I’m a newbie to cars and I’ve neen trying to decide what my second car should be.
I see that on badges and stuff most cars hover around 1.5, but on Holden Commodores VTs I’ve seen as high as 5.7.
Does this mean commodores would destroy even a renowned performance car like the 2.5l WRX?
Veeky Forums likes to shit on the BRZ a lot, is it because it’s a 2l?
Low displacements usually are Turbo engines.
Big naturally aspirated engines are great fun but its just dumb and expensive to drive them around.
It depends on what you are looking for.
But usually a small turbo engine is all you will ever need to have fun and drive around.
Rephrase the question to how much engine displacement matters; the way you've worded it is retarded, as litres are simply a unit of engine displacement volume.
The extent to which engine litres matter is difficult because you've got bore (how wide an engine piston is) and stroke (how far it travels), which both impact the way an engine performs and its size (displacement) differently.
Similarly, you've got compression ratio, which, to simplify things, is simply about how fast the pistons move in your engine.
In modern times, because of forced induction (turbocharged and supercharged cars), high power can be achieved on quite small engines, so size is somewhat irrelevant in terms of correlation to power.
Size, does, however, matter on the intended application. Generally, as you've got a larger displacement engine, torque increases, which is why trucks and buses use giant diesel engines (diesel fuel also generally contribute to greater torque, but thats an entirely different story). Also, with all other engine variables constant, a larger sized engine will result in the engine not needing to work as hard at higher speed, which is why a lot of highway cruisers used to have big engines, this isn't really relevant today anymore with how efficient modern smaller engines are.
Don't worry about size for power. Don't get me wrong, greater displacement results in greater power and torque, but there are many ways to skin a cat. There are so many variables in an engine that contribute to power, torque, fuel efficiency and reliability that it'd be impossible for me to explain. The only people nowadays that actually give a shit about engine size are normal people that have no fucking clue: "My car is so powerful, it has a 4L engine" etc etc.
To go to your other questions, they are also complicated. Just because a car has more power does not mean it will destroy it. I would much rather a less powerful, lighter car over an overpowered piece of shit that cannot handle.
(Cont...)
The reason Veeky Forums likes to shit on the BRZ is because it is slow.
Commodores will not destroy WRXs on the merits of it having a larger or more powerful engine. That doesn't mean that a commodore can't destroy a WRX (there are many generations of either vehicle each with different performance capabilities), but to simplify it down to power is just plain stupid. Factors to consider in vehicle performance include power, braking, suspension setup, weight, delivery of power (All wheel drive results in greater traction than front or rear wheel drive) and tyre setup.
Also people shit on the BRZ because its a 2.0 with no turbos, and it feels slow for the price they are asking, but thats missing the point of the BRZ.
Its not fast in the straight line but people still enjoy it
Also to further my point that size does not matter (as your girlfriend may have told you to increase your confidence), the modern day F1 engine put out about 700hp with a 1.6L turbocharged hybrid V6. But they are much less reliable and work much harder than the modern day passenger vehicle engine.
This is what passenger vehicle engineers have to balance: power, torque, cost to produce, reliability, weight.
Large displacement vs small displacement for a given target HP is an age old argument, but assuming 300hp;
>larger engine, lower economy
>smaller engine, better economy
>larger engine will be more reliable
>larger engine will be less complex
>larger engine may be heavier
>larger engine will have more torque
>smaller engine may rev faster and higher, feeling more 'peaky'
informative posts, im my Veeky Forums?
>smaller engine, better economy
Only if you baby it. Nobody does that.
modern turbos are too boring
>tfw no gut wrenching tarbo lag turning your 150hp shitbox into a 300hp godmusheen
>Similarly, you've got compression ratio, which, to simplify things, is simply about how fast the pistons move in your engine.
That's a weird way to simplify it. Basically compression rate is simply how much the mixture is compressed before ignition. Higher compression means higher effiency and more power. I do think I understand your point, but toobeehoo I think that's just a misleading way of putting it since higher compression isn't always more revs.
if it isn't always more revs then why do you need to run a low compression for a boosted motor?
Because you don't "have" to and with a turbo you'll get more mixture in the cylinder wich increases the compression.
>Because you don't "have" to
I was under the impression that boosting even a 9.5 will blow your shit up
It might blow and it will knock for sure. A full blown race engine, like a full billet drag engine can have high conpression and be boosted.
the LT1 in the new camaro ss's runs a compression ratio of 11.5 to 1. that engine can handle up to 9psi on the stock pistons/rods/head gaskets before shit starts breaking. that being said, the LT1 is all cast internals.. the LT4 is forged.
That must run only on premium I would assume
I have to rev the shit out of my 1.5. It's fun though.
Displacement is a big factor but so is redline limit and compression. Note that horsepower is a funtion of torque by rpm This is a principle about NA engines. My old truck had about 280 ftlbs of torque with 8.5:1 compression and a 5k rpm limit out of 5. Liters. my infiniti G35 has a 3.5liter engine with almost 100 more hp than the truck but it has less torque. it has a higher compression engine and an 8k rpm limit. the higher compression helps make up for displacement and the high rpm limit helps make more power out of a smaller engine. I hope this helps
>giving advice instead of shitpoting
absolute madman
Big engines make big torque. Big torque makes big fun. Big engines turn lower rpms, need less throttle to do same work. More efficient than smaller engines for some applications up to an extent. 5-5.7 liters for a passenger vehicle, 6.5-7.5 for payload truck
It’s mostly about availability of high octane fuel. You can run a higher static compression on direct injected engines since they greatly lower in cylinder temperatures. When you start boosting engines, you have to add more fuel to maintain a stoichiometrically viable mixture, and then on top of that you have to add even more fuel to run them a little rich due to the higher pressures and temperatures. But since there is more fuel, the flame front spreads faster and the combustion happens sooner so you have to retard the ignition timing. So instead of trying to find 130 octane, you just start with a lower static compression ratio
Compression ratio has nothing to do with speed
that is correct. the stock fuel system also can't readily support >500whp.. lots of people swap in the zl1 fuel system(high and low pressure pumps).
Fact
Turbos are used more these days because of anemic as fuck engines