95 M3 Steering rack + Airbag Car

[JCarp90]

Hello all,

Getting ready to order a 95 M3 steering rack for my 91 325i airbag car. I'm told I need to replace the knuckle, but I'm not sure which one I need. Anybody know?

Any help would be appreciated. Thanks!

[RCM3]

I didnt replace my knuckle on my 91 airbag e30. I modified it so it didnt bind, basically removed a small amount of material in the knuckles joint to prevent it from rubbing on itself due to the increased angle coming off the e36 rack. I believe I put a spacer in the knuckle to make the knuckle shorter in length for the airbag car also. I followed the DIY guide on here the first time I did a swap.

Why the 95 M3 rack though? If you haven't already purchased it, research rack speeds a little more to make sure it's what you want. From what I remember and my personal experience it's the slowest of the common rack swap options. I have the data at home for the racks but I believe it goes 95 M3<96+ M3/standard e36<Z3.
I've had all 3, started with the 95, upgraded to the 96+, and finally grabbed a z3 rack. The Z3 rack is by far the best/ fastest rack. Just FYI.

[JCarp90]

I didnt replace my knuckle on my 91 airbag e30. I modified it so it didnt bind, basically removed a small amount of material in the knuckles joint to prevent it from rubbing on itself due to the increased angle coming off the e36 rack. I believe I put a spacer in the knuckle to make the knuckle shorter in length for the airbag car also. I followed the DIY guide on here the first time I did a swap.

Why the 95 M3 rack though? If you haven't already purchased it, research rack speeds a little more to make sure it's what you want. From what I remember and my personal experience it's the slowest of the common rack swap options. I have the data at home for the racks but I believe it goes 95 M3<96+ M3/standard e36<Z3.
I've had all 3, started with the 95, upgraded to the 96+, and finally grabbed a z3 rack. The Z3 rack is by far the best/ fastest rack. Just FYI.

Thank you for the information.

I've actually been talked out of the Z3 1.9 rack which is what I set out to purchase. Of the E36 racks, the 95 is most desirable actually. It's the 3 turns, as opposed to 3.2/3.5.

What I've heard is that though the Z3 is the shortest turn ratio (2.7), it's almost too much. Sneeze and you're in the other lane kind of thing. Also, it's linear vs progressive. Stock E30 racks are progressive meaning when you slide a little, the wheel sort of corrects itself to bring it back to center, which I like. The Z3 rack doesn't do that.

Correct me if I'm wrong, but I've heard a lot of conflicting information.

[RCM3]

So yes it's 3 turns lock to lock but the speed of the rack differs from the L2L turns, don't just look at the 3 turns vs the 3.2. The 96+ M3 if for sure progressive, and *edit* the 95 is progressive also with the z3 being linear (see below for all data on the racks) . But the 95 M3 rack, from the data I've seen, has a slower ratio. I hope someone can chime in to better describe this, and I'll publish the data I have when I get home.

As far as the Z3 rack, it's not so quick to where it's scary. It truly gives that go-kart steering feel. My rack snaps back to center just like any other e30 rack, and I can drive far more aggressively with the z3 rack over the other alternatives that I've used. Again this is just my experience with the racks, I wasn't a fan of the 95 rack, but I know there are those that enjoy them.

[JCarp90]

So yes it's 3 turns lock to lock but the speed of the rack differs from the L2L turns, don't just look at the 3 turns vs the 3.2. The 96+ M3 if for sure progressive, and the other 2 options are linear. But the 95 M3 rack, from the data I've seen, has a slower ratio. I hope someone can chime in to better describe this, and I'll publish the data I have when I get home.

As far as the Z3 rack, it's not so quick to where it's scary. It truly gives that go-kart steering feel. My rack snaps back to center just like any other e30 rack, and I can drive far more aggressively with the z3 rack over the other alternatives that I've used. Again this is just my experience with the racks, I wasn't a fan of the 95 rack, but I know there are those that enjoy them.

Damn it.

I don't understand why there is so much mis-information out there about this topic. It's quite frustrating when I'm trying to make a purchase.

My car will be a daily driver, attend weekend Auto X's, and attend HPDEs at least once a year. I don't want something that's too tight and too fast. I drive a friend's Evo X occasionally and I can't fucking stand his steering. It's too tight and too fast. I feel as though when I hit a bump, I'm going to veer into a light pole.

What do I need that will make me love my car, not want to set it on fire?

[RCM3]

Now that I've done Z3, I wouldn't go any other way. IMO, it's fast, but not so fast that it's uncomfortable. It's one of my favorite e30 mods to date. Hopefully some more ppl offer info, but there are a few threads on this already. Problem is, like you stated, you have to wade through the misinformation.

[djmossm42]

That sounds about right and was advised the same as far as the z3 rack. After thinking about it I think the combination of short ratio and linear travel is too much every day, plus Shitty Cali streets on top of it.

In case you haven't seen it. Here is a very good rack swap thread with all the options/ratios/prices.

http://www.r3vlimited.com/board/showthread.php?p=460756

Sent from my SGH-T769

[davesmystery]

I will soon be doing a rack swap of some sort myself, I've been reading up on the upgraded rack swaps and it doesn't look like you need to modify the knuckle at all, but what does need to be modified is the firewall.

Here's the best link I've found so far on the topic, the one for airbag cars is halfway down with pics.
http://www.rmeuropean.com/bmw-e30-steering.aspx

I'm still trying to find a guide where someone has done this with the engine in the car as getting to the firewall with everything in place looks like it might be a PITA.

[JCarp90]

Now that I've done Z3, I wouldn't go any other way. IMO, it's fast, but not so fast that it's uncomfortable. It's one of my favorite e30 mods to date. Hopefully some more ppl offer info, but there are a few threads on this already. Problem is, like you stated, you have to wade through the misinformation.

I appreciate the input.. and letting me know I don't need to replace the knuckle.

That sounds about right and was advised the same as far as the z3 rack. After thinking about it I think the combination of short ratio and linear travel is too much every day, plus Shitty Cali streets on top of it.

In case you haven't seen it. Here is a very good rack swap thread with all the options/ratios/prices.

http://www.r3vlimited.com/board/showthread.php?p=460756

Sent from my SGH-T769

Yes I have seen that thread and read most of it. Just sucks that most of it is people asking questions they could have found answers to had they read the OP.

Kansas roads aren't bad, but I live in Kansas City meaning I spend a lot of time on Missouri roads as well and they're all shitty.

I will soon be doing a rack swap of some sort myself, I've been reading up on the upgraded rack swaps and it doesn't look like you need to modify the knuckle at all, but what does need to be modified is the firewall.

Here's the best link I've found so far on the topic, the one for airbag cars is halfway down with pics.

http://www.rmeuropean.com/bmw-e30-steering.aspx

I'm still trying to find a guide where someone has done this with the engine in the car as getting to the firewall with everything in place looks like it might be a PITA.

It's funny - both of those links I had open and was reading when they were sent to me. I don't think I need to modify the firewall unless I actually use the Z3 rack though, right? I'm not sure which was used in the RM Euro link.

[Todd Black 88]

Simple 95 m3 rack info.
3.0 lock to lock, but it's actually the slowest on center rack. It moves the least in the first 200 or so degrees of rotation, of any of the e36 racks, because of its progressive design. It sharpens up after that, noticebly.

The z3 rack is linear, so moves the same distance no matter where in its rotation. It's not "fart and your in the other lane quick", just quicker then stock. I had it in my cab, and it's fine.

[ELVA164]

The '95 M3 rack has the least turns lock-to-lock, but it also doesn't travel as far from lock to lock. Due to the different front end geometry on the '95 M3, BMW had to remove some of the lock. If you want a progressive rack, get either the Z3M rack or the regular E36 rack. They're the same. The regular Z3 rack is the linear one. It will be more responsive near center, but the downside to that is a feeling of "twitchyness" on the highway or a bumpy road, as well as a bit of increased effort at parking lot speeds. When I do this swap, I'm going for the regular E36 rack because I don't need super race car responsiveness, but I want a noticeable improvement on the stock rack.

This thread has the most info about the different racks. https://www.r3vlimited.com/board/sho...d.php?t=172261

[davesmystery]

I was under the impression that all e36 based racks required firewall modification, it's what has me on the line about doing an e36 swap versus just buying a reman'd e30 rack. If you find out otherwise let me know because I'll go with that one for the sake of an easier swap.

[RCM3]

1995 M3:
mm/rev on center: 39.0mm
rack type: progressive
on-center ratio: 19.8:1
ratio @ lock: 15.4:1
mean ratio: 17.6:1
rack length: 117mm
turns lock to lock: 3.0

1996+ M3
mm/rev on center: 45.5mm
ratio @ lock: 15.4:1
mean ratio: 15.6:1
rack length: 145.6mm
turns lock to lock: 3.2

Standard Z3
mm/rev on center: 53.5mm
Linear
13.9:1 ratio
rack length 144.5mm
2.7 turns lock to lock

Car-----------mm/ per. turn--------BMW Part #
E30------------36.5 mm------------32 13 1 092 335
E30 M3---------38 mm--------------32 13 2 225 556
E36 M3 '95------39 mm--------------32 13 2 227 191
E36-------------45.5 mm------------32 13 1 096 280
E36 M3 96+------45.5 mm-----------32 13 1 096 280
E36 Z3 M---------45.5 mm-----------32 13 1 096 280
E46 Std-----------50 mm------------32 13 6 755 065
E85 Z4 M----------51 mm------------32 13 7 836 844
E36 Z3 non-M------53.5 mm----------32 13 1 095 575

According to: http://forums.bimmerforums.com/forum...Steering-racks

[ELVA164]

I've never done it myself, but from the look of it the firewall modification is not a big deal. Do some looking around for other people who have done it and see what it involves.

[RCM3]

My 1988 325iS required no firewall modification (pre-airbag). My 1991 318iS and 1991 318i both required a small amount of the firewall to be removed with a dremel or with a file so there was no rubbing. It really wasnt hard, and probably one of the easier steps involved for the rack swap.