Questions on torque curves, ignition vs compression ect

Hello All!

I enjoy this game a ton, and often lose many many hours trying to pull that last HP out of each motor, however I do have a couple questions regarding when to use really high compression and low ignition timing or vice versa and the benefits of each method. I often find myself striking a balance between the two, using timing in the 50-65 range and adjusting compression from there to match the fuel.

This poses a couple questions for me though, if I want to move the torque curve toward the bottom, or stretch it out over a larger rpm band, how about do I do this? Sure we can use a smaller cam profile but it usually cuts top end power quite a bit, for frankly pretty small gains down low. How does changing timing and compression effect the curves? I never really notice a difference if I tune to extremes, like using 100 on timing or super high compression. I have a solid handle on the designer and have built many solid engines that are viable for the game(no insane man hours or huge costs), but I seem to lack that little extra other members do that make them that little bit better.

I specifically have issues with the quality sliders, I tend to leave them all at 0 because of how much they impact man hours. I never know when I can do a -1 or -2 to add that somewhere else. Does anyone have some basic tips on this area?

Anything we can gather here about some tips and tricks to get your engine to the next level I think would help me and the community so post what you can!


I’ve only adjusted ignition to try to smooth out the torque band, as otherwise it can have “bumps” where the engine experiences rises and falls in the curve. It might reduce performance somewhat (I haven’t looked too much into it, but if so it’s minimal), but even if it does it does makes the engines more refined.

Both timing and compression pretty much improve or harm torque across the entire rev range. The main choice that changes the torque curve the most is cam profile, for sure, though that’s always going to harm top end power.

Typically, if I’m really trying to optimize a particular engine I’ll create a spreadsheet and test ignition settings between 50 and 100 along with maximum compression before knocking. Usually I can find a “sweet spot” with optimized peak power as well as the lowest possible peak torque RPM. Generally speaking, the higher revving the engine, the more ignition timing you’ll want to run, but every engine is different. One rule of thumb I’ve found is to try an ignition setting that’s 1/100th of the peak horsepower RPM. For example, if your peak power is at 7500 RPM, try an ignition setting of 75. For some reason this seems to work pretty well in most instances.

That’s actually quite handy advice! I had vaguely noticed something similar, but didn’t know if there was an actual correlation, I kinda just lumped it in with “diminishing returns at the extreme ends of the scale”, although when I go back and look at it, all of my 10-12k rpm engines have ignition timings as high as possible, 100 in most cases.