Author Topic: Using E36 steering rack in E30, some user comments (Read 22644 times)

bmwman91 · « **Reply #15 on:** July 03, 2008, 03:58:32 PM »

I tossed in a 1997 1.9L Z3 rack and love it. It is 2.7 turns versus the stock E30 ratio of 4.0. I am running it with PS assist as going without PS really didn't feel like it had THAT much more road feel. The difference was more than noticeable to me...for the first week or so I would turn the wheel too far for a corner lol.

Hope you work everything out!

bmwman91 · « **Reply #16 on:** July 03, 2008, 04:00:02 PM »

Oh and based upon my research, the Z3 rack is the desirable one as it has the shortest ratio. The M3 ones have a 3.0 turn ratio, and I was told that they are not as robust as the Z3 unit. Either way, it beats the crap E30 stock one. Check out http://www.car-part.com. Call around. I got my rack for $200 with 120k miles on it and NO leaks.

tjts1 · « **Reply #17 on:** July 04, 2008, 01:50:09 PM »

Quote from: bmwman91;52556

Oh and based upon my research, the Z3 rack is the desirable one as it has the shortest ratio.

The thing is, the steering ratio and number of turns from lock to lock are not related to each other. The Z3 has a 12" shorter wheel base than any E36 which gives the Z3 a much smaller turning radius. The radius can become so small that the car would be dangerous to drive for an inexperienced driver. In order to prevent this BMW moved the stops inside the Z3 rack to limit its travel compared to a normal E36 rack. This helps maintain a similar turning radius despite the shorter wheel base. The regular E36 and Z3 share the same rack ratio of 15.4 turns of the steering wheel for 1 full 360 degree rotation of the front tires. Obviously its impossible to turn the front tires 360 degrees but the rack ratio is expressed in this way. By comparison the E30 rack has a rack ratio of 19:1 while the E30 M3 was around 17:1. There no doubt that the Z3 rack is a vast improvement over the stock E30 rack but in normal driving it will feel exactly the same as a 3.2 turn E36 rack. At maximum lock with my E36 rack the the inside front edge of the tire actually rubs the sides of the plastic under tray while the stock rack didn't. I rarely have to turn the wheel that far even in slow speed parking lot situations. In this respect, the 2.7 turn Z3 rack is superior to the normal E36 rack.

cheers
Justin

nickmpower · « **Reply #18 on:** July 04, 2008, 02:17:49 PM »

my tire rubs the undertray with the z3 rack too, its quicker. Why do you think there are e36 m3 guys that upgrade to z3 racks?

peerless · « **Reply #19 on:** July 04, 2008, 05:36:16 PM »

Quote from: Frankie;52514

From there you can read that every E36 has quicker steering than E30

Not trying to argue, but if every E36 rack is quicker then why did you start this thread in the first place complaining that it is no better then the E30 rack?

I mean that makes no sense at all. You start a thread stating not to do this mod because its the same as the E30, yet then you come back and say every E36 rack is quicker. And since the E30 rack is about 4.0 turns L/L and the 'standard' E36 being 3.2 L/L It is indeed quicker.

And I know for a fact the 95' E36 M3 rack is much quicker. And in the case of both swaps, the PS was hooked up and correctly functioning. Maybe if your PS was functioning it wouldn't be so heavy.

In addition for reference, the stock US E30 M3 rack has a ratio of 19.6:1 which is the same as the US E30 Rack, the 95' E36 M3 rack has a ratio of 14.9:1!

And just for reference.

Quote

There are 3 different ratios that E36 cars came equipped with. All non-M 3-series coupes and sedans 92-98 came with a 3.2 turn lock-to-lock rack. M3s and M Z3s 96+ had a 3.2 ratio rack as well. 95 M3 had a 3.0 turns lock-lock rack and a 2.8L Z3 96+ had a 2.7. All of the racks look virtually the same, Z3 rack looks different but all the mounting points and the hose attachments are the same as all other E36 racks. It is really easy to tell the racks apart by just looking at them. Silver (unfinished aluminum) racks are 3.2, Gray (anodized) are 3.0 and Z3 racks look like E30 racks with a steel plated tube.

And when I said the standard E36 rack was the same as the E30 rack, that was a generalization. As the best rack to swap is the 95' E36 rack.

peerless · « **Reply #20 on:** July 04, 2008, 05:42:42 PM »

Quote from: adam12hicks;52442

Hey PEERLESS... does it have to be a 95 rack? Did the 96 and 97 M3 racks have different L2L ratios or something? I have a line on a 97 rack setup.

Since you've done a few of these, if I did a 95 (or 97) rack in my 91 318is are there any adapters or other parts I will need to make it happen? I suppose I'd need new tie rods and a good alignment. I already have new M3 CABs and control arms.

Thanks!!!

Yes it has to be the 95' rack. As I mentioned it is very specific. Info presented in the above posts.

No adapters needed. All you need to do is modify the firewall and make a new cover plate. And yes new tie rod assemblies and a alignment will be needed.

See the following write up.
http://www.rmeuropean.com/Articles.asp?ID=136

tjts1 · « **Reply #21 on:** July 04, 2008, 05:53:49 PM »

Quote from: peerless;52608

All you need to do is modify the firewall and make a new cover plate.

I didn't need to modify the firewall. I ditched the plate Inside the firewall.

captaingomes · « **Reply #22 on:** August 02, 2008, 12:46:16 PM »

The consensus, despite a few contrarians, is that this is a very valuable swap for the E30. I've been toying with the idea of getting the swap done, because the steering is the only serious complaint that I have with my '91 318iS. I've had the control arms replaced recently too, which improved matters slightly, but there's a long way to go.

My complaints are that the steering is far too disconnected at highway speeds, especially when not pointing straight ahead. Not only is the steering too slow, but it's also way too light. If I'm driving briskly in my '97 Jetta TDI, I have a firm grip on the wheel and great control. In the BMW, it almost seems that it needs a delicate touch, and a firm grip only makes matters worse.

Long story short - we know generally speaking that an E36 or Z3 rack is quicker, and that's great. What happens to the weight of the steering with this mod, especially at high speeds? Will it get heavier?

Also, I'd go to a mechanic to get the swap done - what sort of prices should I expect to be fair for this mod?

Hopefully somebody can enlighten me

andrson76 · « **Reply #23 on:** August 02, 2008, 03:24:07 PM »

I have found a bunch of differing opinions on the E36 racks, so I decided to ask BMW.
This was their reply:

Vehicle-------------------------Steering Ratio-----Turns (Lock-to-Lock)
1995 M3------------------------variable � 17.6:1---mean 3.0
1995 and 1996 - other 3 Series--16.8:1-------------3.4
1997 3 Series-------------------15.4:1-------------3.4
1996 and on M3-----------------variable 15.6:1 mean
1996 Z3------------------------13.9:1-------------2.75

I posted this near the end of the R3V thread as well. Someone replied about the amount the wheels actually move compared to the # turns lock to lock, but after looking at the actual ratios, wouldn't the Z3 be the quickest? I thought that the ratio was directly related to the amount the wheels move compared to the steering wheel. Or am I missing something that has to do with the length of the rack and the setup of the tie rods?

captaingomes · « **Reply #24 on:** August 04, 2008, 09:45:47 AM »

My brain hurts, I just want nice steering on my E30 *cries*

Frankie · « **Reply #25 on:** August 14, 2008, 02:13:29 PM »

Quote from: peerless;52606

Not trying to argue, but if every E36 rack is quicker then why did you start this thread in the first place complaining that it is no better then the E30 rack?

I mean that makes no sense at all. You start a thread stating not to do this mod because its the same as the E30, yet then you come back and say every E36 rack is quicker. And since the E30 rack is about 4.0 turns L/L and the 'standard' E36 being 3.2 L/L It is indeed quicker.

And I know for a fact the 95' E36 M3 rack is much quicker. And in the case of both swaps, the PS was hooked up and correctly functioning. Maybe if your PS was functioning it wouldn't be so heavy.

In addition for reference, the stock US E30 M3 rack has a ratio of 19.6:1 which is the same as the US E30 Rack, the 95' E36 M3 rack has a ratio of 14.9:1!

And just for reference.

And when I said the standard E36 rack was the same as the E30 rack, that was a generalization. As the best rack to swap is the 95' E36 rack.

Well, I did not explain my case clear enough. I have a non ps IS and tried to get faster steering by swapping to e36 rack. I drive my IS on track mostly. There I did not notice any significant difference between the 2 racks.

I read from various sources that the difference (including that web source) that is is much faster. Well, its not. As you said steering ratio is not that faster compared to E30 racks.

Froos · « **Reply #26 on:** December 29, 2008, 02:47:47 PM »

hey guys can we put some part no's down to finish off this topic? thanks

cecotto · « **Reply #27 on:** December 29, 2008, 03:53:37 PM »

Attached you'll find an image I've made showing three specified racks.

I have measured how many millimeters the rack moves for each revolution.

I think this shows the different ratios pretty good.

nickmpower · « **Reply #28 on:** December 29, 2008, 04:25:01 PM »

and the e36 m3 is faster then the regular e36 and the z3 is faster still

cecotto · « **Reply #29 on:** December 29, 2008, 04:54:12 PM »

Quote from: nickmpower;63668

and the e36 m3 is faster then the regular e36 and the z3 is faster still

The E36 series has two different racks:
* Standard, which is also used on the 3.2L M3
* M3 3.0 Unit (I have not measured this yet) But this is second hand data i have from another site:
* * M3 3.0 - 39 mm/rev - the slowest available rack. This is a variable ratio but it is slower than standard until 200 deg hand wheel angle