Manual Gear Shifting /w RPM Gauge and Speed Boosting 'Zones'

I’ve been working on a simple drag racing gamemode. I need to figure out a way to call which gear a vehicle is in and output to an rpm gauge. If the user shifts within the proper rpm range, then they get a speed boost. (Anyone ever play NFS Underground?) This seems impossible because the most info I can get on a vehicle is simple entity info like position, velocity, that sort of thing. However, each gear plays a different sound so there must be some way listening to gear events somewhere. Anyone have any ideas?

I’d just make your own kinda system.

I’m trying to avoid rewriting the entire HL2 vehicle setup.

What would you suggest?

no i meant make your own gearing

How would I go about doing that? Nothing too complicated, just looking for a direction.

Have your “speed” be done in velocity, then maybe you could do a min/max for gears.

Gears = {};
Gears[1] = { 1, 5 },
Gears[2] = { 5, 10 },

idk.