[Phil325i]

Originally Posted by Biginboca

I bought this one:

51-61-7-046-337

It came in last week and has 2 fixing points. It’s probably 4mm thick and weighs 2-3lbs. I honestly think it’s more than sufficient I’m actually reluctant to mount it cause of the added weight but you guys have me second guessing not using it so I’ll install it next time I have the car lifted.

It’s nice how cheap these parts are I got mine for $12 with shipping!

According to RealOEM Onicar's one is half the weight of the one we've bought. As it's only $6 in the UK, I might go for his instead. Lighter weight and three securing points...

[Tambohamilton]

Never trust realoem weights! They may be right, but I've also seen 1 tonne light brackets etc etc...

[Phil325i]

Originally Posted by Tambohamilton

Never trust realoem weights! They may be right, but I've also seen 1 tonne light brackets etc etc...

I think you're right - looking at pics of the items I really can't believe one is twice the weight of the other..!

[Biginboca]

Ok a few updates...

I just read the M2 adapted some of the chassis bracing from the F23 convertible along with F80/82 bracing. So using E93 bracing on the E92 seems validated!

“BMW M used a number of different parts specifically meant to increase rigidity. A number of individual components throughout the front of the car were adopted from the F23 as well as F80/F82 and F83:

Front-end struts
Strut brace
Front axle support with additional connection in the side sill area
Stiffening plate
Carrier support struts
Cross member, bottom
Front-end reinforcements of the engine supports by stiffening module made of aluminum in front of the cooling”



I find it interesting to note the M2 uses the chassis plate, the F23 bracing, and also has the chassis supports in front of the radiator. So BMW basically threw every brace they had on that car.


Ok, moving on from bracing back to suspension... and UNIBALLS

Unfortunately a lot of the parts I needed for the rear uniball swap are ordered (and back ordered lol). So I’m waiting on those and decided to really focus on the front for now since all the parts are available. So this leads to the last update... and this is a big one to me...

I now have the complete front suspension (L&R) inbound from a low miles rear ended F80m3. I want to swap to the M spindle geometry and maybe some of the other parts. I was able to get the all the L&R side parts for only $430 delivered so it was very appealing for reasons I’ll outline below:



The geometry of the M spindles (both E9XM and F8XM) is different than the series production units and I wanted the full M steering Geometry. The control arm and tie rod attachment points of the E92M3 spindle are identical to the F80/82/87 spindles. So either one would work for my (our) application as stated in prior posts and there are a few guys running E9XM spindles on E9X series cars now, tetsuo111 for one, but I haven’t seen anyone running the FXM ones.

The benefits of both the E9XM3 and F8XM spindles are:

The tie rods attach farther away from the kingpin axis, meaning they have better leverage which reduces steering effort. This is good because I’m running the M3 rack with Servotronic variable assist not connected, so the rack defaults to the lowest assist and I wouldn’t mind a lower effort.

The geometry is designed to work properly with M control arms (upgrades we all do for added camber). So the scrub radius and Ackerman angles will be corrected to what BMW intended rather than slightly changed by just adding m control arms to a normal spindle.

If anyone running M control arms has ever noticed the inner edge of the front tires wear more aggressively it’s because the steering geometry isn’t correct with just adding M control arms to standard spindles. The inside tire in a turn scrubs it’s inside edge too much hence why bmw changed the tie rod mounting points for the M cars. Fixing this should also give a more precise steering feel.

M Spindles are rumored to also have higher steering inclination angle, so they would add extra camber in turns over normal spindles. So at the same static camber settings (same amount of camber driving straight) when you turn the steering wheel you gain additional camber with M spindles vs Series spindles.

And then there’s a few other advantages of the M2/3/4 parts I found over the E92M3 ones:

Using the FXM spindles also allows cheap brake upgrades from F series Brembo swaps (including M2/3/4 brakes with just bolting on the hubs from one of those cars. The FXM hubs came with the parts I bought.). Or you can use non M F30 brakes (M Sport, etc) running the normal e9x Non M front hubs which are on my car now. So lots of possibilities there.

F8X spindles are lighter than E9XM spindles. I’ve seen reports from 1/2lbs to 3lbs total weight savings. When you look closely at them side by side you can see how BMW started with a E9XM spindle and then they streamlined material away for weight reduction...





Also interestingly enough the M2/3/4 hubs have similar weight reduction treatment with a lot of unneeded material simply cut away. It’s reported they are 1lb lighter than the E9XM hubs which they are interchangeable with except they have upped to m14 lug bolts instead of m12. So that makes them stronger and lighter, how cool!



Lastly one other interesting point. Just like we E90 guys add camber with M lower control arms, the F30 guys add camber with F8X lower control arms. The F8X M control arms (wishbones, not tension arms) are 10mm longer than the standard F30 arms. I am curious about running the F8X arm for even more front camber on the E90 series. This appears it will also shift the wheel slightly forward in the wheel well so might require the F8X tension strut (for added length). This part I’m not sure about due to my wheel tire fender clearance but it’s more curiosity anyway.

The challenges of running the FXM spindles are 2:

The strut mount to the spindle is different. The M series struts have a fattened area that seats against a lip inside the spindle:





The series E9X (non M) spindles have no lip and use a tab on the strut to locate them against the spindle:



The fix I’m going to try for this is a sleeve made by MCS for adapting their E90 series coilovers to be used in M cars:

https://www.bimmerworld.com/Suspensi...or-Sleeve.html



Of course you could always just swap to M struts but then it starts to get very pricey because the top mounts are different, they don’t work with E9X springs, and then if you buy m coilovers you have to swap the rear lower control (camber) arms, etc.

The other obstacle is the ABS sensor mount. On the F series cars it’s rotated 90 degrees from the E series cars. Some E9XM3 guys just bolt it in anyway and run it rotated and they claim it works fine, but I’m thinking I can make a little aluminum bracket to hold it and adapt it to the proper orientation:

[Tambohamilton]

Nice. Will be interested to see how you get on with all this.

[Biginboca]

Originally Posted by Tambohamilton

Nice. Will be interested to see how you get on with all this.

I wouldn't bother rotating the abs sensor...they're not direction sensitive.

Good to know! That really makes this a plug and play.

One other thing I forgot to mention is for safety I also ordered the longer M3 tie rods. I read you can use the E90 ones but it sounded like the thread engagement was minimal at the newly extended length, and therefore potentially unsafe.

[Tambohamilton]

I'll be interested to see just how much longer the m3 rods are! There's so much thread engagement on stock rods even with m wishbones. Just be interesting to have that as a measure of the difference between the stock and m uprights

[mad1stgen]

Originally Posted by Tambohamilton

I wouldn't bother rotating the abs sensor...they're not direction sensitive.

They're definitely orientation sensitive and need to custom mounted in F8x spindle.
We've done couple of those swaps on E91 builds.
You'll get ABS codes otherwise for wrong wheel rotation.

[Tambohamilton]

I stand corrected! I didn't think they were...

[Biginboca]

Originally Posted by mad1stgen

They're definitely orientation sensitive and need to custom mounted in F8x spindle.
We've done couple of those swaps on E91 builds.
You'll get ABS codes otherwise for wrong wheel rotation.

Ok great, good to know! I was already prepared to deal with this so thanks for sharing that.

[Biginboca]

Was just thinking about the upcoming spindles install and realized that adds another new model to my parts car count for this Mutt!

328csl Parts Cars (13... so far)

Euro E90 328i (Airbox)
E90 328i XDrive (3.91 Rear Differential)
E92 335i (Oil Cooler, Throttle Body, and Intake Manifold)
E92 335is (Door Cards)
E92M3 (Control Arms, Steering Rack, and Roof)
E93M3 (Front Chassis Plate)
E93 328i (Front Subframe Brace)
E60 530i (Vented Differential Cover)
X1 (Steering Wheel Trim)
A90 Supra (Rear Control Arm Aero)
F33 335i (Front Brakes)
F80M3 (Front Spindles)
E46M3 (Badges)

[Phil325i]

That gives you top bragging rights I reckon!

[ornicar]

Originally Posted by Biginboca

Ok a few updates...

I just read the M2 adapted some of the chassis bracing from the F23 convertible along with F80/82 bracing. So using E93 bracing on the E92 seems validated!

"BMW M used a number of different parts specifically meant to increase rigidity. A number of individual components throughout the front of the car were adopted from the F23 as well as F80/F82 and F83:

Front-end struts
Strut brace
Front axle support with additional connection in the side sill area
Stiffening plate
Carrier support struts
Cross member, bottom
Front-end reinforcements of the engine supports by stiffening module made of aluminum in front of the cooling"



I find it interesting to note the M2 uses the chassis plate, the F23 bracing, and also has the chassis supports in front of the radiator. So BMW basically threw every brace they had on that car.


Ok, moving on from bracing back to suspension... and UNIBALLS

Unfortunately a lot of the parts I needed for the rear uniball swap are ordered (and back ordered lol). So I'm waiting on those and decided to really focus on the front for now since all the parts are available. So this leads to the last update... and this is a big one to me...

I now have the complete front suspension (L&R) inbound from a low miles rear ended F80m3. I want to swap to the M spindle geometry and maybe some of the other parts. I was able to get the all the L&R side parts for only $430 delivered so it was very appealing for reasons I'll outline below:



The geometry of the M spindles (both E9XM and F8XM) is different than the series production units and I wanted the full M steering Geometry. The control arm and tie rod attachment points of the E92M3 spindle are identical to the F80/82/87 spindles. So either one would work for my (our) application as stated in prior posts and there are a few guys running E9XM spindles on E9X series cars now, tetsuo111 for one, but I haven't seen anyone running the FXM ones.

The benefits of both the E9XM3 and F8XM spindles are:

The tie rods attach farther away from the kingpin axis, meaning they have better leverage which reduces steering effort. This is good because I'm running the M3 rack with Servotronic variable assist not connected, so the rack defaults to the lowest assist and I wouldn't mind a lower effort.

The geometry is designed to work properly with M control arms (upgrades we all do for added camber). So the scrub radius and Ackerman angles will be corrected to what BMW intended rather than slightly changed by just adding m control arms to a normal spindle.

If anyone running M control arms has ever noticed the inner edge of the front tires wear more aggressively it's because the steering geometry isn't correct with just adding M control arms to standard spindles. The inside tire in a turn scrubs it's inside edge too much hence why bmw changed the tie rod mounting points for the M cars. Fixing this should also give a more precise steering feel.

M Spindles are rumored to also have higher steering inclination angle, so they would add extra camber in turns over normal spindles. So at the same static camber settings (same amount of camber driving straight) when you turn the steering wheel you gain additional camber with M spindles vs Series spindles.

And then there's a few other advantages of the M2/3/4 parts I found over the E92M3 ones:

Using the FXM spindles also allows cheap brake upgrades from F series Brembo swaps (including M2/3/4 brakes with just bolting on the hubs from one of those cars. The FXM hubs came with the parts I bought.). Or you can use non M F30 brakes (M Sport, etc) running the normal e9x Non M front hubs which are on my car now. So lots of possibilities there.

F8X spindles are lighter than E9XM spindles. I've seen reports from 1/2lbs to 3lbs total weight savings. When you look closely at them side by side you can see how BMW started with a E9XM spindle and then they streamlined material away for weight reduction...





Also interestingly enough the M2/3/4 hubs have similar weight reduction treatment with a lot of unneeded material simply cut away. It's reported they are 1lb lighter than the E9XM hubs which they are interchangeable with except they have upped to m14 lug bolts instead of m12. So that makes them stronger and lighter, how cool!



Lastly one other interesting point. Just like we E90 guys add camber with M lower control arms, the F30 guys add camber with F8X lower control arms. The F8X M control arms (wishbones, not tension arms) are 10mm longer than the standard F30 arms. I am curious about running the F8X arm for even more front camber on the E90 series. This appears it will also shift the wheel slightly forward in the wheel well so might require the F8X tension strut (for added length). This part I'm not sure about due to my wheel tire fender clearance but it's more curiosity anyway.

The challenges of running the FXM spindles are 2:

The strut mount to the spindle is different. The M series struts have a fattened area that seats against a lip inside the spindle:





The series E9X (non M) spindles have no lip and use a tab on the strut to locate them against the spindle:



The fix I'm going to try for this is a sleeve made by MCS for adapting their E90 series coilovers to be used in M cars:

https://www.bimmerworld.com/Suspensi...or-Sleeve.html



Of course you could always just swap to M struts but then it starts to get very pricey because the top mounts are different, they don't work with E9X springs, and then if you buy m coilovers you have to swap the rear lower control (camber) arms, etc.

The other obstacle is the ABS sensor mount. On the F series cars it's rotated 90 degrees from the E series cars. Some E9XM3 guys just bolt it in anyway and run it rotated and they claim it works fine, but I'm thinking I can make a little aluminum bracket to hold it and adapt it to the proper orientation:

Discussions about suspension and chassis are by far my favorite topics. It is a real pleasure to read you.

I have mounted f8x spindles on my 125i, so don't hesitate to ask questions.

@Mightymousetech is building F8x spindles too, don't hesitate to take a look at his thread.

Big up to @KevM3UK which is I believe the 1st to have discovered the possibility of mounting F8x spindles on E9x E8x.

[Biginboca]

Originally Posted by ornicar

Discussions about suspension and chassis are by far my favorite topics. It is a real pleasure to read you.

I have mounted f8x spindles on my 125i, so don't hesitate to ask questions.

@Mightymousetech is building F8x spindles too, don't hesitate to take a look at his thread.

Big up to @KevM3UK which is I believe the 1st to have discovered the possibility of mounting F8x spindles on E9x E8x.

That’s great, thanks for that info. I still wasn’t 100% sure this was a viable swap I didn’t know anyone else had done it, so that’s reassuring for sure!

I got my parts in today. Started measuring the control arms. So it looks to me like the F80, E92M3, F30/22, and the E9X cars all have the same length tension arms. The arm with the blue uniball is my new arm going into my car and the arm on the knuckle is the F80 arm. So no benefit to swapping that, and in fact because it lacks the clearance bends of the e9x arm maybe it would hit the swaybar or tie rods? Who knows but I’m not going to swap it because I see no reason:



Now the F80 LCA definitely is around 18mm longer than the E92M3 arm.



So this is interesting. Seems like the F80 arm might be too long. It adds 1* camber on the F30 platform and is 10mm longer than the F30 arm. Seems like that would make the F80 arm add maybe 1.7 or so degrees of camber to the E90 platform. But the side effect would be it also moves the wheel outside and forward in the wheel well, maybe too far forward. It’s possible the F30 LCA might be a viable camber swap to get even more than the E92M3 LCA, but not as much as the F80 arm.

I’m very curious what happens with the F80 arm on the E92 so I might mount one up just to see how much camber it adds and how far forward it pushes the wheel. I’m at -1.7 camber now and would really like to be between -2.0 and -2.5, but I don’t want to run camber plates so if these arms can get me there the I’m all for it.

[ornicar]

Originally Posted by Biginboca

That’s great, thanks for that info. I still wasn’t 100% sure this was a viable swap I didn’t know anyone else had done it, so that’s reassuring for sure!

I got my parts in today. Started measuring the control arms. So it looks to me like the F80, E92M3, F30/22, and the E9X cars all have the same length tension arms. The arm with the blue uniball is my new arm going into my car and the arm on the knuckle is the F80 arm. So no benefit to swapping that, and in fact because it lacks the clearance bends of the e9x arm maybe it would hit the swaybar or tie rods? Who knows but I’m not going to swap it because I see no reason:



Now the F80 LCA definitely is around 18mm longer than the E92M3 arm.



So this is interesting. Seems like the F80 arm might be too long. It adds 1* camber on the F30 platform and is 10mm longer than the F30 arm. Seems like that would make the F80 arm add maybe 1.7 or so degrees of camber to the E90 platform. But the side effect would be it also moves the wheel outside and forward in the wheel well, maybe too far forward. It’s possible the F30 LCA might be a viable camber swap to get even more than the E92M3 LCA, but not as much as the F80 arm.

I’m very curious what happens with the F80 arm on the E92 so I might mount one up just to see how much camber it adds and how far forward it pushes the wheel. I’m at -1.7 camber now and would really like to be between -2.0 and -2.5, but I don’t want to run camber plates so if these arms can get me there the I’m all for it.

Do the width is the same (71mm) on the F80 control arm?
If you wish to add camber Without camber plate, one solution is to use special F80 spindles with camber correction # 31217853639 & 31217853640

[Biginboca]

Originally Posted by ornicar

Do the width is the same (71mm) on the F80 control arm?
If you wish to add camber Without camber plate, one solution is to use special F80 spindles with camber correction # 31217853639 & 31217853640

I know they make those spindles but I think they are like $400ea or something. I just got some take offs with these parts for a lot cheaper. It would be nice to find some of the camber adjusted ones on a wrecked car though lol

I suspect a set of F30 LCA would give me exactly what I’m after provided they don’t push the wheel too far forward in the wheel well.

Do the normal f80 spindles change the camber from the “non M” e9x spindles?

The F80 LCA doesn’t have the 71mm end on it, it’s a normal end just the width of a standard bushing/uniball like how the rear arms have them. But I purchased the press tools so I could swap the 71mm from my current LCA on the car into the F80 or F30 arm I’m pretty sure.

[ornicar]

Originally Posted by Biginboca

I know they make those spindles but I think they are like $400ea or something. I just got some take offs with these parts for a lot cheaper. It would be nice to find some of the camber adjusted ones on a wrecked car though lol

I suspect a set of F30 LCA would give me exactly what I'm after provided they don't push the wheel too far forward in the wheel well.

Do the normal f80 spindles change the camber from the "non M" e9x spindles?

The F80 LCA doesn't have the 71mm end on it, it's a normal end just the width of a standard bushing/uniball like how the rear arms have them. But I purchased the press tools so I could swap the 71mm from my current LCA on the car into the F80 or F30 arm I'm pretty sure.

I am agree with you brand new splindles are expensive/ used parts.

Sadly, you cannot swap the 71mm uniball. It is special, a part of the uniball is machined in the arm himself. I ever have explored this way.

[Biginboca]

Originally Posted by ornicar

I am agree with you brand new splindles are expensive/ used parts.

Sadly, you cannot swap the 71mm uniball. It is special, a part of the uniball is machined in the arm himself. I ever have explored this way.

Oh, interesting. So I would have to make a spacer or stack washers to take up that gap if I wanted to run the f arms.

[Tambohamilton]

Yes, and I wouldn't really recommend either of those options...the single spacer for preference, definitely. Would be best if you could have it engage with the end of the ball joint somehow. If you look at some more of fe1rx's threads, you'll find pics of how the ball joint is fitted to the e9x arm, just for reference.

[Biginboca]

ornicar What brakes are you running? I’m now second guessing the fitment of the F30 brakes on the F80 spindles. I found this picture of F80 brakes on non M spindles and hubs:



So there’s spacers installed there to move out the caliper. It seems the F80 rotors sit farther out from the hub (like how lower a wheel “offset” measurement moves a wheel outwards) like 5-10mm vs the non M rotors. And the caliper mounting area of the F80 and F30 Brembos is the same offset.

So I’m thinking maybe the F80 spindles mounting points for the caliper sits father out (towards the face of the wheel) by that same amount, like 5-10mm. If so I would have to machine those mounts thinner or use a rotor that is also moved outwards.

The only rotor I see which might work for me as a bolt on is... the E46CSL rotor funny enough! It looks like it would mount to the M4 hub and has the correct offset and dimensions (345 x 28) vs the F30 M sport (340 x 30).

[Phil325i]

For once realOEM weights can be trusted!

3-holed skid plate (right) 225g
2-holed skid plate (left) 400g

[ornicar]

Originally Posted by Biginboca

ornicar What brakes are you running? I'm now second guessing the fitment of the F30 brakes on the F80 spindles. I found this picture of F80 brakes on non M spindles and hubs:

[img]https://i.postimg.cc/G3s6q53q/8-B66-...65-B081-CE.jpg[/img]

So there's spacers installed there to move out the caliper. It seems the F80 rotors sit farther out from the hub (like how lower a wheel "offset" measurement moves a wheel outwards) like 5-10mm vs the non M rotors. And the caliper mounting area of the F80 and F30 Brembos is the same offset.

So I'm thinking maybe the F80 spindles mounting points for the caliper sits father out (towards the face of the wheel) by that same amount, like 5-10mm. If so I would have to machine those mounts thinner or use a rotor that is also moved outwards.

The only rotor I see which might work for me as a bolt on is... the E46CSL rotor funny enough! It looks like it would mount to the M4 hub and has the correct offset and dimensions (345 x 28) vs the F30 M sport (340 x 30).

I have saying you there was an +11mm axial offset and +5mm radial offset .


https://www.bimmerpost.com/forums/sh...php?p=27133365



I am sorry my English is far to be perfect. a drawing would be better...

I use Brembo 135i 6 pots caliper with 345mm csl 2 parts discs. I have to use 11mm spacers.

Maybe in the future i will buy the hydra brackets, or i will do it myself.