5 hours ago, heyitsrama said:

I wonder how the steering response is with both a short ratio rack and the competition steering arms. It looks like there are several sellers that offer arms now.

As I've used that combination (Japanese market stock 15.8:1 rack ratio, and the 'short' 105mm knuckles) on four of my cars, I can tell you that it is - in my opinion - very sporting indeed, and not *too* heavy, even with the smaller diameter Izumi 'Datsun Compe' steering wheel.

My daughter's 2011 Civic has very quick steering. Seems even more than my s2000. The PO did some tweaks. Specs say 13.7:1 steering ratio. The S2000 is 13.8:1.

I went to a smaller diameter steering wheel on my 280z and it was a great improvement. There are many ways to modify the geometries.

Edited December 30, 20204 yr by 240260280

22 hours ago, 240260280 said:

My daughter's 2011 Civic has very quick steering. Seems even more than my s2000. The PO did some tweaks. Specs say 13.7:1 steering ratio. The S2000 is 13.8:1.

I went to a smaller diameter steering wheel on my 280z and it was a great improvement. There are many ways to modify the geometries.

a smaller wheel doenst alter the geometries, just the lever effort.

2 hours ago, Jason240z said:

a smaller wheel doesn't alter the geometries, just the lever effort.

It alters both actually. they all interplay.  The diameter of the steering wheel determines the amount of circumferential movement of your hand required to turn the wheels a set amount.  Basically the ARC LENGTH S that is swept is the variable that changes with diameter.

1. To turn the wheel a certain amount on a small wheel to take a corner is say 4" of circumference travel (S).

2. If you use a bigger wheel that is twice the diameter, you will have to turn 8" of circumference travel (S) to take the corner.

 

The larger diameter wheel has more mechanical advantage and a perception of finer control for the same steering input.

 

Where can one purchase a new/oem quick-ratio rack for a 1976 s30?

On 12/27/2020 at 2:31 AM, Jason240z said:

Hi all

I've been trying to find a source for LHD steering rack bars and pinions, I'm having a batch made here in the UK, they're about 11% quicker than the racks in US spec cars, effectively bringing them to a euro spec 'quick rack'. 

prices are in £240+vat. Thats for a new rack bar and pinion. if you'd like one, as there's an minimum order, i'd have to get a deposit(50%) as I don't want to end up with a garage full of rack bars!

Most of the racks i've had apart have shown wear/loose spots on.

Any interest on here? 

Hi Jason, I'm very intrigued. The rack in my US-spec 260Z has some slop and I've wanted to go to a quicker ratio anyway. Is the 240 GBP price for a rack bar and pinion which I would then retrofit into my existing (updated cast-iron) housing? How are you ensuring the durability of the parts, what sort of validation testing is being done?

10 hours ago, LeonV said:

Hi Jason, I'm very intrigued. The rack in my US-spec 260Z has some slop and I've wanted to go to a quicker ratio anyway. Is the 240 GBP price for a rack bar and pinion which I would then retrofit into my existing (updated cast-iron) housing? How are you ensuring the durability of the parts, what sort of validation testing is being done?

Hi, yes, it fits into the standard housing.

They're being made to with the correct material by a company that only makes steering racks and parts.

On 1/3/2021 at 2:28 AM, Jason240z said:

Hi, yes, it fits into the standard housing.

They're being made to with the correct material by a company that only makes steering racks and parts.

Thanks Jason. So to confirm, this will fit an Aluminum or cast iron housing? I do have both so this wouldn't be a deal breaker.

Do you know whether the constituent parts to rebuild racks are readily available, e.g, bearings, seals, inner tie rods, boots, etc? Happy to do my own research but I figure you may have already done so. 🙂

Yes especially the brass bearings in the housing. used and no longer avail.

There's no similar brass bearing anywhere or at least the complete dimensions and specs?

Brass is not really a good bearing material. What you want is bronze, not brass.

I don't know if all the racks used the same bearing sizes, but Mike W bought a chunk of bronze and had some bushing cut at a machine shop. Info and dimensions (for the later 260/280 racks at least) here:

https://www.classiczcars.com/forums/topic/48621-steering-rack-disassembly-and-refurb/?page=7&tab=comments#comment-540657

Edited January 8, 20214 yr by Captain Obvious

Bushings or bearings or both are what's needed? I love the idea of a better ratio and resultant feel.

Edited January 8, 20214 yr by gnosez