Hello everyone and welcome.
In this video, we're going to be talking about what the best modification is
to make your car faster, and we're going to do this using some math
Going around a track it's going to be straight out of this book here
which I will include a link to in the video description, but essentially what we've got is
we're gonna have 3 different cars and each of those cars is going to go around this track
and we're going to see what lap times they post.
One of them is going to have new tires, one of them is going to have double the horsepower
and double the torque of the original car, and we will see which one is the fastest.
So this track here, what we've got going on is you've got two straights on each side here
and then two straights on each side here and so each one of these is going to be
300 feet or about 90 meters and each one of these longer straights is about
500 feet or about 150 meters. Clearly, I didn't draw too great to scale, but whatever.
That's what our track looks like. We have a width of about 30 feet or 9 meters
and we've got these corners here so the total track length
is about 2250 feet or 685 meters. You'll notice it's a fairly tight course, but you do have
these decent straights to get up to speed.
So car number 1, which is going to be our base car - our control essentially -
it's able to accelerate at 0.3g's, which isn't all that quick
you know pretty much any family sedan out there could probably hit that these days
It's able to brake at 1.1g's, which is pretty decent, and corner at 1.0g's
which is also pretty good. Typically, your braking is going to be slightly higher
than your cornering g's, but essentially this is our control car. We're going to see how fast
it can go round the track. You do all the math and there's quite a bit of
complicated math in order to get to these numbers but, like I've said, it's all in that book
which I've linked in the video description and you get the top speed on this straightaway
of 73 mph or about 117 km/h, and the car is able to post a lap time of 27.47 seconds
So, the thing is, we want to compare this now to if we were to upgrade to some new tires.
Okay. So our vehicle with the new tires - it doesn't have any more power - so it's still going to
be accelerating at the same 0.3g's.
Braking we're going to say it remains the same. In reality, it would improve a bit but, just to keep the
math simple, we're going to say that braking stays the same.
Cornering is going to go up from 1.0g's to 1.1g's. So, a 10% improvement in the cornering force
based on these new tires. That's something realistically if you were to get a nice compound
versus a lower quality compound or perhaps a summer versus an all season
You could easily get that 10% difference in the cornering force and so if we take this car,
and we go around the track, our top speed is going to be 74.5 mph or about 120 km/h
So, where does this improvement come from? Well, essentially, you're able to
carry more speed in the corners so when you start accelerating on the straight,
you're going to be able to get to a higher speed; slightly higher
74.5 mph rather than 73 mph and, just so it's clear, we're taking the racing line around this.
So, if you were to take the inside line; which is of course one path you could take,
versus the outside line, the inside line will be slightly quicker than the outside
but taking the racing line on this track is going to give you about 3 seconds of improvement
if you kind of, you know, cut these corners. You go wide, cut the corner and then hit the apex
and then come back out wide. That is going to save you about 3 seconds
going around the track, so that's the lap time we're going with.
That's where this 27.47 seconds comes from.
So, doing this with the car with better tires, we're going to get 26.34 seconds
or a difference of 1.13 seconds split versus our car without these tires.
So, we're able to shave off 1.13 seconds just by changing the tires on this
because we're able to carry more speed in these corners.
Okay, now let's take a car and double its torque curve. Let's essentially just take that
torque curve and shift it up twice whatever it is, and that will essentially double the
horsepower as well and so we're able to now accelerate at 0.6g's
Our braking is going to remain the same at 1.1g's. We don't have those nice tires
so we're still cornering at 1.0g's. So now, our top speed on the track because we've got so much more
power in this engine - in this car - is going to be 84 mph on the straights
you're going to be able to accelerate. That's the equivalent of 135 km/h
and this will give us a track time of 26 point - here's the magical moment - 53.
so a split of point nine four over the original car
So here's the crazy thing: we took a car, doubled its horsepower, we sent it around this track
yes, it is a tight track. If you were to have longer straights, you would have an advantage
in a car with more power but essentially the more turns a track has, the more advantage will be
given to a car with nicer tires.
So, what we're seeing here is that a car with nicer tires and half the horsepower - they're the exact
same vehicle, this one just has half the power - is able to go round this track
faster than a car with double the power and slightly worse cornering
So, this has a 10% improvement in tires and this has a 100% improvement in power
and yet a 10% improvement is just as effective on this track
That's crazy to think and it shows you the power of tires out there. This can also explain
you know, if you see a car that's let's say 50 grand; it's kind of heavy, it doesn't have that much power
but it's posting lap times like Ferraris on tracks, a lot of it is probably going to come down to the tires
and, if you look at the tires, you'll probably notice a difference between whatever that car is
and whatever the Ferrari is running and you'll notice that they've probably got a stickier compound
and that's how they're able to do it. The same thing could apply to autocross
If you've got really nice tires on your autocross car and there are more powerful,
lighter weight cars out there, you'll be able to kind of hang with them, depending on their tires
If they've got crappy tires and a really nice car, and you've got a crappy car with really
nice tires, you'll be posting dramatically similar times
That's one of the really cool things about tires. It's one of the most important upgrades you could
ever do to make your car faster on a track
Now, yes, this requires corners so in a straight line, you're not really going to gain any benefit
Unless, you know, you're traction limited because you have so much power
Now, one assumption that is made in doing the math of this is that when you are cornering, you're doing
that at a constant speed. So, you have a constant speed based on your lateral g's
and then, you accelerate once you get to the point where you've straightened out
then you get to a point when you start braking, and you remain back at that constant speed
that you can handle that corner and then you accelerate, brake, corner at constant speed and so on
So, really you know the fastest lap time you're going to be trail braking into that
and then accelerating out but essentially, the time won't be a huge difference
The other benefit, which isn't included in this, is that a car with better tires is going to have
better braking. So, this braking number would improve and this time would actually be better
than shown here because it would be able to brake later as a result of having better tires
So, what are our conclusions? Well, based on this track, this track right here, tires are 10 times
as effective as adding power. So, it's not to say that you shouldn't add power - you definitely
should, it makes cars tons of fun - but you should think about tires initially
That's a great first modification and it's really going to improve how the car handles
and how quickly it can corner
Additionally, as mentioned, our braking is going to improve so it would actually be a better time
than I've shown here and you know one thing to think about is the more corners
a track has, the tighter a track it is, the better times you're going to be able to post simply
with better tires rather than having more power
Basically, the lesson here to learn is, it's not necessary to go super fast
you just don't want to go super slow and the way you avoid going super slow
is maintaining a high speed by keeping a high speed in your corners
So, if you can maintain a high speed throughout the duration of the track rather than
slowing down a lot and then accelerating a lot, you're going to be able to post a better lap time
So, thank you all for watching and if you have any questions or comments, feel
free to leave them below