If i am posting this in the wrong board, please correct me. I've noticed quite a lot of small details in BeamNG that doesn't make sense, specially in the engine department. Things like the way that for a bigger turbo you need a heavier flywheel, or how with a turbo the low end torque doesn't decrease, or how exhaust/transmission dont affect performance, how the game mixes forced induction with fuel feeding or how all cars behave like if they were fuel injected, even if they are not. Does the dev team need someone to talk about related to these things? Or at least do they acknowledge these issues and have them in the "to-do" list? because if not, i would be happy to correct any issue that i see about the engines in the game behaving unrealistically. (i am a mechanic in case there is still any doubt)
nor does a real turbo, particularly with most factory turbos on modern engines still producing some (though insignificant) boost at idle. Hell I've just spent some time looking up dyno charts for engines before and after turbocharging, not one has lost torque, every single one has gained torque from idle, even if only by a negligible amount, they've gained it.
If they have a very small turbo to work at idle, maybe. Turbos require lowered compression, and that means that until the turbo spools up its not gonna produce power, and you've got a "natural aspirated" engine with the turbo slightly blocking the intake entrance and lowered compression. Are you sure that you weren't checking the dynos of car with very small turbos, twin turbos, or turbo-superchargeds? Well, other than what i posted in the OP, there would be small things, like having the turbo be able to break due to different effects, and have the turbo damage constantly if there is no oil to cool it down nor lubricate it. Other than that i guess that what i really find annoying in the game is that there aren't too many ways to increase power. Having a different exhaust or no exhaust at all wont increase power (since they would restrict air flow less), there is no backfire, not even on turbocharged cars with custom high air flow exhausts (i would love to see how the game works with backfires tho, it would look amazing!). And maybe you can find a way to implement some sort of VTEC/VVT copycat for the hirochis and ibishus? in real life, they use oil pressure to modify the opening and closing timing of the intake and exhaust cams, allowing for higher high-end RPM (not that it would make a gigantic difference on a SOHC car), but if not, a new modification option that could be nice would be to allow you to change the individual camshafts, that way you can replace them for high-end ones (high-end power, maybe terrible idle balancing, making the car shake too much on idle, or turn off) or low end power (which increases low end torque, and in some cases, if not all, help with the fuel economy). Then there could be things like having the ability to replace the head gasket to increase/decrease compression (increased compression results in higher power overall, but if its a turbo, specially without intercooler, the air usually gets too hot and all turbo engines will have to reduce compression, resulting in lower low end power and the turbo still adding more high end power when it spins up). And a side-reason to change compression would be to have different types of fuel (higher octane/racing/expensive fuel would allow for higher compression than not, even with a turbo). Other than that there are things that could be added later, like changing spark plugs to have a better ignition, increased stroke to have better displacement and compression at the same time, maybe drilling the engine to increase bore, setting up mechanical pieces as electric (such as modern cars having electrical oil pumps, to have an oil pressure independent from the engine RPM and have the engine loss a little bit less HP to it), changing carburetors to fuel injection to decrease fuel consumption (as i specified earlier in the OP, carburetors will always drain fuel, even when the throttle is not held and the RPM are not at idle, since the carb will always react as if the car is at idle, while the fuel injector realizes through ECU that the car isn't accelerating and at higher RPM than idle so it shuts the fuel injection off, and since they atomize the fuel better it can reach slightly higher compression, and due to the force they are injected, maybe slightly higher power, and direct fuel injections could help to that even more, but these engines have to be made with those things in mind, and cannot be changed for a carburetor) And maybe modifying the ECU to change the air/fuel mix to increase efficiency or power, and modifying the time at which the spark plug works to, also, modify efficiency or power at certain RPM. Last thing i remember that i found quite weird is how SOHC/DOCH changes the idle RPM and the redline. It SHOULD change the redline and it should allow for better intake, resulting in higher power, and some people still discuss wether DOHC increases or decreases efficiency, however, having a DOHC would not increase or decrease the idle RPM at all. Also, it would be nice to have other options to make ways to increase the redline RPM, like replacing the crankshaft, connecting rods, and pistons to stronger ones, having a high revving cylinder head and camshafts, like i stated before, to support better high revs (if you watched initial D you would know what i mean) and the such. As a last detail since i dont want to bore you to death, old cars, without ECUs, things like the Ibishu Miramar, the moonhawk, and the Barstow, dont seem to be from the time in which the ECU was introduced, so its very likely that they shouldn't have a revlimiter either (since the ECU makes the rev limiter) While the Civetta, from a similar time, is more likely to have it, since its an european supercar instead of an american big engine sedan. Of course, revving over the only-graphical redline on old cars to excess could result in the engine blowing up. That's all i remember that the game is missing.................... Yet.
VVT/VTEC is usually a "fixed" system, ie, the amount of timing advance is determined purely by RPM, same RPM, same timing advance every time. As such, the effects of it can already be accounted for in the games torque curve. As for small turbos. 2.5l engine with single turbo at 16psi peak small enough for you? Yes a turbo is blocking the intake tract and typically has lower compression, but, the turbo also isnt stationary within the intake tract. Exhaust gas is spooling through even at idle, its not going to make 16psi from get go, more like 1psi if you're lucky. But it will still be actively pumping air through. Stomp into it, even at low rpm there will still be enough boost to overcome the reduction in compression. Twin turbocharging isnt actually any better than single turbocharging, thats a very common myth. While yes you have 2 turbos and therefore you'd think twice the boost, or each individual turbine weighing less and therefore being more responsive, that doesnt account for each turbo only having half the exhaust gas flow. There are only 3 reasons to go twin turbo, those are sequential turbocharging which is pretty damn rare considering you run a much higher risk of detonation unless you can get 2 large intercoolers in there, usually more efficient to achieve the same boost from a single turbo. Or packaging concerns, alot easier to plumb 2 smaller turbos onto a v8 than 1 larger turbo (also applies to the rb26dett and 2jz, was determined easier to mount and keep 2 turbochargers cool than squeeze one larger turbo in the space available). Cool factor. Actual performance benefits versus a single, none.
I have to say i'm very excited by what i read and then imagine what could be the game with all of those improvments. agressive camshafts with very bad idle, not only made with a custom sound but a real effect on the engine and behaviour, that sounds really great !
You are kinda correct but not 100% correct. If a VVT/Vtec system is implemented as a car, then the point would be that oil pressure and the moment at which the system kicks in would change, and a car starved of oil would see itself withou that feature. And the point about at what power the turbo starts to give more power than in the low torque N/A i think it depends on what RPM idle we are talking about and we are getting kinda mixed up. On most turbos ive seen, specially on small cars, it wont start spinning up until it reaches around 3k RPM and it wont fully work at until 4.5K or 5K. Of course, some engines can be tuned to produce more power at idle. And while you are right, having a small turbo in front of the big one will drain some power since when at high speeds the small turbo slows the intake down (after the big one its working) this effect its not THAT big, and for racing purposes having low turbo lag with a smaller turbo can be quite essential (maybe a future feature? to add more than 1 turbo? to go crazy and use 1 turbo per cylinder?). Sequential turbocharging (just so we are clear, using the same turbo twice, one after the other) hasn't been seen much after most air forces swapped piston-engines for jets. Then again, there is the concept of having two turbos, the small one and the big one, with their own individual intake, having their forced air pipes become one that feeds the entire engine. This at first sounds cool, and it might be the bi-turbo concept with the least turbolag and least turbo draw, but there is also the issue about having the intake air of the smaller turbo be forced into the intake of the bigger turbo (until the big one also forces pressure inside, but then the big one would also be throwing forced air into the place where the small turbo was throwing air before, so it gets messy since we've got a Y-shaped pipe connection in which 2 of them, at different pressure, has to feed air to the engine.
