Tag: Yaris

LDRL TH5 2020 recap

Late Start

Due to unforeseen circumstances, we left for the track about 9 hours late. We were supposed to leave Davis at 9 am but David was delayed and he didn’t arrive with the truck until almost 6 pm. We quickly loaded up and then headed for Esparto where the Yaris was vacationing under the care of Mike “Tinyvette” Meier. We made it to the track just about 8 pm when the tech inspection was supposed to be closing, but there were 10 cars still in line, so no problem. Everything checked out fine for us, but my old Miata was getting some extra scrutiny.

Miata #581

Before the Yaris, I was on a team that raced a Miata. It participated in Lemons, Lucky Dog, ChumpCar, a bunch of HPDEs and even an SCCA race school. It went through half a dozen Lemons themes, hosted an all women’s racing team, and was rented out to a friend’s team while their car was getting fixed. During its tenure with us, it grabbed 3rd place in B class in Lucky Dog (Laguna Seca) and 3rd place overall in ChumpCar (Thunderhill). Eventually I started to spend a lot more time with the Yaris and the Miata sat in my driveway for a year with a bad engine. And then we got a JDM engine and it sat for another year doing nothing. I was going to sell it and then instead I donated it to Deaf Power Racing, a new team whose mission is to get more deaf people into motorsports.

Under DPR care, #581 has had a whole host of problems. They inherited an incomplete build and a partial Lemons theme. In their first outing, a few weeks ago, the engine bent a valve. So they went into the Thunderhill race needing to install a new engine, which they did the day before. Their reward for all their hard work was LDRL officials giving them a hard time for the cage. Not only was the cage built by Evil Genius Racing (owner John Pagel is head of Lemons tech), it also had previously passed inspection by NASA, SCCA, Lemons, ChumpCar, and even Lucky Dog themselves! Anyway, their cage issues got resolved but that was just the start of their problems.

When the green flag was thrown on Saturday, they didn’t make it through the first stint before they came in with a broken diff hanger. That never failed on us, but I guess they fail eventually. The next calamity was that the axle wasn’t replaced correctly, so the diff oil leaked out and the diff over heated. So after working for several days straight they had a pile of broken bits to show for it.

Guest Drivers

I run guest drivers on my race team all the time. There are lots of people who pay money to enter a race only to find that the car they were supposed to drive has died for one reason or another. Being the sap that I am, I like to give such unfortunate people a chance to walk on the mild side. I’ve met some really nice people doing this, and that’s probably what reinforces the practice. DPR had 3 arrive-n-drives and no car. So we cut our stints down and made room for them. I would have made room for the owners too, but they thought it would be best to prioritize their paying customers.

Lucky Coincidence!

It turns out that one of the drivers, Taylor, had a rather unexpected connection to me. Not only does he know Ben Dawson, a dear friend and former teammate of mine back at the start of my racing adventures, he had also driven on his racing team. That meant Taylor had actually driven the second car I had given away: my 1986 BMW 325e. That now lives in North Carolina with Winsome Racing. Now if you’re counting cars, you might think that Miata #581 was car #1, but actually that was #3. The first racecar we gave away was our 1988 MR2. Don’t get excited, I don’t have any immediate plans of making the Yaris #4.

Lucky Find!

Guest driver #2 turned out to be a really important person to meet. Ryan is a former StopTech employee. Not only could I share with him my love for the StopTech 309 compound, he also told me what was wrong with my brakes. The Yaris doesn’t use stock calipers because the pad choices were so limited. It was either EBC Red or Hawk HPS, neither of which was very good. So I upgraded to a larger caliper from a Corolla. You have to use a different rotor, but otherwise they bolt right up. StopTech 309s are made in Corolla sizes, which is why I made the swap in the first place. Here’s the problem: the Corolla piston is probably a little bigger. That means it takes more pedal travel to operate the brake and it results in a softer pedal feel. And here I thought I could never remove the last bit of air. Ryan said he would give me a professional brake analysis if I sent him my part numbers and corner weights. How cool is that?

Change Happens

Lucky Dog Racing League is changing. While some change is inevitable, the direction the league is going is away from me. It’s probably better for the health of the series to embrace fast, expensive cars, but it’s leaving budget, grassroots racing behind. Sure there are a few teams showing up with single axle trailers, but there are more with stackers. And while there’s nothing in the rules preventing someone showing up in a 1980s econobox, there’s also apparently nothing stopping people from bringing cars that compete in NASA E0. The speed difference isn’t safe or fun. Next year they will have a B-Spec class. On the one hand, that’s a nice concession for newer cars like mine that are currently illegal because they are too new. On the other hand, B-Specs are rare, and I’d probably be the only one in class. Participation trophies don’t motivate me. I want to dice with cars of similar speed. The growing speed differential between my Yaris and the top cars is making racing less enjoyable for members of my team. As a result, the Yaris is leaning towards more Lemons and less Lucky Dog in the future (I think).

Video!

I drove a half dozen laps at the start of the race on Sunday before the double yellows came out. I got to dice with a few Miatas during that time. Thanks, that was fun!

Incident Report

Just got back from a race weekend at Thunderhill with Lucky Dog Racing League. This happened to one of our drivers.

https://youtu.be/1s4N8IgWE5A

The new splitter didn’t survive. It got bent pretty bad and we had to remove it because it was cutting a tire. Here’s what it looked like before the incident.

I’ve got to collect my thoughts for a bit before I write the race report. It was an unusual race for many reasons.

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”.

Post-race analysis: drivers

Let’s take a look at some of the telemetry traces of the Triple Apex Racing drivers from the last race.

Danny vs. Danny

The first thing I want to discuss is Danny. I’m usually a couple seconds faster than Danny. I was on Saturday. Then we switched tires on Sunday and everyone went faster. But was it really the tires? In the speed trace below, Saturday is black and Sunday is red. I’ve displayed the top 3 laps each day. Saturday he was doing 3:39-3:40 while Sunday it was 3:36s. What I see here is that he’s driving differently. On Sunday (red) he started backing up the corners. He gets his braking done earlier and gets on gas earlier. Most of the time, his minimum corner speed is higher despite the change. The fresh tires may have contributed a little to his higher speed, but I think it’s mostly because he’s getting better at driving a low powered FWD car with an open diff. His usual car is 911 GT3, so yeah, it’s a little different!

 

Danny vs. Ian

Due to yellow flags, I didn’t get many fast laps. I did a 3:38 and 3:37 back to back. You can see these starting at the 10:00 mark in my video from the last post. In my 3:38 lap, I lose 1 second passing an E36 in T2 when it changes line mid-corner. Then I pass the yellow Miata in T5, messing up my T6 entry, causing another loss of a second on the run up to 9C. The 3:38 could easily have been a 3:36. On the 3:37 lap, I lose a little time making a pass in T2 and then 1 whole second in T3W while I wait for a fast E36 to get around me. So that too could have been a 3:36. Had I gotten a bunch of clean laps, I’m pretty sure I would have been doing a bunch of 3:36s. Could I have broken into the 3:35s? I don’t know. For the most part, Danny and I drive pretty similarly. Below, the red lines are Danny’s fast laps (as above). The black is my 3:37 and the blue is 3:38. This is a speed trace from 7W to the SF line. We have a slightly different way of doing 1W, but the rest is similar enough that you might think it was the same driver.

Randy vs. Danny

So I’m sure everyone wants to know how fast Randy was (green lines below). Faster than Danny (red lines). Where is he faster? You might expect it’s the fast corners, but it’s the slow ones. He gains nearly 1.5 seconds in T9C alone! And he was only 1.8 seconds faster than Danny. T9C is on the far left of the graph. But he’s also faster in T7W and T11. How? Mostly by running over curbs. As the car owner/builder, I don’t really approve of that.

Post-race analysis: aero

At the last Lemons race I did a lot of lightening, which is good, but I also turned the car into a parachute and destroyed our top speed. This race we made two aero improvements.

1. A-pillar deflectors

This is simply a piece of plastic that bulges out a bit. The intent is to have the air go around the window instead of into it. Randy Pobst signed it.

Let’s take a look at the top speed on the main straight before and after the new “aero package”. The top speed went up from 92.0 to 95.4. It’s even more dramatic when you look at the speed trace.

2. Rear wing

Normally, all you have to say is “wing” but I need to emphasize “rear” here because we made an aero joke at the last Lemons race.

Note that we didn’t actually run this on track.  It was just to give Mario and Daniel a laugh when they drove in and saw the wing on the wrong end of the car. Here’s a picture of the same wing installed on the roof. Also, there’s a note I wrote to try to persuade Randy to take a stint in the Yaris.

So what did the rear wing do? The #1 place I felt it did something was in T1. I usually have to brake in T1, but with the wing holding down the rear end, I was able to do a brief lift and then go right back to throttle. You can see how much faster I can do T1 in the graph below (blue is with wing).

The wing also turned T8 into a straight. It’s normally a corner that gives some people a fright, but with the wing on there was no drama at all.

Conclusions

I think the new aero worked. I guess the next question is if we can make it work better.

Randy Pobst is a sweetheart

The Lucky Dog race at Thunderhill was good fun. Ultimately, we didn’t place particularly well, but as we’ve found out over the years, it’s more fun racing for giggles than trying to win. So we were leisurely about pit stops and put some guest drivers in the car. One of those drivers was the Internet celebrity pro driver Randy Pobst. Randy has a reputation as a fast driver but there’s a lot more to the package. He’s very approachable and knowledgeable, and he listens as well as he talks.

FUUUCK. I only had one camera working on Sunday when Randy was driving and it was pointed to the rear.

When Randy got in the car I told him to “bring it back whenever”. Given that he drove it until the end of the race (~60 min), I think I believe him when he said he was having a lot of fun. Apparently the Yaris reminded him of his old 80s Golf. Randy wasn’t the only person who had a great time in the econobox of doom. Lemons veterans “Crazy Mike” and Steve “Chotus” Warwick also drove and loved it. Mike was an “official” Triple Apex Racing driver this race and Steve was a stud driver, piloting some 4 or 5 cars on the weekend. That reminds me of a quote.

I never had a 10, but one night I had five 2s… and that ought to count for something.

— George Carlin

Every time I race the Yaris, it reminds me of why I built it. I love driving and hate wrenching. Despite appearances, the Yaris is a great driving car. It’s also cheap to run and tougher than it looks. It got side swiped twice during the race and just shrugged them off. The one annoying feature of the car is inside wheel spin from the open diff. That’s something I may address in the off season.

Look for some video and telemetry posts in the near future.

Aero Thoughts

I haven’t looked at the data yet, but here’s my seat of the pants impression of what it did.

  • The wind deflectors on the A-pillars did something. There seemed to be less noise in the cockpit. Did they improve top speed? I think so. In the last Lemons race we lost a few mph on the main straight and I think we got that back.
  • The wing probably added useful downforce in T1 and T8. I always take T8 flat out, but this time it was a really boring flat out. In T1, I usually brake lightly, but this time I would just breathe the throttle off for a heartbeat and then go right back on. No brakes needed. That allowed me to make some passes on higher powered cars.
  • The interior of the car still smells a little of catalytic converter, so I think some fumes are getting in from the rear. I want to fix that somehow.

I won’t know if these impressions are correct until I check the data. I’m fully prepared to be wrong!

Thunderhill Ready

Before the last race, I did a lot of lightening. The biggest win was getting an extra set of doors and gutting them to metal skins. While they weigh 50 lbs less each, they leave a larger hole and have no mirrors. That probably negatively affected our drag as top speed was off by 5 mph. Lap times were about the same though, probably due to better acceleration. Since there wasn’t much to do to get the car ready, this weekend we added some features that may improve our aerodynamics.

In the picture below, you can see a white piece of plastic on the A-pillar. This bulges out a little which we hope will deflect some of the air outward, so that the window doesn’t act like a parachute. The plastic is very heavy and shouldn’t move even with high air speed.

I also added a wing to the rear. This is a present Mario gave me that we had at one time installed on the front of the car as a sight gag. Now it’s installed in the correct place with mounts I hacked together. It’s more sturdy than I would have thought. No idea if it works, but even if it doesn’t give much down force, maybe it helps prevent air from the tailpipe going back into the cabin. Or maybe it creates lift and gives us carbon monoxide poisoning. Who the hell knows?

The last piece of our “aero package” is an air dam that I will attach once we get to the track. It will be interesting to compare data from the May Lemons race to see if top speed improves on the main straight and if we get any extra grip in the fast corners.

The only thing I’m concerned about at this point is the rear tires. The 8″ rims aren’t fully covered by the wheel wells. I guess I’ll order some fender flares.

Race Prep: Lucky Dog Thunderhill

The last race of the year for me is just 1 week away. I love racing on the 5 mile track and I love Lucky Dog Racing League. I just checked the supps and was met with a bit of a shocker. At some point I believe this race was advertised as running the second day in the reverse direction, but somehow that changed. That’s a real bummer. I was looking forward to that. Or maybe I’m mistaken and that came to me in a dream. Sometimes I confuse dreams for reality. I have a funny story about that…

I don’t follow politics at all, but early in the Obama presidency I remarked to a friend that I thought it was a really smart that Obama’s VP was blacker than he was. That way people wouldn’t assassinate him for fear of the next guy in line being even more threatening (or whatever). That was something I dreamed because apparently Joe Biden is actually white. Back in the 70s, Saturday Night Live used to do skits where Garrett Morris played Mondale as VP. The joke was that Mondale was so easily overlooked that nobody realized he was black (Garrett Morris). Anyway, I had somehow confused Garrett Morris, Walter Mondale, and Joe Biden. Then again, there are people who would say that Obama is actually whiter than Biden… so maybe I had it right all along. I try to steer well clear of political content on this blog, so apologies for this short political interlude.

Speaking of dreams, wouldn’t it be awesome to get Randy Pobst to drive a stint in my car? Well, it turns out, he’s going to be at the race and he’s going to be driving various cars. I immediately sent an email to HQ to sign up for this, so it may happen. That would be a dream come true. If it does, I’ll be sure to post some video and telemetry analysis. I’d love to see how much better Randy drives.

Prep

As it turns out, the Yaris requires minimal prep, and there really isn’t much to do between races. The car is amazingly robust and simple.

  • Change oil and filter
  • Change front brake pads
  • Swap doors (I keep the ones with windows on when parked)
  • Reinstall fire bottle (I just had it recertified)
  • Reinstall window nets (I had them out for the Lemons race)
  • Pack

So what’s the packing list look like? Some things are large and bulky, like tires, but I also have lots of “kits” that aggregate related items, which makes packing and storing simple. I can generally get everything ready to go in a half hour.

  • Stuff
    • Jack, jack stands, wheel chocks
    • Fuel jugs, fire extinguisher, splash pan
    • Chairs, table, ice chest, EZ-up
    • Tires (see below)
  • Kits
    • Tool box (sockets, box wrenches, gloves, etc)
    • Power tools (impact, drill, air pump, light, vacuum)
    • Spill kit (absorbent litter, brush, scoop)
    • Brake kit: pads, fluid, catch can, brake tool
    • Service kit: oil, filter, funnel, paper towels, glass cleaner
    • Radio kit (UV-5R radios and accessories)
    • Race kit (tire pressure gauge, pyrometer, log books)
    • Telemetry kit (RumbleStrip, AiM Solo DL, Yi cameras, memory)
    • Fix kit (nuts, bolts, tapes, adhesives)
    • Electrical kit (multimeter, fuses, wires, crimper, etc)

Tires

The Lucky Dog Racing League is now sponsored by Hankook, and part of that arrangement is that the Hankook RS-4 is THE tire for the racing series. In order to get on the podium you have to run that tire. Ultimately, this is a fine thing, because it saves money on average. The RS-4 is a great endurance racing tire that has a combination of grip and longevity that is hard to beat. In very rough terms, they are a couple seconds slower than the cheater 200s like the RE-71R, but last 2-3 times as long.

Given that my car isn’t 15 years old, meaning I may get classed in Super Dawg, and is slow even for a C class car, it’s unlikely I will get anywhere near the podium. So the tire rule doesn’t really impact me. That’s good because I have several tires to burn through. This is what I’m bringing to the race.

  • 2 Federal 595 RS-RR 225/45/15 on 15×9 rims
  • 2 Federal 595 RS-RR 225/45/15 on 15×8 rims
  • 2 Hankook RS-3 225/45/15 on 15×8 rims
  • 2 Bridgestone RE-71R 205/50/15 on 15×8 rims

 

Lemons Telemetry Analysis

After a race I like to look at telemetry. It shows what each driver is doing. It’s important to also run video so you can point at a corner that is 10 mph off and say “there was a yellow flag”. As usual, my telemetry is recorded with an AiM Solo DL and I view it with Race Studio Analysis. I’ve taken a screen shot of the fast laps of each driver (actually a pair of fast laps) with my fast lap as the reference lap (black line). The screen shows three graphs (1) GPS speed (2) engine RPM (3) time delta. Ideally, I’d love to have brake pressure and steering angle, but these are generally enough to infer what’s going on inside the cockpit.

One of the first things to note is that the blue driver’s RPMs are so much lower. The blue driver shifts well before he needs to. However, this doesn’t impact his speed or lap times very much. The red driver shifts much more often and is in 2nd gear several times, also not affecting lap times very much. When in doubt, drive the higher gear.

None of these laps were completely free of traffic. The red driver lost ~4 seconds in T3W to a yellow flag, for example. You can also find GPS errors where the speed is clearly recorded incorrectly for a brief time. That’s why it’s a good idea to examine multiple laps and have the corresponding video.

The biggest issue I find in the driving is that the green and red drivers slow down too early and too much in the faster corners. They do okay in the slow corners, and their final speeds may be as good as the reference lap. In slow, out fast, does actually lead to high speeds on straights! But in slow also leads to throwing away speed, and in a momentum car with very little engine, that’s a no-no. The better mantra is: in on the limit, out on the limit. That’s easy to say, but not easy to do.

Exiting a corner on the limit is like tightrope-walking; entering a corner on the limit like jumping onto a tightrope while blindfolded. — Mark Donohue

So how does one get better at jumping on a tightrope blindfolded? Do I really need to say it? Practice. And where does one practice such a dangerous activity? Do I really need to say it? Simulation.