[B58 _gran_coupe_]

Originally Posted by johnung

The F3x chassis and the F8x M3/M4 chassis are different cars. The engineering is totally different. They share very few parts. Suspensions have many parts and are designed as a system to work together. People have this idea that if they took a part off an M3 that it would make their F3x better but that’s not the case.

Absolutely agree. Different chassis completely

BTW your private message inbox is full.

[B58 _gran_coupe_]

Turns out I was helping a friend install eibach rear springs on his 2018 f80 today.

The difference in the chassis components over the F3X cars is pretty much everything. It's like a jungle gym underneath a f80.

Everything is beefy and braces upon braces.

Here's some pics

[B58 _gran_coupe_]

To add. We drove both cars. Back to back. The difference in rigidity and poise of the f80 was night and day. You're never gonna get similar chassis dynamics with a few components in my opinion. The f80 is running a little over stock power and my f36 is running around 625whp and the disconnect between the engine and the chassis is rather pronounced at that power level. You can feel the back end compressing and catching up tor the engines input. The f80 was much more connected. Kind of makes me wish I'd bought an m4 to begin with but I'll keep tweaking. I'm sure I can improve the softness of the f36 with a few mods but it will never be as focused as it's big brother the M

[rlesko]

Originally Posted by B58 _gran_coupe_

To add. We drove both cars. Back to back. The difference in rigidity and poise of the f80 was night and day. You're never gonna get similar chassis dynamics with a few components in my opinion.

yea, of course not! There a so many more chassis rigidity components on the M, plus factory tuned suspension etc.

There are numerous things you can do on the F3x platform, such as dampers, springs, strut braces, subframe inserts / solid subframe bushings, etc.

But yea, as you put it at the end of your post at what point do you just resign to the fact that you should have gotten an M car?

[B58 _gran_coupe_]

Originally Posted by rlesko

yea, of course not! There a so many more chassis rigidity components on the M, plus factory tuned suspension etc.

There are numerous things you can do on the F3x platform, such as dampers, springs, strut braces, subframe inserts / solid subframe bushings, etc.

But yea, as you put it at the end of your post at what point do you just resign to the fact that you should have gotten an M car?

Yeah when I bought the car I was (and still am) interested in thr b58 platform. The 4 door coupe hatchback appealed to me due to its practicality and the fact it's a bit different.

Since then I have been given a company car so now I can take the build a little more balls to the wall.

Hindsite is always 20/20 but I never knew my vehicle circumstances would change.

I've gone so far with the f36 with a new turbo recently that I'm just gonna keep going. Great cars but not as race oriented as an m3 or m4.

Blows the doors off fbo m cars with its 625 whp but it needs the chassis to keep up with the performance now.

[fortythirtyfive]

Originally Posted by B58 _gran_coupe_

Yeah when I bought the car I was (and still am) interested in thr b58 platform. The 4 door coupe hatchback appealed to me due to its practicality and the fact it's a bit different.

Since then I have been given a company car so now I can take the build a little more balls to the wall.

Hindsite is always 20/20 but I never knew my vehicle circumstances would change.

I've gone so far with the f36 with a new turbo recently that I'm just gonna keep going. Great cars but not as race oriented as an m3 or m4.

Blows the doors off fbo m cars with its 625 whp but it needs the chassis to keep up with the performance now.

Over the weekend whilst doing an oil change I decided to give my steering rack bushing a TINY tighten. Went for a quick test drive and honestly it makes things a little nicer experience in terms of steering input (it's the little things that add up) I would advise marking its original position to put it back if you don't like it though.



I wouldn't say it causes the steering to feel immensely tight it just adds a little more weight, it gives me a sense of feeling that little bit more connect imho. I run Millway LCA monoballs and KW V3's just as a general idea of setup, but yeah that little tighten made things feel that bit more connected/planted; maybe not physically but in my your hands it appears to make a difference.

[B58 _gran_coupe_]

Yeah I recently replaced that steering rack bush. I did note the wheel binding so I backed it off a touch till it released. I felt a small.improvement too

[B58 _gran_coupe_]

Update to the arms. I bought a set of upper VAC monoball control arms from the classifieds on this forum. Will see how those feel and maybe buy the lowers on another pay cycle. Think the owner had them on for 7k miles so far from worn out.

Will give some feedback once installed and ran

[B58 _gran_coupe_]

Installing the arms.

Quick question cos I'm debating this with my f30 friend.

The long spacer is on the engine side (facing towards the rear) and the short spacer is on the wheel side (facing towards the front)

Correct?

[B58 _gran_coupe_]

Another question.

What are these heavy iron things on the end of the control arm mounting bracket?

Their purpose isn't obvious?

[alohasurftoad]

my 2016 428i F36 does not have it, however my 2020 440i F36 does

if i have to guess, i believe it absorbs/dampens vibration coming from within the UCA.

i actually left my right side off because i was having such a time lining up the bolt, running out of daylight and wanted to put everything back together. whatever it is doing is undetectable to me.

i'll try to re-install it someday when i have nothing better to do, lol

[B58 _gran_coupe_]

Originally Posted by alohasurftoad

my 2016 428i F36 does not have it, however my 2020 440i F36 does

if i have to guess, i believe it absorbs/dampens vibration coming from within the UCA.

i actually left my right side off because i was having such a time lining up the bolt, running out of daylight and wanted to put everything back together. whatever it is doing is undetectable to me.

i'll try to re-install it someday when i have nothing better to do, lol

That idea makes a lot of sense.

Agreed, what a pain that right side is. I opened it up last night and ran out of time. I'll start unboltinf the cooler and other things tonight so I can get to that bolt