GT vs GTI

This weekend, March 7th to be specific, Tiernan and I are signed up to coach at Thunderhill with Hooked on Driving. Between coaching sessions we hope to get a few laps in for fun. So which car do you think will be faster, Ian’s GT or Tiernan’s GTI? Let’s look at the specs.

GT

  • 2003 Hyundai Elantra GT with 130k miles
  • Automatic transmission
  • 2698 lbs curb weight
  • 135 crank hp
  • 19.98 lbs/hp
  • 215/40/17 Federal 595RS-Pro (200TW)

GTI

  • 2002 Volkswagen GTI with 109k miles
  • Manual transmission
  • 2932 lbs curb weight
  • 180 crank hp
  • 16.29 lbs/hp
  • 205/55/16 Federal ST-1 (300TW)

Optimum Lap Simulations

The GT has the grip advantage being on softer and wider tires. It also weighs 234 lbs less. Is that enough to overcome the 45 hp engine advantage of the GTI? Let’s ask Optimum Lap.

I found a dyno for a stock 4 cylinder Tiburon, which has the same engine as the Elantra. It has a peak of 120 hp at 5500 rpm. The engine apparently revs to 6.4k, but the auto shifts at 6k. That’s a pity because the tractive force graph below shows I could really use those revs. Each curve represents how much acceleration there is at each speed in each gear. There’s a huge drop-off after 40 mph and 74.3 mph.

The stock GTI dyno I found shows a peak 149 hp at 6000 rpm. As you can see from the tractive force graph, the transmission ratios fit very well with its engine.

Tires are an absolutely critical component of performance and manufacturers don’t label them with their lateral G limit. That means I have to estimate it. I generally set 200TW tires at 1.0G. With such a round figure, you might suspect 1.0G is more convenient than accurate. Indeed it is. The exact figure isn’t so important, but the relative difference is. Given that Tirenan’s ST-1s are 300TW, I will make a wild guess and estimate that they have 0.95G grip

Optimum Lap says the GTI beats the GT 2:19.60 to 2:21.51. However, the predecessor to the RS-Pro, the RS-RR, was definitely on the sticky end of the 200 spectrum. And my car is both lower and stiffer than Tiernan’s. So if my tire and suspension package is worth 1.05G it turns out my predicted lap is 2:19.28, which would beat the GTI by about 3 tenths. So my best guess is that the GT is near the same second as the GTI.

How accurate is Optimum Lap? I think it’s not bad if you have the right parameters. If I input my Yaris in its pre-B-Spec days with 1.0 grip, Optimum Lap estimates 2:23.40. That’s very similar to my real world fast laps, which were in the 2:22-2:23 range. So the GT should be a little faster than the Yaris when they have equal grip. But there’s only one way to find out. Check back for real world results.

Virtual Rally Training

Driving with low grip is a great way to improve your racetrack driving skill. That’s why the Kenny Roberts Ranch is a dirt track. It’s also why the Skip Barber Formula 2000 rides on BFG T/A Radials. If you want to get better at driving, leave the sticky tires at home and drive on all-seasons. The same is true of virtual training. Drive on loose surfaces and with hard tires if you want to improve your feel for vehicle dynamics and develop your car control skills.

DiRT Rally

My favorite rally sim is DiRT Rally. When I first discovered it, during the Steam Early Access release in 2015, I knew nothing about rally. But I soon became such a huge fan that I built my Yaris to do double-duty as a rally car. Truthfully, I haven’t done much rallying in real life. I attended the Primitive Rally School at the Santa Rosa Fairgrounds and goofed around a bit at the Prairie City Off Highway Vehicle Park. Those experiences told me 2 things: that rally driving is the best kind of driving, and that DiRT Rally felt pretty realistic.

So why don’t I do more rally? I only subscribe to a few YouTube channels, but one of them is “Racing Fail!”. I like it so much that I donate to it monthly via Patreon (you can even see my name at the start of the videos). Every week, Racing Fail! shows motorsports crashes from the previous week. And every week there are multiple rally drivers wrapping their cars around trees, driving off cliffs, and rolling through fields like mechanical tumble weeds. Occasionally they catch on fire. That’s sort of terrifying. Racing Fail! is a weekly reminder to stay safe and not to wreck my Yaris (or burn myself crispy).

Back to the sim world. DiRT Rally is old enough that it can be picked up on Steam for as little as $10 when it goes on sale. There are newer rally sims from the same developer, Codemasters, but neither DiRT 4 nor DiRT Rally 2.0 is actually better. One of the downsides of DiRT Rally is that there is no community-created content. While DiRT Rally has some great vehicles (by great I mean lower performance cars similar to what I drive) the collection cars and tracks are fixed. There’s nothing new coming. Community-content is what makes Assetto Corsa great. So that begs the question “how good is Assetto Corsa as a rally trainer?”

Rally Training in Assetto Corsa

While you won’t find much official (Kuno Simulazioni) rally content, the community has created plenty of cars and tracks. While the choice of rally cars ranges from the modern WRC Polo to the historic Lada VFTS, you don’t need a rally car for rally driving. For tracks, there are rally stages on gravel, dirt, and snow, as well as hill climbs, street races, and stadium rallycross. As with all AC community content, the cost is mostly free and the quality highly variable.

For training purposes, it’s a good idea to drive both RWD and FWD layouts because they behave differently. For RWD I go with the NA Miata because Miata Is Always The Answer. I say this even though I no longer own a Miata. The Assetto Corsa NA Miata is such a great model that it’s the first thing I turn to, even on dirt. For FWD, I like the Chevy Monza. The motor is on the weak side and the suspension is on the plush side, just like the cars I drive. The Miata is faster on asphalt but the Monza is faster on dirt. But they are very close on any surface, and make a great set of cars to play with for any occasion.

One of the things that makes rally driving unique is the co-driver. In DiRT Rally, you can have visual or audio cues, and you can specify how early or late you want to hear them. Personally, I use audio only and have them announced as far forward as possible. I really enjoy having a co-driver, but for the purposes of training it’s not necessary or even desirable. So while you can download a co-driver app for AC, and you can drive long rally stages, the best way to use AC for low grip training is on a small, closed course. Below are three tracks I recommend and some target times for a Miata/Monza.

  • Karelia – This is a fantasy rally circuit with a good mix of low and high speed corners as well as compromises. It’s probably my favorite rally trainer. Fast laps: 1:04.
  • Gentlemen Rallycross – Although the graphics are sorely outdated, the track is a great mixture of turns and surfaces. There is a joker section. Fast laps: 1:12 (non-joker).
  • Kouvola Rallycross – This is a stadium rally cross that alternates asphalt and dirt. The graphics on this track are much better than the others. There’s more than one fast line, so experiment. The lap features a joker. Fast laps: 0:50 (non-joker).

Conclusion

While DiRT Rally is the king of rally sims, there are a few things Assetto Corsa does very well. It gives you a HUGE selection of cars and tracks to play with. And if you want to change the grip of any track, simply edit the surfaces.ini file. I’m not going to pretend I’m an expert on force feedback, but the Miata and Monza feel really good. Good enough to program your muscle memory anyway, and that’s the whole point of virtual rally training.

Postscript

Some people say that Richard Burns Rally (RBR) is the king of rally sims. That platform is so old that you can’t even buy it anymore. That said, there are people making content for it, even though the game never supported that. The only way to get RBR is by violating copyright, which I try not to do, so I don’t have personal experience with it.

FWD vs. RWD rain: part 2 (thanks Paul)

I have to thank YSAR reader Paul for sending me down this path, because it’s been really fun. I truly appreciate feedback that makes me look critically at a problem. In this part 2, I do some testing in Assetto Corsa, and come away with some surprise.

Testing scenario

To do the fwd vs. rwd and dry vs. wet experiments, I had to choose a track, two cars, and two grip levels. I like to use Brands Hatch Indy and the NA Miata as a baseline. Sometimes I use the Street 90s tire and sometimes the Street tire. The Street 90s are a couple seconds slower. When you have the AI drive the car, both tires have the same lap times. I think it uses the default (Street 90s) tire. So that’s what I did too.

For the FWD car, I chose the Chevy Monza Classic 500EF. This model is a free download. One reason I chose it is because the dry lap times are very similar to the NA Miata when both cars are on their default tires.

For the wet grip, I reduced traction from the default 0.98 to 0.75. That figure is a little bit arbitrary, but I’ve seen various tables that show a reduction of about that much.

  • Track: Brands Hatch Indy
  • RWD: NA Miata
  • FWD: Chevy Monza
  • Dry – 0.98 grip
  • Wet – 0.75 grip

How to modify Assetto Corsa grip

There are three ways to modify the grip of cars in AC that I know of: run a server, change tires, change track surface. The easiest is the last, but for completeness, I’ll describe the other two first.

If you set up your own server, you can set the grip level of the track. This requires a separate program running as the server. That’s why I’m not recommending it. But on the plus side, it’s just one line of one file.

If the cars are developed in the legacy way, they have editable text files for individual components like tyres (yes, that’s spelled with a ‘y’ because AC uses the British English spelling rather than American English). Most cars these days have binary files that aren’t easily edited. Both the Miata and Monza use binary files. This is why I’m not recommending this way.

If you look in a track folder, you will find a surfaces.ini text file that you can edit. A track may have several surfaces. For example the Brands Hatch Indy file has 11 surfaces. Before you go editing this file, first make a backup copy so that you can restore it to its original configuration later. The grip levels of the various parts of the track range from 0.98 on asphalt to 0.6 for grass. To simulate rain, I set everything to 0.75 because I was lazy and didn’t want to multiply everything by 0.75. But that would be a better way I suppose. However, I planned on driving on the track, not grass or curbs.

AI driver

The first thing I wanted to test was how much the AI driver was affected by reduced traction. Here are the values.

  • RWD -7.31% loss
  • FWD -6.95% loss

There is more loss in RWD than FWD. To put it into the perspective of a typical lap, if your dry time is 2:00 minutes, your RWD wet time will be 2:08.78 and your FWD wet time will be 2:08.34. 0.43 seconds is pretty significant in a sprint race, but we’re not talking about 10 seconds here. It’s just a little time. However, this is the AI driving. What about a human?

Human driver

Move over AI, it’s time for Ian to step into the car.

  • RWD -9.06% loss
  • FWD -6.92% loss

That looks a bit more significant. Let’s put this into perspective of my Toyota Yaris at Thunderhill last May. My fast dry time was 3:43. If we multiply these 223 seconds by 1.0906 and 1.0692 we find that the difference between RWD and FWD is nearly 5 seconds. That’s pretty significant! Given that my Yaris is heavier, higher, and less powerful, than a Miata, the Miata has all the advantages on a dry day, but given some rain, the advantage just might tip in my direction.

Here are the graphs for the simulation experiments.

However, this is a human driving a simulator, what about in real life?

More data diving

Let’s look at the actual laps from the race. On a dry track, I was averaging about 3:50 in traffic. Bring on the rain and that drops to 4:20. So about 30 seconds. I had to make a lot of passes, and when I had a clean lap, I got down to 4:03, which is a loss of just 9%. Driving around slow cars in the rain really kills your lap time.

Some of the fast RWD cars I passed included the Miata of Eyesore and the Celica of Uncle Joe’s. Eyesore’s fast lap was 3:29 but in traffic it was typically 3:35-3:40. They dropped to 4:35-4:40 in the rain, a loss of 60 seconds. Uncle Joe’s fast lap was a 3:34 and it’s traffic laps were in the 3:40-3:45 range. In the wet, they dropped to 4:25-4:30, or about 45 seconds.

Two of the fast FWD cars I passed were the Integra of Big Test Icicles and the Neon of Neon Pope. The Integra went from 3:50 dry to 4:25 wet. The Neon was 3:45 and 4:30.

The race winners, Shake and Break (E30), were typically lapping at the same speed as Eyesore in the dry (3:35) but much faster in the wet (4:10).

Let’s take a look at the relative losses of these cars.

  • Yaris -13%
  • Celica -20%
  • Miata -28%
  • Integra -15%
  • Neon -20%
  • E30 -16%

Summary

Given equal lap times on a dry track, a FWD car definitely has an advantage over a RWD on a wet track. How much? I think it depends a lot on the skill of the drivers. At the high end, maybe 0.5 sec per lap. At my level, a couple seconds. At the “you can’t drive for shit in the rain” level, I think it’s less about which wheels are connected to the engine and more about the driver lacking the skill and confidence to maximize traction in the rain. Pedal mashers who over-brake and then hammer the throttle are the ones most severely affected. A Miata doesn’t normally spin when you stomp on the throttle. But it does in the rain, and if one’s driving style isn’t very nuanced, rain will be very unkind to your lap times. However, in a FWD car, stomping on the throttle may cause a bit of understeer, which is easily mitigated by lifting. FWD cars are more noob friendly. I’m not a noob, so I don’t see that FWD and RWD are that much different. But to someone not used to sliding their car around, RWD could be a major disadvantage.

I just watched the “you suck at racing in the rain” video again asking myself “where does the Yaris have an advantage?” The expectation is under acceleration. But that’s not where I’m catching people. It’s under braking. There is no FWD braking advantage. If you’re thinking it’s because my car is newer than the others and has ABS, that’s a good idea. However, you can hear the tires sliding in some corners when they lock up because my ABS has been broken for a while.

So to sum it all up, the reason for Yaris Rain Domination (YRD) is a little bit of FWD advantage and a shit-load of “most people suck at racing in the rain”.

Race Report: Lemons Thunderhill

I’ll be updating this post each day.

Thursday – arrival

In the picture below you can see how simple my race operation is. I flat tow my Yaris behind a 3.0L Ranger. It’s a very flat route so the 145 hp Ranger has no problems towing the car and gear. I arrived at the track at 4:30 the day before the test and tech day to try to get a good pit spot. I wanted something under the awning so I could shelter the pit from sun/rain. Mission accomplished.

Friday – test and tech

Tech was a breeze. The car has raced in several other series and all the safety issues are well sorted. We got into the B class with zero penalty laps. That was what we expected.

We had decided that the full test day was too expensive. $349 for 1 driver and $149 for each additional. We considered doing the half day at $249 + $100 but then decided to play a joke instead. People walked by and  puzzled: “why is the wing on the front”. We dead-panned “it’s front-wheel drive”. The look of disbelief on Daniel and Mario’s faces was worth the effort.

The weather forecast changes hourly. The latest news is that Saturday should be dry all day with a high of 78. Sunday may be wet in the morning. I told the team I get to drive the wettest stint. That may screw up driver order, but as team owner, I’m putting my foot down on that. There’s no way I can keep up with the fastest cars on a dry track, but give me puddles and let’s see who comes out on top.

Saturday – race day

The race day didn’t start the way we wanted. Our first driver got 2 black flags. One of them was for going off track to avoid a collision. I’ll take a black flag over dents any day. But 2 black flags pretty much put us out of contention. Also, there was some blisteringly fast B cars we could never catch. Our second driver didn’t like the way the car was driving. Actually, neither did the first driver. When I asked if the rear had no traction, he said neither end had traction. Puzzling. So we decided to turn the rest of the race day into a tuning day.

Mario went out and came back in after a few laps complaining that the car was oversteering badly. We were running Federal 595 RS-RR 225/45/15 15×9 on the front and Falken RT615K+ 205/50/15 15×7 rear. So we decided to switch the rears out for a stickier compound: Brigestone RE-71R 205/50/15 15×7. This time he stayed out a while and had a great race with a pickup. When he came back in, he said the car was much more neutral now and that I should get in to see what I thought.

The first thing I thought was the brakes are still mushy. The pedal starts hard but just mushes out and goes to the floor. That’s really disconcerting because it gives you very little brake feel. And without a firm pedal, it’s pretty hard to heel-toe shift. Oh well, I just did more straight-line braking and eased in the clutch. Not ideal, but I’m okay working around problems. It’s likely an aging master cylinder.

The next thing I thought was that the 225 RS-RRs 15×9 aren’t that much different from the 205 15×7 I had run in earlier races. The tires don’t actually feel very fast. Part of that is because they are miserable under braking. They slide way too easily. They aren’t a particularly loud tire, like say the NT-05, and in 225 they are definitely on the quiet side. I started to understand why driver 2 thought the car had no grip on either end. The RS-RR doesn’t feel like it stops very well, so it appears to have no front grip. But once you get into a corner, it’s side grip is really good and overwhelms the thinner and harder rear tire, leading to oversteer. Mario said it was a lot of work just keeping it on track. I didn’t get to try the 615K+ rear setup, but the RE-71R rears felt pretty well planted.

While the car felt like it had better acceleration at low speeds, surely due to the weight loss, the drag was noticeably higher. This may be because the cut down doors don’t have mirrors or the wind deflectors I added. So the inside of the car turned into a parachute. It meant that top speed on the main straight was just 90-91 mph, or about 5 mph lower than usual. That didn’t stop me from having fun though. I managed a 3:43 in my few laps on track. You can see the entire stint in the video below (quality is not good because Windows 10 Movie Maker sucks. I may re-encode this on my Mac later in the week).

Sunday – race day

The forecast was wrong. We arrived at the track to find it drying. I was expecting a lot of rain early so I could one-up some fast cars but it just wasn’t very wet. Discouraged, I decided not to drive first. Danny drove first and while he was out we got our pit crew member, Tiernan, a driving wristband. He got in the car next and despite all the warnings about the blind turn 9C that connects the East and West tracks, he did what a lot of people do, and drove straight though. When he got to the penalty box, they decided to throw the book at him. My book. I had dropped off about 15 copies of the book to be sold for the Alex’s Lemonade Stand charity. Tiernan’s penalty was to read a passage from the book while being filmed. If it doesn’t make the Lemons wrap-up video, I’ll post it here.

The rain started picking up and it seemed there was enough rain to have a bit of fun. And fun was had. I got my wish and was able to dice with the fastest cars on track… and beat them.

Mario drove next and also had a blast splashing around (in the muck and the mire). But then the track started drying and he decided it just wasn’t as much fun. We wanted to get Daniel and Tiernan back in the car one more time, so they split the time on a mostly dry track. In the end, we were 56th out of 110 entries, or something like that. After we realized we weren’t in contention, we relaxed and had a lot of fun. This weekend reminds me how much fun Lemons is. That said, Lemons is changing, and not necessarily for the better. I’ll comment on that later.

Lessons Earned

Guest post and 3rd place in the 2018 YSAR Author Contest. This one from my twin brother Mario. Editorial comments in red.

Lessons Learned Earned

I’ve been endurance racing for six years now, which is that middle ground where I’m no longer a noob, but I still don’t know shit. I’d like to think I’ve learned a thing or two, but if I add up the time and money spent, I think it’s fair to say the lessons have been earned, more than learned.

Alignment first – When we got our 1997 Miata it was set up with toe-out in the rear because the previous owner wanted to drift it. I found out really quick in Sonoma by spinning in T4. The instructor with me said “this doesn’t handle like a Miata.” I skipped a session, got everything aligned to zero, and it fixed everything. Another time our MR2 got sideswiped and it would crab sideways through a corner thereafter. Our teammate Ben Dawson could drive it like that, but I couldn’t get through two corners that way.

It wasn’t sideswiped. The axle broke from metal fatigue and the only replacement we could find on the day was from a previous year MR2 whose suspension geometry was slightly different. You had to saw the wheel just to keep it going straight. Mario got out of the car after one lap and said something like “I value my life too much to drive this”.

Don’t be obsessive about tire pressure – 200TW tires seem to work under a variety of tire temperatures. At a Hooked on Driving day I was at the center of a fairly volatile conversation between a Spec Miata guru and a tech from Tire Rack who completely disagreed on what my tire pressure should be. The former said to run my tires at 38-40 psi, the latter at 28 psi. The comments went from “You’ll fall off the track,” to “the tire will fall off the rim,” and back and forth.

Grassroots Motorsports recently did a 200TW tire test and tried a range of tire pressures. They found out that it didn’t matter much.

It was a bit shocking to find that the lap times were all the same. I think pressures start to matter more when you don’t have square setups. When goofing around I pump my rears up absurdly high. Also, off road so that the tires stay on the rims. 

Safety wire your oil drain bolt – I ruined half an HPDE day for everyone because the oil drain bolt came loose. If the corner workers had flagged me there would have been less cleanup, but for sure it was my fault. I now drill and wire the drain plug, and you should, too.

Get an infrared thermometer – If you’re a pro driver then you need a pyrometer to measure tire temps, but if you’re reading this blog, you can use a $20 infrared gun. It’s great for checking tire temps, seeing how hot your rotors get, checking track temperature, and various things under the hood.

MR2s are great endurance cars. Not. – Our MR2 spun every other race. No, it didn’t spin from snap oversteer like everyone wants to tell you, but it spun bearings all the time. And that requires rebuilding the bottom end. If you want to have a couple really great races and then replace the engine, the MR2 is an ideal platform. If you want longevity, look elsewhere.

Black flags matter – After too many black flags and unnecessary pit stops, we calculated the amount of time lost for a single pit stop vs different lap times. I wrote a whole blog post on this subject, but I can sum it up by saying the fastest driver with a single black flag is the slowest driver.

On some tracks where the stewards are outside the timing loop, a black flag can cost an extra lap.

Don’t trust a racing resume – We’ve had arrive-and-drives with impressive racing resumes, but they don’t mean much. One guy was slipping the clutch on purpose to keep the revs up (and bragging about that being the fast way around), and another had his hand on the shifter the whole time. He also downshitted and put our car to 9k revs, fucktard.

You need a coolshirt – We ran our first couple races without coolshirts and could manage 40-minute stints before we were a danger to ourselves and others (it was over 100 degrees and probably 114 off the pavement). One time we used dry ice to super-cool our ice, but haven’t done that since because most of the energy is locked up in the phase transfer from solid to liquid, and so it’s not worth the hassle of cooling ice further. A big block of ice is better than ice cubes.

Pit stop strategy – No battle plan survives contact with the enemy; no pit stop strategy survives the weekend. But it’s fun to plan them anyway. Also, you can make up time in the pits easier than on track. But like black flags, an unplanned stop takes more time than driving slowly.

Miata is always the answer – They handle, there’s always spare parts at the track, and they don’t break too often. They are underpowered and a bit too common, but still the answer.

Wear a diaper and a big hat – It took me a few races to get to where I could comfortably drive a two-hour stint, and when I was finally ready, my bladder wasn’t. Forty minutes into it and I was weighing the pros and cons of a pit stop vs peeing in my suit. I pitted and ruined our race strategy, but at least I didn’t soil the seat for everyone else. Now I wear a diaper (Depends) every time, and weirdly, have never had to use it.

I also wear a big hat because the sun can tire you out as much as anything. We were racing at Willow Springs one day and it was 108 degrees IIRC, and I had just finished my stint, so I was wearing nothing but a diaper and a big hat. I thought it was funny, so I texted my two sons a picture. One said “I can never un-see that,” the other said “Now I have to burn my phone.” It was so worth it.

Pit board > radios – We’ve had terrible luck with radios and headsets. We now run Boefang radios, but at the lower, and legal, 2w setting. And they still suck. Have a pit board on hand.

Bring a skateboard – Skateboards are great pit transportation, and if you have a longboard, you can carry a gas can on the front.

Don’t race on untested components – At the 24 hours of Buttonwillow, Ian put on tires we’d never used before, and the best brake pads we could find, but also hadn’t tried before (the Yaris has a dismal selection of brake pads). The tires sucked. And we ran out of brakes in the 8th hour. Of a 24-hour race. We only had one extra set of brake pads, and so the last 8 hours was pretty much downshifting and coasting with no brakes. Still placed third overall, tho!

Me culpa.

Put your most aggressive driver in last – I flew across the country for a race weekend. Our most aggressive driver went first. Nobody went next.

FWD is great – I love rear-wheel drive cars, especially in slow corners, but most of the time it doesn’t matter which wheels are driven. Some of the most fun I’ve ever had racing has been in my brother’s Yaris and Tom Pyrek’s Honda Odyssey minivan (Ninja Turtles theme). FWD is especially fast in the rain, and at the NJMP Lemons race, Tom’s rain laps were within 1% of our team’s best dry laps.

Quit racing – Ian and I keep talking about the day we sell our race cars. Then we’ll buy a couple brand new Miatas (him a Fiat) and do HPDEs and arrive-and-drives. Maybe we’ll still be saying this five years from now? I don’t know, but my wife was ready for that yesterday.

Mine too. Racing sucks most of the time.

Backing up the corner

When you first start driving on track, the most common phrase you hear is in slow out fast. That’s generally a good idea for safety and lap times. Some drivers think they can go faster by holding more speed, but if they have to lift at the exit, it’s an overall loss. Another misconception is that one can reduce lap times by braking harder and later. This is only true for the novice who has no confidence in braking.

When people talk about advanced driving techniques, the most common topics are heel-toe shifting, trail-braking, and left-foot braking. All of these are physical things one does. All can improve lap times. They are considered advanced because they take some physical coordination and practice to apply. Doing them badly can get you into trouble. But the upside is lower lap times and a greater feel for the car. Myself, I trail-brake almost every corner and heel-toe shift every time. I don’t left-foot brake because I haven’t practiced it enough.

What about advanced techniques on the mental side? That’s the topic today. I want to talk about backing up the corner. You may have heard that phrase before and wondered what that was about. It means getting the braking, turning, shifting, and throttling done earlier in the corner. This technique is especially important for low powered FWD cars like mine.

There are two things to consider when backing up the corner, the mental discipline to do it, and the physical ability to execute it. Let’s talk about the mental side first. You must first recognize the nadir of the corner. As far as I know, that’s a term I made up. If every corner has an apex (top) it should also have a nadir (bottom).

The nadir of a corner is the point of lowest speed.

Where exactly is the lowest speed in the corner? Usually at the place where your cornering G-forces are highest. If you think back to your traction circle, the traction of your tires can be used for braking, cornering, accelerating, or some mixture. So max cornering is not under braking or accelerating, but strict cornering. If you’re trail-braking into a corner, which you should be doing most of the time, the maximum cornering should be at the time you’re taking your foot off the brake and moving it to the throttle (assuming you right-foot brake). If you want to back up the corner, you need to move the nadir earlier on the racing line.

That seems simple enough, right? Just do everything a little earlier. Well, it’s not that easy. If you want to be on the typical racing line, you’ll need to get the car pointed straight earlier. Simply braking and turning earlier will see you hitting an early apex and running out of track at the exit. You have to rotate the car early in the corner without losing speed. That means you have to slide the rear of the car out, countersteer to keep it on line, and add throttle before you’re fully straight.

Let’s take a look at what that looks like in telemetry. You’ll probably want to click on this image to see it full size as it’s pretty large. The track is Laguna Seca. The panels are speed, RPM, throttle, and time going top to bottom.

Point 1 is turn 1. The blue driver has shifted to 4th gear here. That’s why there is a 4 in the RPM panel. The time panel (bottom) shows there isn’t much difference switching to 4th briefly vs. banging off the rev limiter. When I saw this, I drove in 4th for my second stint as it’s nicer to the engine.

Point 2 is turn 2. The two drivers have very different approaches to this. The red driver does a double apex while the blue does a single. As you can see from the time graph, the double apex loses a bit of time and then makes up for it. Double vs single apex isn’t really the conversation today. Instead, I want to focus on the three 90° corners that follow. As you can see from the time panel, the red car gains a lot of time here.

Looking at the speed graph (top panel) it looks like the red line is shifted left compared to the blue line. This is especially apparent at points A-D. This isn’t a GPS alignment issue. It’s the red driver backing up the corners. Unfortunately, I don’t have a brake sensor on the CAN bus, but one can infer that the red driver must be off the brakes much sooner than the blue. He doesn’t necessarily get to full throttle sooner than the blue driver, and in some cases later, but he’s applying the throttle sooner. The points marked W indicate wheel spin in the RPM graph. The red driver is clearly trying to maximize throttle and steering because he’s at the limit of both (sadly, the car has an open differential).

How important is backing up the corner? Like other advanced techniques, it’s something that can drop lap times when done properly and a bit hazardous when not. It’s fun to work on. Like other advanced techniques, I suggest working it out on a simulator rather than a track session, and never on the street.

FWD Drifting: Part 2 and Cones in Practice

Last week I talked about some of the tuning and techniques for drifting FWD cars. Some readers may be asking “why bother?” Well, because it’s a driving skill. And if you can drift a FWD car, it will help you drift a RWD car. Inducing oversteer by dynamically changing the balance of the car is important regardless of which wheels are providing power. I shot the video below on the skid pad at Thunderhill between coaching sessions.

The first part shows an exterior view of some switchbacks. It’s sort of comical how slow I’m going and how little my car looks like a racecar. But even at slow speeds it will slide around corners. In the second part, the camera is inside the car. You can see that I don’t use the hand brake. The car oversteers by changing the balance of the car, not locking the rear wheels. It’s also set up with a lot less grip in the ear. The car has RE-71R tires on front at 26 PSI (cold) and Hankook runflats on the rear at 38 PSI (cold).

The next series of shots are what I’m calling point to point. It’s just going around two cones but with different turn radii. I start with a large radius and progressively shorten it. Which one do you think takes the least time? Back in December, I posted on this topic. See Cones in Theory. If you don’t want to read that whole post, here’s the short version: I make the statement that path A takes less time than B, C, or D. That’s the experiment I’m performing in the point to point videos above.

I timed the various runs and indeed, the tiny radius is the fastest (path A). It’s also in a very bad spot in the power band. I’m driving in 2nd gear the whole time, and there just isn’t as much power when driving the tighter radii. But it didn’t change the outcome. Path A is the fastest way around a brace of cones.