Steering Rack swap?

[The Dark Side of Will]

I'm in for one if you can bring it to market at your price.

As an alternative, this and four u-joints can cut the lock-to-lock turns by a third to half:

http://www.colemanracing.com/Steering-Quickeners-P4753.aspx

[nando]

Those work, but they also double the input force.

[stonea]

I guess the million dollar question is..... What ratio do we go with?

[nando]

I think you try to mimick something from a modern BMW (before electric steering, of course).

For example, the steering feel of an E46 ZHP or an E90 is really, really good. Basically, what's the rate of that, and just copy it.. I already posted the E46 330xi rack ratio (late model).

[The Dark Side of Will]

Those work, but they also double the input force.

Which is fine if, like me, you think power steering is too light and has poor feedback anyway.

[madman23]

Count me in. My rack needs a rebuild BAD!!!

[Kershaw]

Which is fine if, like me, you think power steering is too light and has poor feedback anyway.

[downforce22]

interested, depending on price.

[The Dark Side of Will]

Chuckle.
I do most of my driving in Fieros, which are light in the front with manual steering. The way that hydraulic power steering essentially "clips" the feedback to steering effort has always felt not so great to me.

Installing the steering quickener above of the spool valve will increase the wheel torque necessary to crack the spool valve by the inverse of the quickener ratio and, in my estimation, improve steering feedback.

Of course no matter what iX's have crappy steering feedback for hard pavement driving due to their essentially non-existent caster angle.

[madman23]

Has anyone ever angled the strut mounts back to gain more caster? Any negatives to that? I never understood why BMW did that for the IX.

[nando]

It's been discussed before. It was optimized for weight transfer under acceleration/braking on slick surfaces (ice/snow).

You can use M3 offset CABs and GC camber plates to gain a bit more camber. I think the max is around 2.5-3 degrees - stock is about 1.2 degrees. No real downsides IMO - aside from the camber plates being pretty harsh on the street (zero rubber isolation).

[The Dark Side of Will]

I'm warming up to building an AWD car in a RWD chassis, though.

[madman23]

Nando- I have GC camber plates and offset CAB's and it helped immensely. Now I am getting excited about this steering rack fix. Now all I need to do is lighten the car up 200lbs and i'm good.

[berlow94]

Sorry for the lack of updates guys. I am starting a new thread for this now in the group buy section.
please take a look!

[nando]

bump.

Having another look at this while goofing around with my N52 parts - I think it may be feasible to swap the guts from another rack into the ix rack, with modifications.

the E46 xi rack is wider, but the diameter is really close (16mm vs 17mm), and all the centerlines seem to match up. The E46 input shaft is 3/4" shorter though. I think there's about a 50% chance of those parts working, but there would need to be modifications.

I guess another question is, would the internals of an E36 rack possibly work (flipped over), as I'd bet the width is closer to the E30 ix than the E46 is. Or any other ZF rack with similar dimensions..

What made me think about this again was the E46 rack has a lot of issues with fitment, and it would be waaay simpler to do using the original rack housing. You could use ix tie rods, PS hoses, steering joint, etc.

In the end one of the two bolts that holds the input shaft housing together was rusted to nothing, so I couldn't get it all apart to see - but it's worth investigating further IMO. The thing I notice the most about the E30 when jumping in for a spin is how ridiculously slow the steering is, it drives me crazy.

Anyone have a cheap E36 rack I could borrow? Or take measurements off one? (rack length/diameter, input shaft length).