e30 steering rack ratio

[ross_jsy]

Does anyone know the actual ratio of an e30 rack? I don't have one to hand so I can't go out and measure.

The reason I ask, my car came with an Impreza rack fitted. One of the local rally boys does a conversion with them. However it's never felt particularly fast, especially compared to the z3 rack in my other car. Looking at the ratio, they have a relatively feeble 16.5:1 (z3 is 13.9:1 iirc)

[jmc330i]

Differences between racks

E30 PAS rack:
4 turns (20.5:1).........shocking!!!


E36 (non-M) and E46 standard rack (incl. M3):
3.4 turns (15.4:1)


E46 M3 CSL and CS:
3.2 turns (14.5:1) Probably the nicest if you don't like twitchiness but you'll pay for them!!!

E46 330 clubsport/ZHP pack:
3 turns (13.7:1) The holy graile of E30 quick racks due to it being quickest and having better weighting:D
Also needs an oil-cooler fitted


Z3 rack;
2.7 turns (13.9:1)
Was thought to be the fastest rack availible but if compared to the E46 Sport rack in terms of ratios, it actually isn't. Just has .3 of a turn less overall lock

E36 M3 and Z3m racks: crap due to lock tabs and appearing faster than standard racks because of this and/or progressive steering and being an "//M part" therefore overpriced accordingly

[ross_jsy]

Perfect, thanks for that. e30 rack is slower than I thought! But it's been a while since I've driven an e30 with a standard rack in place.

[Brianmoooore]

There's more to it that that, when you use a rack from one car in a car of another make. The length of the steering arms come into it as well.
A 'slow' steering rack from a car with 6" long steering arms, will become a 'fast' rack if fitted to a car with 3" steering arms.

[ross_jsy]

It uses e30 steering arms so the total length is going to be roughly similar