E46 steering rack

Post Wed Aug 26, 2015 9:21 pm

Going to fit e46 rack my 325.

Bit uncertain as to which steeringjoint I need.

Read about a 14mm spacer. E34 joints. E36 ect.

Thanks in advance.

Post Wed Aug 26, 2015 9:27 pm

PM DanThe - he's the man that can. He stocks everything you need for your conversion.

Post Wed Aug 26, 2015 9:42 pm

I've just fitted a Corsa steering joint on mine. Fairly simple to DIY - about an hour to get it all sorted and there's plenty to be found in breakers yards.

Post Thu Aug 27, 2015 10:35 pm

Hi guys . Just bought the e46 club sport rack myself for my e30 325i sport . How can I search for this DanThe person to see what parts I need to fit ?
Thanks

Post Thu Aug 27, 2015 10:39 pm

send me a pm, I have pipe kits and linkages available

Post Thu Sep 03, 2015 7:03 pm

Corsa c steering linkage and top half of e30 uj. Bit of a frustrating job but looks bice and "proper" and its very simple.

Post Thu Sep 03, 2015 7:36 pm

Mines gone together with stock linkage, and the rubber bush too...

Standard exhaust though

Post Thu Sep 03, 2015 8:36 pm

TriggerFish wrote:Mines gone together with stock linkage, and the rubber bush too...

Standard exhaust though

The rack will be in the wrong mounting holes if so

Post Thu Sep 03, 2015 10:51 pm

It's defo in the right holes. The rear ones (i.e., nearer to the driver than to the lights).

I'll try and grab some photos when I go down to it next if you like?

Post Fri Sep 04, 2015 6:45 am

Slightly off topic but I'm fitting an 067 to my touring shortly and noticed that the wiki guide says to fit the spacers above the rack, now my cars lowered so does this not make the steering geometry even worse? I don't know if e30s suffer terribly from bumpsteer but lowering the rack will surely worsen it?! Is there any reason why the spacers can't be fitted underneath to raise the rack?

Post Sat Sep 19, 2015 7:40 pm

DanThe wrote:
TriggerFish wrote:Mines gone together with stock linkage, and the rubber bush too...

Standard exhaust though
The rack will be in the wrong mounting holes if so

As promised, some photos while it was getting the tracking done/tyres replaced. Yes, I know, I forgot the heat shield off the guibo.

Please ignore the state of grime on everything.

Post Sat Sep 19, 2015 7:47 pm

Looks like its gone near enough all the way down the input shaft on the rack, didn't think there would be enough room in the bottom of the linkage, looks close!
As long as you can get the input shaft dust cover back on should be fine

Post Sat Sep 19, 2015 8:50 pm

Yeah, it's a looong way onto the rack, but the dust cover is on and not being trapped. It is close, but it does all fit. There's a little bit of space on the top, where the spline exits the bulkhead, but that UJ wasn't going anywhere easily, so I left it, given it works OK.

Post Sat Sep 19, 2015 10:30 pm

I couldn't get the standard E30 linkage to fit without the end of the rack input shaft hitting the inside of the UJ.

Post Mon Sep 28, 2015 10:27 am

do people always put the rack spacers on the top? wouldnt it make more sense to have it centered with a spacer top and bottom?

Post Mon Sep 28, 2015 7:10 pm

I'm working at German car spares Kent and we always have the purple tag racks in stock . Please give us a search we mainly break the e46 ..thanks

Post Mon Sep 28, 2015 10:02 pm

reggid wrote:do people always put the rack spacers on the top? wouldnt it make more sense to have it centered with a spacer top and bottom?

Spacers are positioned to keep the rack in the same vertical position as it was with the E30 rack. The 'missing metal' on the E46 rack is at the top, so that's where the spacers go.
Moving the rack vertically produces bump steer.

Post Mon Sep 28, 2015 11:35 pm

Brianmoooore wrote:
reggid wrote:do people always put the rack spacers on the top? wouldnt it make more sense to have it centered with a spacer top and bottom?
Spacers are positioned to keep the rack in the same vertical position as it was with the E30 rack. The 'missing metal' on the E46 rack is at the top, so that's where the spacers go.
Moving the rack vertically produces bump steer.

its odd, the reason i bring it up is i notice some bump steer with my z3 rack on poor quality roads and the spacers are on the top. others i know have put spacers below and have no bump steer according to them. i cant do that as exhaust gets in the way hence thought "centrering" it halfway may help, but if its already centered.........

is the z3 rack the same as the e46 rack in terms of the brackerty?

i'm renewing my steering coupling with a DanThe splined job so will see if things improve in this regard but unlikely that anything other than the excess slop will be removed as when the coupling was new the same issues were there. everything else suspension wise is basically less than a year old.

Post Tue Sep 29, 2015 8:18 am

As I said previously, on a lowered car I'd imagine spacers fitted underneath (to move the rack up) may well be beneficial. Without getting the bump gauges on the car this is just an estimated guess based on other cars I've worked with, I'll endeavour to get the gauges on mine when I fit my rack.

Post Tue Sep 29, 2015 8:47 am

Ive never measured the exact position of the rack gear compared to an E30, always fitted the spacers on top mainly due to clearance with the 24v sump etc, will have to have a measure.

Post Tue Sep 29, 2015 8:49 am

allanallen wrote:As I said previously, on a lowered car I'd imagine spacers fitted underneath (to move the rack up) may well be beneficial. Without getting the bump gauges on the car this is just an estimated guess based on other cars I've worked with, I'll endeavour to get the gauges on mine when I fit my rack.

so if i look at the tie rod geometry the ends connected to the strut are noticeably higher than the rack centre due the car being lowered (its not stupid low about the same as an eibach prokit) this angle obviously gets worse under a heavy bump situation . will making this more parallel to the ground be one way of making an improvement? or does how parallel to the ground the tierod is not mean much or bear little relevance to likelihood of bump steer?

like dan said i cant add the whole spacers to the bottom due to clearance with other shit but i may be able to split the difference. i notice there are bump steer kits for the e30 m3 and thses as best i can tell are either 1/2" or 1" spacers that bolt to the bottom of the strut housing so the tie rod end is lowered as opposed to raising the rack.

Post Tue Sep 29, 2015 1:47 pm

The M3 spacers are the ideal solution as they put the tie rods and wishbones back at the right angle for the roll centre of the car. All a complex subject but its like moving the axles up on the strut instead vs compressing the suspension.

A normal E30 obviously cannot take advantage of this as the steering and wishbone mounts are fixed so cannot be spaced.

I have my E36 rack up against the top hole and do not really feel any bump steer. Can't try it lower though as I moved the bottom tabs to meet the rack so I am fixed in the upper position.

As Dan said the key dimension is the centre of the tie rod ball joint to the mounting lug faces and I don't think anyone has measured this for the different racks.

Post Wed Sep 30, 2015 1:07 am

http://www.ground-control-store.com/pro ... .php/II=12

there is an option for the e30 with e36 rack but shame there isnt a boot with them

Post Wed Sep 30, 2015 7:49 am

Well if spacing the TRE's down (like in your link) reduces bumpsteer so will raising the rack up in the car. Boots for rose joints are readily available for peanuts too ;)

Post Wed Sep 30, 2015 7:56 am

willnz wrote:Bump steer.. an interesting phenomenon.

I was bored so put this VERY basic sketch together on CAD to simply demonstrate how steering angle changes in relation to suspension travel .. commonly called bump steer. Hopefully this will help a little to enlighten those who have no idea what bump steer is all about..??

I also added two tie rod lengths (350mm and 450mm) to demonstrate how this differing length has an effect on the degree of steer with suspension travel.

Please note that this diagram is highly theoretical and very basic; I am not trying to emulate the system in any car, just trying to demonstrate what happens when your road wheel moves in relation to the steering rack- steering/suspension geometry is a VERY complex system that has seemingly endless variables, and is the bane of every petrolhead who just wants to go round corners faster!!!

The top diagram assumes a 350mm tie rod. The measurement starts with the tie rod horizontal with the steering rack, and then moving the end upwards in 50mm steps up to 200mm.

At 50mm up, the change in effective length of the tie rod is 4mm. This pulls the road wheel in by 1.21 degrees (assuming the tie rod end is 190mm ahead of the axle centre).
At 100mm up, the effective length shortens by 11mm, which pulls the road wheel in by 3.31 degrees.
At 150mm up, the effective length shortens by 19mm, this pulls the road wheel in by 5.71 degrees.
At 200mm up, the effective length shortens by 29mm, this pulls the road wheel in by 8.68 degrees.

When the tie rod is lengthened to 450mm, the effect on the road wheel is reduced for the same suspension travel, 200mm travel results in the road wheel turning in by 'only' 6.31 degrees as compared with 8.68 degrees for a 350mm tie rod length.

Most lowered cars have a tie rod which is already at a steep upward angle in relation to the steering rack. This steepened angle results in an increased sensitivity to bump steering. You can reduce this bump steer by moving the rack upwards (if possible),and reducing the angle between the steering rack and the tie rod. You can also install a bump steer kit which effectively reduces the angle between the steering rack and the tie rod by lowering the tie rod end to be more in line with the steering rack (not my favourite bit of kit though... I would rather try to improve the rack position etc to rectify the angle issue..).

If you are still confused, ask, and I will try to better explain what is going on here.

That sums it up nicely. It's often not possible to move the rack on cars so spacing the TRE's is the only option. It's not something that can be guessed either, it's amazing the difference spacing the TRE by only 1mm has on the bump curve! Most cars have bumpsteer as standard to give particular driving characteristics, it's not always desirable to have 0 bump either....

Post Wed Sep 30, 2015 10:16 am

is moving the rack up 6mm likely to make any sort of difference? or is a waste of effort?

would this be equivalent to raising the car ride height by the same amount given the tie rod angle will be the "same"?

does negative camber have a strong effect on bump steer? i have adjustable top mounts but conservative camber numbers

Post Wed Sep 30, 2015 10:37 am

Neg camber can be horrendous on a bumpy road, as I found out recently 'testing' my track car on local roads!

The only way to see for sure is to try it both ways with the same steering parts

Post Mon Oct 05, 2015 11:59 am

Something not to forget about is there is a relationship between the wishbone and the tie rod to maintain as well, the wishbone has its own sweep angle and "length change" which effects both the camber of the wheel and the hubs position from the centre line of the car.

If you end up with a situation where the wishbone is effectively "shortening" and the track rod effectively "lengthening" then it will try to turn the hub. In the case of the E30 this would steer the wheel outwards.

The best way to measure this on a built car is to take the wheel off, bolt an new disc in place of the wheel to use as a measuring plate. Compress the spring with spring compressors and cycle the suspension using a jack while checking a DTI on against the disc.

Edit - By "best" I mean easiest/simplest with what you will have available. The best way is to obviously use a dedicated set up to measure it with everything stripped down.