Baby BMW Forum banner
1 - 20 of 339 Posts

·
Registered
Joined
·
10,211 Posts
Discussion Starter · #1 ·
3 dr cars have a much better brace mid ships to fwd rear subframe connections.

Installed the hardware this week on my 5dr.

Best way to describe impact is its like having upgraded bushings in the rear subframe and rear suspension arms.

Much less flex when putting the power down on straight or out of a corner. Car feels more stable and less squirmy. Not sure why but steering feels sharper but that might something to with DME read/writes done whilst at the dealer for service / LPFP quality enhancement.
 

·
Banned
Joined
·
85 Posts
Forgive me but this of interest as just waiting for delivery of a 3dr M135i.

The three door you would expect to have a higher torsional rigidity, as there are less holes in the shell, but you say they also have a better brace as well. This seems counter intuitive, as surely you would expect the better brace to be on the 5dr?
 

·
Registered
Joined
·
10,211 Posts
Discussion Starter · #3 ·
I think brace is omitted off 5dr to save weight and help with omissions.

I agree with your logic as my car feels all the better for this OE upgrade. I also installed m3 alloy cross plate as spacer under the new brace to give further rigidity.
 

·
Registered
Joined
·
292 Posts
I don't know the figures, but saloons can be stiffer than coupes depending on how they've been designed. Sometimes two smaller openings with a pillar in between them can be stiffer than a single larger opening. I don't know if this is the case with the F20 though.
 

·
Banned
Joined
·
85 Posts
Blind Pugh said:
I think brace is omitted off 5dr to save weight and help with omissions.

I agree with your logic as my car feels all the better for this OE upgrade. I also installed m3 alloy cross plate as spacer under the new brace to give further rigidity.
So we'll credit you with discovering a simple upgrade for five door drivers to improve the handling! :)
 

·
Registered
Joined
·
10,211 Posts
Discussion Starter · #12 ·
Paul

1 x 33326797099
6 x 33326764505 (or 07119907189 longer bolts if using m3/4 spacer, part no. 33312284647)
1 x 33326793651
1 x 33326793652
2 x 33306793892
2 x 33326796225
2 x 33306861221

BP
 

·
Registered
Joined
·
785 Posts
BP Nice mod, where did you order your parts from? What about the labor, how long does this mod take to install?
 

·
Registered
Joined
·
10,211 Posts
Discussion Starter · #15 ·
Toube,

I bought all the bits from Cotswold BMW - forum sponsor and their parts guy, Phil Ennis, is a top bloke to deal with.

I had access to a lift and used my own hand tools including star sockets. Leisurely 1.5 hrs. An indie could get it done in < 1 hr.

BP
 

·
Registered
Joined
·
785 Posts
BP, 1.5 hours that's not bad at all, Paul is about to do this also.. so this mod is straight forward replacing parts no adjustments needed?
 

·
Registered
Joined
·
10,211 Posts
Discussion Starter · #17 ·
Toube,

Correct. Bolt off and bolt back on. The only tip I was given by a BMW tech friend is when unbolting fwd rear subframe bolts, keep the cars weight on the wheels and level as possible.

Hence the lift as opposed to jack and axle stands.

BP
 

·
Registered
Joined
·
10,211 Posts
Discussion Starter · #18 ·
Update following this mornings commute.

On my way in there's a roundabout with my exit having a tight left immediately after the exit. 2 different road surfaces - grippy on the r'bout and shiny on the road with the tight left at the exit.

Normally, with a firm squeeze on the throttle, I get a tad of "hip wriggle" as the car's rear axle makes the transition from grippy to shiny surface. That's gone now with F21 brace and M3 x brace spacer.
 

·
Registered
Joined
·
785 Posts
BP check that, sounds good. What mods have you now done to your car?
 
1 - 20 of 339 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top