[1QuikWS6]

Originally Posted by BMW DIY Guy

Hahahaha.. absolutely right, fixed in like 10 seconds. Well done man, thank you!

No problem

Sometimes forest gets lost for the trees

[1QuikWS6]

This is the one I'm curious about





Never seen anyone feel it necessary to brace that area b4...

Our F32 already have the triangulated rear bar, I don't think there version would make any difference other than it's more rigid.

I do have the M4 aluminum plate under the front plate of my factory cross brace with longer screws. Sure that's stiff enuf

[BMW DIY Guy]

Originally Posted by 1QuikWS6

This is the one I'm curious about





Never seen anyone feel it necessary to brace that area b4...

Our F32 already have the triangulated rear bar, I don't think there version would make any difference other than it's more rigid.

I do have the M4 aluminum plate under the front plate of my factory cross brace with longer screws. Sure that's stiff enuf

STELLAR question honestly! I have pondered the same, and also thought about the M4 CF brace. The M4 has a (more elaborate) rear brace than the F3X, and then has that (big sexy) CF brace across the nose, tying it all together. This wouldnt have those links all the way back like the OEM CF, so just point to point, for flex across the nose of the car as it were. Assuming my assumptions ( ) are even vaguely right.

[FaRKle!]

Originally Posted by BMW DIY Guy

What do you think of the torsion brace (V brace) with the cross bar?

I think the crossbar portion doesn't do much since it's again just connecting two sides of the sub-frame. If a car doesn't have the v-brace and the KC 4-pt bar is cheaper than the factory v-brace, then it can be a good buy, but if you already have the OE v-brace, this part isn't worth it.

Originally Posted by 1QuikWS6

This is the one I'm curious about





Never seen anyone feel it necessary to brace that area b4...

Our F32 already have the triangulated rear bar, I don't think there version would make any difference other than it's more rigid.

I do have the M4 aluminum plate under the front plate of my factory cross brace with longer screws. Sure that's stiff enuf

Vert cars and M2s have braces there, HOWEVER, they extend past the radiator area and connect with the body and shock towers. Parts that just brace the radiator area I don't see as worth it. FWIW CPM Japan also makes that front brace. Johnny250 has it, and said he didn't notice any difference.

[BMW DIY Guy]

Originally Posted by FaRKle!

I think the crossbar portion doesn't do much since it's again just connecting two sides of the sub-frame. If a car doesn't have the v-brace and the KC 4-pt bar is cheaper than the factory v-brace, then it can be a good buy, but if you already have the OE v-brace, this part isn't worth it.



Vert cars and M2s have braces there, HOWEVER, they extend past the radiator area and connect with the body and shock towers. Parts that just brace the radiator area I don't see as worth it. FWIW CPM Japan also makes that front brace. Johnny250 has it, and said he didn't notice any difference.

**ponder** wonder if the OEM vert brace then would fit into a coupe? Off again I go to RealOEM! lol

[FaRKle!]

Originally Posted by BMW DIY Guy

**ponder** wonder if the OEM vert brace then would fit into a coupe? Off again I go to RealOEM! lol

You'd have to weld on the mount for it onto the shock tower as it's not included on vehicles that don't come with that brace. There are official parts you can buy to do that.

[BMW DIY Guy]

Weld?? Yeah.. thats not happenin'... lol.

Thanks man, wellspring of wisdom as always.

[BMW DIY Guy]

updated and completed the rear series with the rear differential bushing inserts!

[BMW DIY Guy]

Originally Posted by jh_f30

Can you speak to the improvements each of these mods make as you install them? Perhaps some driving impressions/reviews on differences with/without? Thanks!

improvements are already quite noticeable. Body roll feels significantly less with force across the tail in cornering feeling more planted.

[Jvac]

Originally Posted by BMW DIY Guy

improvements are already quite noticeable. Body roll feels significantly less with force across the tail in cornering feeling more planted.

Thanks for taking the time to make these videos while doing the work. I hope they net you some $ for your efforts.

[BMWILUVU]

KCdesign claims their strutbar to fix understeer. This will not help at all for understeer on the F-series and the F also already has braces running from the firewall to the towers. What might be helpful are the underside braces. The rears attach at the 5 in the picture and would help with torsion and bushings slop around fast corners but I would not bother on any of the chassis & body stiffening unless you are pushing this car on the track.

[dsc888]

Originally Posted by BMWILUVU

KCdesign claims their strutbar to fix understeer. This will not help at all for understeer on the F-series and the F also already has braces running from the firewall to the towers. What might be helpful are the underside braces. The rears attach at the 5 in the picture and would help with torsion and bushings slop around fast corners but I would not bother on any of the chassis & body stiffening unless you are pushing this car on the track.

Good to see this kind of discussion. I was on the fence about a strut tower brace as well and wanted to hear what folks thought of them. The F30 is the stiffest car I've ever owned. And I don't track my car so the benefits are minimal. The only place where increase chassis stiffness may be of any benefit is when I go up a driveway at an angle.

[FaRKle!]

Here are my impressions of the KC strut bars from my log when I got them in 2017. I found the front strut bar useful even in spirited daily driving.

Chassis Stiffening
In an effort to stiffen my chassis further I decided to try a front and rear strut/support bar. There's been plenty debate on the forums whether this really does anything, and I wanted to see for myself. After seeing BEM-S4's post on them, I decided to go with the KC Design front and rear bars. KC Design was super easy to work with over email and the items arrived quickly from Taiwan.

KC Design Front Strut Bar


Installing the front bar is very easy and straight forward. BMW's documents show the front LCI bolt torque to be 30nm + 90deg, however when I was loosening all the bolts, none of them required close to 30nm of break torque, hrm...

KC Design Rear Bar


The rear bar has some peculiarities for it's install, and I ran into a couple of issues I had to solve during it. When removing the rear cargo mounts to install the rear bar, I found a factory issue, and another source of rattling. It appears as if the factory didn't thread the hole straight, and then cross threaded the cargo mount bolt in it. It actually crushed the threads on the bolt. The cargo mount ring that the bolt is supposed to hold down could rattle around since the bolt never secured it fully. To fix this I mentioned this issue to my dealership during my next visit and they re-threaded the hole properly under warranty. KC Design provides two standoff shims/cylinders to put between the rear mounting holes and the bar. This is to elevate the bar above the rear cargo area trim. On my vehicle these shims were far too short. I went to the hardware store and bought washers to get the appropriate height. Additionally, the bolts supplied with the bar were a bit too short. I ended up getting 45-50mm long bolts, which will allow you to place the original cargo mount ring on top of the bar, and bolt both down.

KC Design Rear Bar Mount (note hint of washer peeking out underneath the black cylinder and factory cargo ring on top)


So how much did the bars change the ride? I'm happy to say that the front bar produced a very noticeable difference. When cornering harder the front end of the vehicle feels more solid and predictable. Additionally, it seemed to improve the steering feel a bit too. Unfortunately, I can't say the same for the rear bar. I really don't notice any difference with it.

[JaredG_F30]

What size pass-through socket do you need to remove the drop-link nut to the front strut? I know you need a T30 torx bit to hold the stud but want to make sure I have the right socket size before getting into the removal.

[BMW DIY Guy]

Originally Posted by JaredG_F30

What size pass-through socket do you need to remove the drop-link nut to the front strut? I know you need a T30 torx bit to hold the stud but want to make sure I have the right socket size before getting into the removal.

I used a 16mm ratcheting wrench, and a T27 torx socket if we are talking the same thing, and it worked really well! Check 17minutes in on the video and you can see it.

[JaredG_F30]

Which video? I don't see one for front strut removal. Did you need an 18mm pass-through socket to remove the strut top hat nut?

Originally Posted by BMW DIY Guy

I used a 16mm ratcheting wrench, and a T27 torx socket if we are talking the same thing, and it worked really well! Check 17minutes in on the video and you can see it.

[BMW DIY Guy]

Originally Posted by JaredG_F30

Which video? I don't see one for front strut removal. Did you need an 18mm pass-through socket to remove the strut top hat nut?

My apologies.. FRONT strut. I will be doing the front sway bar this Friday.

[BMW DIY Guy]

Front sway bar is done, and I am working on the video today and tomorrow. Easier than the rear but maybe because of it being similar, lessons learned were less.

The irony? Get the work done, car put back together and race out for some appointments..

5min later, smoothly and with precise control avoid a SUV that swerves into my lane to avoid another car, all at 60mph. Super smooth, quick right avoid and lane correct back into my lane avoiding the dumpster fire.

Control was precise, smooth and felt completely grounded with ZERO slop or body roll.

If that moment wasnt the greatest testament to the improvements, I dont know what is.. I very likely would have still avoided the SUV pre-upgrades but not nearly as smoothly or precisely. Car felt 100% responsive through what was a very quick series of control inputs.

Yall want (subjective) feedback of the improvements thus far?

WORTH EVERY PENNY.

[BMW DIY Guy]

ok yall.. I still dont have the front control arm bushings done yet due to some logistics, but my coilovers are done! I started a new thread for the DIY. Also I will update here once the control arms are done, I hope very soon.

[pkiledj]

Originally Posted by BMW DIY Guy

All right yall.. I have the second video set completed with rear sway bar and bushings! Thank you to FaRKle! for such a great write up a little while ago, and I should have taken him literally on the shock bolt (only).

Any questions please let me know!

I wanted to finish out the rear series with the video DIY for the rear differential bushings. These are a very easy update, and worth it especially with simple tools and quick to do. I highly recommend it, and then will be now moving onto the front.

What are your thoughts on polyurethane rear sway bar bushings vs the stock rubber ones? I am about to install the M440 15mm rear sway bar on my f30 335i xdrive using the bmw rubber bushings but I would like to know other people's opinions/experiences. The car is my daily driver, don't drive hard but I like tight suspension.

[FaRKle!]

Originally Posted by pkiledj

What are your thoughts on polyurethane rear sway bar bushings vs the stock rubber ones? I am about to install the M440 15mm rear sway bar on my f30 335i xdrive using the bmw rubber bushings but I would like to know other people's opinions/experiences. The car is my daily driver, don't drive hard but I like tight suspension.

I don't think PU rear sway bar bushings are worth it. The metal brackets do a pretty good job of limiting bushing deflection, and the rubber used back there isn't very soft.

[pkiledj]

@FaRKle!

I found these monoballs for the xdrive with a quick google search. Know anything about them?


https://www.splparts.com/products/fr...3x-xdrive.html


https://www.splparts.com/products/ad...3x-xdrive.html