You could combine a split with a switch.
e.g.
[{"id":"17576336cded5386","type":"inject","z":"1d319bc3005a51a2","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"{ \"speed\": { \"_set\": 8.5, \"_get\": 0 }, \"info\": { \"current\": 0, \"Vdc\": 321, \"state\": 0, \"Vout\": 0, \"torque\": 0, \"Pout\": 0, \"pf\": 0 } }","payloadType":"json","x":90,"y":740,"wires":[["f5ff82e8913a92e0"]]},{"id":"f5ff82e8913a92e0","type":"split","z":"1d319bc3005a51a2","name":"","splt":"\\n","spltType":"str","arraySplt":1,"arraySpltType":"len","stream":false,"addname":"","x":210,"y":740,"wires":[["4ae02073b26113f2"]]},{"id":"4ae02073b26113f2","type":"switch","z":"1d319bc3005a51a2","name":"","property":"parts.key","propertyType":"msg","rules":[{"t":"eq","v":"speed","vt":"str"},{"t":"eq","v":"info","vt":"str"}],"checkall":"false","repair":false,"outputs":2,"x":330,"y":740,"wires":[["5980bfbc3811ca4b"],["c66dee150c0135b4"]]},{"id":"5980bfbc3811ca4b","type":"debug","z":"1d319bc3005a51a2","name":"debug 298","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"payload._set","statusType":"msg","x":550,"y":700,"wires":[]},{"id":"c66dee150c0135b4","type":"debug","z":"1d319bc3005a51a2","name":"debug 299","active":true,"tosidebar":true,"console":false,"tostatus":true,"complete":"payload","targetType":"msg","statusVal":"payload.current","statusType":"msg","x":550,"y":760,"wires":[]}]