How can I get more power out of this I4 2.0L engine without sacrificing too much cost/mileage?

Car in question:

Only 90hp where a 2004 Ford Focus would have at least 110, any easy way to improve this? Let me know if more details are needed.

At first glance your compression looks way too low for a modern naturally aspirated engine. In general a car like that would run on 95RON fuel so unless you really messed up some of the other sliders (or have ridiculously low negative quality set) you should have more than enough to spare.

I suggest you take a look at the scenarios to help you build more efficient engines.

(Also, give that car bigger wheels, please.)

Okay that helped a bit, thanks! Up to 103hp now, I just chose 91 regular because I figured you’d use that for a standard family car. I was able to get the compression up a bit without sacrificing too much efficiency. I played through all the A and B tutorials. I found them to be a lot of information to retain and a bit mundane to work through, I’ll have to go through the rest eventually.

As a rule of thumb: try 10.0 compression, small turbine, bigger AFR (around 1) and from there play with the boost and ignition timing to make the engine not knock. It’ll also have a good side effect, reducing turbo lag

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You sir, have made a 1980s engine. A modern I4 would be utilizing an aluminium alloy SOHC or DOHC cylinder head with four valves per cylinder, maybe VVT and definetely Multiport injection. Just applying those will improve power and efficiency and enable you to raise the compression ratio and timing which again improve power and efficiency further.


I guess that’s what I get for trying to be cheap lol. Awildgermanappears’ advice did wonders, thanks! At least this ended up being a good lesson to use modern stuff.

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Even Dacia is more advanced than your first idea, hold your horses in being cheap :smile:

Also ladder is a big NOPE for any hatchback after about 70s, and that’s including commie stuff. 4 speed auto would be ok in the 90s, but for 2004 it’s a bit outdated (but I guess still could exist in a cheap car). On the other hand DW suspension all around is unnecessarily raising the cost - McPherson front and semi trailing arm or even torsion bar rear would be much more realistic and reasonable for that kind of car.


So, to start, I would recommend almost always using DOHC, as from what I have noticed, it will almost always result in a more desirable engine.
I would also recommend using AlSi material to make the engine block and head out of.

To start:

Set the compression at minimum, and put the cam profile at 35.
35 is ideal for most economy engines, 64 for most sport, and 91 -100 for racing engines.

Use standard air filter, and set the fuel mixture to be as lean as possible,
Then set the ignition timing to be at 100 and revs to max for now.

Use a short cast exhaust, and dual reverse flow mufflers.
Also set exhaust size to max for now.

This is how I start most of my engines.


Increase compression until it starts knocking, and then lower ignition timing until it’s no longer knocking.
Hold the engine.
Increase compression by one tick and lower ignition timing until it stocks knocking.
Compare to held engine, and if it’s better, hold it.
Repeat until it no longer increase performance or efficiency, and then revert to where it peaked.

Next, reduce exhaust diameter to where it reaches peak performance.
If you want it to be more efficient, reduce the exhaust an extra tick, and you might have to reducing ignition timing again so it doesn’t knock.

Finally, reduce the max rpm until it starts reducing performance.

This is the short and general guise of how I tune NA engines

If you want I can take a look at your car and make some more specific recommendations


use AHS Steel Unibody Construction/Monocoque instead of Steel Ladder (unless your car company wants to make cheap cars for some 3rd world countries with rather poor road maintenance like where i live, then Corrosion Resistant Steel Ladder is viable)

oops, sorry for bumping old threads


Also why revive this thread?

something’s just get over my head lol

…and about body on frame still being used in “some 3rd world countries” :
that’s (probably) a 2012 model Toyota Wigo/Agya/Daihatsu Ayla

I’d rather say that it is a Lotus chassis, maybe from an Europa. As far as you can get from a modern small economy hatchback.

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I live in “some 3rd world countries”, and I can assure you that the Agya does not have body-on-frame construction. Only the larger pickup trucks and SUVs use it to some extent.

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For any mid-'00s FWD hatch, a transversely mounted engine would make a lot more sense… it’s more space-efficient and cheaper to build and engineer.

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