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quicker steering ratio??

Joined
31 October 2002
Messages
601
Location
OC/SD, CA
does anyone sell parts to modify the steering box for a quicker steering ratio?
anyone done this to their car?
after the prime canyon drive this weekend, doing a mod like this has moved to (near) the top of my list.
 
I've had the same complaint. If you want a slower steering ratio to mitigate snap oversteer, the then perhaps it would be better to dial out the snap oversteer rather than slow down the steering ratio. I autoXed a Viper ACR and its steering ratio should be a lesson for the NSX designers...
 
If it's enough for you to improve the steering response you may go with thicker sway bars - you'll feel a much sharper turn in - if you don't already have some of those Dali oder other bars. To alter the steering transmission would be a hell of work if you have an electric steering.

2nd possibility: A steering wheel with smaller diameter...
 
NSX-Racer said:
If it's enough for you to improve the steering response you may go with thicker sway bars - you'll feel a much sharper turn in - if you don't already have some of those Dali oder other bars. To alter the steering transmission would be a hell of work if you have an electric steering.

2nd possibility: A steering wheel with smaller diameter...
i already have the dali track swaybars and do not have the electric steering rack but the amount of work it will take is not really a concern of mine.
a smaller diameter steering wheel is still going to require the same amount of turns to navigate through those tight 180 degree turns.

does the steering rack in the automatic transmission model have a quicker steering ratio? how about the zanardi? NSX-R?
just looking for options here. the only real complaint i have with the way my car drives is with the steering.
 
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I believe supergreen is referring to the scenarios where one has to dial in a lot of steering, like in a hairpin. In a formula ford/dodge, you wouldn't have to take your hand off the 3-and-9. In the NSX, you'd have to shuffle steer or do some serious hand-over-hand action. BTW green, the Zanardi has the same steering ratio as its 99 contemporaries, but lacks the electric power assist.
 
Number9 said:
I believe supergreen is referring to the scenarios where one has to dial in a lot of steering, like in a hairpin. In a formula ford/dodge, you wouldn't have to take your hand off the 3-and-9. In the NSX, you'd have to shuffle steer or do some serious hand-over-hand action. BTW green, the Zanardi has the same steering ratio as its 99 contemporaries, but lacks the electric power assist.
that's exactly what i'm referring to. it really becomes an issue in an oversteer situation. if i'm deep in a hairpin and begin to lose the backend, i pretty much have to release the steering wheel and return my hands back to the 3 and 9 position to keep the car on the road. every other car i've owned allowed me to keep my hands in one position... which is what i'm hoping to accomplish in the nsx.
 
supergreen125 said:
that's exactly what i'm referring to. it really becomes an issue in an oversteer situation. if i'm deep in a hairpin and begin to lose the backend, i pretty much have to release the steering wheel and return my hands back to the 3 and 9 position to keep the car on the road. every other car i've owned allowed me to keep my hands in one position... which is what i'm hoping to accomplish in the nsx.

As I mentioned in an previous post, I had a 95 and now own 99 Zanardi. The 95 with variable ratio power steering had quicker turn in because it was variable ratio. 18.2:1 to 20.8:1 as compared the non assisted 99 at 18.6:1. If your drive the two back to back on the track, you can feel the difference on any "quick tight turn".
 
Chuck - I had been told the Zanardi has the variable rack, just deleted the power assist. It sounds like that is not correct and they went back to the original 18.6 fixed rack?
 
I looked at my 99 brochures, the manual coupe and T have the variable ratio and the automatic has the fixed. The darned Zanardi brochure was silent on the steering ratio issue, so no help there. I also owned a 95 prior to the Z and I didn't notice the steering in the latter to be any quicker.

Since the quickest ratio in the variable ratio case is only nominally different from the fixed ratio case (i.e., 18.2 vs. 18.6), I can't imagine that one would be able to notice the difference (other than the power assist vs. not) and as the variable ratio transitions to the higher numerical ratios, it's steering gets even slower than the fixed case.

So still an open question...
 
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The specifications listed in my Zanardi press kit specify the steering ratio as 18.6:1
 
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I would really like to know if a quicker steering ratio is available. I hate having to adjust my grip just before a tight turn.
 
I agree with you. I just test drove a 2001 NSX today for the first time and loved everything about the car except for the steering. It felt too light and much less responsive than my Boxster S's steering. Is there a way to improve the NSX steering (quicker ratio)?
 
My recent ownership of an s2k gave me an appreciation for a tighter ratio. It took me many miles of city driving to get used to the loose ratio of the NSX.

I too would like to see a tighter replacement similar to that of the s2k (2.4 turns lock to lock as opposed to NSX 3.07). BTW s2k is elec power assist.
 
Sorry... here is the relevant information. Maybe we can have the same done for the NSX. This is for the 91-95 MR2 with power steering rack.

------------------------------------------
Tired of turning your steering wheel so much when darting through the slaloms?
Want to improve your auto-x times by not having to reposition your hands so much through the cones?
Always feel like the steering on your MKII is just too slow and unresponsive to the driving conditions?

I have the solution:………

The stock MKII power steering rack is a good, but somewhat slow a ratio of 17.1:1 with 3.2 turns lock to lock.

The Stock MKII Manual steering is an awful ratio of 21.2:1 with 3.75 turns lock to lock.

The solution I am providing will convert any power steering housing to a 13.6:1 ratio and 2.6 turns lock to lock.

The conversion consists of a reconditioned pinion drive gear that has had the gear pressure cast and cut to an improved ratio.

Unfortunately, we cannot refurbish the stock manual pinion for my conversion, However; using a PS rack and venting one side of the piston to the other, will not require the other PS parts and have minimal effect on the steering feel.
Using the rack manually will be a bit tougher to steer at slow (parking) speeds, but it is still surprisingly easy to manipulate.

The conversion requires a PS rack and purchasing one of these beautiful drive gears from me. If you have the PS rack already, your half way home….. Pictorial instructions and Teflon seals will be included. The swap only takes about 1hr or less to perform.

The cost will be $395.00 shipped + a $100 core charge for your stock pinion that you will be refunded once I receive it. Availability is about 2 weeks from your order. The core refund is good for 30 days of your order.

------------------------------------------------------

Stock gear

SteeringControlvalve001.jpg


New Gear

pinion.jpg
 
I agree with OP, for track use that has a lot of hairpins, a quicker steering ratio would greatly help.

The point of the thread was to figure out how to make a quicker steering ratio for the NSX, not whether it was a good idea/for everyone or not...:rolleyes:
 
is nsx's gear removable from the shaft? if it is i do have means to design and make a new one.
 
+1 for this thread. In my mind, I'm making/keeping a list of the things I'd like to see improved in the next NSX.

o slightly more head room (ie made for Americans)
o tighter steering ratio
o performance brakes (aluminum calipers, quick change pads, etc)
o better stereo system

My list really isn't that long. I'd be very happy with just an update. Mid-engine, a V8 (or V-10) version of the S2000 motor, updated styling, and a few things listed above. SH-AWD, paddle shift, etc, area all things I can easily do without. CVT would be killer, however. Not sure about seemless shift tranny but it might be cool too.

Sorry for the hijack. Tighter steering ratio would be better for both street and track, IMHO, even with no power assist.
 
Sorry... here is the relevant information. Maybe we can have the same done for the NSX. This is for the 91-95 MR2 with power steering rack.

They use an electro-hydraulic system, which is quite different than the 2K or NSX.


My recent ownership of an s2k gave me an appreciation for a tighter ratio. It took me many miles of city driving to get used to the loose ratio of the NSX.

I too would like to see a tighter replacement similar to that of the s2k (2.4 turns lock to lock as opposed to NSX 3.07). BTW s2k is elec power assist.

I agree with OP, for track use that has a lot of hairpins, a quicker steering ratio would greatly help.

The point of the thread was to figure out how to make a quicker steering ratio for the NSX, not whether it was a good idea/for everyone or not...:rolleyes:


Practically I don't think it is going to happen. A higher ratio on the street means more driver input to negotiate low speed turns or parking lots. On the track in a 180 degree hair pin as well, sure. Seems like a minor issue.

I'd like electronic cockpit EPS adjustment and perhaps a tighter CART inspired ratio too. :wink:

However, assuming maintaining assist and other stock characteristics is a priority.... I suspect from what little I've read in the service guide that people will need to deal with what Honda gave us in the NSX PS department. If you study the service guide you'll realize how involved the stock PS system is. While I haven't delved in too deep, I highly doubt it is as simple as changing out a pinion or gear for the later model EPS racks.

While usually it is just that simple, the electronics for the EPS assist likely complicates the issue greatly in this instance. To expand on that...

For starters yes, the steering shaft drives a fixed pinion which we could use to machine a replacement. However, note that it is also connected to a series of transmission gears, and then to a rotation and torque sensor which simply converts the speed and direction of steering input into voltage signals, which is then sent to an interface circuit and then on to the control box.

The control box software then calculates the duty signals from the cars speed sensor, torque sensor, and steering rotation sensor and outputs electronic signals to the power unit which then drives the rotor, which mechanically drives a ball screw, which transfers motion to the re-circulating ball screw, which provides the assist you feel on the rack when engaged.

So, my first premise would that assuming you changed the steering ratio with an alternate pinion, the assist benefit of the PS would be totally out of wack as it would be expecting different input, and some way would need to be devised to compensate electronically which would take some R&D. Otherwise, as the PS would cycle through the various control modes (Normal, Return, and Damper) it would be doing so using the wrong input position for each of the duty cycles.

There is an adjustment rack guide screw which helps to see the pre-load, but it wouldn't solve the root signal issue.

I am also skeptical that even given the change-over was successful, that over the long haul the over-voltage cut-out would operate normally and not burn out the motor unless something was devised there. Otherwise you might hit the end of lock, and the motor may still try to provide assist.

Ultimately, it comes down to this. Has anyone cracked open an NA2 power steering assembly yet and really delved in on steering tech? I haven't seen anything on 2K boards either with these style of units. It seems to be hands-off.

I noted in the service manual it emphasizes to not service, disassemble, or otherwise screw with it as it is a 'higher precision' and to always replace as a unit.

However, I suppose doing the completely opposite couldn't hurt either. :smile:
 
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John@Microsoft, what are your thoughts on early model (no power assist) steering sytems? Could they be modified for quicker ratio at the expense of more effort needed in slow speed turns (parking lots, for instance)?
 
John@Microsoft, what are your thoughts on early model (no power assist) steering sytems? Could they be modified for quicker ratio at the expense of more effort needed in slow speed turns (parking lots, for instance)?

I don't see why not. It should be as simple as fabricating a pinion and/or tie rod to your specification. I don't see why you couldn't have any reasonable fixed ratio and lock you wanted.
 
I also find the steering too slow in the NSX, and would love to find a way to speed it up.
 
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