First of all I want to preface all of this by saying that there is always the chance I am just completely insane
About two weeks ago, I was testing one of my creations in BeamNG – specifically the Everette Vancouver GLR8 – and I noticed something strange. After several laps around both the Automation test track and Hirochi, the brakes on my regular street car were still performing admirably. This was rather contrary to what I would expect because most regular cars will boil their brakes after 5 or 6 good stops.
To cut a long story short, I got sucked down a rabbit hole investigating brakes and my conclusion is this:
Brakes in Automation do not supply nearly enough force but are also FAR FAR FAR too resistant to brake fade.
Well its like this. The first thing I suspected was either
- My own tuning
- Or a glitch in the exporter
So the first sanity check I did was load up a couple native BeamNG cars and hoon them around the track for a while. Specifically, I used the Ibishu Pessima, the ETK 3000ix (BWM E30 clone) and the Bruckel Moonhawk V8 Sport. Sure enough, these cars boiled their brakes after about 5-10 laps. I also did a rapid succession panic stop test – 100 km/hr to 0 – whereupon I found all the cars boiled their brakes after about 6 panic stops. My Vancouver – I lost count at 12 and was probably up to 30 before it even started hinting at boiling brakes.
Next up, I considered brake spec. My Vancouver was using 315 mm twin piston vented front discs and 275 mm single piston solid disc rears with a 35 pad. Perhaps slightly overspec’d considering it is a 1999 car but nothing especially fishy here. So, this is sounding like an exporter bug. Except Automation’s own brake fade tests also showed virtually no fade…
Things got a little bit more suspicious when I tried a car by @Marcus_gt500 from the Automation BeamNG user repository. As Marcus_gt500 spec’d it, the car stops from 100 km/hr in something like 95 meters! Lolwut?
I tried tuning it up a bit but was highly unsuccessful. Even with 15 inch wheels, 300 mm drums, and full race pads, I best stopping distance I got out of that car was about 73 meters. And yet, even with regular spec pads, the brakes again showed very little fade according to Automation.
This is when I got sucked down the rabbit hole.
I started looking up old brake test videos and performance reviews. There were a couple I found particularly intriguing. The first one that really caught my attention was this:
In summary, that video was a Chevrolet promotional video from 1936. At 6:34 in the video they quoted the stop time of a 1936 Chevrolet from 60 mph (~100 km/hr) to 0 at 4 seconds. Now if we remember our physics, distance traveled under constant acceleration is 0.5 * a * t^2,
so if we assume 1G deceleration, then the car goes about 80 meters in the 4 seconds it takes to stop. EDIT: I realized this morning I am a dunce and have all the numbers to calculate the exact stopping distance - 60 mph is 28 m/s so 28 m/s divide by 4 seconds means a deceleration of 7 meters per second. Plug that back into our formula and we get… 56 meters! Also even assuming worst case number firing on Chevy’s part ie 4.9 seconds, we still get a stopping distance of 68 meters. Now I realize that is only an estimate making some perhaps generous assumptions but In 25 years, I would expect that braking technology would have improved at least enough for Marcus_gt500’s 1960 land barge to stop in less distance than that WITHOUT the use of full race pads. (Also, if you look at the design of the brakes in the video, they are single leading shoe on both front and rear)
I also found some old performance reviews of specifically a 1967 Ford Mustang GT:
And a 1967 Chevrolet Camaro SS 350:
The Camaro stops from 80 mph (130 km/hr) in 280 ft (85 m) and the Mustang stops from the same speed in 312 ft (95 m). And again that is from 80 mph (130 km/hr) not 60 mph. So if we do the maths, we find that these cars stop from 100 km/hr in about 48 and 53 meters respectively. And these figures line up well with other cars of their type. Even Ferraris of the same era had about the same stopping distances.
Now I realize these are schporty cars and both models would have had front disc brakes. But even taking this into account, a Mustang / Camaro like sport sedan I made in Automation:
Cannot achieve the same stopping distances without either using twin piston disc brakes (uncommon in the 1960s except on limousines and exotics) or very aggressive brake pads:
But these are also smaller cars from the 1960s. What about land barges? Well, this is where I found the smoking gun so to speak that really solidified by my conclusion:
Although this performance review was conducted in the mid 1990s, the 1961 Impala SS 409 in question was a faithful stock build. If you download the original PDF article, you will find it even had the factory 11 inch (275 mm) drum brakes, front and rear! How did its stop test go? 253 ft to stop from 70 mph. Or 77 meters to stop from ~115 km/hr. Which – do the maths – translates to a 100 km/hr stopping distance of… 57 meters!
How many 1960s land barges can do that in Automation even with full race pads? I think we all know the answer to that - 0.
So what does this all mean then?
Brakes in Automation do not supply nearly enough force!
The aforementioned Impala’s performance raises a particularly interesting question. If a 1960s land barge can get into the 50 meter club with drum brakes only, a feat we have always needed disc brakes for in Automation, then why the hell did we ever need discs in real life? Well, remember how I was talking about how the brakes wouldn’t fade on my Automation cars in both Automation and BeamNG?
So after browsing numerous car forums and reading various opinions, they all start to say essentially the same thing. In those old cars with drum brakes, if you really stand on them, you can lock wheels (going to point 1 - brakes don’t supply enough force in Automation) and you will be able to stop the car quickly. But you will only be able to stop the car quickly ONCE!
Drum brakes don’t cool nearly as well as disc brakes so once you panic stop with drum brakes, they fade BADLY! Hell, just go watch the most recent episode of Roadkill. Their 1966? Impala made to the top of Pikes Peak, Colorado but they couldn’t get back down. Why? Because 4-wheel drum brakes meant they boiled and faded nigh instantly.
The point here is this: with drum brakes, you actually get pretty decent stopping power. But you get two, maybe three, good hard stops out of them in a typical street car and then you’re sliding into the next county.
Even with disc brakes, cars will still brake fade. In my own car, a 2006 Scion xB, I can confirm that it will brake fade severely after the 5th or so hard stop from 60 mph. And yet many of my cars in Automation with conservative tunes exhibit zero brake fade both according to Automation’s calculations and BeamNG’s simulation. They often need multiple decades of panic stops before hinting at brake fade.
At very least, this indicates to me that brake fade is not handled correctly in exporter.
I my opinion, brakes in Automation are both overpowered and underpowered at the same time. On one hand, they don’t supply nearly enough force (especially in the early years) but on the other hand are impervious to fade.
One thing I had considered for why brakes are so shit in early years in Automation was that many cars up until the 1970s, had no brake booster meaning the pedal was VERY firm and it required significant effort from the driver to stop the car. Now, while I can see this as affecting drivability and comfort, it does NOT cap the absolute maximum force that the brakes can exert; that is something only the hydraulic system can do. I mean heck, the hydraulic system could be designed to support an arbitrary amount of pressure and by extension and arbitrary amount of force. The problem becomes engineering such a system.
This actually points to another weird thing I noticed. For any given brake configuration, maximum brake force doesn’t scale with the size of the vehicle which to me seems wrong because many larger cars do employ higher pressure hydraulic systems to extract more braking force without requiring different components. I realize that getting into hydraulics and system operation is a whole boatload of complexity I don’t think most people want to deal with so I would suggest either:
- Raising the maximum brake force provided by in particular drum brakes to better reflect reality
- Incorporate a “Maximum Brake Force” slider which can raise the maximum force but lengthens engineering time, much like how the “Brake Airflow” slider works
Furthermore I would also suggest:
- Power brakes should be added as an additional driver aide before anti-lock brakes (ABS), unlocking in about 1960 and should provide a buff to safety, drivability, and comfort
- Brakes need to be a LOT more prone to fade, ESPECIALLY DRUM BRAKES!
Woof. Sorry for wall of text. But this issue has been bugging me for a while and I want to see what other people think.
And again, there is always the chance I am just completely insane so that being the case, prove me wrong. I am listening.