This was one of the best things I did to my E30, and would be one of the first things I'd do if I had another. Preferably simultaneous with an engine swap for access to the rack... The kit would've been handy.
While we had no real issues with the steering in our E30, we had heard about various steering racks being used to quicken the steering ratio.
We were going to start with the stock rack and see how we liked it. We liked it fine, until it blew out, just minutes after finishing the car. It was one of the few chassis parts we did not replace while restoring the car. Initially, we just cleaned our original steering rack and put new tie rod ends and boots on it. Murphy’s Law caught up with us rather quickly.
The stock E30 rack is said to be 4.0 turns lock to lock. An E36 steering rack from an M car is said to be 3.5 turns and the Z3 steering rack is a razor quick 2.7 turns lock to lock.
FCP Euro now makes a kit to install a Z3 rack into an E30. This kit includes the spacers and different power steering hoses you will need, as the hoses are mounted differently on the Z3 rack.
Installation was fairly straight forward but will still take a bit of engineering to get a few details worked out.
We never really considered E30 BMW steering to be slow, but once the Z3 rack is installed, you quickly realize what you’ve been missing. While some have said the Z3 rack makes the E30 twitchy, we haven’t found that to be true at all in the three thousand miles of driving we done thus far, including two trips to VIR where we ran the full course.
There is more steering effort with the quicker rack and parking and moving around tight places is now noticeable, but not objectionable.
FCP Euro’s Quick steering rack kit comes with just about everything you need to make the swap. Notice how the power steering hose mounts differently on the Z3 steering rack.
This was one of the best things I did to my E30, and would be one of the first things I'd do if I had another. Preferably simultaneous with an engine swap for access to the rack... The kit would've been handy.
2.7 turns lock-to-lock is "razor quick"? Aside from the strange expression (razors are sharp, lightning and other things are quick), this doesn't seem exceptional; maybe it is for a BMW.
Steering quickness isn't just a matter of turns lock-to-lock anyway. If comparing to other vehicles, rack travel and steering arm length also contribute to the overall steering ratio, and the wheelbase determines what ratio is effectively quick. So, with the 2.7 turn rack, is the result Corvette-quick ('Vettes have had less than 2.7 turns for decades) or Spitfire-quick, for instance?
You need to be more specific if you're going to throw information out there for readers:
e36 racks = all have the same variable/progressive ratio, except the '95 M3, which is actually slower. Just that year of the M3. A few M3 racks have slightly less turn lock to lock (like a 1/4") due to need for wheel well/frame clearance for wider tires. But same exact rate.
z3 1.9 rack = same as the e36 rack (possibly a bit shorter lock-to-lock due to wheel well/frame clearances)
The only one that's quicker (and presumably the one you have) is the Z3 2.7 rack, which is the same "main" ratio but is fully linear, so it's quicker in the center, giving an quicker overall ratio. It has the same overall travel as the e36 racks, but in less turns due to the linear center.
All of these I've used, and measured myself and compared. There's a lot of misinformation on the internet so I checked myself.
ANyhow, may want to edit to specify that it's the Z3 2.7 rack that is quicker, so readers dont' go pick up 1.9 Z3 racks and find them exactly the same as any e36....
In reply to irish44j :
That's awesome info. I couldn't tell you which Z3 rack I had, nor can I tell you whether I could have told you at the time... I'm guessing 2.7 Z3 given that it seemed like a huge improvement.
I suppose at least if someone gets an E36/1.9 Z3 rack it's still quicker than the E30 unit. While there are lots of things that improve an E30, the ponderously slow steering was the first thing that jumped out and really bothered me about the stock car.
Ransom said:In reply to irish44j :
That's awesome info. I couldn't tell you which Z3 rack I had, nor can I tell you whether I could have told you at the time... I'm guessing 2.7 Z3 given that it seemed like a huge improvement.
I suppose at least if someone gets an E36/1.9 Z3 rack it's still quicker than the E30 unit. While there are lots of things that improve an E30, the ponderously slow steering was the first thing that jumped out and really bothered me about the stock car.
Oh yeah, I had the e30 rack, then a e36 rack, and now the z3 2.7. The 2.7 rack is noticeably quicker off-center (which is important for rallycross precision). For track/street driving not sure if the extra cost/effort to find that one would be worth it over the standard e36, to be honest.
Does the firewall still need to be notched for airbag equipped E30s? Or does the FCP kit no longer require the firewall modification? Link to the FCP kit please! I couldn't find it on their website.
irish44j. Thanks for the clarification on the rack. And let me get a link from FCP Euro. I don't believe we notched the firewall, but let me check again, as it was a while ago since we did this.
In reply to Tim Suddard :
Thanks! I replaced the rack on my 318is a few years ago with a stock refurb. Still works great, but I'd love something with a better ratio without having to notch the firewall.
I've said it before, but I absolutely love this build. You guys really knocked it out of the park. I've picked up a bunch of useful information for my project and I'm looking forward to how yours compares to the E30 M3 at VIR.
I don't suppose the internals from the Z3 rack can be swapped into the e30 housing? I was thinking this may be a way to get the quicker steering without having to use an adapter kit.
stuart in mn said:I don't suppose the internals from the Z3 rack can be swapped into the e30 housing? I was thinking this may be a way to get the quicker steering without having to use an adapter kit.
I don't know the answer to your question, but having disassembled an e30 steering rack and reassembled it......just doing the adaptors is way less work. And on a non-airbag e30 it's actually pretty easy.
Displaying 1-10 of 17 commentsView all comments on the GRM forums
You'll need to log in to post.
