e36racks ratios

[rc]

Anyone know the turns lock to lock for all the e36 racks?

[ian332isport]

Anyone know the turns lock to lock for all the e36 racks?

The following info was taken from another site, but is pretty much gospel for the UK.

As there has been a lot of hearsay going around about the various steering rack ratios fitted to the E36 and the M3s I have spent some time doing some measurements (and have used some of M3 Compact's measurements) plus confirmed the data direct with ZF (I know someone who works there who can access drawings on their system).

The standard way ZF quote on-centre (straight ahead) ratio is in mm/rev, which is the travel in mm of the rack bar per revolution of the hand wheel. The higher the mm/rev the faster the rack.

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

M3 3.2 and standard E36 - 45.5 mm/rev- the M3 3.2 rack has restricted lock.

Z3 1.9 rack - 53.5 mm/rev- by far the quickest rack you can fit.

E46 compact rack - 50 mm/rev- this also fits the E36

Because the M3 3.0 has a variable rack it has the smallest lock to lock at 3.0 turns but don't be fooled it is the slowest by a country mile. A worthwhile upgrade for any 3.0 M3 would be to fit a standard E36 rack which is what I did a year ago with a noticeable improvement.

The bit about the E46 compact rack is not 100% correct, as the 50 mm/rev rack was only used on E46 models with sport suspension, so not all E46 compacts would have one. I have one on my car, and it's from a 330ci Clubsport.

Ian.

[hoshy]

Very interesting - do you know how many mm/rev the e30 and e30 m3 racks are ??

[ian332isport]

Very interesting - do you know how many mm/rev the e30 and e30 m3 racks are ??

I don't know the mm/rev for the E30 racks, but the standard E30 power rack is approx 4 turns lock to lock, and the M3 is approx 3.5 turns.

As a comparison, the standard E36 rack (45.5 mm/rev) is 3.4 turns (need to remove the lock limiting tabs if it's from an M3 Evo), and the E46 sport rack (50 mm/rev) is 3 turns.

Ian.

[hoshy]

Cool. is there much of a difference in fitting difficulty between an e46 sport rack and a z3 1.9 rack?

[ian332isport]

Cool. is there much of a difference in fitting difficulty between an e46 sport rack and a z3 1.9 rack?

Virtually identical to look at, and both exactly the same to fit, except you can't use the E46 track rod ends, as the taper is a lot bigger. Just use E36 rod ends, or complete E30 track rods and ends.

Ian.

[drifty325i]

Is there a rack from an e36 perhaps a 318ti that comes off at the same angle like the e30 one? ie my e36 rack does not clear my v8s extractors that were designed around the factory e30 rack.cheers

[ian332isport]

Is there a rack from an e36 perhaps a 318ti that comes off at the same angle like the e30 one? ie my e36 rack does not clear my v8s extractors that were designed around the factory e30 rack.cheers

That's about the only downside of using the E36/46 rack. They all have a different pinion angle to the E30 rack.

Ian.

[DIBLY]

Is there a rack from an e36 perhaps a 318ti that comes off at the same angle like the e30 one? ie my e36 rack does not clear my v8s extractors that were designed around the factory e30 rack.cheers

That's about the only downside of using the E36/46 rack. They all have a different pinion angle to the E30 rack.

Ian.

Is there a rack from an e36 perhaps a 318ti that comes off at the same angle like the e30 one? ie my e36 rack does not clear my v8s extractors that were designed around the factory e30 rack.cheers

Think in your part of the world there was a company who got an m3 e30 rack took out the internals, made a new pinion and shoe horned it back into a rhd steel cased rack. try the S14... Net site?

[odbod]

Depends what you are fitting it to, if you have a 318IS use the Z3 Rack it's a straight fit to the coupling (so you miss out most of the pain of rebuilding/sourcing bits for the coupling) if you use the front mounting holes in the subframe, you have to do some pipe bending whatever approach you take. The Z3 Rack is good and is ~2.8 turns lock to lock.

I mostly do motorway miles and have had no issues with stability of such a quick rack, make sure you get the tracking done though.

[hoshy]

why is the pinion angle important and what problems does it cause ?

[ian332isport]

why is the pinion angle important and what problems does it cause ?

It's not particularly important as far as operation of the rack is concerned, but it does cause steering coupling/exhaust manifold clearance problems.

If you have an exhaust manifold designed to clear the standard steering coupling, it probably won't clear if you fit the E36 style rack. The pinion angle changes, which effectively moves the steering coupling lower joint closer to the engine block.

Ian.

[ian332isport]

Depends what you are fitting it to, if you have a 318IS use the Z3 Rack it's a straight fit to the coupling (so you miss out most of the pain of rebuilding/sourcing bits for the coupling) if you use the front mounting holes in the subframe

Not always an option. If I tried to use the front holes on my car, the rack would hit the sump. I assume this is the case with any M50/52 or S50 conversion.

Ian.

[hoshy]

interesting - cheers ian.

I have an iS / m42 so I guess no problem for me to use a z3 rack.

Can they be swapped without removing the engine/sump or anything?

[odbod]

Not always an option. If I tried to use the front holes on my car, the rack would hit the sump. I assume this is the case with any M50/52 or S50 conversion.

I've only done it with the M42 engine, there is a pipe mounting boss that needs grinding down in length to clear the lower M42 Sump.

I have an iS / m42 so I guess no problem for me to use a z3 rack.

Can they be swapped without removing the engine/sump or anything?

I did mine with the engine out but have had it off since, it's a bit awkward but not too bad if you don't mind lying on your back for a few hours! You'll need some 13mm spacers to go on the bolts as the rack mounting points are narrower than than the E30 rack, alternatively you could use a stack of washers in the interim, I have my spacers below the rack to ensure ground clearence is level or higher than the bottom of the sump.

Worst case you might remove the lower sump on an M42 to make life easier, If you have any questions drop me a line here or on a pm

[hoshy]

cheers for the info guys!

I had put off getting a new rack but I'm more tempted than ever since... My route to work (like most people's I'm sure) has quite a few 90deg bends and it's surprising how much wheel turning you have to do for daily driving... then of course there's the primary reason of being able to get the counter-steer on and off quicker

[Dan318-is]

I have got a z3 rack on my i.S. I fitted it with the engine in place, and although fiddley at times there are worse jobs. Like odbod says, the only pain in the arse is the pipes but these can be overcome pretty easily. New banjo crusher washers & fluid is also needed obviously! As long as you can source a rack its a must do conversion in my opinion, the car drives ten times better with one,

Iam, any idea of the relation between z3 & e30 pinion angles? My rack bolted straight on and i have no bumpsteer issues etc and it clears everything excpet the undertray which needed modifying ever so slightly.

[alan1272]

has anyone fitted the E36 rack to a 318is? i need to know if it clears the manifold. i'd like a Z3 rack but they seem difficult to find.

[ian332isport]

Iam, any idea of the relation between z3 & e30 pinion angles?

As far as I'm aware, the Z3 and E36 rack have the same pinion angles, and are both different to the E30.

[papercutout]

Depends what you are fitting it to, if you have a 318IS use the Z3 Rack it's a straight fit to the coupling (so you miss out most of the pain of rebuilding/sourcing bits for the coupling) if you use the front mounting holes in the subframe, you have to do some pipe bending whatever approach you take. The Z3 Rack is good and is ~2.8 turns lock to lock.

I mostly do motorway miles and have had no issues with stability of such a quick rack, make sure you get the tracking done though.

Would you say the Z3 rack is the best to fit the 318iS for quick steer9ing then?
What mods do you need to do to make it work straight off? (besides getting tracking done), does anything actually need changing for it to work? Clearance fine etc?
Thanks

(If not the Z3 rack, what other quick turning rack is good?)

[odbod]

I wrote this up for someone else the other day so I might as well share it...

This thread has some more information if you want to read all 8 pages...

http://www.e30zone.net/modules.php?name ... ck&start=0

In terms of the Z3 Rack I used the front mounting holes in the subframe and a stack of washers underneath the rack to ensure ground clearence with no ill effects regarding bump steer etc, although on a road car you'd have to really mess it up to notice. If you are getting some spacers made up they want to be about 13mm long.

On the rack there is a welded on mounting boss for the hydraulic pipes that needs grinding off to clear the lower M42 sump.

I used E36/Z3 Steering arms which are a straight fit and you might as well change them for new at the time. When you pick these up make sure you have the nut and cone that come with it or you'll be off to BMW for new ones. E30 arms will work but you will have to change the rack ends as well which is a bit of a pain in the arse. Also get some new ally washers from BMW, I have changed mine as the old ones I re-used leaked.

You will need to cut a bit from the undertray to clear the gators.
I used an E36 318IS return pipe and bent it a little bit to fit and the original E30 pipe for the pressure feed (don't try jubilee clips on this one unless you want to pump all the fluid onto your drive!) and bent it a lot to fit. It might be as easy to get some custom hoses made up at a local hydraulics place. I might yet to tidy things up. The original pipes are really easy to crack when bening them so your better off using a pipe bender, but they are steel so it's hard work, you can make life easier with a blow-torch or oxycetalene if you can get your hands on a torch!

In terms of fitting it's easier without the lower sump off especially to fit the pipes although you'll want the sump to hand to check clearences. The Z3 Rack fits straight onto the IS pinion and clears the exhaust manifold. just make sure you push it far enough up the spline, you will be able to see the cutaway portion of the spline on the rack inside the coupling once fitted, if it's not far enough on it won't go into the subframe holes. A rubber mallet helps alot here!

Having a jack to hand to support the rack as you fit the bolts and washers makes life easier as the rack twists in it's mounting and is difficult to align the bolts. It twists becuase the mounting flanges are so far apart relative to the rack casting height thickness at the bolts.

Mark the rack entreline before you fit it and centre the steering wheel with the steering lock on, get it tracked as best you can by measuring the old rack ball joint to centre line and setting the steering rods on the floor before fitting to the car. Then get over to a laser alignment place and have it done properly (unless you want an excuse to buy new tyres!).

[oze30]

What about the e36 318ti rack? Or E46 318 rack? Anyone know the ratios??