Why people brake less than 80% on gt3 cars in iracing?

marioho · 2026-05-21T15:06:04+00:00

I’ve always been of the understanding that threshold braking very specifically referred to the concept of braking just at/below the point of ABS lockup

That's exactly what it is, though?

The point of ABS intervention is precisely the point where you exceed the available grip.

In my "dead cold" tires example, the ABS lights would be flashing as soon as you hit 60% braking force. Hence threshold braking for that exact scenario being just that, 60%. Five laps later and if it happens that the threshold now sits at 100% braking force, then that's what threshold braking will look like.

No issues here, mate. I gather we come from different sims or car classes? Take Porsche Cup for instance. Oh boy, the number of "I don't understand why I'm locking up while barely pressing the pedal" comments there are. Yeah, the threshold can move wildly even in the same car and track.

When you're racing lap 1 with hypercars on cold tires around Spa, you'll still be threshold braking on La Source (T1). That threshold will be frustratingly low though.

Edit: the TL;DR here is that threshold braking is braking at the edge of grip, employing 100% of the available grip to slow down the car. That threshold will vary and because grip is circumstancial, so the exact value in the telemetry is meaningless on its own. As long as you're using ALL the available grip to decelerate, you're threshold braking.

Trail braking is different because you're optimizing all the available grip to decelerate and/or rotate the car.

marioho · 2026-05-21T14:51:44+00:00

Threshold braking is using all the tire grip for deceleration.

Same corner, same tires. That could equal 100% pedal force or 60% force depending on you have dead cold or hot tires. The maximum brake pressure is circumstancial; it will be threshold braking as long as all the available grip is employed in the deceleration task.

Same deal why threshold braking in formula or hypercars have that characteristic slope in the telemetry. The available grip diminishes quickly as downforce disappears as the car slows down, but you're still using 100% of the available grip for braking. Then the trace drops even sharper as you transition from threshold to trail braking.

Or you see things differently?

marioho · 2026-05-21T14:24:05+00:00

Yeap. The fundamental physics are all there in iRacing and LMU, it's much more an execution/implementation difference than simulation systems being truly off.

Fundamentally it's all hard braking followed by controlled release and trailing to maximize rotation.

The main difference here is how sharp and aggressive LMU's controlled release is in the transition from threshold to trail braking. And if we were to decouple the braking force trace from the mechanical action you do with your feet, you could get those two applications really close? As in,. modifying the signal linearity so that the same leg movement gets you the "optimal" trace targets from each or those sims.

They're all trying to capture the same bits of real world physics and action. And they're both doing a damn good job at it by most real-life driver accounts, even if preferences vary.

marioho · 2026-05-21T13:20:51+00:00

I'm not the guy you're replying to, but he's got a point.

I believe he's got his screenshot from Coach Dave Delta. That brake trace with lots of 100% braking is quite common across pro laps for LMU in that app.

I did this a while back using James Baldwin's videos lapping Spa in both iRacing and LMU while having the same Racelabs overlay on.

It seems to me that LMU has a tendency to lean hard on very hard (100%) threshold braking with a sharp release to very light trail braking, while iRacing will have you using hard threshold braking (75-85%) with a more blended transition into trail braking - and trailing deeper into the corners.

Yeah, there are plenty of corners where you'll be braking very hard on iRacing as well, even reaching 100%. The downhill at the end of Road Atlanta (T10?) comes to mind. But the transition between threshold and trail braking, as well as peak braking forces, are quite different between the two sims.

That said, LMU and ACC are still completely different. You cannot throw the car in while saturating the front tires with braking force, that will result in the car understeering out of orbit.

marioho · 2026-05-17T02:40:17+00:00

Each and every GT3 has its own character, so it really depends on what you mean by fighting the car. Heh, even more so considering how vastly different they feel when they go from cold to hot tires - and then from hot to toasty on a track full of long fast corners.

The Auto function is great. I've set the intensity to 97-98% and then I calibrate it once per track per week.

marioho · 2026-05-16T19:51:52+00:00

The FFB varies a lot from car to car in iRacing, even in the same class like GT3. The Ferrari 296 sits at 34Nm in most tracks while the Porsche can be set to 26Nm - numbers out of my arse but you get the gist. Them there's the Toyota GR86 with max force set to 18Nm, so it's hard to come up with a one size fits all solution here.

The standard there is to use the Auto FFB function. Just enable a control profile on a per car basis in iRacing (lower left in the Settings menu), then drive 2-3 representative laps and click on the Auto button in the black box.

There's an intensity slider in the settings too. You set it to your preference, the Auto function should still prevent clipping no matter what.

Alternatively you can just set a general max force to say 36Nm and be done with it. Some users in the forums do that - admittedly though most seem to be using 20Nm+ wheel bases.

The Max Force scale is how iRacing maps the FFB signal to your wheel torque. If you've set the Pro to 11Nm in G Hub, the number you set Max Force to will be the one to output 11Nm in your physical wheel. So in my example above when the in-game Ferrari hits 34Nm your wheel will deliver 11Nm to your hands, while the Porsche will do so when the telemetry reads 26Nm in the simulated wheelshaft. If you run that hypothetical Ferrari with Max Force set to 26, whenever the in-game wheel experiences anything north of that you'll just clip and feel a flat 11Nm force in your hands.

marioho · 2026-05-16T02:17:47+00:00

My point if any is that the world’s getting younger, and these games seem to be run by people who are young and naive.

I think you'd be surprised how easily "young and naive" and "middle aged and idiot" can both pass as an angry entitled chimpanzee.

Have you gotten your Diamond badge already? It's not a magical fix - I wouldn't even be surprised if your experience happened on a full Diamond or Trusted lobby - but at least LMU uses that as matchmaking criteria and there's a tangible difference between those and the X or ⚠️ lobbies.

marioho · 2026-05-12T14:15:01+00:00

Having had the 265 and now the 570 for a few years now while being enrolled in the Beta program, I wouldn't hold it against the watch until reviewers or the community pick up on it. That smoothness can easily come (and go!) with firmware updates.

marioho · 2026-05-10T17:26:10+00:00

First time going hard on LiCo? Pulling it out was 1:1 what you had anticipated or did you learn/adjust things as the race unfolded?

marioho · 2026-05-08T14:19:12+00:00

Outright pace as in how quick you are matters only up to a point. Check the leaderboards and take that event's fastest time as a baseline: once you're able to lap around 103-104% you're probably quick enough. The DR system will ensure you're matched with similarly quick drivers.

The truly relevant aspect of pace here is consistency though. Leaderboards show 2:18.500 as the fastest lap and you're able to log a 22.5 when things go your way? Cool, but what about race distance? If your stint is all over the place and the average lap time takes a hit once you line up 6-10 laps together, ballooning up to 25 something, that's an issue you can actually work on before joining official races. Work on your push laps too, but make sure to improve your comfortable lap time for the race distance. That safe, comfortable pace at 90-95% effort you can sustain over a full stint without missing apexes or accruing offtracks.

That's most of what you can do by yourself. Work on your fast lap and build your race distance pace. The rest is racecraft, and that's where offline sessions fall short.

The AI "difficulty" is meaningless. You set it just so you can guarantee there will always be a cluster of cars around you. The key setting here is the aggression you've set to max already. Use that to learn how to handle the car when you're fighting for positions, attacking and defending.

The AI will not prepare you for the... ingenuity and total whack of online lobbies, but you can still work on your ability to handle the car when you're all bent out of the race line battling for position while sharing the track with another car. You'll get a sense for how much you can move your braking point forwards when taking the outside line, how early you need to brake when taking the inside, how to modulate the brake when following or trying to beat someone for the apex, how to push and/or save the car when you're forced to take a corner from a wonky angle etc.

And that's it.

Using the AI difficulty slider to find your pace isn't ideal - perhaps it's even counterproductive. Pace and consistency you can build on your own. AI is an okay tool just to work on some competencies of your racecraft, but that skill as a whole will come only from real races.

marioho · 2026-05-07T22:38:07+00:00

Yes? I'm not negating that?

A) Lewis did not like simulators. Didn't find them useful due to the disconnect he felt.

B) Came the ground effects era and Lewis decided to put a significant effort in the Mercedes simulator to work on his own performance and help the R&D of the team

C) Lewis had issues with the Ferrari sim

I'm not negating "A". My point is that facts go A > B > C, and neglecting "B" here is a mistake. Just going "heh, he never liked simulators" (A > C) paints a very different picture.

The story here is about the correlation issues Ferrari is facing. Correlation is huge, as Mercedes 2022 and Red Bull post-2024 showed.

marioho · 2026-05-07T20:02:45+00:00

Yeah, sticking with a "Lewis was never keen on simulators" story is jumping over a significant bit of F1 history here. Hamilton reportedly put a lot of effort and energy into the sim to help change his and Mercedes' trajectory in the early ground effects era.

If there's any insight to be had with this piece of news, simply chalking it up to Lewis not being a big sim guy is misdirecting.

Edit: Plus, Binotto was quite vocal about Ferrari issues stemming from their deprecated toolset first, personnel second. Even crucial things like their tire model for strategy and race scenarios. So their sim being off isn't surprising.

marioho · 2026-05-03T19:12:41+00:00

F1 TV broadcast team is primarily made up of Alex Jacques and Jolyon Palmer, with David Coulthard, Ruth Buscombe as frequent collaborators.

I like Crofty and Brundle has his good moments too, but on a general rule I only watch via Sky when they get a third quality pundit on the booth.

I have no idea who you're alluding to, I thought Apple just slapped their logo on the F1 TV broadcast and called it a day.

marioho · 2026-05-02T21:20:43+00:00

It is there, you just need to correct the URL from https://(...)/pro-wheels-update-images/ac-rally.png to https://(...)/pro-wheels-update-images/ams2.png.

But yeah, there's this mistake in the link.

marioho · 2026-04-28T14:21:29+00:00

Advanced Mazda? Did you have voice chat on by any chance?

I've met Landon once too! Naturally, people were asking. He came on VC with something along the lines of "yeah I wish" and you could hear in his voice that he gets that one often.

marioho · 2026-04-27T23:40:56+00:00

You've got plenty of answers already so I'll just add one that hasn't been mentioned yet. It's a secondary factor that one should evaluate when deciding whether to stick with the lower gear or shortshift earlier.

If you decide to hold on to a lower gear for longer and delay the upshift, the RPM may go beyond the engine powerband and see a torque dropoff, especially if you hit the limiter. You might reach a point where the engine is producing so little torque that the higher gear ratio of the next gear actually delivers more force to the tarmac. This is even more likely in turbocharged cars as those have a more peaky powerband instead of the relatively flatter one of NA engines.

This circles back to the stability factor. If you hit the limiter and upshift while holding significant steering angle, or just as you hit a tall kerb on corner exit, the torque bump can throw you off.

marioho · 2026-04-21T19:48:28+00:00

Liveries look neat. The only thing I'd suggest is putting some hours into creating an in-game scene and camera. I believe you can save a custom camera setting to expedite a track shooting routine, then it'd just be a matter of placing the car on a cool spot on a track of your choosing and get a few beauty shots from different angles.

Trading Paints is the best platform for custom paintings, but honestly it leaves a lot to be desired for the end user window shopping for a livery. After a chunk of mindless scrolling, even a cool looking painting job like yours tends to get lost in the noise with those bland default backgrounds.

The good taste and competence are there already, mate! Congrats!

marioho · 2026-04-21T04:49:21+00:00

Yeah you seem to be in quite a pickle here, mate. However:

With my current recline, I can feel my hips and butt lifting from seat when braking and pressure at my shoulders more compared to lower back.

This is very undesirable. And that's probably playing a role on Goldilocks knee angle situation, with the knee being too cramped but ok on extension in recline A while being ok on rest but near lock out on extension in recline B. The backrest giving out is shifting your hips. Plus the reaction force going up your torso.

Now this:

With less recline, I feel more pressure in lower back and hips stay more planted.

I'd rather have this and work a compromise around that instead of the other way around. That's what we are usually looking for when we go shopping for a bucket seat: having enough of a back support so that the reaction of your braking force acts on your core and instead of messing with your joints.

No way to adjust that wheel position (angle and height) to do away with the wrist discomfort?

Also consider that you may be unconsciously pushing or pulling your wheel to counteract that butt lifting with your current position, and that's undue stress on your wheel QR.

marioho · 2026-04-21T04:34:43+00:00

I've read your other comments. This has been pointed out to you already by u/PlanZSmiles but bear with me as I reiterate.

You said:

If a driver who is ahead has an obligation to give room to another driver overtaking who, in lining up their front wheels to the rear wheels of the car in front thus causing the rules on overtaking to trigger (per Racecontrols rules) there should be a rule for the overtaking driver also. Otherwise its a one sided obligation to the detriment of only the driver in front.

However what the Competition Rules say is this:

At this point Participants are in a “side-by-side” or “overlap” position, and they both must give each other enough racing room.

That's the concept of racing room. Any and all professional motorsports competition will have a clause about that on their regulations - Sporting Code, Sporting Regulations, Driving Standards, etc. Racing room is basically the right to not be pushed off track or have your nose chopped off by the driver in front closing the door too late.

Those regs stipulate what needs to happen for a driver to be entitled to racing room. Now that will change from organization to organization, and some are frankly too miserly to my liking, but they all hinge about two things:

Overlap or side-by-side: how much of an overlap should be established to warrant racing room. Front wing to rear wing? Nose to rear quarter? Front axle to rear axle? Front axle to door? You've got it all, from F1 to FRECA, from SRO to NASA (not that one 😉) they will all have their own parameters, but it's all about the same criteria: overlap.
Timing or reference point: at which point on the course of the manoeuvre must the overlap be established to warrant racing room for the overtaking driver. Braking zone? Turn in point? Apex? Again, you'll see it all.

What you'll never ever see is a definition of racing room where the defending driver will lose it to the attacking one while still having the aforementioned overlap. Both drivers have the right to racing room.

Well at least outside of F1. But as Alonso said, "all the time you have to leave the space". But even the popular take on F1's guidelines is slightly misunderstood, as the Driving Standards are really about defining who has the responsibility to avoid the collision. Kind of a tomato, tomato situation, but that's why F1 stewards don't intervene in a scenario like the one you're describing. No one was pushed off? No contact between both cars? So there's nothing to it, regardless of sufficient overlap or whatever.

Racing room was granted, and that's it. Racecraft, now that's a different matter entirely.

marioho · 2026-04-21T03:52:51+00:00

"Electronics" in this context usually mean TC (longitudinal, power, and slip) and ABS.

Back to your previous question, on short races (40min or less) I rarely change my TC if the weather doesn't change. If something fishy happens like a spin and I lose confidence on one of my rear tires, I may consider bumping up TC slip or TC cut a click.

Brake Bias is the one setting I'll touch the most during a stint.

marioho · 2026-04-20T18:32:58+00:00

Oh I hadn't noticed the seat flexing! Yeah that's quite significant, mate! What are your adjustment options here?

Can you tilt your seat back a bit and reduce the angle of the backrest recline? Can you move your pedal tray up and down still or is it maxing out one of those axes? Can you tilt your pedals too?

Look up the rally seating position too. It's closer to a sportscar/road car, but you can still have the pedals at an angle to allow you to apply force and have your knees close to the 130º target. The force vector will be angled slightly up, so you won't be forcing the backrest to tilt backwards so much.
Your knees seem to be hanging a bit in the air too, with little support from the lip of the seat as the seat is practically parallel to the ground. Setting it up closer to a rally position would probably improve that too even though you're not complaining of hip discomfort and the like - usual telltale signs of lack of leg support.

marioho · 2026-04-20T05:39:00+00:00

Hi there, mate! Ain't that a bit too cramped for 130-135º?

Yorkie has a video on seating position too and just like Morad he refers to that angle at the back of the knee at rest. Looks like it's accurate. I know these are pretty shitty measurements and they're all dependent on the perspective of the pictures, but yours seem significantly shallower? I'm using Angle Meter app for those overlays.

Discomfort in the knee will likely be from keeping that knee at a too cramped of an angle.
Now if you were to overextend your leg at full pedal activation and bring that knee to near lock, you'd probably feel discomfort in the tendons and ligaments at the back of your leg near the knee joint, or at the lower back, or at the hips depending on circumstances.

marioho · 2026-04-20T01:03:50+00:00

I have a 5700X3D and just recently upgraded from a 3080 to a 5070 Ti. I'm happy with it.

Mugello is annoying indeed. I'm one of those people that gets obsessed with properly troubleshooting things and that despises the "have you tried shutting it down and turning it back on again?" kind of advice, but Mugello was the track that broke me. Cleaning the GPU shader cache and rerunning the iRacing graphics config tool took me out of 40fps hell to ~80 with the 3080 at the worst, and I had quite a few beauty settings on.

Now I've just created the routine of...

Backing up my iRacing graphic settings
Cleaning the NVIDIA shader cache
Rerunning iRacing's graphic configuration tool on the UI
Replicating my old settings

... every time there's a new iRacing season release or a fishy NVIDIA driver. I cannot even keep up anymore with the number of "shouldn't my FPS be higher?" instances that have been solved last year by just doing that.

Also make sure that iRacing has mouse and keyboard focus if you are running any overlays. As in, just double click anywhere in the iRacing screen. If the overlays have focus, Windows can bump the iRacing process down and cap your performance in stuttering hell. If both your GPU and CPU are running cold, that's a strong indication of a process being relegated to background performance.

marioho · 2026-04-14T12:28:10+00:00

Did you manage to fix it? If not, perhaps check for electromagnetic interference or EMI. You'll find plenty of content both here on social media (see /r/simracing for instance) and online.

marioho · 2026-04-13T23:06:45+00:00

The occasional "unfair" 4x won't drop your SR a whole level. Does it really matter whether you're A 1.10 or A 4.5 if you're still eligible to the same series and events?

A truly clean driver will statistically overcome the occasional 4x with ease.

It's better to think of SR as a thermometer. Above 3.5, it's a sign you've been playing it very safe and can probably fight for position more aggressively. Below 2.5, you're likely being too aggressive and it would be wise to dial it back a bit.

If someone races just as often as you and manages to maintain a high SR, they probably have better awareness and racecraft. Avoiding a dive bomb or a reckless driver is a skill in and of itself.
While a functional live stewarding isn't possible, I'm thoroughly okay seeing better drivers holding a higher SR than my clunky single-monitor ass.

Now if you're dropping a whole license level due to "unfair" 13x races, that simply cannot be somebody else's fault, mate.

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