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  • [CAR ENGINES]

  • 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.

  • We've had Swansea University, who are the world's leading

  • experts in this, they developed the technique 15

  • years ago that we used.

  • Intel have given us a huge amount of computing power.

  • And we've done some genuinely world leading modeling

  • supersonic ground effect, and got a shape which, at all

  • speeds, will stay on the ground.

  • And that actually, when you think about it, is the only

  • safety requirement for a land speed record car.

  • As long as you can keep it shiny side up, keep all the

  • wheels on the ground, and the fin is the right size to keep

  • it pointy end forwards, you've cracked it.

  • CHRIS HARRIS: But you don't want to drive it into the

  • ground so hard that it disrupts the surface and makes

  • it unsafe [INAUDIBLE].

  • ANDY GREEN: Exactly.

  • That's why the aerodynamics have to be so precise, to

  • actually bound the load so you don't crush the wheels, but

  • you don't at any stage finish up with them lifting.

  • Or, with the front-rear distribution so far out,

  • particularly front-heavy, the car becomes

  • uncontrollable as a vehicle.

  • Because before it becomes totally dominated by the

  • aerodynamics, which is 500, 600 miles an hour high speed,

  • but at 300 or 400 miles an hour, which is slow to medium

  • for this car, it is behaving like a car at least as much as

  • its behaving like an airplane.

  • So it's dominated by its vehicle dynamics as well.

  • And we need to get that balance right.

  • CHRIS HARRIS: 300 to 400, slow to medium speed.

  • It's a different reality, isn't it?

  • Anyhow, back to the racing.

  • Andy started race one, and in the dust and mayhem held his

  • nerve for 24 minutes before handing over to me.

  • For his first time in a fast racing car, it really was a

  • stellar effort.

  • The change was reasonably smooth, but there was a

  • problem with my reproductive equipment.

  • My right spud was being crushed by the belt.

  • This was agony, so I tried frantically to adjust on the

  • small straights.

  • It didn't work.

  • I then got overtaken a few times.

  • The only thing for it was a pit stop for testicular

  • adjustment.

  • As racing driver excuses go, you have to

  • admit it's pretty good.

  • We started 16th.

  • We finished 15th.

  • Anyways, this is Andy talking about rear suspension design.

  • ANDY GREEN: We have to have the rear wheels outside the

  • body work, first of all because the shock waves under

  • the body will tear up the desert.

  • This is a dry lake that we're going across.

  • The front wheels and the shock waves between them will rip up

  • the surface they're running over.

  • So we need some fresh surface outside the body work for the

  • rear wheels to run on.

  • And we need them wide enough apart that we've got some

  • really good rollover stability so that even if the car does

  • get a little bit sideways, there's no chance of it

  • digging in and rolling over.

  • So we've got a 50% safety mark on the rollover ability.

  • Pushing the wheels out puts the strut out into the airflow

  • and the shock waves over them, the sudden deceleration of the

  • air, supersonic as it hits those struts.

  • Sudden slow-down, the pressure goes up.

  • It's like traffic suddenly stopped and all the cars

  • compressed.

  • Finish up with a high-pressure ridge around

  • the back of the car.

  • It's underneath the car, lifts the tail off the ground.

  • Now, the way to fix that, simple way, is to angle the

  • struts down.

  • Problem is when you're subsonic, say 600 miles an

  • hour, no shock waves, so no high pressure.

  • But the angled-down struts are now generating 10

  • tons of down load.

  • So you've got to find a solution that works subsonic

  • and supersonic.

  • And although it's more a combination of things, a

  • significant part is the double wishbone.

  • So you've got a pair of structure at the top, pair of

  • structure at the bottom supporting the wheels.

  • That pair at the bottom will be filled in, so it's almost

  • like a big delta plane, like a Vulcan wing.

  • CHRIS HARRIS: Race two was a little more straightforward

  • because I didn't have any knacker problems.

  • This time I started and Andy took over.

  • We started in 13th.

  • We finished in 13th, and everyone

  • was very happy indeed.

  • I hope you'll join me in wishing everyone involved with

  • Bloodhound the very best of luck.

  • And I want to leave it here with Andy talking about the

  • numbers involved in Bloodhound, because that's

  • what it is, really.

  • It's a collection of amazing numbers.

  • And that's what always captivates us about the land

  • speed record.

  • ANDY GREEN: Our car's going to have three engines.

  • It's got a state-of-the-art Typhoon jet engine, nine tons

  • of thrust, which is about 65,000 horsepower.

  • We've got a hybrid rocket, Falcon rocket which gives us

  • about 70,000 horsepower.

  • And to pump the hybrid rocket, we've got a Cosworth Formula

  • One engine, because we need 700 horsepower just for the

  • rocket pump.

  • [CAR ENGINE]

[CAR ENGINES]

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