Interest for aluminum front spindles for E46 M3, roll center and bumpsteer corrected?

[paulkots]

Hey guys, trying to gauge interest for front aluminum spindles for E46 M3. I have been emailing companies to see if anyone is interested in developing a product and there is some interest but the main question is who will purchase them.

In my email I have asked for the following.
- roll center correction
- bumpsteer correction
- aluminum/lighter weight
- E9x M3 bolt-on hub
- bolts-in like factory to OEM control arms and tie rod ends

What would you guys expect from these spindles?
- Price?
- Weight savings?
- Correction for which ride height?

I am been trying to correct bump steer on my mostly street driven E46 M3 but everything that is sold comes with exposed heim joints(not street friendly). To correct both bumpsteer and roll center with the current market kits, it usually costs $1250-$1500 since you need tubular control arms for roll center correction.(SLR, VAC)

[ScotcH]

You don't need tubular arms. Can be done with just balljoint replacement and tierods. But a since set of new spindles would sure be sweet ... I suspect they would run like $3k though based on the buy in numbers you'll get. Why are you trying to correct roll center on a street car? Just seems like it would be so far down the list of priorities ...

[paulkots]

You don't need tubular arms. Can be done with just balljoint replacement and tierods. But a since set of new spindles would sure be sweet ... I suspect they would run like $3k though based on the buy in numbers you'll get. Why are you trying to correct roll center on a street car? Just seems like it would be so far down the list of priorities ...

The ball joint replacement is only offered my MRT but their kit also quickens the steering by 30% which won't work with MK60 ABS. I already bought and tested VAC bump steer correction kit and was left disappointment, it seems like roll center needs to be corrected for the bump steer correction to work properly.

Rough measurements I did at home on my E46 M3. I have a Longacre bump steer gauge coming this weeks so I will double check my measurements.

Stock tie rod with 13.5" front ride height]
11.5": +6.2mm (toe-in) (0.087 degree of toe in per wheel)
12": +3.5mm
12.5": +1.9mm
13": +0.5mm
Static 13.5": 0mm
14": -0.6mm
14.5": -1.0mm
15": -1.0mm (0.014 degree of toe out per wheel)
15 3/8": -0.7mm(toe-out) (0.0098 degree of toe out per wheel)

VAC 35mm correction kit with 13.5: front ride height
11.5": -2.5mm (toe-out) (0.035 degree of toe out per wheel)
12": -2.0mm (0.028 degree of toe out per wheel)
12.5": -2.0mm
13": -1.0mm
Static 13.5": 0mm
14": +1.0mm
14.5": +2.5mm
15": +3.5mm (0.049 degree of toe in per wheel)
15 3/8": +5mm(toe-in) (0.070 degree of toe in per wheel)

[bluptgm3]

I like the idea...I think it is crazy for a street car.

You are trying to replace a critical suspension component that is forged steel with a machined billet aluminum component? Do you have rough order of magnitude of the gage increases required and the impact of packaging (suspension attachments) this proposal poses?

For a notional look at what I am addressing, compare the E36 forged steel forward lower control arms to the E46 forged aluminum FLCAs, then look at the E46M3 FLCAs. Note how much material has to be added.

Winters Performance produces aluminum spindles for a number of racing classes. Midget, Mini Sprint, Sprint spindles for track only cars that weigh a third of what an E46 weighs.

This ‘stuff’ requires heavy gages and these type of parts in aluminum would be life limited as aluminum components generally have a fatigue life.
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[paulkots]

I am a customer that is interested, I am definitely not qualified to create this. I have reached out to multiple companies and there is interest from some big companies that we trust, the question is, will people buy these. This is the reason I posted a few questions that I am hoping you guys can answer.

What would you guys expect from these spindles?
- Price?
- Weight savings?
- Correction for which ride height?

What I am hoping for is a company like BBi Autosport(BBi is not interested, I asked)(they created 964/993 spindle) would R&D and create a spindle that would be lighter, as strong or stronger and came with bump steer/roll center correction.

Edit: What I am hoping a company creates is a spindle that can be used by guys like myself that want them for a street car just because I like spending time in the garage dicking around with my M3 and track guys that would actually see a benefit from having these. Current roll center and bump steer correction kits are limited to track guys only and they are a band-aid by extending studs which need to be always checked so they don't fail.

[Matt330LS]

I am been trying to correct bump steer on my mostly street driven E46 M3 but everything that is sold comes with exposed heim joints(not street friendly). To correct both bumpsteer and roll center with the current market kits, it usually costs $1250-$1500 since you need tubular control arms for roll center correction.(SLR, VAC)

https://www.turnermotorsport.com/p-5...i-328ci-330ci/

This kit is for a non-M. They may have one for the M but I'm not sure since I don't own one.

[paulkots]

https://www.turnermotorsport.com/p-5...i-328ci-330ci/

This kit is for a non-M. They may have one for the M but I'm not sure since I don't own one.

I asked all companies that make E46 kits, none make it for M3s, its something to do with our control arm. MRT does offer a kit for E46 M3 but only with 30% quicker steering ratio like the Turner kit, that doesn't work for me since it will not play well with MK60 ABS system.

[ScotcH]

Good point ... we run non-M e46, so easily replace the outer balljoint with GC e36 correction kit. You could fab in a custom balljoint (spherical with stud) but you'd be stuck with the same not street friendly joints.

[bluptgm3]

How about this approach, though not aluminum, not light weight...have THL create spindles to your specs

Winters Performance produces a variety of Spindles, with Stainless or Titanium ‘pins’.
Probably need to use a bolt on strut attachment similar to E36, as the ‘pinch’ style E46 complicates construction and material selection.

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[aeronaut]

Why won't quicker steering and MK60 ABS work well together?

[paulkots]

How about this approach, though not aluminum, not light weight...


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I can’t see an attached image. Lightweight is good but not mandatory. I wouldn’t want a heavier spindle but most important is the bump steer and roll center adjustment. I personally would pay more for a product if it checks off everything from my “want to have” list.


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[paulkots]

Why won't quicker steering and MK60 ABS work well together?

You can program a ZCP steering rack to MK60 abs but from my understanding, it’s either impossible or you need a custom program($$$) for something very different like 30% quicker steering rack. Also quicker rack doesn’t mean better, it can mean twitchy at high speed.


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[aeronaut]

You can program a ZCP steering rack to MK60 abs but from my understanding, it’s either impossible or you need a custom program($$$) for something very different like 30% quicker steering rack. Also quicker rack doesn’t mean better, it can mean twitchy at high speed.


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"Program a ZCP steering rack"?
I'm still lost.
ABS and steering ratio, somehow linked? Especially steering ratio that's increased at the kingpin.

- - - Updated - - -

There are several folks that will TIG weld the OEM kingpins for improved roll, bump, ackerman, and steering ratio. That's a price point you'd have to compete with.

[aeronaut]

Ok...probably something with the steering angle sensor and DSC. I assume the ABS computer uses steering angle via the steering column to make DSC decisions. Related to ABS, but different. Still, yes, I could see an issue. Just turn DSC off.

[paulkots]

Ok...probably something with the steering angle sensor and DSC. I assume the ABS computer uses steering angle via the steering column to make DSC decisions. Related to ABS, but different. Still, yes, I could see an issue. Just turn DSC off.

Thats correct. Steering angle sensor will see a 15 degree turn while the speed sensors and lateral sensor will sense a 15 degree turn plus 30%. When on track, this can also lead to ABS going into ice mode because the MK60 does not know what is going on.

[ScotcH]

Thats correct. Steering angle sensor will see a 15 degree turn while the speed sensors and lateral sensor will sense a 15 degree turn plus 30%. When on track, this can also lead to ABS going into ice mode because the MK60 does not know what is going on.

You can just disconnect the steering sensor. ABS works perfectly fine without it.

[aeronaut]

You can just disconnect the steering sensor. ABS works perfectly fine without it.

Yea, when I first saw the comment, I was like WTF is there some odd case preventing me from installing a MK60 on my E36 AND quicker steering ratio? But now I understand.
No DSC and no steering angle sensor required in an E36/MK60 application. I'll be moving along...

[paulkots]

Since I have a street car, I want all electronics to work. If this was a track car, I wouldn't have an issue.

MRT showed some interest is revising their correction kit so it would be street friendly(boots) and without the 30% quicker steering. I think there is a good market for such a kit since most HPDE guys also street drive their cars so exposed heim joints are usually a no-go.

[Matt330LS]

Since I have a street car, I want all electronics to work. If this was a track car, I wouldn't have an issue.

Since it is a street car what exactly is the end result you're trying to achieve with all these requirements you noted, particularly the E9x hubs? What is the issue you're trying to address?

[paulkots]

Since it is a street car what exactly is the end result you're trying to achieve with all these requirements you noted, particularly the E9x hubs? What is the issue you're trying to address?

Main requirement is corrected roll center/bump steer with no adverse effect on electronics and no exposed heim joints. Secondary is weight savings, its an added bonus that I would pay extra for but not a requirement.

E9x hub can be bolted to an aluminum hub and its OEM so it should have a good service life.

[jakermac]

Also quicker rack doesn’t mean better, it can mean twitchy at high speed.

This is a complete and total fallacy. I have the SLR Speed roll center/bumpsteer correction blocks on my E36, ALONG WITH a Z3 steering rack. I have effectively reduced my steering ratio IN HALF. I have less than 2 turns lock to lock. The car is not twitchy in any way shape or form, unless of course you are a strung out crack head whore that can't control motor skills.

[aeronaut]

I'm with Jackermac on this one.
E46 330 rack in an E36. MRT rollcenter/bump kit. Both reduce # steering wheel revs needed lock-lock.
I'm also running zero toe. (soon to go to toe-out)
It's wonderful, and not at all twitchy.

Faster steering, and more front neg camber, are the 2 mods everyone should do to make these cars FUN.

[paulkots]

Bimmerworld is interested in producing a spindle, question is if there is a market for it.

We can argue steering ratios and pedal response(I don't like the quick mapping of sport E46 M3 pedal) over a beer.

[bbrtuning]

I'd be super interested in this, been weighing options to correct bump steer/roll centre for a couple years now. This does seem like one of the best ways to do it, especially since I also get quite a bit of knockback due to our garbage wheel bearings/hubs. If this doesn't happen or is a long ways off, I'm going to go with the MRT setup.

[ScotcH]

If this doesn't happen or is a long ways off, I'm going to go with the MRT setup.

Lol ... read the thread right above your (e36 roll correction)