skru_fase

Hey guys, for those of you that have driven both, can you provide some insight on the difference between iRacing and Assetto Corsa (ie track selection, car selection, driving dynamics/realism etc)? I have read reviews on Assetto Corsa, some of which weren't good, however I think a lot of the reviews might be from a 'video game' crowd that might not like the level of realism. At the same time I have heard that Ferrari and Porsche train their drivers in AC? iRacing seems to be widely used on the forum, but I don't seem to hear much abt AC.

Comments appreciated.

ProCoach

I think AC is terrific. AC is built by Kunos Simulazioni, builders of the Ferrari Drivers Academy simulation and a number of others. I became aware of it and used it's predecessor, NetKar Pro. It has very good car licensing (meaning wide variety of cars and manufacturers), lots of tracks (although biased towards RoW rather than US) and outputs car data in AiM Race Studio Analysis format, for detailed study. Constantly updated with more tracks, DLC car packs and always something new. I prefer the driving physics (more) and tire model (not quite as much) to iRacing.

I think iRacing is terrific. Been a user since beta testing for almost ten years. GREAT US tracks, very well modeled cars. GREAT graphics and artwork. Outputs car data in MoTeC i2 Pro for later analysis and detailed study. Updates take longer to come, but the detail is worth it. Great value for me is that I can host virtual private sessions with individuals anywhere in the world, one on one. Awesome.

I have both, and many others including rFactor2 and some older titles and mods. But these two (AC and iRacing) are the two I use most.

Unbelievable variety of mods (cars, skins, tracks) here: http://acmods.net

ace37

I like the AC graphics a bit better.
AC has a lot of great street cars including Porsches. iRacing has mostly race cars.
iRacing has better racing than anything else as you are going against real people. There is no AI - either race with real people or run alone. You have to conform to the scheduled races to make this work.
Both have good physics. I couldn't say confidently which is better in that way.
iRacing has better VR support - it's in work in AC but quite buggy presently. They'll get it right.
AC is cheaper to start on as iRacing has you pay annually and buy a license to each car and each track you want to use. I spent <$100 for AC and car packs vs ~$500 for iRacing.
iRacing has many many more US tracks available.

I play AC for arcade racing, iRacing for better racing with people, and usually iRacing when going alone due to the better track selection. I also use VR which currently favors iRacing. I really like the Porsche packs in AC and they have a lot of great European tracks. It's also nice to just play an arcade game sometimes. Both are worth having.

ProCoach

Not to go wide of the OP's comparison question, but I would add Project CARS into the mix. Their Watkins Glen is spectacular! Plus I like the car selection.

hsmith

These are the two software sim's i use exclusively. I agree on most points already mentioned. iRacing has better racing and online platform (subscription based). I wish AC would adopt iRacing's online model as i think it works so well. AC's physics are excellent and slightly better than iRacing's.

squid42

AC is also pretty agile in trying to address weaknesses. They have different versions of their tire model and keep all versions accessible. There is always bitching about tire models, doing it that way offers choice to the users. Current weakness in the v10 tire model seems to be excessive cooldown even when driving hard.

There are some weaknesses in the physics model that I would like to see addressed. Weight distribution is only front-back distribution but makes no attempt to define how centered the mass is (think mid-engine car versus car with front engine and rear gearbox both having 50:50 distribution but the mid-engine car needing less impulse to rotate (but also generating lower forces towards rotation, so it sounds complicated and worth simulating)). They put all multi-link suspensions in the double wishbone category which isn't 100% accurate. Error messages when trying to start cars where you currently screwed up the data could be more informative.

Mods in AC have a significant problem with power curve data supposed to be entered as torque in Nm over rpm, and that is *wheel* torque. I have a script that compares the power that comes out of that with the claimed power in the UI and it is obvious that a lot of modders put engine power and/or put ft-lb.

I think the whole "wheel power" thing as a base is not good for a simulation. The assumption that every drivetrain takes 15% in every situation is obviously oversimplified. Furthermore the way that you get data for this is that you have a dyno measure wheel power, then multiplying by some factor to get engine power (and you hope but usually don't know that it is just multiplied by 1.1764705 for 15% assumed loss, and that is just assuming they document that they assume 15% loss). Then you take that shaky "engine power" and convert it back to wheel power by multiplying it by 0.85, not that anybody can be sure that people don't end up with 0.86956525.

AC has a very nice telemetry interface in where all telemetry is dumped to UDP network packages at about 5 Hz. So you can have a separate computer save it or do stuff with it or display something.

ProCoach

By telemetry, you mean the real-time feed of detailed info used to model the performance of the sim, correct?

For driver performance analysis in AC, AiM SPORTLINE has integrated into their Race Studio Analysis software the ability to import a .drk file of a run and to open and analyze using their software.

Obviously, more limited than the "telemetry stream" you reference (I imagine you can use this to stream to a separate tablet?) but more than enough for driver development and car engineering optimization within the desired parameters of the sim driver.

squid42

The AC network stream is used at least by one Android app that serves as a configurable dashboard (outside the regular computer monitors). I haven't used it myself, it sounds pretty cool if you want to have a clean computer screen with no UI elements, just the rendering of the car and the world, and then have rpm counter and tire slip on a separate screen.

Myself I use the stream to save all the data to disk and later munch on it in a larger software system. The important point here being that although that software is not finished (and never will be), saving a complete log with all data from now on will give me more data later. My setup also saves a copy of the car's setup files and of the data/ directory for the car, so that I don't get confused later.

I expect that my main use of the data is vehicle height (per corner) analysis. I find it hard to find a good spot between ride height, suspension stiffness and how wheel alignment goes out of wack as the suspension compresses. Ever since I started being a bit more serious I realized the value of a soft suspension, but there is little feedback about how you bottom out, how much contact you lose when raiding curbs and there is no feedback (outside telemetry) on how much damage your lap time takes from simple suspensions not keeping the wheel pointed where they should on compression.

skru_fase

I have been impressed with iRacing thus far, but haven't raced yet as I keep learning new tracks and cars so my consistency (or ability to avoid walls) is less than ideal for a race. I'm also focusing on North American, specifically local tracks right now too. Practice for next year... VR isn't an issue for me yet, I just bought three monitors, so I think I will stick with that route for the time being.. At this point, I guess either sim would be about the same for me then.

I am looking forward to the actual racing in iRacing though especially as I won't likely get the chance to do it in real life anytime soon. I wouldn't have a clue what percentage of people in iRacing actually race in real life, however it would be nice to see more street cars (if only even the popular street/track cars), similar to AC in iRacing, allowing for more comparable driving experiences. ie. I have an M3 on the track, but the closest thing I have come across in iRacing is the Z4 GT3 which is light years ahead in handling. I guess the demand isn't there.

ace37

How about the mustang FR500S? Obviously the torque and rear axle are going to be different but it's probably more similar than that Z4 GT3. Maybe the v8 supercars would be worth a look as well.

Hatzenbach

Bonus question: I just signed up for two days at the Nürburgring later this year (very excited). I am now learning the track via sim. I know that both iracing and AC have laser scanned the ring. Which one is more realistic to prepare for actually driving there?
For example: in iracing Hedwigshöhe has a nasty bump on the crest which can badly upset the car. The same bump doesn't exist in AC.
My setup is Oculus Rift and Logitech G29 by the way

ProCoach

IRacing is laser-scanned... not sure about AC.

squid42

Which variant of the ring is that? AC has the GP and Sprint layouts for the main track, 4 variants of Nordschleife and at least one user-contributed Nordschleife from before it was official. All official tracks are supposed to be laser-scanned.

I think as far as preparation is concerned the choice of simulation is probably more dependent on how the car dynamics are modeled for the particular car. Some kinds of car just work better in some computer models. If you are going in a 997.2 c4s then the problem starts with AC not having official 997 cars, at least no street variants.

Generally Porsche has been reluctant to allow themselves to be modeled in games, which lead to a flood of user-contributed 911 mods of all kinds of quality. Now that Porsche did go official they use it a bit as a marketing tool and only "sell" you the current turboed 991.2 and 718 cars plus classics, GT3 and Cup.

The user contributed mods are not really community developed like an open source software. All decisions about physics are in the hands of the original creators, which usually means 2-4 people for 3d model, physics, sound and general assembly. Some physics modelers out there are really good, the problem then being that mods are generally not clearly marked for authorship, and have no change logs.

ProCoach

In preparation for Ross Bentley and RSR's trip from NA to the Nordschleife last summer, I sold two static sim hardware setups to people who wanted to study beforehand. At the time, iRacing's Nordschleife had not yet been released, so they both started with Project CARS and then moved to iRacing when it became available. Very helpful to both folks. Here's a story on the 'Ring and Project CARS: http://www.projectcarsgame.com/home/...he-nurburgring

It was less about car modeling and more about inculcating and memorizing muscle memory as well as where to look next. Before the PC sims, the top consoles had reasonable versions, too.

Hatzenbach

In iRacing I am using "Nordschleife Industriefahrten" and in AC the track is "Nordschleife". To compare both I used the McLaren 12C GT3 as it is available in both iRacing and AC

In AC I am using track surface "Fast" (I don't think that you can control that in iRacing, but maybe I missed that). It always feels that iRacing offers way less grip than AC. But that also hold true to real life: When I drive Laguna Seca or Infineon in iRacing I am much more likely to spin as in real life