D1GP in Japan uses a system called DOSS (d1gp original scoring system). DOSS is a proprietary implementation of the DriftBox. Keeping in mind that the majority of this blog has been tech based, one would assume that I would love the DriftBox. After seeing its usage in D1GP, the response from drivers, and my own research, I’ve decided that the DriftBox is a half baked attempt that hurts more than it helps.

Subjectivity vs Metrics

Drifting has its roots in subjectivity. Inherently, that gut reaction/impression cannot be taken away. Many fans consider putting solid numbers behind judging to be killing the spirit of the sport. They don’t necessarily need to be mutually exclusive. For example, Formula Drift currently uses decel zones as judging criteria. But without the metrics behind it, there isn’t a final truth behind someone brake checking the car behind them.

DOSS

The DOSS system is a driver’s upper roll cage mounted unit that mounts to the front of a vehicle. According to the spec sheet, it’s no more than a GPS and a 6 axis accelerometer/gyroscope. The GPS module is a 10hz unit that can theoretically do up to 10 samples per second. 10hz is pretty industry standard so the GPS module itself has stood the test of time. The accelerometer also seems pretty industry standard with its accuracy and update rate.

The screen doesn’t look too sexy, but that’s not really that necessary for judging.

Per this Japanese article for the 2019 season, the DOSS system scores by totaling , vehicle top speed, highest angle, maintenance of angle (not wavering), average speed (per section), rate to angle, and rate of change of angle in transitions. This is a pretty big difference in judging criteria in the US. Specifically Formula Drift. The difference is likely due to both the Japanese ideals, and the limitations of the DOSS system.

Breakdown by classic FD judging criteria

Line Judgement

Internet searching for how the DOSS module judges line came up with nothing. Their literature says it scores “per section” but I don’t see specifics on how this works. It’s conjecture, but it seems like sectors/sections are done by a remote computer that live analyzes by GPS coordinates and arbitrary lines drawn on a map. By its own literature, being off line (off course) is human judged. So proximity to inner clips and outer zones are not judged by DOSS.

Angle

The spec sheet specifies an angle calculation but it’s most definitely wrong. Without external sensors and multiple accelerometers (I can’t find any literature pointing towards this), angle must be judged by the main unit on the front of the vehicle. The distance between the front axis of rotation (between the front wheels) and the unit itself will yield different angle measurements depending on the distance between those two points. These will differ greatly between car models.

Regardless of that, there is no intuitive way for the module to be able to tell if the vehicle is understeering or oversteering. With all my research of angle measurements, no one system is foolproof and each has their own pros and cons. The DOSS system in particular, uses an overly simplified system that can yield very incorrect information.

Speed

It’s a GPS. That’s what it does. Speed is the only measurement that is accurate. The 10hz refresh rate does leave something to be desired. But 10 measurements per second is more than enough for basic judging. This is also why the main complaint about the DOSS system is that it heavily favors speed. It’s the only good measurement possible.

Bringing it all together

The total judgement score of the DOSS system is heavily weighted towards speeds and acceleration. Assuming someone attempts to properly calibrate each unit for angle on each car and the flawed angle calculation at least being consistent between vehicles, the angle calculations are mainly used for “highest angle achieved”. The rest of the angle calculations are rate to angle and consistency of angle. These calculations all favor the fastest driver and not the highest angled driver or the most accurate driver.

Many drivers have complained that you “drive to what the box wants”. And that’s pretty accurate. The DOSS system was setup to use the data given to find a measurement that it could produce. The criteria given by the DriftBox is very limiting and judges to a very skewed ideal of what drifting is.

As usual, this article is written from my point of view and is limited to my current level of knowledge. Fight me in the comments.

Main Purpose

The main purpose of a “Bash Bar” is to provide a replaceable, bolt on crush area for the inevitability of front/rear contact between cars. The aim of this is to absorb the impact on a part that can be quickly replaced, instead of tweaking the actual body of the car. In the event of an impact, a new bash bar can simply be bolted on or the old one can be repaired if needed.

Secondary Purposes

Alternatively, bash bars have several other benefits. Increased air flow (theoretically), added jack points to the car, lowered weight, custom mounting brackets for body panels/lights, and added space in/around the bumper area.

Hobbyist vs Pro Bash Bar

Most general drifters replace the front bumper with a bash bar that mounts to the stock bumper. Many pro-am drivers and all pro drivers adhere to their rule books to cut off as much of the frame rail as possible to add a larger crash area. This gives more engine bay space and more area to crumple without transferring the impact to the main chassis. Many pro teams run 2 separate crash supports. One for the bumper, and one to replace the cut off frame rails. Doing this allows easier replacement and more crush area.

Design Considerations

Most basic bash bars are a single bar that goes in place of the OEM bumper. The design above has the potential to puncture the tire in the event of an impact. A remedy to this would be to curve in the end piece so that the tire would hit a rounded edge of the bar instead of the corner.

Frequently, drift cars run a dual bar system. Dual bar systems are useful for oil pan and frame rail protection and a rigid mounting point for bumpers. The major down side is the added weight and complexity.

Alternate thoughts

Years ago, when it was allowed, JR ran an aluminum bash bar on the front with a secondary steel frame behind it. While aluminum is more expensive, the weight savings was likely worth the effort. Formula Drift has since changed the rules so now all bash bars must be magnetic.

Another outlawed tactic was to use coilovers with weak springs to absorb the impact but spring back out to preserve the physical chassis body. While it added weight, it lowered the amount of body work and repair needed.

The Absurd?

Samuel Hubinette for 2009 attempted to roll out a rollerblade wheel design to glide along walls. It didn’t make it into practice and Formula Drift may have outlawed this before its debut.

Here is another Japanese translation, mainly for my education. If you have requests, feel free to comment or email me to let me know. Parenthesis generally denote my notes or comments.

Title: Drift tire commentary. Test & Check

Red banner and Subtitle: Zenkova’s 2 types. How will this footwear stack up?

Article body (top left onto next page): Within the past several years’ tires, Zeknova stands out. This company’s tires are very useful for a main tire that can be used for competitions or regular driving. 2019 D1GP driver Daigo SAito is driving his Fat Five A90 supra using their RS606 tire. Even with this new car and development, the car has placed second and 4th in previous standings. The RS606 has much potential to go beyond this level. Formula Drift Japan Masadai (sp?) managed pretty well after a typhoon wet the track. The RS606 is a good high level/high grip tire while the Super Sport has a greater cost per lap ratio. There’s no doubt that Zeknova will be a tire to watch out for in the future.

Red Title Super Sport RS: Strongest tire for fun driving or competitions

Super Sport Subtext: Decent value to grip ratio. Good life for the cost per tire for drift practice. This tire also lasts very well for drift competitions. Tread wear was even across the tire sizes at 240.

Red Title RS606: Comp winning high grip tire.

RS606 Subtext: High speed high grip tire that can be used for competitions. This tire also has good tread to make it through water but also has good dry grip. Tread wear is 140/160/200/240 across the 4 subtypes. Even with full air, the large size responds very well.

Text Bubble: Pick a tire size based on your power level! The Super Sport can be used for comps or fun!

Caption: The RS606 is used by pro drivers for it’s high grip in D1 and FD. The Super Sport RS was picked by D1 judged for use in the series (note to self, clarify this). This tire has placed 6th in the top 16 frequently.

*For text body see 2 panels above

Green/White Text: New Drift Tengoku tire test mule!

Body: Wataru Mashisan (sp?) the school of drift champ and FD Japan driver and this year’s tournament champion. This S15 has been his general test car and competition car for a while. It is used to test both competition and general drift tires.

Black Box Text: Testing Rules – Tire pressure starts at 2.5kg/cm2 (~35psi) to get a feel for the car. On the second heat, pressure is lowered to 1.2kb/cm2 (~17psi) to test grip. The test car is the “MassBear” (????) S14 with a TD06-20G good for 400ps (395hp). Front tires are a Valino Pergea 08R with 235/40/18. Testing is done at Nikko about 1pm at 56.6 degrees (130F) road temp. This testing effected not only the tires, but the car and driver.

RS606 Heat 1 (top left): This tire was tested at great speeds. Even with the air so high, the side might not have done well (side bite?). Flooring it causes a feeling of side traction loss. It’s hard to stop the rear once it’s out so less air is likely better.

RS606 Heat 2: Just as we though, lowering the tire pressures gave more side grip. This felt much better. Even with 400ps, there still is some grip left in the tires. Although, these tires have a shorter life than the Super Sport RS tires. Even with this, it is still a very usable tire.

Super Sport Heat 1: This is way too much air for this tire. After 5 laps they were hard to catch and maintain in a drift. The overall balance really isn’t that good at this pressure when it comes to side grip. There’s still some ability left in the tire.

Super Sport Heat 2: This completely changed the tire but also eats through the tire faster. With partial acceleration, this helps this tire become a pro level tire [D1 light series]. This has a good amount of grip left in the tires.

Bottom Right Pic: Soukoukai tire – These are the tires after our 2 heats. Corners 1-6 and about 5 laps per heat overall.

Red Middle Text: The RS is an FD/D1 capable car while the Super Sport is great for practice and just having fun. Both are very good tires!

Under Left Graphic: Even with the high road temps, the RS606 would be a great battling tire for comps. In our second heat, the RS606 seemed like a very capable dry tire that wears very evenly.

The RS Super sport was pretty good even with high pressures and had very good life in them. At a soukoukai, these could go for a full day on 2 sets. With about 300ps, these would be a great cost per tire. I will be using these as my practice tire on my silvia.

This article will go into the very basics of how CAN Bus works in the automotive world. Things like transmission arbitration and bits/bytes are beyond the scope of what’s necessary for a basic understanding CAN Bus systems. There’s also a TON of other uses for Controller Area Network (CAN) systems, but this is an automotive blog (among other things).

The Old Way

Older analog technology required a physical wire between every sensor and every recipient. The coolant sensor from the engine went to the ECU and the ECU had a separate output to read the temps to the cluster panel. Splitting a sensor between multiple outputs wasn’t easily possible (EG tapping the stock coolant sensor to run an aftermarket gauge). Every new electronic sensor/gauge/output/input had to have a single wire or more linked from that module to its destination. Each new element added complexity and weight.

Modern CAN Bus

Modern day CAN Bus systems use 2 wires to communicate between modules on a “bus”. A bus is a system of modules all joined together using interconnected wiring. In the example above, there are 2 buses. One for the light modules and another for the engine and stability control system. Modern cars can have several buses for various sub systems. For example, the lighting module doesn’t need to know what the engine’s RPM is so there isn’t a need to run the extra wiring. A simple real world example of a bus system would be a computer’s USB (Universal Serial Bus) hub. Many devices can be connected to a computer through a single cable.

Why Use a Bus?

As cars get more complicated and filled with electronics, a CAN Bus type solution is necessary to keep cost/weight/failure points/etc to a minimum. Less wiring inside of a car can only be a good thing. For example, a car could have CAN Bus modules in each seat to tell if they are buckled, tensioned properly, occupied, reclined, and can be told to turn on the seat heaters/coolers, all with 2 wires.

Why Should I Care?

Because we can hack it! Why buy expensive aftermarket gauges when an android tablet can read out all of the engine’s vitals? CAN Bus information can also be used to diagnose issues beyond normal OBD2 codes that the factory didn’t expose. There are even tools to push commands to CAN Bus modules. Right now this type of hacking seems to be in its infancy, but in the future, it’s very possible to reverse engineer entire CAN Bus systems easily and manipulate any module or even add/remove them. For example, CAN hacking could be used to interface motor swaps with the factory cluster and body buses, eliminating the need to perform major rewiring jobs.

Much like the swap from carbs to EFI, CAN Bus systems are now prevalent in every current generation car. As a tuner or tinkerer of cars, it is quickly becoming a necessity to learn to use these systems and understand how they work. At the very least, they are useful for diagnostics. At its best, it is a new opportunity for tuning and enhancing vehicles far beyond what was possible in the past.

When swapping motors, the factory DME is no longer receiving signals. As a result, the cluster panel won’t show rpms, coolant temps, and lights like the oil pressure dummy light and the CEL. The E46 chassis also uses a ton of can bus connections between modules to double check VINs and pass data for other modules to use. Despite having can bus technology, the cluster panel and other modules still use analog/pwm signals for various instruments. For instance, the speedometer is a pwm signal from the ASC/DSC module. With my M3 rear end swap, this sensor no longer communicates with the ASC/DSC system so the cluster doesn’t receive that signal. But also, the can bus signal gets a ASC/DSC not working dummy light command from that module to the cluster.

To maintain most of the lights and VIN checks, I kept my factory DME installed but severed the can bus connection to the DME to the cluster. I don’t use the ASC/DSC system so the arduino uno just sends a signal to the cluster that it’s as ok as it can be.

I still have my “carduino” freematics module that plugs into the factory LS2 GTO PCM via the OBD2 port using an ELM327 chip. The ELM327 is just a generic chip used in most off the shelf OBD2 autozone/advanced auto parts stores to connect to most OBD2 systems. This reads things like coolant temp and RPM that is then fed to the arduino uno to send to the cluster. The carduino also has a GPS module to replace the speed input to the cluster via an analog output as well.

Once things start working, I think the cluster can bus has access to things like brake pressure and steering angle that I can send back to the carduino to log in the SD card. Having 2 arduinos isn’t really necessary but giving the cluster its own unit makes sense. Also it saves me time of mashing together all the components into one unit. The general idea is simple, but the execution has some nuances and isn’t always as straight forward as the diagram suggests.

Turns out the e46 cluster won’t tween between values. It just shakes between the two values. So I severed the can bus connection from the chassis and made sure important features still worked. It turns out the e46 cluster is a combination of can bus, k bus, and analog inputs. The can bus inputs seem to only be a direct DME input. Maybe some ASC/DSC.

At this point, the tachometer works and the general can system has been setup. By reading this blog, I found out that the speedometer is actually a 12v output from the cluster that can be conditionally grounded to output a proper speed. A 2N2222 transistor with a 1k inline resistor in cahoots with the arduino tone operation go the speedometer working correctly.

The can bus managed to get most of the nasty lights out. I know the seat belt is done via K bus but I’m not sure about the red brake light. That’s likely the parking brake analog input. Also, the temp gauge is centered as a proof of concept. I’m not sure I will actually hook it up.

Next steps are to read rpm inputs from the LS PCM’s output and probably the start of the arduino to arduino communications to gather ELM and GPS data to feed to the cluster.