Suspension refresh - critique my life choices

[Estoril]

I knew this would come up, maybe you can elaborate on your stance for posterity's sake.

I realize the flaw in the argument of "I know lots of people who have roll bars and have never had a problem in an accident" so I won't go there. Nor would I bring up factory crash tested cars with factory roll bars. I would just say my best data point is the legality of cars like ours with roll bars like these in Europe, namely Germany, where TÜV is satisfied. TÜV is not without its flaws, like any government agency, but they don't typically allow things that are flagrantly dangerous to the occupants.

And very few of them (if any) are OE bolt-in cages. Its your head - your choice.

[heinzboehmer]

Good call on the clips!

MK20 has different connectors for the front wheel speed sensors: https://nam3forum.com/forums/forum/m...ors#post227034

[bmwfnatic]

good point on the bearings, I didn't think about that. I will probably still run these SPL arms though, everything I've listed I have already bought. I might reconsider the diff mounts.

In that case, I would personally source a boot, since the diff needs to come out in order to get the bolt out to change them.
The term for them is "rose joint boot" they can be had for just a few dollars on eBay.

For the rear upper arm inner bushing, I was under the impression that it isn't advisable to do a spherical joint because tha tcan limit movement which can in turn negatively impact how the rear sway bar moves since it's attached to the arm. Is that incorrect?

I think you have it the wrong way around, it would effectively allow the arm to pivot, it wouldn't limit movement but create movement that wasn't possible previously.
Apart from that, your statement is probably correct, I haven't looked much into it, just noticed that some vendors like Turner and Millway do sell the spherical joint for that position, hence I mentioned it.

[PSUEng]

On the rear subframe: it’s going to be the little things that give you grief:

1) Wiring: the ABS wheel speed sensor and brake pad wear sensor. The plastic connector on the car side will crumble in your hands. Plan on replacing all three connectors with BMW ABS Wheel Speed Sensor Connector (2 Pin) - Genuine BMW 61131392246, they are $8.09 each. You will need small picks to remove the terminals. On the passenger side, paint or mark one so you can remember which is which.
2) Wiring: the cable clips that hold those wires to the rear trailing arm will break or have already. Get 10 or so because zip ties won’t be on par with everything else you’re doing. BMW Cable Clip - Genuine BMW 34521164653. They are $1.09 each.

Good Luck!

PS: new OEM bushings on the diff are my vote. Solid on the subframe is fine.

Good call on the cable clips, mine have broken easily. I'm curious, though, are those 61131392246 connectors used on E46 originally, or just usable, on the E46? I don't recall the chassis side connector being blue like that, but that doesn't necessarily mean anything. My chassis side connector had a locking clip break, so if I can replace it, that would be great.

EDIT: Is it maybe 61131393742 ?

[OldRanger]

are those 61131392246 connectors used on E46 originally, or just usable, on the E46?
EDIT: Is it maybe 61131393742 ?

I would consider them "usable" on the E46. I took a guess on them based on the fact they had the same shape. They are a different color than the OEM black and blue, probably a different part number as well like you mention. I installed them yesterday to address fault codes I was getting. Granted, I've only driven a few miles, but no codes returned immediately so I think they are compatible.

The two original wire terminals and rubber seals install properly, and the side release clips fit into their retention slots on the other part of the connector. It was a firm push.

[repoman89]

Re: rear camber arms I ended up with the Bimmerworld sealed spherical ones after doing the research last year. They seemed the closest to the OE CSL arms while being adjustable. Happy with them, no noticeable additional NVH and my installer and alignment tech didn’t complain about adjusting or anything. Running -2.0 degrees in the rear.

Bimmerworld sells bearing replacements too but hopefully they last a long time.

[Slideways]

Re: rear camber arms I ended up with the Bimmerworld sealed spherical ones after doing the research last year. They seemed the closest to the OE CSL arms while being adjustable. Happy with them, no noticeable additional NVH and my installer and alignment tech didn’t complain about adjusting or anything. Running -2.0 degrees in the rear.

Bimmerworld sells bearing replacements too but hopefully they last a long time.

They use a Febi (Bilstein) bearing which should last a while. When it comes time to replacing them, I imagine the stock lower/upper Lemforder ball joints might fit that BW housing.

[bigjae46]

Engine and trans mounts - OEM or solid.

I would shim the PS pump relief to lower the system pressure. I think this helps with the system's reliability.

Make sure the air ducting in front of the radiator is good - ensures your coolant system works as well as it can.

I would clean, inspect, and repack the axle and driveshaft CVs. Probably best to replace the axle CVs since they are probably really old. I'd just keep running the driveshaft CV until you start getting a high speed vibration.

I know...roll bars are a slippery slope but its important! So for the roll bar - I would highly recommend installing a fixed back seat with a roll bar. The OEM seat back is designed to flex and might break. If you go with a roll bar - then fixed back seat, 6pt harness, HANS at a minimum.

If you are installing a roll bar for rollover protection...consider this...deaths and injuries in a rollover are rarely caused by the roof collapsing, extremely rare. Most injuries and deaths are caused by body parts hitting the pavement when the car rolls over on its side - specifically death due to the head hitting the pavement which curtain airbags are supposed to prevent.

So if rollovers are a concern, you want at a minimum a containment seat in addition. Also a window net would be a key safety device but you kinda need a roll cage for that. For me, my biggest concern is a side impact.

+1 on the Viton O-rings ( I bought mine on eBay and they came with the snyth lube, https://www.ebay.com/itm/295468391970 ), regardless if you go with OEM or aftermarket water hoses.

Wow...I need this. Thanks!

[heinzboehmer]

Good call on the cable clips, mine have broken easily. I'm curious, though, are those 61131392246 connectors used on E46 originally, or just usable, on the E46? I don't recall the chassis side connector being blue like that, but that doesn't necessarily mean anything. My chassis side connector had a locking clip break, so if I can replace it, that would be great.

EDIT: Is it maybe 61131393742 ?

I think the difference between the 61131392246 blue ones and the grey/black ones that come on the car is that the blue ones have no keys in them. Meaning that any plug with that same basic shape will fit. IIRC, the stock grey/black ones are keyed so you don't mix the sensors up.

[Nate047]

In that case, I would personally source a boot, since the diff needs to come out in order to get the bolt out to change them.
The term for them is "rose joint boot" they can be had for just a few dollars on eBay.

Good looking out, I'll take a look at that. Anything simple that can make my life easier and more maintenance free is a good thing.

I think you have it the wrong way around, it would effectively allow the arm to pivot, it wouldn't limit movement but create movement that wasn't possible previously.
Apart from that, your statement is probably correct, I haven't looked much into it, just noticed that some vendors like Turner and Millway do sell the spherical joint for that position, hence I mentioned it.

I'm gonna look into this more and see what people are actually running in the real world. That piece is also not exactly easy to get to though so I would like to do it once and not want to change it out again soon after if possible.

[9kracing]

The rollbar debate has been beat to death in the Honda community, and in 20+ years I've never see one person that has bashed their heads open on a rollbar on the street, but I've seen several threads where people crashed and the rollbar either helped, or flat out saved their life.

I wouldn't lose any sleep over it.



I'm curious though, since this car is mostly track, why not run a bump steer kit, why the OEM tie rods?

[Nate047]

Engine and trans mounts - OEM or solid.

I would shim the PS pump relief to lower the system pressure. I think this helps with the system's reliability.

Good call, I hadn't thought about the PS system much. The car has Bimmerworld engine mounts and I believe Rogue trans mounts of some sort, I'm going to leave those alone for now.

[quote]I would clean, inspect, and repack the axle and driveshaft CVs. Probably best to replace the axle CVs since they are probably really old. I'd just keep running the driveshaft CV until you start getting a high speed vibration.[quote]

Also a good call, this is a job I have never done before on any car... I'll see if I can find a good DIY video. Any part recommendations as far as OE vs OEM vs original BMW etc...? I feel like there are definitely winners and losers in that area.

I know...roll bars are a slippery slope but its important! So for the roll bar - I would highly recommend installing a fixed back seat with a roll bar. The OEM seat back is designed to flex and might break. If you go with a roll bar - then fixed back seat, 6pt harness, HANS at a minimum.

If you are installing a roll bar for rollover protection...consider this...deaths and injuries in a rollover are rarely caused by the roof collapsing, extremely rare. Most injuries and deaths are caused by body parts hitting the pavement when the car rolls over on its side - specifically death due to the head hitting the pavement which curtain airbags are supposed to prevent.

So if rollovers are a concern, you want at a minimum a containment seat in addition. Also a window net would be a key safety device but you kinda need a roll cage for that. For me, my biggest concern is a side impact.

Thanks for the input, so I do have Racetech 4100 seats going in, with 6-point belts. I have a HANS for track days. For now I don't want a head restraint seat, I'm keeping the air bags in the car for now too. I'm thinking about putting some pads on the roll bar, it's very unlikely that my head could hit the bars, but better safe than sorry. Also, for now I am doing seat sliders but I feel like not too far in the future I may be mounting the seat solid and adding a back brace.

[Nate047]

The rollbar debate has been beat to death in the Honda community, and in 20+ years I've never see one person that has bashed their heads open on a rollbar on the street, but I've seen several threads where people crashed and the rollbar either helped, or flat out saved their life.

I wouldn't lose any sleep over it.



I'm curious though, since this car is mostly track, why not run a bump steer kit, why the OEM tie rods?

TBH I have thought about that, what are the options there? Turner and Ground Control? I have also considered getting offset bearings for roll center correction in the rear. I had roll center correction on my last pure track car which was a Honda (B18 EK hatch), I loved that single mod more than almost anything else.

On the other hand I have spent kind of a lot on this project already lol, and I kinda want to just get it out there, see how it is, and worry about that later.

[9kracing]

I was looking at the Achilles ones.

[bigjae46]

The rollbar debate has been beat to death in the Honda community, and in 20+ years I've never see one person that has bashed their heads open on a rollbar on the street, but I've seen several threads where people crashed and the rollbar either helped, or flat out saved their life.

I wouldn't lose any sleep over it.



I'm curious though, since this car is mostly track, why not run a bump steer kit, why the OEM tie rods?

I'd say...not the best idea to daily drive a car with a roll car. I don't see a huge issue for occasional drives on the street. The risk of getting into an accident is relatively low but there is a chance. Definitely not a death sentence.

Why a bump steer kit? I'm on OE tie rods, never really ran into a steering issue although my front ride height is higher than most track E46s.