How does switching a car into sport mode work?
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Buckle up, this is my specialist subject.
I come from a BMW world, it’s mostly based on that, but the general rules are the same for most others.
The first most basic one was around since the 80/90’s, and that was switchable transmission programs, you often had an eco mode, change gear up as soon as you can, sports mode, hold onto lower gears for acceleration, but at the cost of a higher revving engine and less economy, and a snow/winter/manual mode. That was often either start or stay in one particular gear. You’d use this in icy weather, maybe start off in 3rd gear, nice and gentle rather than 1st gear where it would just spin the wheels and not go anywhere.
The next modes can with the introduction of electronic pedals, a control module (sometimes the main engine ECU (**E**lectronic **C**ontrol **U**nit) or sometimes a separate computer than just did the throttle. These would read the position of the pedal electronically, and then more the throttle to a position to do something.
These aren’t always 1:1, halfway on the pedal won’t always mean half open on the throttle. It’ll often do 50% on the pedal, the throttle controller will move to 70% open, and then slowly roll back to 50%, and hey-presto, your car feel sharp as a razor and super responsive.
What you didn’t realise is the car nailed the throttle to get you rolling and then backed off.
A good example – the BMW E39 M5, around 2000 model year.
These had an electronic pedal, and a Sport/Comfort button.
Comfort dulled down the pedal, so 40% on the pedal might give 32% on the throttle. Sport mode was 1:1, 60% pedal = 60% throttle.
What you see here is an engine so sharp, they had to tone it down a little for normal driving, and “Sport” mode was the raw, natural performance, which a lot of people didn’t like.
Newer cars are even smarter, the pedal requests the amount of torque you want from the engine, the engine ECU will then decide what to do to get it. Agian, pedal position is not directly linked to throttle position.
The Sport modes in these pretty much all still do the same sort of thing, they just add a modifier onto the pedal position. That’s he reason why in Sports mode, the car doesn’t have any higher power output, and you don’t see stickers in the window saying “400bhp* (sport mode only)
One exception I know of, the BMW E60 M5, this was 400bhp in the normal comfort mode, and 507bhp in Sport mode. This was done with torque limiters as far as I’m aware.
Current cars now have the Sport button linked into other stuff. It might change the dash display to different colours, tell the suspension to go into a firmer mode, maybe lower the car if if can, it’ll often do that same auto transmission thing of holding lower gears, and there’s also “show-off” stuff.
Because the manufacturers know people like these little buttons, they try to make them seem as fancy as possible. One thing they can do is tell the engine ECU to fiddle around with cam timing and ignition advance on deceleration so the car starts making pops and burbles from the exhaust. Sometimes they’ll have two different exhaust paths, one quiet one, and then an electric valve that opens out to a noisier one so the car sounds different, and ends up spitting flames out the back.
So –
1 – it rarely makes the car faster, it’ll usually just fiddle with the accelerator pedal settings so it does 10-20-30% more pedal than you wanted.
2 – it’ll also try and do anything else sporty if it can, tell the gearbox to stay low, stiffen up suspension, and pull a few gimmicks to make it sound more like a race car.
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