How to optimise your starts in ACC to jump the competition

You’ve probably had this happen at least once: you did everything right at the start, yet the person behind you is already ahead after not even a hundred meters into the race. There’s two options: he’s cheating (highly unlikely), or your starts aren’t as good as you think they are.

I personally thought that ACC’s starting procedure was clear as day, but with nearly 1200 hours ingame my experience is not your average player’s. This thread on the ACC subreddit made it clear to me many people are struggling to find the limits, since there’s some ‘wiggleroom’ Kunos left in the starting procedure in order to not be seen as overly punishing.

So, I got to work to find this wiggleroom and write another guide on it so you too can exploit the limits of the game!

This guide (which applies to all platforms) will try to explain the different factors of the starting procedure in Assetto Corsa Competizione, and how you can use this knowledge to your benefit to get the literal jump on your competitors!

Please note: this guide was written for v1.6.5. If anything changes to the starting procedure, I will either edit this guide or write a new one (depending on the scope of the changes) and put a disclaimer here.


In GT World Challenge, there is a rolling start procedure with the leading car dictating the tempo. Other cars are prohibited from overtaking before they either enter a previously indicated starting zone or if the green light is given (see point 190 on page 65 of the rulebook). For a good example of this, look at the (timestamped) video below:

Even though ACC is a simulation, it is still a game. This means there will always be someone looking to ruin the fun for someone else. That’s why Kunos developed the current system, after a couple of less succesful iterations. It allows people some degree of freedom while adherring to the spirit of the rules.

What makes Kunos’ system better over a carbon copy of the official ruleset is that it prevents the (intentional or not) mistakes of others to influence your start, while also being a forgiving to well-intentioned but less experienced players.

Phase 1

Phase one is all about positioning. Not only to your position on the grid (left or right), but especially your positioning relative to the marker. The ‘marker’ being this neat little HUD-thingy that pops up (see pictures below). You can visualize the marker as a 2D rectangle which is moving forward at ~63 kph (39 mph), and within which you need to keep your car.

The limits of this rectangle, however, do not line up perfectly with the green area in the marker, as you can see in the final picture. I will detail them all below, from left to right:

  • The first picture shows me driving too far to the right;
  • The second one shows me being too far forward;
  • The third shows me being in a good, safe spot, between the middle and front green lines;
  • The third shows the optimal position you can achieve without being too far forward.

If you are too far to the left (or right), simply move to your lane a bit more. There is no rush, you need to be in the right position only when phase one ticks over into phase two.

If you are too far forward, you could simply lift off the throttle. It is better, however, if you modulate your speed using your brakes while maintaining (or even increasing) your throttle. It is a bit harder, but using your brakes makes sure you keep putting temperature into your brakes. This means your brakes will respond better going into turn one, decreasing the braking distance. As an added bonus, brake temperature in turn heats up the tires, ensuring you have more grip going through turn one.

The difference between the third and fourth picture comes down to approximately three meters. It doesn’t sound like much, but when you do everything right, it might just mean the deciding factor in overtaking someone at the start!

I tried visualizing what this looks like using a screenshot of a recent race (the same I used for the picture up top). Each box represents the 2D-plane within which each car needs to be to not get a drive through. You can clearly see the amount of space you can gain just by optimising your positioning in phase one!

Phase 2

Phase two is about consolidation of your position. The marker makes place for a big spedometer with two speed limit signs showing a limit of 70 kph (43 mph). As with the marker before, this isn’t 100% true. But we’ll get to that later. First, let me show the spedometer:

This spedometer works great, as you can judge from a glance whether you’re going too slow (it turns yellow), have a good speed (green) or if you’re going over 70 (red).

When phase 1 ticks over into phase 2, you are probably still driving around 63 kph (if done correctly). You need to build that speed up quickly, or you’ll lose meters on your competition. You’d think.

You could also take it slow. You see: the 70kph limit isn’t a hard limit. I found that it’s an average. Your average speed needs to be below a certain treshold to not receive a drive through penalty.

This means you can go over 70 for a short amount of time without fear. What’s more, if you time it right, you can go over 70 kph exactly when the race starts as you can see in the short clip below. I don’t need to tell you that this gives you another tiny advantage if you get it just right!

An optimum trajectory would be an average just below the upper treshold (i.e. possibly 70kph). However, make sure you aren’t going 75 kph (46 mph) or over when the lights turn green: in one of my test runs I got a drive through for going 75.2 kph. This leads me to believe that (next to checking for your average speed in phase two), the game does a final check on your top speed at the exact moment the lights turn green.

Below you can see an example of how to, ideally, tackle phase two. First, you’d slowly build speed to somewhere around 70 kph. Then, with a little dab of the brakes you lose the speed again to secure your average isn’t over the treshold. When the time is right and when you are sure your average speed isn’t too high, go a little bit over 70, but keep it just below 75 kph.


  • In phase one, be as close to the limit as you can be without going over. Preferably, have your front bumper overlapping the top green bar while going 63 kph to maintain your position.
  • In phase two, keep your average below 70 kph, but go a little bit above 70 right before the lights turn green (but keep it below 75!).

Ultimately, reaction speed is 50% when the lights turn green. But, you can help the odds in your favor by adherring to these tips!

Keep in mind though: optimise at your own risk. I’ve shown you the limit, I won’t be held accountable if you go over them in your league race!

Also keep in mind that my findings might not be 100% correct, since I have no idea about the actual variables being used, so read this with a grain of salt. I am confident though in that my underlying assumptions in how the systems function, combined with rigorous testing in a private server, I am at least close to being correct.

You may also like...

2 Responses

  1. Anonymous says:

    Great read bud

  1. December 16, 2020

    […] Read my extensive guide on how to optimize your starts by following this link! […]

Please, let me know what you think!