[MUSIC PLAYING AND CAR REVVING]
CARLOS LAGO: We love our new Corvette. And the reason why may sound surprising, because it’s actually the on-road behavior that we’re really enjoying. This thing is comfortable, quiet, and smooth in ways you don’t typically expect from a sports car. And it makes for a driving experience on the streets that’s just really pleasant. This is actually a really nice car to be stuck in rush hour in. You can read more about those kinds of things in our ownership report by clicking the links below to visit the Edmunds long-term page. But that’s not what we’re making this video about. We’re making this video about performance, because it’s a Corvette after all. It’s got 500 horsepower. We do performance things with it. We’re actually going to test it in this video twice. Why is that? Well, the owner’s manual specifies an alignment setting for street use and an alignment setting for track use. In this video, we’re going to explain what that is, why you should know and care, and what to expect from the performance data that we’re going to find as we test this thing.
Now, let’s go nerd out on alignment data. First, a crash course on alignment settings and especially how they apply to a Corvette. Now an alignment is essentially a series of suspension adjustments you make to control how the tire interacts with the ground. The three main adjustments you can make– I’ll demonstrate with my hand. Imagine my hand’s the tire– front of the tire, back of the tire, and the wheel right here.
You can make a camber adjustment. You can make a toe adjustment. And you can make a caster adjustment. I’ve exaggerated those, just kind of demonstrate the movements. Now you typically make an alignment setting on most cars to minimize tire wear and to prevent the car from pulling in one direction or another. On a performance car, like the Corvette, you make alignment adjustments to control the handling balance of the car, because you don’t really care as much about tire wear and all that stuff. Now the track alignment setting on this Corvette specifies the biggest difference with regard to camber. The street alignment setting is like negative half a degree– front and rear– which is a largely straight wheel entire setup. And that’s going to keep the tire wear to a minimum. And it’s also going to make the car a little bit understeery to make it more safe handling on public roads. The track alignment setting calls for negative 3 degrees of camber front, negative 2-and-1/2 degrees of camber rear. That’s a really big change– such a big change that you actually have to unbolt some suspension components and remove washers in order to have enough real estate to make that adjustment.
And that also makes for a more expensive alignment process if you’re paying dealership shop labor rates. Now, those changes will sacrifice tire wear because less tire’s touching the ground, and it’s going to get abused when you’re driving straight for a long period of time. But it also should minimize that understeer characteristic that you would get during the street driving. Now, a PSA for Corvette owners intending on going to alignment shops. This applies to C7 and C8 Corvettes. Your Corvettes have adjustable rear caster . A lot of shops, dealerships included, will tell you that is not a thing. It is most certainly a thing on C7 and C8 Corvettes. And if you don’t monitor rear caster while you’re changing the alignment of a Corvette, you can end up with some really undesirable handling characteristics. I’ve personally experienced them, and I can tell you don’t want to experience them. It makes for not a very fun car to drive. So go to a shop that either understands that you can control the rear caster or monitor the rear caster of a Corvette or trusts you when you say that. I’m working on my own tool that I’ve learned from reading the Corvette forums on how to keep that setting monitored. But look at Edmunds.com, look at the long-term blogs for more information about that, because we’re kind of getting into the weeds here. So let’s stop nerding out about alignment settings and get to nerding out about testing. OK, I’m going to turn first. Put that there.
[MUSIC PLAYING] It’s a mile away. When are we going to stop doing that? Wait for it. First thing we do whenever we start testing a vehicle is weigh it, of course. You know that if you’ve been watching a long time. A vehicle weight obviously won’t change based on the alignment, but that’s what we do anyway. How much does our Corvette weigh? About 3,600 pounds, and about 60% of that weight is centered on the rear axle. That’s the weight balance you may expect from a mid-engine car, like a Porsche Cayman or a Boxster, but not necessarily the weight. This is heavier than you may assume. Why is that? Well, it’s a larger car than those Porsches that I mentioned. It has a V8 and a lot of other luxury features, and those add up over time. Now, let’s talk about power to weight. That’s when you divide the weight by the power or the power by the weight– semantics. If you divide 495 horsepower by about 3,600 pounds, you get 7.4 pounds per horsepower. What is that? And why is that important? Well, it’s a rough approximate gauge at how fast a car is. My threshold on where a car tends to start getting really fun from that standpoint is about 7.5 pounds per horsepower. So it’s a good start for the Corvette. What I’m curious though is how much that roof weighs. Let’s back the car off, take the roof off, and weigh the roof just because– I don’t know– I got scales. Do you? SPEAKER 1: Try to squeeze here.
CARLOS LAGO: Sure. It’s going to be fun in the wind too. It’s like a sail. [WIND BLOWING] The roof is 20 pounds– the more you know, I guess. Let’s get to performance testing.
[ENGINE REVVING] It’s a good sound. That’s a real good sound. For our braking test, we do a series of simulated panic stops, from 60 miles an hour. We report the shortest stopping distance, and we also use the sequence of stops to gauge how the braking system is going to perform under repeated heavy use. Now, in the case of the Corvette, we have Michelin summer tires. They’re Pilot Sport 4S, if I recall correctly. And they have a treadwear of about 300. Pretty solid performance tires that you can drive daily in Southern California where weather’s always nice, but not necessarily the most aggressive tires on the market. Still, let’s see what braking performance we can get. I’ll call out too that I’m not doing the braking test for real. I have no data acquisition hardware in this car. We’ve already done the test. I’m just going to tell you the result once we do the stop for demonstration purposes. And we’re already at 70. Gotta slow it down a little bit. Get close to 60. And here’s our stop. That gets done quick. In fact, we recorded a best stop from 60 miles an hour of 101 feet in track alignment. In street alignment, the result was the same. So that’s cool. Let’s go to acceleration next. Now we get to acceleration, which is what we all want to see and what I want to do. We’ve already tested this particular car. I’m doing this just for demonstration purposes, so bear with me. Also, it’s a lot of fun, so I just kind of want to do it.
Now, to get the best acceleration in the C8 Corvette, you dial in track mode; and then you hit the Stability Control button twice to activate Performance Traction Management– if you have that option, which we do. It’s going to be different if you don’t have that option. Once you’re in that mode, you put it in Sport or Race or whatever. At that point, accessing Launch Control just requires hitting the brake as hard as possible with your left foot, mashing the gas with your right foot. Engine speed’s gonna shoot up to about 3,500 RPM, at which point you just hold on. How much faster is street alignment or track alignment? I’ll tell you after this word from our acceleration run sponsors. [ENGINE REVVING] [LAUGHS] Oh, that feels good. And it sounds good. Woo-hoo-hoo-hoo! Now our best acceleration to 60 miles an hour, it was 3.4 seconds. Our best acceleration to 60 with a 1-foot roll out was 3.2 seconds. Roll out is when you subtract the first foot from acceleration because all the car magazines do it. So that’s the numbers everybody uses to compare because they’re all lower– whatever. 3.2 seconds. The quarter mile result was 11.5 seconds at 120 miles an hour. Now a question for you.
Was that the track alignment or the street alignment settings? I’ll wait. Trick question. It was both. We got the same acceleration results regardless of the alignment settings. So it’s good to know that regardless of how you have your car set up between those two different options, you’re going to get the same pretty stout acceleration. And it’s stout– certifiably stout acceleration. And it sounds good too. Listen to this.
[ENGINE REVVING] Next up, the skidpad test. Now, the skidpad test. If you recall from previous videos, our skidpad is a 200-foot diameter circle that we drive around in both directions as quickly as possible. Doing so allows us to calculate out an average lateral g-figure that shows us effectively how much grip there are in the tires and how hard you can corner. Surely this would be the test where we would see a difference between the street alignment setting and the more aggressive track alignment setting, right? Nope, it turns out the tires generated the same 1.08 average g in both directions and on both alignment settings. You don’t see the benefits of a track alignment on a 200-foot skidpad because the speeds are too low. The track alignments benefits really don’t come into play until speeds increase, then the balance of the car becomes far more improved. We found this out during our own evaluation on our handling track. Well, a skidpad test is a good test. It’s showing you one specific attribute of tire gripper– of overall vehicle grip. But it’s not a race track. It doesn’t have the variety of corners, the complexity of corners, the range of corners you might experience on a race track.
And there, on a track, is where the differences in alignment settings are going to be more noticeable. As part of our testing protocol, we also drive all of our vehicles around a handling track. And when we did that with this car– in both alignment settings– our team reported that the street alignment setting had more perceivable understeer than the track alignment setting. Net understeer, we feel would slow you down on track because it reduces the amount of fun you’re having. And it also takes away your confidence in the car to go with the amount of control you would hope it would have. That’s why you do the track alignment setting. And so at the end of this video, I guess our conclusion is that if you’re going to go to a race track, be sure your Corvette is in the track alignment setting which, come to think of it, is exactly what the owner’s manual says. So we haven’t really proved anything. But we validated, and validating is a very important part of testing. Yes– validation. Sometimes we need some validation, yeah.