Z3 1.9 Steering rack conversion

[MagnusKK]

Been thinking of doing this conversion as I think the stock rack is dissapointingly slow. However I would like to keep it looking original. Is there a way I can use parts from the Z3 rack into the stock E30 M3 case so I can get best of both? If so has anyone done it before?
If not who sells complete kits for this conversion? Must be new or reconditioned.

[HANDBLT]

i have a Z3 rack in my '91 race car. It transforms the steering response. If you have an airbag car, you need to get a non-airbag column for it to line up correctly.

T

[GeoS]

Zionsville has kits. LINK

I remember them being pricey when racks were fairly plentiful. Not sure what the current availability / going rate is for a Z3 rack.

[jimmy p.]

Have any of you tried this Z3 rack with no PS assist?
I use a stock M3 rack drained and run manual.
I have no intention of going back to power steering,,, but if the Z3 rack is as awesome as everyone says it might be worth a try if its not too little mechanical advantage to run manual..

[Todd black 88]

Having had a z3 rack in my mtech II cabby, and a M3 with the stock rack, I have to agree it is a great upgrade. BUT...................I found it a bit ....twitchy for a street car.
Personally, if I were to do it again I would, but I would use an e46 rack if keeping power steering, or if dropping the power steering i would get a z4 rack. Z4 rack had electric power assist so it was designed without power steering. The e46 rack is plentiful and cheap.

[AttilaS]

I have the Z3 1.9 rack in mine (using kit from zionsville) and love it. My car is mostly used on the street and an occasional autox. I have no issues with it being too fast/twitchy on the street. So much better than stock.

[HANDBLT]

Have any of you tried this Z3 rack with no PS assist?
I use a stock M3 rack drained and run manual.
I have no intention of going back to power steering,,, but if the Z3 rack is as awesome as everyone says it might be worth a try if its not too little mechanical advantage to run manual..

Jimmy I don't have PS in mine and I love it. Feels just like stock one without PS. Hard around the paddock but over 10mph no need. I have small diameter steering wheel too.

T

[AlpineRunner]

I love the 1.9 Z3 rack. It makes the steering match the chassis/suspension. If you have a non-airbag car, you need Zionville knuckle or to file the stock one. If you have an airbag car you need to trim the bushing that goes through the firewall quite a bit, but don't need to cut any metal and don't need to touch the steering knuckle. You'll need small spacers for the rack to subframe mounting in either case.

[jimmy p.]

Thanks Guys,
Those are good reviews. Maybe I will give this a try if I come into either a Z3 or Z4 rack. I did a little reading on the Z4 rack which sounds like a good option and also small and light like the rack in my Gruppe A car. The Z4 rack also seems to be more plentiful and cheaper.
In any case I'm in no hurry to do it, I'll collect the parts along the way and probably give this one a shot.

I have been driving this car for so long with the stock M3 rack,,, its going to be a learning curve to have something different in there.
I;ve always kind of liked the stock rack, I think it very much promotes smooth turn ins,,, but I am sure that can be re-learned with the new one.
Thanks for the info.

Does anyone make a race oriented solid steering adapter knuckle to swap in either rack?
The Zionsville stuff always seems very street oriented.

I did some searching and found a thread on Rev by some guy who provided just enough information to be virtually useless.
The thread had a load of posts,,, but basically said hey it works,,, but I really can't explain how,,, and ultimately said NOTHING of substance about how to employ the swap,,, except about a 4th grade level of do this and do that and it works. I'm assuming that guy never actually touched the car during the swap, his buddy did it and he watched while drinking beer.
If anyone knows of a solid technically savvy tutorial on either the Z3 or Z4 rack install into an E30 please post a link.

Thanks again guys.
Cheers
jimmy p

[Dietrich]

I love the 1.9 Z3 rack. It makes the steering match the chassis/suspension. If you have a non-airbag car, you need Zionville knuckle or to file the stock one. If you have an airbag car you need to trim the bushing that goes through the firewall quite a bit, but don't need to cut any metal and don't need to touch the steering knuckle. You'll need small spacers for the rack to subframe mounting in either case.

I too am interested in this topic. I've got an airbag car & have had a Z3 rack on the shelf collecting dust for a decade. It's always been my understanding that to do the swap in an airbag car you had two choices: hack up the firewall sheet metal or swap in a non-airbag column in addition to the Z3 rack. Neither of these options seem practical for me at this point (definitely NOT hacking my firewall anyway). If there's a way to do the swap without the cutting I'd love to know more. Alternatively, if the Z4 rack avoids the hacking or column swap, I'd consider that too.

Thanks,
-Dietrich

[AlpineRunner]

I too am interested in this topic. I've got an airbag car & have had a Z3 rack on the shelf collecting dust for a decade. It's always been my understanding that to do the swap in an airbag car you had two choices: hack up the firewall sheet metal or swap in a non-airbag column in addition to the Z3 rack. Neither of these options seem practical for me at this point (definitely NOT hacking my firewall anyway). If there's a way to do the swap without the cutting I'd love to know more. Alternatively, if the Z4 rack avoids the hacking or column swap, I'd consider that too.

Thanks,
-Dietrich

Yea I'd always heard from Zonsville that the Z3 rack into airbag car was impossible. I think what they meant was you don't need their parts and therefore they aren't interested. It's honestly easier than in a non-airbag car because you don't need to change or clearance the knuckle. I would say you remove 75% of the radius of the rubber bushing that goes through the firewall... but NONE of the the metal firewall.I do remember bending the high pressure PS line, but nothing impossible. The only problem is I can't remember if the spacer goes above or below the rack.

[jimmy p.]

I have been completely down a rabbit hole on this thing ever since I posted in this thread the other day.
I don't think i am going to do it this winter but I have amassed a bunch of notes. I'm aiming at doing the Z4 rack swap.

My car is an old Non airbag car,,, but in my reading it does seem that the common thought that the airbag cars were impossible,,,, is the opposite. Its just a column shift.

The one part I was hating on with either Z3 or Z4 conversion was the whole mess of a steering u-joints / shaft / conglomeration and having to drill and grind it.,,, I hated it and wanted a much cleaner and simpler setup.
Its actually very easy to achieve with 3 Flaming River parts.

Flaming River Parts (satin)

3/4"-48 X 3/4" DD STAINLESS STEEL U-JOINT
Part No.: FR2528DD
$96.90

17MM-54 X 3/4" DD STAINLESS STEEL U-JOINT
Part No.: FR2563
$79.00

18" STAINLESS DD SHAFT - MILL FINISH
Part No.: FR1850SS
$75.97

Thats what I will be doing when I do the job.

The one thing that is still not clear to me from all the crap I have read,,, and maybe those of you who have done it can clear up once and for all.
What is the deal with Tie Rod Assemblys?
Do you re-use the E30 assemblies or some people have said you must use E36 Tie Rod Assemblies.
Any clarity there?

[nauqneyugn]

From what I have read, you have to use both inners and outers from an e30 or an e36. No mixing the two.

[HANDBLT]

I have been completely down a rabbit hole on this thing ever since I posted in this thread the other day.
I don't think i am going to do it this winter but I have amassed a bunch of notes. I'm aiming at doing the Z4 rack swap.

My car is an old Non airbag car,,, but in my reading it does seem that the common thought that the airbag cars were impossible,,,, is the opposite. Its just a column shift.

The one part I was hating on with either Z3 or Z4 conversion was the whole mess of a steering u-joints / shaft / conglomeration and having to drill and grind it.,,, I hated it and wanted a much cleaner and simpler setup.
Its actually very easy to achieve with 3 Flaming River parts.

Flaming River Parts (satin)

3/4"-48 X 3/4" DD STAINLESS STEEL U-JOINT
Part No.: FR2528DD
$96.90

17MM-54 X 3/4" DD STAINLESS STEEL U-JOINT
Part No.: FR2563
$79.00

18" STAINLESS DD SHAFT - MILL FINISH
Part No.: FR1850SS
$75.97

Thats what I will be doing when I do the job.

The one thing that is still not clear to me from all the crap I have read,,, and maybe those of you who have done it can clear up once and for all.
What is the deal with Tie Rod Assemblys?
Do you re-use the E30 assemblies or some people have said you must use E36 Tie Rod Assemblies.
Any clarity there?

I have all the paperwork from where Harrison Motorsports installed installed one in the '91 car I have. I will look it up and see what was on the bill.

T

[Ironhead]

This is something I have wanted to do for years.....but the common thinking was always that it was impractical to do on an airbag car.

Following with interest....