The Power of Weight: How Less is More in Racing

James May, a car enthusiast and journalist, has always been fascinated by the relationship between weight and power in racing cars. In this article, we'll delve into the world of racing and explore how less weight can be more important than horsepower.

May begins by asking a question that gets to the heart of the matter: "If you wanna go faster, you need James." He explains that while more power is often associated with faster speeds, there are cases where less weight can be beneficial. For example, Miatasso's quickness on track days and Tacomi's ability to beat a GTR in a Corolla.

May notes that the power-to-weight ratio of a car can affect its performance. "Since it's expressed as weight over power, the lower the number, the better the ratio." Cars with high power-to-weight ratios are often heavy and don't have much horsepower, while cars with low power-to-weight ratios are lightweight and powerful.

However, May warns that this relationship is not always straightforward. In drag racing, equal power to weight ratios can yield similar performance, but in other types of racing, like road courses, horsepower doesn't always help. Weight, on the other hand, is a constant factor that affects every aspect of a car's performance.

May also discusses how wind resistance and drag affect cars at high speeds. "This drag increases quadratically with speed," he explains. "It's not exponential growth." He notes that while weight can be overcome by more horsepower, it's the inertia of an object that really matters when it comes to acceleration.

Finally, May mentions the importance of a car's contact patch - in other words, its tires. "Your tires are like your feet," he says. When you're rolling along at 50 miles per hour, your car has much less acceleration and torque than it does when it's standing still.

In conclusion, May emphasizes that weight is not always the most important factor in racing cars. While horsepower can be beneficial, especially at high speeds, less weight can also be more important in certain situations. As May says, "It's a little trickier than that."

WEBVTTKind: captionsLanguage: en(rock music)- Okay.- Feeling good?- Feeling good.(indistinct).- (laughs) Are you feelinggood about launching this guy?- Not really, especially with this clutch.But, whatever.- Right, you ready?- Yeah.- Here we go.Three, two, one, go!(car engine revving)- We all know that if you wanna go faster,you need,James.(screaming)(grunting)- More power!- But if that's true, then why are Miatasso quick on track days?Why can Tacomi beat a GTR inthe downhill in a Corolla?Could it be that lessweight is more importantthan more power?Well, we're going to lookat how each affects a car's performanceand find out if it'sbetter to be featherweight,or powerhouse.I'm a power bottom.(laughs) let's go.(lottery machine bleeping)(smooth jazz)A big thanks to Off The Recordfor sponsoring today's video.July 4th, it's known for four things.Fireworks, America, speeding tickets,and double the fireworks.Now were you one of the manythat had fun, but Kaboom,a speeding ticket blew up your holiday?Well, don't worry'cause off the worker ishere to help save you money,and your driving record.With a 97% success rate,Off The Record offersa network of attorneysto fight your ticket.And will even give you a refundif they can't reduce or keepit off your record entirely.So get back to enjoying your summer.And register now, use code DONUT,and you'll save 10% off your first ticketat offtherecord.com/donut.Weight and horsepower.When you think about it, they'reactually just two forces.Weight is the downwardforce of gravity on a caras determined by its mass.And horsepower is a measurementof work produced by the engine,which is just a force appliedover a specific distanceover a certain amount of time.One horsepower is the amount of workit takes 3,300 pounds togo one foot in one minute.Or an average 3,300 pound carto go one foot in six seconds.If you play around with the variableson either side of that equation,it's easy to see that youcan go further or fasterwith more power or less weight.Now, on the surface,the relationship between power and weightis pretty straightforward.Every car has a constantweight and a peak power.The ratio of the two is calledthe power to weight ratio.James, he did a D list on carswith interesting power toweight ratios a while back.You should check it outafter you watch this video,but for those who haven't watched it,the power to weight ratio works like this.Since it's expressed as weight over power,the lower the number,the better the ratio.Cars that are really heavyand don't have a lot of horsepower,have a high power to weight ratio.And cars with lots of powerthat are also really lightweight,have a low power to weight ratio.And in the middle,you have cars that maybehave one or the other.For example, a Lotus Exigeand a current Mustang GThave very different specs interms of horsepower and weight,but their power to weightratios are about the same.So does that mean thatthey're as fast as each other?Well, hold on a second.It's a little trickier than that.If you were looking ata drag race, then sure.Equal power to weight ratioswould yield similar performance.But other racingdisciplines are different.On a road course, yourhorsepower doesn't helpwhen you're braking or cornering.You can't benefit from yourhorsepower all the time.Weight, on the other hand, it's different.It's constant.It doesn't change with application.I wish it did.Could you imagine being allskinny whenever you wanted?But then someone tries to kidnap youbecause you're the son ofa diplomat and then, boom.Now you're a 600 pound guy.Try to move me now, you suckers.Besides, my rich dad doesn'thave kidnapping insurance.You're not gonna get anything from me.Then they cut your tongueoff and cut your fingers offand then saw them (beep)Anyway, so since weight is always a factorand horsepower is only sometimes a factor,that means weight is better, right?Right, is that right?Actually, we're not done yet.Back when we did our episodeon why it's almost impossibleto go 1,000 miles per hour,we talked about wind resistanceand the drag createdfrom punching through airas you drive along.Now, this drag increasesquadratically with speed.It's not exponential growth.I know people throw that term aroundlike it's quadratic growth.Okay, nevermind.But that force is the square of the speed.The mass of the car, it isn't increasing,but the weight of the car is increasingdue to the air pressing down on top of it.And that can only beovercome by more horsepower.At high speeds, weight beginsto matter less and less.See what's really affecting the carisn't so much the weightas it is the inertia.Inertia is an object's resistanceto change and accelerationin that is directly tiedto an object's weight.But once an object is already in motion,the effective inertia is minimal.As the car accelerates, itsacceleration tapers off.The most G-Force is createdright at the initialpoint of acceleration.And after that, everythingbegins to equalizeas the car's mass begins to move.This is why you can't do a burnoutwhen you're rolling alongat 50 miles per hour.Your car has much lessacceleration and torquethan it does when it's at a standstill.Which actually brings me to my next pointand the limiting factor forboth weight and horsepower.And that is your contact patch.That's your tires.It's just a cool way to say tires.You're like, "Hey, I'vegot a big contact patch."You're like, "Oh, sick dude.I got a tiny contact patch."And you're like, "Heydude, it's fine, man.I love all tire shapes.Tires are universal, man.You know, all shapes and sizes.They're all beautiful.They all smell good."And we can get into a longdiscussion about tires.But for the purposes of today,all you need to know is that atire has a certain threshold.An amount of force thatif you push beyond that,the tire is gonna slip.This is the coefficientof static friction.Every material has twofriction coefficients.You got static friction.That's the amount offorce needed to move it.You've got your kineticfriction or sliding friction,which is how much force isneeded to keep it movingonce it's already moving.The coefficient of kineticfriction is always lowerthan the coefficient of static friction.If you've ever pusheda heavy piece of furniture or your mom,and it all of a sudden jerked forward,that's you overcoming thecoefficient of static frictionand moving into the realmof kinetic friction.Now for tires,they're in static contact with the ground.The wheels, they roll tokeep the tire and asphaltin constant static friction territory.For the average road tire,the coefficient of static friction is 0.7.That means that to stick to the ground,a tire can only handleseven tenths the force of theweight that's acting on it.In a 4,000 pound car withperfect weight distribution,each tire would have 1,000 pounds of forcepushing it into the ground.And therefore could onlyhandle 700 pounds of forcebefore the tire slip.This is why the tiresare a limiting factor.If you're braking heavily,the weight of the car goesto the front two tires.They now have the forceof the inertia of the car acting on them.The more the car weighs,the more force you're askingthose two front tires to handle.Eventually, you can have toomuch weight for the tire.And on the power side,you can have too much power for the tires.Rear wheel drive cars with too much powercan have problems gettingon the power too earlyout of a corner 'causetheir weight is on one sideand delivering more forceto that outside wheel.They'll send you to a nice little spin.I did this one time in mycatfish Camaro at Buttonwillow.And Canaan loves to show peoplehow I messed up at the track one day.So to recap, mass isa constant of the car,which only affects the carduring changes in motion.Accelerating, decelerating,and changes of direction.Horsepower only affects acar during acceleration.Different types of racingfavor the two sides ofthe power to weight ratio.A high horsepower V8 might bereally good at an oval track,but a lightweight hatchbackmight be good at auto cross.Now, there are plenty of other thingsthat affect a car's speed on track.That's your suspension setup, tire choice,mechanical grip, aerodynamics,gearing, power band,and not to mention, driver ability.But now we've got a better understandingof power in weight'srelation to performance.What's that?You want proof of that?Oh, I got ya.No problemo.So to help demonstrate apractical example of this,we're out here in the middle of nowhereand we got two very fancy cars.We have my lovely catfish Camaro,and we have our rider,Joey Russell's Yaris.So we got both of these cars weighed.And then we went down toour buddies at EF1 Tuningwhere Richard dynoed both carsso we could get an accuratehorsepower to weight ratio.So my catfish has a betterhorsepower to weight ratio.So in a functional test,say from zero to 60,it's gonna do better than the Yaris.But all that power is irrelevantwhen you're going from 60 to zeroin a braking test where mass matters most.And that's where the Yarisis gonna beat the catfish.So we came out here todayto test if that really is the case.You're ready?- Let's do it.All right.(door banging)All ready.- God.- It's not a total death trap.- Damn.(door bangs)(laughter)I feel like I just broke something.(rock music)Right here we go.Timer, set.- All right, you ready?- You good, yep on you.- Gimme, gimme,gimme that count.- Okay, three, two, one, go.(car engine revving)Okay, 9.42.(laughter)- Okay, a little too much wheel spin.- All right, are you ready?- Yeah.- Here we go.Three, two, one, go.(car engine revving)- Stop, 7.11.- 7.11, okay.- I'm actually, gettingnervous now 'cause,he's got big front calipers.(tires screeching)All right.Right there?- Mark it.- Mark it, all right.- Aww, little guy.(car engine revving)So we're doing our 60 to zero test.This is where my Camaro stopped.Joey just went out.He's gonna do his run.If we did this right,Joey's car is gonnastop sooner than my car.It weighs less, so ithas less mass to stop.But we'll see.(Joey cheering)Look at that.- Look at that!I guess it goes to show that,power's not always important.Yes, more power, baby.But also, less weight baby.- In practice,weight and power are only two factorsamong many that go intoa properly set up car.Ideally, you always wantmore power and less weight.But knowing what eachdoes to a car is importantfor understanding how itwill react on the trackand on the road.All I know is that my catfishis fricking sick looking, man.Who's in Southern Californiaand wants to go do a track day with me?I gotta get my catfish out there more.I gotta do better.I gotta be a better driver.Thank you guys so much forwatching this episode of B2B.Follow is here at Donut onInstagram at Donut media.Follow me on Instagram at Jeremiah Burton.Thanks so much for watchingguys, until next week.Bye for now.