I have an issue where my vehicle will do very heavy (0.8G) engine braking if the throttle is not pressed down, rendering the car practically undriveable. How do I lessen the engine braking? Steps I have tried: Setting the inertia of the engine very high (0.95-1.0). This reduced engine braking slightly but was still persistent. Plus it made the engine behave in other unwanted ways. Messing with friction values. This seemed to not affect engine braking. Changing brakingCoefRPS. This seemed to affect nothing as well. Reducing Clutch Torque. This eliminated engine braking but made the engine unusable as there wasn't enough clutch torque to drive the engine. Here are the relevant jeams: Engine: Code: "sunburst_engine_5.0": { "information":{ "authors":"Spaceballs the Username", "name":"5.0L V8 Engine Block", } "slotType" : "sunburst_engine", "slots": [ ["type", "default", "description"] ["sunburst_exhaust_I4","sunburst_exhaust_I4", "Exhaust"], ["sunburst_transmission3","sunburst_transmission_7DCT", "Transmission"], ["sunburst_enginetuning3","sunburst_v8_tt", "Engine Config"], ], "flexbodies": [ ["mesh", "[group]:", "nonFlexMaterials"], ["sunburst_engine", ["sunburst_engine","sunburst_transmission"]], ["sunburst_radiator", ["sunburst_body", "sunburst_rad", "sunburst_engine_bay"]], ], "enginetorque":[ ["rpm", "torque"] [0, 0], [500, 0], [1750, 0], [2000, 0], [2500, 0], [3000, 0], [3500, 0], [4000, 0], [4500, 0], [5000, 0], [5500, 0], [6000, 0], [6500, 0], [7000, 0], [7500, 0], [8000, 0], ], "engine":{ "idleRPM":1800, "shiftDownRPM":5000, "shiftUpRPM":7870, "maxRPM":7990, "soundGroup":"v8_perf" "inertia":0.080, "clutchTorque":250 "friction":13 "brakingCoefRPS":0.15 "burnEfficiency":0.27 "throttleSensitivity":0.9 "torqueReactionNodes:":["e1r","e2r","e4l"] }, ... Configuration: Code: "sunburst_v8_tt": { "information":{ "authors":"Spaceballs the Username", "name":"Twin Turbo V8", } "slotType" : "sunburst_enginetuning3", "flexbodies": [ ["mesh", "[group]:", "nonFlexMaterials"], ["sunburst_turbo", ["sunburst_engine"]], ["sunburst_intercooler", ["sunburst_engine_bay"]], ], "enginetorque":[ ["rpm", "torque"] [0, 0], [500, 932], [1750, 1004], [2000, 1023], [2500, 1156], [3000, 1189], [3500, 1258], [4000, 1301], [4500, 1363], [5000, 1426], [5500, 1604], [6000, 1771], [6500, 1944], [7000, 2030], [7500, 2088], [8000, 1944], ], "engine":{ "idleRPM":1800, "inertia":0.05, "clutchTorque":2400 "friction":1 }, ... Transmission: Code: "sunburst_transmission_7DCT": { "information":{ "authors":"Spaceballs the Username", "name":"7-Speed Dual-Clutch Transmission", } "engine":{ "transmissionType":"manual", "dct":true "lowShiftDownRPM":2250, "lowShiftUpRPM":3500, "highShiftDownRPM":3600, "highShiftUpRPM":7800, "gears":[-3, 0, 3.764, 2.475, 1.773, 1.267, 1, 0.833, 0.707] "differential":2.92 "clutchDuration":0.002 "clutchTorque":500 "autoGearChangeDelay": 0.06 }, ... Differentials (both F/R are the same): Code: "sunburst_differential_F_LSD_race": { "information":{ "authors":"BeamNG", "name":"Limited Slip Race Front Differential", "value":1200, }, "slotType" : "sunburst_differential_F", "flexbodies": [ ["mesh", "[group]:", "nonFlexMaterials"], ["sunburst_halfshaft_F", ["sunburst_lowerarm_F","sunburst_hub_F","sunburst_engine","sunburst_transmission"]], ], "pressureWheels": [ ["name","group","node1:","node2:","nodeS","nodeArm:","wheelDir"], {"propulsed":1}, ], "nodes": [ ["id", "posX", "posY", "posZ"], //--diff weight-- {"selfCollision":false}, {"collision":false}, {"nodeMaterial":"|NM_METAL"}, {"frictionCoef":0.5}, {"group":""}, {"nodeWeight":16.15}, ["fdiff", 0.0, -1.31, 0.33], {"group":""}, ], "beams": [ ["id1:", "id2:"], {"beamType":"|NORMAL", "beamLongBound":1.0, "beamShortBound":1.0}, {"beamSpring":3000600,"beamDamp":150}, {"beamDeform":30000,"beamStrength":"FLT_MAX"}, ["fdiff","e1r"], ["fdiff","e2r"], ["fdiff","e3r"], ["fdiff","e4r"], ["fdiff","e1l"], ["fdiff","e2l"], ["fdiff","e3l"], ["fdiff","e4l"], //halfshafts {"beamPrecompression":1, "beamType":"|BOUNDED", "beamLongBound":0.03, "beamShortBound":0.03}, {"beamSpring":0,"beamDamp":0,"beamDeform":3600,"beamStrength":9500}, {"beamLimitSpring":7501000,"beamLimitDamp":300}, {"optional":true}, {"breakGroupType":1}, {"breakGroup":"wheel_FR"}, ["fw1r","fdiff", {"name":"axle_FR"}], {"breakGroup":"wheel_FL"}, ["fw1l","fdiff", {"name":"axle_FL"}], {"breakGroup":""}, {"optional":false}, {"breakGroupType":0}, {"beamPrecompression":1, "beamType":"|NORMAL", "beamLongBound":1.0, "beamShortBound":1.0}, ], "differentials": [ ["wheelName1", "wheelName2", "type", "state", "closedTorque", "engineTorqueCoef"], ["FL","FR", "lsd", "closed", 0, 0.92] ], "engine":{ "axleFriction":8 }, }, ...
Did you change the gear ratio. Messing around myself, I found that the gear ratios had the strongest effect on engine braking
If clutchTorque is too high (2400 is pretty high!) you will get drivetrain instability which will add a lot of braking effect in low gears.
How do i create an engine with such torque (isn't completely unheard of to have 1500nm in really powerful cars) without having clutch torque so high then?
Make it have taller gears, or make the wheel hubs heavier. Unfortunately its just a limitation of our simulation right now that when the torque is too high compared to the inertia of the wheels (multiplied by gear ratio) things start to have problems.
May or may not help, but try messing with the closedTorque value under the diff. Try matching that value with the max torque you put out, and add/subtract up to double the difference to adjust. ex: if you have a max output of 2000 ft-lb, start around there with the closedtorque value. Depending on the setup, you might end up with 2750 as a good number, maybe even 3275, or sometimes less will work better, like 1500. I don't know if this will help, but it is possible. This trick is very useful to fine tune the lsd, which can give a way better response for many types of maneuvers
I have a car right now with around 1200Nm of torque with the biggest turbo it can have. It's not as insane as the braking on the 2400Nm car I was working with when I made this post, but I still want to lessen it. I wonder if i can artificially limit the minimum torque to 0 if I'm above idle RPM and not braking using LUA. The amount of engine braking caused by clutchTorque is -clutchTorque so it should be easy to test for.
