Steering ratio and turn-in
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From: Dry Branch
Yup, the CR is using the AP1 rack, so swapping an CR rack for an AP1 rack doesn't make much sense.
There is much more to the way a car turns in than just the steering ratio. The CR will not have the AP1 roll steer characteristics and will most certianly have its own shock, spring, and bar rates.
There is much more to the way a car turns in than just the steering ratio. The CR will not have the AP1 roll steer characteristics and will most certianly have its own shock, spring, and bar rates.
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Originally Posted by boofer,Aug 31 2007, 11:55 AM
so no one knows why the steering ratio is so high? you'd think Honda would want it to have super responsive, quick steering. instead, i find that it's pretty gradual from 10 to 2 o'clock turns. not sluggish, not indirect, just a little more gradual than i would like or expect.
why you think they dont do the 4 wheel steering anymore like some of the preludes had
people are not use to the steering response and might over turn.. imo
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I think the steering ratio of a 997 911 GT3 is 17:1 and the steering ratio of the Elise is something similar. Point is...
Steering ratio alone MEANS NOTHING. THere are many other factors that come into play such as tire size. Its one of the reason as to why there is no perceived difference in steering quickness in an AP1 and AP2 despite the different ratios. AP2s wear wider rubber in the front.
Steering ratio alone MEANS NOTHING. THere are many other factors that come into play such as tire size. Its one of the reason as to why there is no perceived difference in steering quickness in an AP1 and AP2 despite the different ratios. AP2s wear wider rubber in the front.
dont change your Ap1 rack with a 2008 ap1 rack
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From: Dry Branch
OK guys, let's stop for a minute and get our facts straight.
The steering ratio of a car is just a gear ratio; Specifically, it is the ratio of the gearing in the steering rack. Knowing the steering ratio tells you NOTHING at all about how far the wheels turn in response to a given amount of steering wheel movement. Absolutely NOTHING! The steering rack turns the wheels through a lever arm, and the length of that arm is what determines how far the wheels turn as the steering wheel is turned. If the arm were 10' long the wheels whould hardly turn at all, no matter what the steering ratio was. If the arms were only an inch long, the steering would be so quick that the car would be almost impossible to drive, no matter what the steering ratio might be. IOW, the steering ratio does NOT tell you how quickly a car steers.
One of the problems in looking at specifications is that you can draw incorrect conclusions if you don't really understand what the specifications mean.
Other factors also affect the steering rate of the car. For example, extreme caster will result in the wheels tilting rather than turning, slowing the cars response to steering wheel movement. Tires and wheels are also a factor.
ALL THE STEERING RATIO NUMBERS TELL YOU IS WHAT THE GEARING IS IN THE STEERING RACK OR BOX. PERIOD.
As for the difference in the way different MY cars turn-in, I was about to call BS on those who are saying there is no difference, but after thinking about it a bit I can see their point. In normal driving the differences are pretty meaningless. However, if you can't feel the difference when driving the cars hard, you're probably not paying attention. AP1's use roll steer to achieve a dynamic change in the handling as the car rolls into a corner, while the AP2's have a linear handling bias. Each approach has advantages and disadvantages, and the difference in MY cars is not huge, but it's very real and very hard to miss as the car approaches it's handling and/or turn-in limits.
As for the risk of roll over, that also has absolutely nothing to do with steering ratio. You can throw an S2000 from full slide in one direction to full slide in the other direction, as violently as you possibly can, and the car will never even get close to rolling over. To roll the car you'll have to hit a curb, find a bad enough off camber situation (like rolling down a hillside or going over a cliff), or have something go horribly wrong (like having a wheel come off mid turn).
Cars with quicker steering (regardless of the steering ratio) require more attention from the driver. You can nod off in our Lexus for a few seconds and the odds are that the thing will just continue to go straight down the road. If you turn around to yell at the kids, and pull the steering wheel a little as you do, it doesn't really matter, because the thing will just keep going straight anyway. In the S2000, if you breath too hard you'll steer the car slightly, and most people need a period of adjustment when they first start driving cars with quick steering response. Many people mistake it for twitchiness, when they're actually the source of the twitching. Most cars have steering rates that are in line with the way the manufacturer expects the car to be driven. If the driver is going to be focused on the driving, then he'll appreciate quick steering response. If he's going to be more of a passenger than a driver (even though he's behind the wheel), then quick responses are the last thing he wants.
In general, the steering rate is matched to the cars intended use, and the steering ratio does not, in and of itself, determine the cars steering rate.
The steering ratio of a car is just a gear ratio; Specifically, it is the ratio of the gearing in the steering rack. Knowing the steering ratio tells you NOTHING at all about how far the wheels turn in response to a given amount of steering wheel movement. Absolutely NOTHING! The steering rack turns the wheels through a lever arm, and the length of that arm is what determines how far the wheels turn as the steering wheel is turned. If the arm were 10' long the wheels whould hardly turn at all, no matter what the steering ratio was. If the arms were only an inch long, the steering would be so quick that the car would be almost impossible to drive, no matter what the steering ratio might be. IOW, the steering ratio does NOT tell you how quickly a car steers.
One of the problems in looking at specifications is that you can draw incorrect conclusions if you don't really understand what the specifications mean.
Other factors also affect the steering rate of the car. For example, extreme caster will result in the wheels tilting rather than turning, slowing the cars response to steering wheel movement. Tires and wheels are also a factor.
ALL THE STEERING RATIO NUMBERS TELL YOU IS WHAT THE GEARING IS IN THE STEERING RACK OR BOX. PERIOD.
As for the difference in the way different MY cars turn-in, I was about to call BS on those who are saying there is no difference, but after thinking about it a bit I can see their point. In normal driving the differences are pretty meaningless. However, if you can't feel the difference when driving the cars hard, you're probably not paying attention. AP1's use roll steer to achieve a dynamic change in the handling as the car rolls into a corner, while the AP2's have a linear handling bias. Each approach has advantages and disadvantages, and the difference in MY cars is not huge, but it's very real and very hard to miss as the car approaches it's handling and/or turn-in limits.
As for the risk of roll over, that also has absolutely nothing to do with steering ratio. You can throw an S2000 from full slide in one direction to full slide in the other direction, as violently as you possibly can, and the car will never even get close to rolling over. To roll the car you'll have to hit a curb, find a bad enough off camber situation (like rolling down a hillside or going over a cliff), or have something go horribly wrong (like having a wheel come off mid turn).
Cars with quicker steering (regardless of the steering ratio) require more attention from the driver. You can nod off in our Lexus for a few seconds and the odds are that the thing will just continue to go straight down the road. If you turn around to yell at the kids, and pull the steering wheel a little as you do, it doesn't really matter, because the thing will just keep going straight anyway. In the S2000, if you breath too hard you'll steer the car slightly, and most people need a period of adjustment when they first start driving cars with quick steering response. Many people mistake it for twitchiness, when they're actually the source of the twitching. Most cars have steering rates that are in line with the way the manufacturer expects the car to be driven. If the driver is going to be focused on the driving, then he'll appreciate quick steering response. If he's going to be more of a passenger than a driver (even though he's behind the wheel), then quick responses are the last thing he wants.
In general, the steering rate is matched to the cars intended use, and the steering ratio does not, in and of itself, determine the cars steering rate.
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well, i wasn't drawing any conclusions....i was merely asking. no need to USE CAPITAL LETTERS. or maybe there is. at any rate, the turn-in is about as slow as the TSX, which is kind of disappointing to me.
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From: Dry Branch
Originally Posted by boofer,Sep 1 2007, 03:07 PM
well, i wasn't drawing any conclusions....i was merely asking. no need to USE CAPITAL LETTERS. or maybe there is. at any rate, the turn-in is about as slow as the TSX, which is kind of disappointing to me.
Have you seen any actual measurements of the turn-in rates? It's sometimes hard to judge the rates based on feel; For example, the RX-8 has about the same turn-in rate as the S2000, but subjectively (to me, at least) it feels much slower. I think (in the case of the RX-8 at least) that it's a function of the cars settling time, with the longer settling time making the turn-in seem slower.
Exactly what aspect of the S2000 turn-in or steering action do you find dissipointing?
Compared to the TSX, the S2000 has a lower polar moment and a stronger bias toward oversteer, both of which produce quicker turn-in, so forgive me for not understanding what it is that you find dissipointing.
(I'm not fussing at you; Only trying to understand.
)
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From: Denver, CO
Originally Posted by MULDER,Aug 31 2007, 01:18 PM
You already own a 2000 model per your info... they are using the Ap1s rack.
You got me on that one. I don't know why I was thinking AP1 = AP2; I must have read through it too fast due to excitement.Somebody make a quicker ratio rack (okay, okay, a more "responsive steering SYSTEM," for you extremely technical folks). I'll throw money at you in return.