Because the ard part of maing a car with engine is to make the engine fast and strong. If you increase frequency you get more power, which is pretty much frowned upon. It's like on a spring engine, you've got a slider that if you increase, the power increases. It's too easy!
Try to make a strong engine at 100 Hz or 150 in the most desperate case!
You should redo the speedometer, because the bus can get to 200 Km/H. But it's good!
P.S: forget my bus. i'm VERY angry with algodoo because it got out of memory and crashed, so most of my work is lost.
Also if you increase the frequency you're getting more juice from the engine "for free". I don't like that, because actually the challenging part of moving 13 tons with just spawning pretty light balls is making the engine work with a decent weight and size, in a hard frequency like 100 Hz (the old default). That's enough in most cases
It's much better to spawn ONE big ball that fits in the entire cylinder block. Also try to use a box for the cylinder instead of a polygon (if you want, make the box transparent and leave the polygon in front)
I always bother with the same things just because noone cares about them. one of those are frequency, which in your scene is pretty high!
You can make a gun to fire and extract with 100 or 150 Hz. I don't have much practice on guns as I've made four or five but the secret is trying to refine the mechanisms!
Also why the scçhell is ejected forwards? That seems weird for me
It doesn't really "work" at 150 Hz. I mean this because most people doesn't care about if the round spins after it gets out of the muzzle, but yes if they have got lag.
A solution for the round and empty shell getting shot back from the cahmber is the too insane strenght the spring has.
The main problem of increasing frequency is lag, as you may know
Don't be so mean Kilinich. he's starting here
Looks more than epic from my point of view. really, it has a good acceleration, goes fast and has a nice gearbox
P.S That must be the best engine type you can do. I've done one that is pretty similar (Fiat Bravo's) and worked that well too! And if you change damping to the springs, you can make a nicer idle mode without lowering so much the balls' weight.