CHRIS HARRIS: A few weeks back, I did a race with Andy

Green in the Dunlap Radical UK Cup.

We shared a car for two 40-minute

races at Brands Hatch.

Now, if you don't know who Andy Green is, you should.

He's the holder of the world land speed record at 763.035

miles per hour.

And soon he will drive Bloodhound SSC, a machine that

aims to top 1,000 miles per hour still

connected to the ground.

He's basically a hero.

And he used to fly fast jets for the RAF.

The race weekend was a chance for Andy to see how a small

race car with wings and slicks would help his training, and

for me to pepper him with irritating questions like,

ooh, does it feel really fast going 700 miles per hour?

Well, this is a kind of video blog vlog pastiche, collection

of stuff, whatever you want to call it, from the weekend.

And for starters, here's Andy.

ANDY GREEN: The thing probably that surprises most people

about straightline racing world's land speed record is

that cars, the faster they go, like any track car, the

lateral corner or lateral grip tire cornering stiffness,

whatever you want to call it, goes down.

And the faster you go, the less grip you've got sideways.

If you're going to extreme speeds, 400, 500, 600, 700,

800 miles an hour, then the car is sliding pretty much

continuously at that stage.

The wheels are planing on a dry lake bed.

The vehicle is moving around in the

slightest of cross winds.

Having more paint on one side of the car than the other will

produce a side force.

There are so many things that will move the car around.

And experiencing that for the first time at 600 or 700 miles

an hour is inevitable if you're

driving a brand-new car.

Experiencing the sensations of having a car sliding around

underneath you and, first of all, not panicking, second of

all, working out whether it's OK and that's normal, so

you're somewhere near your stability limit where you're

actually nice and comfortable, or you're over your stability

and the car is starting to get away from you, and what you

can do about it.

And then, because you haven't panicked, putting in the right

amount of steering correction or backing off on the power a

little bit--

all of that decision-making process, I don't have the time

to practice at 600 or 700 miles an hour.

Coming here to a racetrack and practice going around in

circles and scaring myself at 100 miles an hour and getting

used to a car that's moving around, recognizing whether

I've got a bit more to push, whether I've slightly

overcooked it and I need to start doing something to

collect the car, that same principle and the same mental

process and the same psychological getting used to

being a little bit scared but not too scared and being right

on the top of the stress performance curve, that's a

brilliant thing to practice for the weekend.

And as you and I are both discovering, the Radical is a

great car to practice it in, because it is quick.

Its handling does change with speed

because of the aero package.

And that actually is quite useful for me.

I haven't done that before.

And it's relatively forgiving.

We've both been backwards down the main straight.

That wasn't intentional for either of us.

But we've both learned quite lot about it.

And the car's forgiving enough that it's out there now, ready

for the race.

CHRIS HARRIS: So the race [INAUDIBLE] was a pretty

normal setup--

test Friday, qualify Saturday morning, race Saturday

afternoon and Sunday.

This is the car we were racing, a Radical SR3, which

to me is the classic Radical--

a tweaked Suzuki Hayabusa motor taken out to 1,500 cc.

That's 210 horsepower and 130 foot-pounds of torque.

The car weighs just 570 kilograms.

And as you can see, it has a [BLEEP]

load of aero.

It has a paddle shift gearbox, and it runs Dunlop SLICKS.

The challenge with a Radical is

getting used to the downforce.

Even compared to a fast GT car, the turning and cornering

speeds are breathtaking.

And you have to take a leap of faith to find

the limits of grip.

The braking performance is startling, too.

It only has little 260 millimeter steel rotors, but

it'll pull 2 Gs on the brakes all day long.

From a very high speed, you also have some aero effect,

which allows you to use big initial pedal pressures, but

not that big, as you'll see later.

Friday was a chance to get comfortable in the car, or as

comfortable as two people sharing a drive who are about

8 inches apart in height can be.

You see, I was wedged forward with a load of foam.

Brands Indy is an evil circuit.

Andy worked his way into the car.

I did the same.

In the last session, I pushed harder in the braking zone

into paddock, because that's where I was losing time.

I found some time, but sadly I lost the car.

Now, Radical were understandably miffed at me

wrecking the rear end of the beautiful

Bloodhound liveried SR3.

They went and found more stickers for the next

morning's qualifying session.

I went to look at the data.

Too much brake pressure, plain and simple.

Didn't feel like it from the inside, but the

numbers don't lie.

The rears locked, and my neck got stretched.

This seemed like a good time to ask Andy what it's like to

go really fast.

I just find this stuff mind-bending.

You had opposite lock at how fast?

ANDY GREEN: Between 600 and 650 miles an hour.

CHRIS HARRIS: How much lock did you have to apply?

ANDY GREEN: Well, the steering for the car is about twice the

ratio of a road car.

So you get about half the wheel response.

So for a normal road car if you've got 90 degrees of lock

on, you get about 6 degrees at the rear wheels.

We had a 30-to-1.

So 90 degrees of lock, which is what I had on at 600 miles

an hour, is about 3 degrees at the rear wheels.

And we're rear wheel steering.

That is part of the problem.

The twin jet supersonic car we built last time had so much

jet and structure at the front, there was no room for

the steering gear, just enough room for the wheels.

So the wheels were behind me.

So every time you put in the steering input, the car moves

the wrong way before it starts to go, which is quite

confusing for a simple brain like mine at

600 miles an hour.

And to add to that, aerodynamically the car became

unstable in the transonic region--

not uncontrollable.

And the difference is, in a push bike at slow speed, you

can actually ride a push bike.

If you let go of the handlebars, it falls over.

It's controllable, but it's not stable.

Multiply that up to 600 miles an hour, and I have much the

same problem of fighting the car.

And it's set off sideways, usually left because of the

aerodynamics.

And I ended up putting 90 degrees of lock on and backing

off on the power to just try and change the front rear

balance a little bit, get the weight off the front so that

we finished up with a better balanced car.

Soon as it started responding to the steering--

because we've got about probably two or three degrees

of yaw on now as the car's sliding sideways.

And it's about 15, 20 meters offline.

Soon as it starts responding and coming back, I've got to

get the power back down again.

Because I've only got another mile and a half to the

measured mile.

Got to get up about 750 miles an hour.

So it's full power.

Start to wind the lock back off.

So that will the car straightened up on the line

going into the measured mile at supersonic speeds.

And of course, I've got to do that two ways within one hour

to set the world record.

CHRIS HARRIS: This was my qualifying lap.

I'm a bit of a pussy through paddock, I have to admit, but

it left us 13th on the grid.

Andy qualified for the first race.

I did the second.

Neither of us made much of an impression on

the computer screens.

His excuse was valid.

He hadn't raced a car at Brands before, and this was

only his second event.

Mine was more tenuous.

I felt that if I bent the car again, I was

probably a dead man.

And the combination of seat and

downforce was plain torture.

That's [INAUDIBLE]

of what you're trying to achieve.

Because we're both learning that the [INAUDIBLE]

car, but it has lots of aero effects here in two places,

Paddock Hill and [INAUDIBLE].

For me, an aero effect on my car is when the car forces you

to do something your brain tells you you shouldn't, to

turn at a speed that mechanically you think is not

suitable for the vehicle, that means the

wings aren't working.

Is that a reasonable description of it?

ANDY GREEN: Absolutely right.

And the classic here is coming into, at the bottom of Brands

Hatch, the S-bend, Surtees, for those that

have driven it here.

And first day I was braking quite hard.

By the time I got to the end of the first day, you can go

through there almost flat.

So I'm braking a little bit.

Now I'm just lifting very slightly, and the car is going

through like everybody promised it would be.

But it doesn't make sense.

The performance of the Radical loaded up at best part of 100

miles an hour, it just does stick to the tarmac

astonishingly.

CHRIS HARRIS: We had a discussion the other day about

the aero when you go to 1,000 miles an hour.

That's remarkable.

So talk us through the speed ranges of the car.

ANDY GREEN: First of all, the aerodynamic forces are

absolutely dominant at the high speeds.

To go about 15 years to Thrust SSC, one degree nose down

would generate 10 tons of download on the front and

crush the front suspension into the desert.

One degree nose up would generate 10 tons of lift.

The car would pitch up, pull 40 G. The body work comes off.

Engines tear out the bottom of the car.

That's the end of my interest in the afternoon.

So that precision, it needs to be incredibly precise.

And with the thrust shape 15 years ago, we didn't have the

tools to set that so it was the same

angle all the way through.

We actually had to change the pitch angle of the car as it

was accelerating.

The problem with that is if that system fails, you finish

up in an uncomfortable place.

And we limited with Thrust SSC, because we were only just

going supersonic.

Step forward 15 years.

We're now trying to do 1,000 miles an hour.

That's almost 40% above the speed of sound, like 1.4.

So tweaking the car a bit isn't the solution.

We're actually going to have to solve the fundamental

problem of a shape which generates virtually no lift or

downforce all the way through the speed range.

And that's been the single most difficult technical

problem we've had.