There are two old addages about driving. They are, "smooth is fast" and "slow in, fast out". Neither of these expressions are in doubt. However, despite this the number of drivers that I see whilst sim racing who completely forget or ignore these two sayings is huge.
This is especially noticeable with "rookie" drivers and also with drivers who end up being at the back end of the field. I am not trying to be disrespectful to those "slower drivers" because without them there would be no race, pace is relative, someone has to be the quickest, whilst inevitably someone will be the slowest.
If you are one of the drivers that struggles for pace, it may well be worth trying to slow down to be faster. This sounds like a ludicrous statement but it might prove more sensible than it sounds. When you enter a corner you want to be in as much control of the car as possible. Therefore it can prove fruitful to brake early, so that you are fully in control of your vehicle, this in turn allows you to apex accurately and get on the power early to maximise straight line speed.
Unfortunately a lot of less experienced drivers seem to think that racing is about braking as late as possible. Technically it is, but not if you are out of control, miss the apex and due to understeer have to wait an age to get on the power or go in so hot that you don't make the corner. Braking isn't just about slowing the car down, you also have to think about weight/load transfer as this is a fundamental concept in understanding vehicle dynamics. By braking earlier, you allow the car to settle more than if you brake late. This helps to keep the car level or more of a stable platform for corner entry. If you brake too late, there is no time for the car to settle and this makes cornering harder than it needs to be.
If you find yourself with one of the faster drivers behind you and then magically out of nowhere they seem to gain large amounts of speed over you, try braking earlier. Their speed gain will have come from getting on the power earlier than yourself. This may come from overall talent, but a lot of the time you will find it comes down to their experience of both track and vehicle and how much earlier they have put the power down, usually from early braking and on some corners, pre-apex acceleration.
I always think that you are better off driving a couple of percentage points below your ability than driving a few above it. By being fully in control of your vehicle you will be faster than if you are constantly just over the limit of adhesion.