Lonnie-S wrote:
1) 15:1 to 17:1 typical of modern sports sedans
2) 12:1 to 14:1 "fast" or "quick", perhaps better suited to track cars versus street cars for most drivers.
3) Race cars -- I couldn't find anything based on what I have on hand
Any smart guys out there have better information?
Cheers,
I'm not nearly as smart as many here, but I'll add some 2 cents here based on my research:
1. The whole "ratio" thing is left over from the recirculating ball steering days. IT is commonly used 'cause the hot rod guys still are mentally in that place.
2. This standard was replaced by another measurement -- "inches of rack travel per turn."
16:1 is roughly 2" of rack travel per turn.
14:1 is roughly 2.36" per turn.
12:1 is 2.62" per turn.
10:1 is 2.88" per turn.
3. Some donors and their inches per turn (based on numbers I gathered off of the 'net):
Chevette -- 1.6" per turn
Miata -- 1.77" per turn
Gen IV Camaro -- said to be 2.1" (standard) and 2.3" (sports) but mine was 1.6" per turn.
Fiero -- 1.5" per turn
Pinto -- 1.26" per turn
4. The circle track guys are dumping their manual slower racks for new, faster racks (ie, faster than 3" per turn) with power steering. The upshot is that guys like me can buy a virtually new (never installed!) slower manual rack for "Cheap" -- in my case, 2.5" per turn, 18" wide, for $165 delivered. Having said that, I've spent almost that much getting the thing hooked up to the steering arms and steering shaft.
5. Some other parts to this math problem:
- Faster racks mean, all things being equal, higher steering effort. IF you've got a torn a rotator cuff, or if you want your girlfriend, mistress and/or wife to drive this, keep this in mind. Anything over 2.5" per turn generally requires either power steering or an ape to drive the thing, all things being equal.
- shorter steering arms mean quicker steering, longer arms mean slower. If you use a quick rack and short arms, you're gonna have very quick steering. Oh, and all things being equal, more effort.
- Smaller diameter steering wheels mean faster steering and higher effort too.