Sunday, May 9, 2010

The High Cost of iRacing

Now that iRacing allows hosting races with multiple car types - but requires every participant in such a race to own all the cars in that race - the clubs I race with are debating whether to adopt multiplayer racing. One of the big concerns is the cost of buying the cars.

I'd like to weigh in here on the "high" cost of iRacing. Compared to other sims, yes, it's more expensive. Three cars roughly equals the cost of most other sims. But with iRacing you get so much more: incredibly detailed car models, which all feel drastically different from each other, plus constant development, improvement, and expansion, and a large, well-supported online community.

This is very unlike other sims, where ostensibly very different cars often feel so similar that it's hard to distinguish between them in terms of handling; where the community is fragmented; and where you're lucky if you get a handful of patches in the multi-year wait before the next release.

And you can drive iRacing's cars on amazingly detailed and accurate laser-scanned tracks, which are not available anywhere else. (The tracks scanned for rFactor don't compare, because rF's track modeling uses polygons, which hides the details, and the scanning is not anywhere as high resolution as iRacing's.) I've driven Mosport, NHMS, Watkins Glen, Summit Point, and Lime Rock in real life, and I can tell you that the accuracy of iRacing's versions of these tracks is astonishing.

Instead of comparing the cost of iRacing to the cost of other sims, I prefer to compare it to the cost of real-world track time. After all, with the accuracy of the car and track models, and the superb force feedback, iRacing is pretty darn close to the real thing.

What do you miss out on with iRacing that you'd get in real life? The inertial feedback, of course, and the wind in your face and the sun on your skin. These are nice - unless you get a sunburn!

You also miss out on the risk of wrecking your car and hurting yourself. And the huge cost and effort of maintaining a car for the track and getting it and yourself there and back. When I was running my Cobra in seven or eight two-day time trial (not racing) events per year, I was spending four or five thousand dollars each year - not including development of the car. That could be thousands more.

This was for track days which were mostly practice sessions, with single-car, three lap time trials on the afternoon of the second day. No wheel to wheel racing at all, ever. If you want to do that, you have to go with a club like SCCA or NASA, and you spend much more.

Compared to those costs, iRacing is a fantastic deal. For what I'd spend for a handful of events in the real world, I can race for years in iRacing, and own every car and track they produce.

Fifteen bucks each for a car that I can drive on fabulous race tracks all over the world, with never a lick of maintenance?

I'll take it.

Tuesday, January 26, 2010

Lateral Separation

Recently, in the Radical at Laguna Seca, I had an interesting experience which highlighted one of the hazards of racing online.

I qualified on the second row, and in the early laps the drivers ahead of me all got involved in incidents and I found myself in the lead. I led for much of the race, driving carefully, staying within my limits, but near the end I could see another car closing on me.

Knowing how difficult it is to pass on this track, I decided it was better to keep running at a safe pace and let the other car catch me than try to speed up and risk throwing it off the track.

But when he caught me he followed very close behind me and when I braked, the other car hit me. This happened twice, first entering the carousel and then again entering the hairpin. The second hit pushed me so far off line that the other driver was able to just drive right by. The collision also bent my rear suspension, and after that I was off the pace. Luckily I still managed to finish second.

In a discussion afterward it became clear that the other driver was unaware of at least one of the collisions. From his perspective there was no contact.

This incident shows how much of an effect a little latency can have on the respective experiences of two drivers racing together in iRacing.

Let's imagine that you and I are racing. Even if both of us have good connections it takes a fraction of a second for the position and velocity information to make it from, say, my computer to yours. The iRacing software has to predict where it thinks my car is going to be and display that to you; by the time it gets the real information from your computer through the server, you've already moved some distance.

The result is that sometimes there are small discrepencies between what iRacing makes a remote car do (based on the iRacing software's prediction algorithms) and what the remote car actually did.

In this case, I braked but iRacing on the other driver's computer didn't predict precisely when I did that. It apparently didn't show me braking until a faction of a second later. He presumably braked in time to avoid my predicted car, but not in time to avoid my real car.

At my end, the prediction code on my machine failed to predict the precise moment when he braked. His car didn't slow on my system until a fraction of a second too late. Instead, his "predicted" car thumped into mine, pushed me off line and bent it.

I think the lesson to take from this is don't follow closely directly behind another car, especially when approaching a braking zone. Either leave a larger gap, or - and this is what I try to remember to do - establish what fighter pilots who fly tight formation call "lateral separation." As you are moving down the straight toward the braking zone, ease over to one side of the car you're chasing. Usually this will be the inside. This way, if the car ahead brakes earlier than you expect, you'll just shoot by on the inside. If it doesn't, no harm done.

You can see pro drivers do this all the time on TV. The announcers get excited and yell "he's taking a look down the inside!!" Maybe, but that's only part of the story. The driver is actually establishing lateral separation to avoid the possibility of rear-ending the other car if it brakes earlier than expected.

This is especially important if you are not familiar with the driving habits of the driver ahead. Some drivers are dead consistent, braking at precisely the same point every lap. But this is rare. Most drivers vary their braking points by a few feet either way. Later one lap, earlier the next. You can't safely follow most drivers very closely; sooner or later you'll hit them.

Moving to the inside on the straight before the braking zone has a secondary benefit: it serves as a signal to the driver ahead that you'd like to pass. In many situations, such as lapping a slower car, this is of real value. You're asking politely for a pass, which tends to make the driver ahead more inclined to give you the corner.

When you're dicing for position late in a race, as that other driver and I were, the leading driver is likely to be less willing to let you by, but on the other hand this move can ramp up the pressure a bit and make it a little more likely that the other driver will make a small mistake which will give you the position.

When following a slower car, the lateral separation tactic is the best option, IMHO. There's little or no downside, and the upside is a safer and more fun race for everyone.

Sunday, January 10, 2010

The Art of Being Passed

There's been some discussion in some of the iRacing league forums about whether to move over and let a faster car past, or stay on line and let them find their way by. Here are some of my thoughts on this.

When I was doing endurance racing in the real world, I drove with a team running RX-7's in 24 hour races in which there were also Corvettes and turbo Porsche 944's. Our RX-7's were a lot slower than the 'Vettes and Porsches, so we were always having to deal with getting passed.

At first, when one of the faster cars came up behind me, I'd try to just stick to my line and figure they'd get around me on the next straight or whatever. Wrong. If their pace put them at a corner entry at the same moment as me, they'd just barge right in there. I'd end up having to go way off line and into the marbles to avoid a collision, which would end up costing me a lot of time because I'd be slow down the next straight.

So I learned how to get passed: figure out where they're going to catch you, and then ease up a little to time the pass so it will cost you a minimum amount of speed and lap time. Better to give up a few tenths now and be able to maintain your speed after they get by than to keep driving flat out until the other car screws you up and costs you a big chunk of time.

The best place to get passed is on a straight; if a faster car is on your tail coming out of a corner, breathe out of the throttle a bit until they're alongside and then go back to full throttle. This will cost you almost nothing in terms of lap time, and is very low risk for both cars.

When doing this, you can either keep to your normal position on the straight and let them go off line to go by, or you can make a clear and definite move off line - before they are about to pass - to let them know you're letting them by. But the most important thing is to just breathe out of the throttle. Don't make a big lift that would cause you to slow suddenly, forcing them to make a big avoidance maneuver. Just ease up. The goal is to ease into a 5 or maybe 10 MPH difference. On a long straight, that should be plenty for them to get by.

If they're catching you near the end of a straight, then you can brake early so they can get past before the corner. This way you'll lose a lot less time than if you enter the corner together.

But if you're going to brake early, make sure you don't catch the other driver by surprise! You can use your car's position on the track as a signal. If you move to the inside down the straight as you approach the corner, and they stay on the outside, on line, that means they realize you're going to let them go, so you can brake early, let them by, and tuck right back in, both of you having lost minimal time. When executed properly, this is a very satisfying move. You might even be able to draft them down the next straight and gain back some of the small amount of time it cost you to brake early.

Another way this can play out is if the car behind moves to the inside as you approach the corner. This means they're asking you to let them by. Stay wide, on line, but brake a little early and let them go down the inside. Since they're off line, they will also have to brake a bit earlier than usual, and their entry into the corner will be slower than usual, so be sure to allow enough room for this by braking early enough to create a little gap. Again, if you can allow them to complete the pass before the corner then you'll both lose minimal time, and you might catch a bit of a draft down the next straight.

On the other hand, if someone is all over you going into a corner, stick to your line and your pace. It's not your problem or your job to save them a few tenths in the middle of a turn. They can wait till the next straight, where you can let them by as above. If they are desperate, let them go off line and take the risks.

There have been a number of instances lately where I've seen people go off line in a corner to let me by, go too wide, and end up going off the track. Nobody wants that, least of all me! So please be cool, be patient, and use the straights or find other safe, low-stress points to let other cars by.

If you're the car coming up to pass someone, keep in mind that climbing all over their tail entering a corner is probably going to be counter-productive. (I know I'm guilty of this sometimes, and I'm working on it!) If you make them feel pressured they're more likely to make a mistake, and you could get caught up in it.

Also if you're right on their tail entering a corner then you have to take the corner at the same speed, which kills your advantage at corner exit. Better to drop back a bit before entering the corner and leave enough of a gap that you can take the corner at your own speed. That way, if you're quicker through the corner, then your exit speed will be higher, making it much easier to pass them on the following straight.

Learning to pass and learning to be passed are two important - and rewarding - aspects of racecraft, and in the iRacing leagues we've got a great environment to acquire and refine these skills.