E36 Steering Rack Question(s)

[topnotchrally 160]

I have been driving an 1997 E36 318i Motorsport sedan for 10 years. It's a made in SA car and it's a fantastic car.  I am the 2nd owner, the first owner brought it with him from SA. It has no modifications.  I recently bought a 1995 M3 sedan and am annoyed to discover that the steering ratio is lower than my 318i.  It's not a lot but enough that I noticed right away.  Any ideas on why this is?  The rack part numbers are different (on realoem.com).  Why would they be different?  

Thanks.

[KwS 2448]

Its well known the M3s have a shitty steering ratio. Get a purple tag rack in there.

[M M 250]

Agreed, purple tag makes a massive difference.

[NZ00Z3 190]

BMW has done it to other models too.

The standard Z3 has a 2.7 turn to turn ratio, one of the fastest for a BMW.  The Z3M has a standard E36 rack, which is slower.  Why?  The interweb/forum logic is that the Standard Z3 is for normal road speeds.  Whereas the Z3M is likely to be track/performance driven and the fast rack at high speeds becomes dangerous.  Don't know if that's BMW's thinking or not.

[M3AN 4112]

Whilst most of the above is true the most important thing hasn't been mentioned... the S50B30 M3 (~92-95) (i.e. your one) has a unique steering rack which is considered amongst the worst BMW has provided, it has no redeeming features, it's not used on any other vehicles.

Unless there's a ZA difference the rack in your 318 will be the same as in an M3 Evo which is still considered vague as best.

In ascending order of preference:

95 M3 Rack -> Standard E36 (inc. M3 Evo Rack) -> Retrofitted E46 Sport Rack ("purple tag") -> retrofitted Non-M Z3 Rack.

Some are progressive, some are linear, some have other changes, tons of info out there on the 'net. 

Edited January 7, 2021 by M3AN

[euroriffic 630]

I’ve heard the e46 zhp gold tag from the late model 330ci trumps all, but I think it was mostly made for the American market, so a rhd maybe hard to come by. I need to do some more research on that 

[M3AN 4112]

11 hours ago, euroriffic said:

I’ve heard the e46 zhp gold tag from the late model 330ci trumps all, but I think it was mostly made for the American market, so a rhd maybe hard to come by. I need to do some more research on that 

LHD only and it's comparable to the "purple tag" rather than the Z3 rack IIRC.

[wrs 120]

Does the purple rack have slightly more overall travel than the standard E36 rack?

I recently failed a warrant because a new anal guy at VTNZ noticed 2 tiny rub marks on my inner guards where the wheels just rub slightly from time to time (20mm mark in the underseal but no metal exposed). I'm sure it didn't do this prior to the purple rack. I had to pop the boots and put a 3mm spacer on each rack shaft end to reduce the travel - once done there was no issue with the warrant.

[M3AN 4112]

I'm not 100% sure now, I measured it back in the day, I think the purple tag + e46 inners are 10mm too much for the e36, which is why I got my e36 inners machined to allow internal venting. I think the racks have the same travel.

That's a picky WoF! you can get OEM rack stops if required.

[euroriffic 630]

On 1/8/2021 at 12:16 PM, M3AN said:

LHD only and it's comparable to the "purple tag" rather than the Z3 rack IIRC.

Thought it would be.