I'm a bit confused. How is it 40mm/rev for the first 180* but starting at 60.2mm goes to 40.14mm at 180*? (20.06mm change).
If the ratio is slower past 180*, then its likely to reduce steering effort at low speeds in parking lots, since you never really go past 180* on track.
In this case, using a linear rack will make steering effort a lot higher in parking situations.
Will the rack have the same same overall travel as stock? If not, then there will be rubbing at full lock.
Good data from the other thread:
I must admit that I too felt like the NSX's steering was subjectively slower than many other cars. I decided to look at the in-car videos of various cars around Buttonwillow raceway and compare their steering inputs to a few different NSXs of varying degrees of build. I took a screenshot of each car in two different corners at the point of their maximum steering angle.
The cars I looked at were:
-NSX - Mild build: My personal car: 235/40-17, 275/35-18 NT05 street tires, KW V3 coilovers, and NSX-R rear wing
-NSX - Extreme build: FXMD's record holding Time Attack car: 305/35-18 345/35-18 racing slicks, KW 3-way motorsport dampers, MASSIVE aero
-NSX - Moderate build: BellWilliam's car: 235/40-17, 275/35-18 NT01 R-comps, coilovers, big splitter and wing
-2015 Mustang GT - Mild Build
-S2000 - Mild Build: Stock Aero: 255/40-17 Dunlop ZII StarSpec, HKS Hipermax IV SP coilovers
-S2000 - Extreme Build: Evasive's record-setting Time Attack car: 275 street tires? and massive aero
-Lotus Elise - Moderate Build: Manly's record-setting Time Attack car with massive aero
-Lotus Exige - Mild Build: Relatively stock with Hankook Ventus Z214 tires
Turn 2 "Buttonhook" is one of the slowest (<50mph) corners that you'll find on any racetrack. It requires a lot of steering input at low speeds and while trailbraking can reduce understeer, the corner as an up-hill right at the apex that causes almost any car to understeer at the apex. This is a great corner to determine how much steering lock is needed in a technical and quirky haripin.
-All of the NSX's required ~180-degrees of steering input at the apex of this hairpin.
-The 2015 Mustang GT also required ~180-degrees of steering input.
-Both S2000s required ~160-degrees of steering input, slightly less than the NSX -by 20 degrees
-Manly's yellow Elise required the same ~180-degrees of steering input as the NSXs.
-The Exige required ~150-degrees of steering input, about 30 degrees less than the NSX. Keep in mind he was turning 2:03s, which was much slower than the rest of the cars in this group other than the Mustang doing 2:06s.
Turn 4 "Grapevine" is a pretty standard corner with very little camber/banking. I chose this corner because it does not require much braking or lifting of the throttle, so the balance and steering inputs aren't affected as much by differences in driving styles and trail-braking, and singles out the setup and balance of the car and the steering inputs needed.
-My NSX required ~95-degrees of steering input
-The FXMD NSX required ~100-degrees of steering input
-William's NSX required ~80-degrees of steering input - quite a bit less than the other NSXs.
-The 2015 Mustang GT also required ~80-degrees of steering input.
-The stock S2000 required ~75-degrees of steering input and was quite loose and oversteering through this corner
-The Evasive S2000 required ~80-degrees of steering input
-Manly's yellow Elise required ~85-degrees of steering input
-The Exige required ~55-degrees of steering input, about 40 degrees less than the NSX. Keep in mind he was turning 2:03s, which was much slower than the rest of the cars in this group other than the Mustang doing 2:06s.
I will let everyone draw their own conclusions on the difference of required steering input between the NSX and a cars like the S2000 and Elise/Exige which are considered to have very quick and responsive steering. The Elise/Exige are the only cars without power steering (like the NSX) but they also have much smaller wheels and tires, and the car is about 1,000lbs less than an NSX.
Keep in mind that the driver's inputs and setup/balance of the car does affect how much steering input that is needed. Which is why I took samples of moderate to extreme car builds, as well as varying levels of driver ability. Overall, I think the required inputs between all of these cars are very similar.
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