bumpsteer and e36 rack spacer location

[rturbo 930]

FYI: If you want to put the spacers on the bottom with a Z3 rack, it won't fit. The problem is that the top of the rack hit's the top bracket on the subframe, leaving the rack about 1/8" out from where it needs to be. You will need to either cut off a bit of the end of subframe bracket on both sides (1/4" would be plenty), or make a new set of spacers so that the rack is spaced down a bit from the subframe bracket. I think 1/8" on top and 3/8" on bottom would work. I don't feel like taking the rack completely out, so I will be doing the latter.

Edit: I made and installed new spacers, 3/8 bottom, 1/8" top. Tie rods appear to be much more level with the control arms when the car is on the ground. They certainly weren't before. However, it didn't fix my issue, although I think it did improve it, so I'll be looking at my alignment next.

[Sagaris]

Hey Sagaris, could you repost these pictures? I'm debating moving my spacers from top to bottom to hopefully fix an issue I'm having.

Thanks for the heads up, I will see if I can find them

[rturbo 930]

Hellabad is correct, everything I have read about e36/z3 rack swaps is wrong.

Here is the tie-rod angle with the spacers above the rack


Here it is after moving the spacers below the rack


My car drives normal now after putting the spacers below the rack and has a normal/basically undetectable amount of bumpsteer

Hey Sagaris, could you repost these pictures? I'm debating moving my spacers from top to bottom to hopefully fix an issue I'm having.

[LJ851]

Sorry for the delay, here are pics of mine. It was difficult to get a good shot.

[Sagaris]

It took a whole 15 minutes to jack the car up, change spacer location, take pics, correct the toe-settings and be done. I didn't even have to remove the fluid lines on mine. I still haven't ground down any of the firewall to clearance the steering shaft even though it was <1mm away from touching, now it has about 2mm of clearance and I will just open it up just a little bit for peace of mind but really one could probably get away with not bothering with it.

I cant speak for everyone but you can see the geometry difference in the pictures and I noticed a very positive change from using the spacers under the rack.

[bastianshaw]

wow, so i messed up good huh lol sweet

[jeffnhiscars]

I did a rack swap yesterday and wrapped it up today. There was no way to get the spacers underneath the rack as the hard pipes hit the pan. I wasn't too concerned as my 84 318i rack did not look at all like the e36 rack and its center line (rack plane) would have been higher than the original with the spacers underneath. I also have Eibach Prokits and Bilstein Sports.

The steering is more stable and just enough quicker to make me smile. I'm wondering if its possible that the revised geometry could have eliminated the bit of bump steer I had ?

[LJ851]

I'll try to take a pic of mine and post it here.

[Sagaris]

Good to know. About a month passed between the start and finish of my rack swap and I didn't quite remember how the lines were routed when it came time to put it together. Everyone seems to say it is just a small bend in the HP but I wasn't seeing it. I will have to take a look at someone else's e30 and see how the stock lines are routed again (its just that coiled portion of the HP hose that threw me off, it wasn't fitting nicely anywhere)

[LJ851]

If you run power steering it would be great to see how you route/bend the power steering lines to get them to work, I have mine working but there has got to be a better way to do it than how I did.

I just bent my E30 line a little bit and it worked fine.

[Sagaris]

If you run power steering it would be great to see how you route/bend the power steering lines to get them to work, I have mine working but there has got to be a better way to do it than how I did.

[pantelones]

Good to know, I am doing an e36 rack right now and I was wondering about the orientation myself.

[Sagaris]

Hellabad is correct, everything I have read about e36/z3 rack swaps is wrong.

Here is the tie-rod angle with the spacers above the rack


Here it is after moving the spacers below the rack


My car drives normal now after putting the spacers below the rack and has a normal/basically undetectable amount of bumpsteer

[bastianshaw]

Bump steer can definitely steer your car by itself on the street. All you need to do is hit a good bump with one wheel or one wheel first like a set of train tracks at an angle. A friend had a '59 bugeye sprite with bumpsteer issues we were fixing and it was all you could do to stay in your lane in those situations.

bastianshaw, do like hellabad suggested and get some toe boards, it's really easy to do and if you take your front springs out you can check your own bumpsteer by raising and lowering the chassis through its normal travel and measuring the toe change.

cool

[LJ851]

Bump steer can definitely steer your car by itself on the street. All you need to do is hit a good bump with one wheel or one wheel first like a set of train tracks at an angle. A friend had a '59 bugeye sprite with bumpsteer issues we were fixing and it was all you could do to stay in your lane in those situations.

bastianshaw, do like hellabad suggested and get some toe boards, it's really easy to do and if you take your front springs out you can check your own bumpsteer by raising and lowering the chassis through its normal travel and measuring the toe change.