How I Use Data To Tune My Car

How I Use Data To Tune My Car


Hey everybody, Matt Covert here again from
howtobecomearacecardriver.com and I just made a video that was all about using data as opposed
to just guessing and hoping for positive change in your car. And in this one I’m going to
tell you exactly what I do and how I use data to make real, quick, positive changes to my
car. And I’m excited to share this with you because you don’t see a lot of these things
at the track. And this stuff will definitely help you out. OK? So let’s hop right on in. This is going to give you real, actionable,
information that you can implement into your racing program immediately and those are my
favorite ones and I love that. So let’s talk about what I’m doing. Number one, I don’t
like that circle, I’m going to make another one. There we go. Number one. The first thing
I do, and this is something I do after every single run, I take twelve tire temperature
readings. And I do it like this, let’s say we’re looking down on a tire, OK? I take a
reading on the inside tread, the middle tread, and outside tread. And there’s a video about how to do this and
why and why it works and I’ll link to that to you can hop to that if you want to see
it. OK? This will help you find your – oh, no, this will help you stay inside your optimal
temperatures. People don’t realize it but the driver has a huge amount of control over
what temperature the tires stay at while he’s driving. And he needs to stay inside these
optimal temperatures and that’s really important. If you go outside of them you’re either leaving
grip on the table if they’re too cold you’re not driving hard enough. Or if they’re too
hot you need to chill a little bit. OK? This will also help you find your perfect
tire pressures. And that’s really the important thing, the thing I use it for the most, is
dialing in the right pressure for your tires, OK? The contact patch of a tire, and I know
we’ve gone over this stuff in other videos, the part of the tire that actually touches
the ground surface is the contact patch. That is the only thing connecting your car to the
ground. If the pressures aren’t right then you’re really losing out. There isn’t much
touching the ground and your pressures can help maximize that contact patch. You want
the whole tread section to be touching the ground. And that’s the goal there. Mmmk? So taking twelve tire temperatures will help
you do this, like I said I’ll link to the video so you can – we won’t do that again,
we’ve already done that in a video. OK? So the second thing that I do, and this stems
off of tire temperatures again, there’s so much information to be had from just reading
the temperatures of your tires OK? The car’s balance. We’ll just put temps again. OK? This
has helped me dial in the anti-roll bar, or sway bar, settings of my car. And I’ll show
you why. A neutral handling car, there’s a video about that too, a neutral handling car
has the same amount of slip in the front tires and the rear tires. And there’s a video about
slip angles too. Man, all kinds of awesome information coming out. I am really excited
about giving you all this free information. So I’ll link to that slip angles video as
well, because that’s really important. Let’s see. When I got my BRZ, I have a 2013
Subaru BRZ which I have been racing. I like it. There are things I don’t like about it.
But since I’m in a Street category I can’t change them so I’m working with what I have.
And that’s the whole point of this website, driver skill over throwing money at the car.
When I first got the car, I’m going to use some theoretical numbers because I don’t have
my data sheets in front of me, but I saw this all the time for the first couple races before
I started dialing things in, OK? When I came off the track my front tires were always always
always hotter than the rear tires. And that’s an indication that the front of the car is
doing more work than the rear of the car. Because they’re producing more friction, which
means more heat, and that’s why they’re hotter. OK? And I don’t like that. Because that means
the car is understeering all the time. And that’s not good, that’s not a balanced car.
OK? So, because I was taking tire information I was able to see this, as well as feel it,
OK? So what I did was I put a big rear bar on because nine times out of ten a bigger
rear bar will help the car oversteer, OK? And so I started seeing temperatures a little
closer, even within ten degrees, often. Which is great. And you could feel the difference
was huge. It had better rotating into corner entry under braking. It was much quicker through
the slalom sections, OK? And this is an example of using real data to tune your car. OK, without
these numbers you would just be guessing. And I’ll give you an example of – let me just
do a quick tuning example. The BRZ, the Subaru BRZ and the Scion FRS are virtually identical
aesthetically. OK? But the BRZ has a natural tendency to understeer and the FRS has a natural
tendency to oversteer. So even though people think these corporate sisters are exactly
the same, they are not. They have very different spring rates when they come out of the factory.
That’s basically the only difference between them, alright? So I know a guy who has an
FRS. He’s a winner. He’s an incredible driver. I look up to him and he mentors me whenever
he’s around. His FRS is remarkable, he has it tuned very very well. He has a giant front
sway bar to help curb that natural oversteer. OK? So if someone is using that monkey vision
that I talked about in the last video, the video of data versus guessing, if some people
are just monkeyvisioning these two cars because they think they’re the same and they put a
giant front sway bar on the BRZ, it’s going to make the car horrible. Because that is
just compounding the natural tendency of this car to understeer. Alright? Without this data
you don’t really know. Even two cars that are virtual identical – they’re not going
to have the same tuning preferences. And this is something you really have to understand
because this goes for anything. Someone’s Miata versus a three series BMW or whatever
you have. Just because the cars are basically the same they don’t all respond to the same
tuning preferences. So keep that in mind. That’s really important.
This why we use data. We’re using data because our car is unique. And just because something
is working for someone else doesn’t mean it’s going to work for us. So you want to make
positive scientific change based on really solid theory and strategy. And that’s what
this is for, and I love this stuff, OK? Let me go on to another one. Let’s move on
to the third one. I think this is going to be a longer video than normal, but that’s
OK. Tons of free information and I’m just excited to share whatever I’ve learned with
whoever is going to listen so I’m going to keep on going here. OK, let’s talk about choosing
tires. There are a lot of good autocross tires out there right now. And there are all kinds
of people talking about it on forums. There’s a separate video all about forums somewhere.
I stay away from forums. I’ll talk about that at some other point though. So how do you know what tire to pick? OK you
can talk to all the guys who have them, all the guys who like them. Ninety five percent
of people who are racing autocross have only used one tire and they have no idea what the
other ones are like. OK? So their opinions don’t really matter because they haven’t done
any type of scientific comparison, OK? That’s why I defer to experts like The Tire Rack
who, every year, they take all kinds of autocross tires and test them on the same vehicle and
they give you great data plots and all kinds of information about which tire is actually
better. There’s a link to a really good article they did with all kinds of graphs and spider
charts and all that kind of stuff that makes me really excited. So I’m going to put a link
to that so you can go see which tire is actually better. I used the Dunlop Direzza last year. I’m going
to do it again this year because it is the best, no questions asked on that one. OK?
Choosing the right size tire, though, that’s up to you. Because you do have a number of
options. If you’re in a Street class you can use whatever tire fits on the rim. You can
go up a rim size, you cannot change the width. So you have to choose what size you want your
tire to be. OK let’s use an example. My factory tire size, I think, is a 215/45R17. I’m going
to go with seventeen wheels again this year OK? But I’ve got a really neat option. I’m
going to jump up to the 225. And why would I do that? This is the factory
size. There’s a very good reason to do this. OK, and I’m not doing it based on a guess.
I’m doing it based on data that comes specifically from Dunlop. And, I think, let me try to switch
screens here. I think I can show you some real – yeah look at that, real information
from Dunlop. This is on the TireRack website about the Direzza tire. See this little red
dot? That shows you the factory tire size for my BRZ. Alright? And you can see over
here that this is an eight inch tread width, which is good. OK? But if I hop up to the
next size, which will fit on my rim. Seven inch rim. If I hop up to that my tread width
jumps up to eight point two. And while that doesn’t seem like a lot – let’s
go back to the other screen here. While that doesn’t seem like a lot, let’s talk about
contact patch for a second. Alright? If this is a tire, looking down from above on the
tire, this is the only part of a tire here that is actually touching the ground. OK?
So what we’re doing is we’re going from here to here. Last year I had an eight inch tire
and now I’m going to add point two inches onto the side of that. OK? This is probably
only a two or three inch section right here that goes all the way across. Adding almost
a quarter inch on the side of that on all four tires is going to make a big difference. OK? And I’m not just guessing on this either.
This is something I talked to a multi autocross champion about. That’s what he did last year
on these. He has the FRS. And he jumped up to the 225s and he loved it. He said that
he difference was absolutely incredible. We’re talking about a ten millimeter difference
here. OK? Ten millimeters? Point two inches doesn’t seem like a lot but it’s going to
rock your world. And that’s really exciting, OK? So here we have three really great examples
in the Street category where you can’t really make a whole lot of changes. Three great examples
of using real data to make real changes for positive improvement. And that’s what we’re
striving for all the time. And I think I’m going to end there. There’s a ton of awesome
information in the video. Watch this video again. It’s really long, I think it’s going
to be about eleven minutes long, OK? If you haven’t, please subscribe to the YouTube
channel. You’ll never miss another video like this ever again. There isn’t anything else
out there on the internet as far as I know like this. So go ahead and subscribe. I’ll
give you a link, we’ll put it somewhere right there in the middle. And I’ll be back soon
with another video from howtobecomearacecardriver.com.

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