well talks abt steering, quite my bread and butter at work so lemme hand you couple of opinions before you spend your cents on those shiny steer wheels:
1. If your target is to eliminate those kind of vibrating/shimmy feel at on centre of steering while you're doing speed, that means you need to check these things on your car:
a. irregular tyre thread
b. wheel imbalance
c. FR spring too soft
d. incorrect and unequal static kerb camber
e. uneven or low tire pressure
if everything is intact and acceptable, those vibration might came from loose linkages, loose ball joints and loose steering gears which definitely not DIY things.
2. If so your target is just to add solid feel to the steering, which i guess should be laid as weighted feel at on-centre and a continuous friction feel throughout turning the wheel. it is just impossible to put solid feel on steering, what you could do is to put rubberiness into it. there are 2 ways of doing that which most importantly DIY stuff:
a. Adjust your FR total toe to around
-10mm to -15mm. A negative total toe will statically direct your tyres facing outside forward, which is common practice for production cars (but this can easily 'lari' due to excessive turning until 'clok2' sound and excessive bump steer). -ve toe will create lateral pre-load resistance on the tyre patch. One, this will help better your steering on centering and returnability which it will eliminate that elastic feel of the steering when you flip the steering and let it return by itself. Two, upon cornering, the resistance from the outside tyre will give you more lateral feedback which you as the driver (on your palm) will feel more weighted, friction feel and all in all rubbery feel.
OK here comes the DIY stuff. This can be done by manually adjusting your tie rod end. on typical car which the tie rod lays at the rear of the wheel hub track, you will need to reduce the length of the steering rack. But if the tie rod is at the front end, you will need to do it otherwise by increasing the rack length.
Typically, you will require a size 17 spanar to loosen the tie rod and size 12 to adjust the length.
Its worth mentioning that you need to becareful with the amount of length you adjust because if you excessively negative the toe, you vehicle response will be unlinear to your steering turn due to excessive resistance created by the tyre. and once your toe to excessive, you will require realignment on the machine.
b. you could add damping sheets at the steering locking knob, add damping sheets at the locking key between your steering column and steering wheel assembly. basically what you will try to do is to prevent the vibration from your tyres to reach your steering wheel. adding weight at the wheels theoritically wont eliminate anything but will add unnecessary weight to pinion, column universal joints and will add more work to the steering gears.
ps: Hopefully my first post here will help and please lemme know the outcome.
Happy DIY-ing..