger.
There’s millions of small block Chevys out there. Joe: Well, to make that kind of horsepower,
Gale, you obviously had to make some changes to the inside of the engine. For example? Gale: Well, what you do with a supercharged
engine or a turbocharged engine, is you build a real rugged piece to start with. Cam shaft,
that’s specific to turbocharging. Piston design, for blowing air supercharged or turbocharged
engines has to be lower compression. This one, that we build, is the Banks Blower piston.
Has a reverse deflector. It’s down the hole here, where you’d normally have a pop-up in
a high compression, and quench area here. This helps you prevent detonation. We also
go over to the combustion chamber and we polish it out a bit to remove hot spots that could
also lead to detonation. Joe: Some of you might be thinking, “Now,
I already have a good, healthy small block. What I need is some serious boost” and this
looks like a serious twin turbo kit you got here, Gale. Is it everything a guy needs? Gale: It’s everything you need, you don’t
have to own a hardware store to install this baby. Also, you don’t have to own a machine
shop. Simple hand tools gets the job done. And the kit resolves one big aftermarket turbo
issue and that’s the exhaust manifolds. Instead of a fabricated tubular manifold, what we’ve
done is we’ve gone ahead and invested in high silicon ductile manifolds, left and right,
so you don’t have the cracking, the turbo sagging and the gaskets blowing that you encounter
with a hand-built tubular exhaust manifold. And the layout of the turbo system is such
that it’ll fit 55 Chevys, both cars and trucks. Man: Well, we have to take a short break,
but when we come back, Joe and I are going to take that turbo kit, put it on this small
block and even fire it up. I know you don’t want to miss that. Well it looks like we’re
ready to install the Banks turbo kit. Now one of the most important things is, you want
to make sure you start off with a good electronic fuel injection system, like the one we got
from Accel DFI. We bolt each manifold on with the heat shield between the manifold and the
cylinder head. With the studs installed, drop the gaskets and spacer over the manifold flange.
Then install the turbo assembly to the manifold with the turbine outlet facing to the rear. Joe: Each one of these turbos is capable of
flowing enough air for 560 horsepower. That means that the turbine and compressor are
going to be spinning up to 100,000 rpms, so oil supply to this center section’s critical.
Now, we get that handled by first installing this elbow fitting, and from there a hardline
that connects to a T-fitting for both turbo chargers, and from it this braided line connects
to the black of the block. Man: Since we have an oil feed line, we need
an oil drain line too. Now the kit comes with these two buns that get welded to the oil
pan, but we already have that covered, so let’s get started on the waste gate. It controls
the amount of boost delivered to the engine and installs just under the turbo, here on
the manifold. Joe: Now we drop on this pressure chamber.
Inside it is this shuttle valve that opens when manifold vacuum rises. Now that also
means that even when you’re off the throttle, the boost has a place to go. The turbos stay
spooled up and, well, you got full boost when you hit that next gear. With that chamber
installed, now we need to get boost pressure from the turbos to the intake manifold, so
we’re installing these boost tubes from the compressor outlets to the inlets on the pressure
chamber. In order for the waste gates to operate, they need boost reference from the pressure
chamber and that’s what these hardlines are for. Well now we need to prime the oiling
system to ensure that those turbos are properly lubed. Then after installing the heat shields
and exhaust pipes, we can bulk up this O2 sensor along with the distributor and wiring
harness for our fuel injection system. Man: Finally we can bolt the radiator to the
engine stand and run our water hoses. Joe: Well, believe it or not, we’re about
ready to fire up this turbocharged mouse and most of you guys can install one of these
Banks Sidewinder kits at home in about a day and you can bolt it up to your stock small
block if you’re only shooting for about 600 horsepower. Now if your goal is 1,100 or more,
well, you’ll need to build your motor from scratch. All right Gale, why don’t you do
us the honors? That’s the sweetest sound we’ve heard here in a long time. Of course, you
will need a three inch exhaust for maximum power, but whether you bolt on a kit or drop
in a twin turbo crate engine, what a way to save parts while you make some amazing horsepower
and torque. Stay with us, we’re coming right back.