Two-Stroke Race V4 - The Parts Catalog

Two-Stroke Race V4
by derpturtle

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True two-stroke (2-stroke) 1352cc 90-degree V4 (4-cyl) engine with a 180-degree crankshaft and shared crankpins (1+3, 2+4). Uses custom camshaft lobe profiles to simulate two-stroke aspiration and features individual throttle bodies (ITBs). This high-revving sim motor redlines at 12,000 rpm.

Runs and idles the best of any published two-stroke sim motor I've come across, but tuning while maintaining stability can be tricky. The formula used for deriving the custom two-stroke camshaft profile is provided in the script.

Firing order 1-90*-3-90*-2-90*-4-90*

[Edit 12/16] Leaned out AFR slightly and made sure the custom impulse response works.

[Edit 1/23] Changed impulse response to default to make it easy to run for people with no coding experience/incomplete sound file library.

main.mr

import "engine_sim.mr"
import "themes/default.mr"
import "engines/derpturtle/2stroke-v4.mr"

use_default_theme()

main()