[Guy Fieri]

Originally Posted by feuer

Well is a fact. Source is BMW. I wrote that in my original reply to you. Look it up. Do some work. Because as per you recommendation I need to chill.

Just want to clarify that the figures you quoted are for the E46. The same source you used lists the following the the E9x:

E90: 22,500
E93: 15,750

http://youwheel.com/home/2016/06/20/...ehensive-list/

There are no figures for the E92 but journalists reported that the E92 is 25% stiffer than the E90. It is not known how much of the increase in stiffness is due to the chassis itself or the additional bracing BMW added to the E92.

Originally Posted by feuer

Chassis is stiffer, all 4 vs 2 doors are, due to spacing from pillar to pillar, thus engineers deemed them not needed.

This is possibly true if the E90 and E92 were equipped with the same bracing. I still believe that the E90 does not have the E92 bracing due to cost cutting. MSRP on the E92 was $1700-2700 more than the equivalent E90 model:

https://www.e90post.com/forums/showthread.php?t=78473

[ornicar]

Originally Posted by freedomfries

Just want to clarify that the figures you quoted are for the E46. The same source you used lists the following the the E9x:

E90: 22,500
E93: 15,750

http://youwheel.com/home/2016/06/20/...ehensive-list/

There are no figures for the E92 but journalists reported that the E92 is 25% stiffer than the E90. It is not known how much of the increase in stiffness is due to the chassis itself or the additional bracing BMW added to the E92.

This is possibly true if the E90 and E92 were equipped with the same bracing. I still believe that the E90 does not have the E92 bracing due to cost cutting. MSRP on the E92 was $1700-2700 more than the equivalent E90 model:

https://www.e90post.com/forums/showthread.php?t=78473

I have found this excellent document on the cars reinforcement effects.

https://publications.lib.chalmers.se...391/219391.pdf

One of the conclusions is that local lateral stiffness may have more effects on handling steering and ride characteristics than the global torsional rigidity.

" The results presented in Section 4.2 show that the largest factor affecting handling and steering characteristics is lateral stiffness for front and rear, whilst camber stiffness front is shown to be the third largest factor. Global values for torsional and bending stiffness is shown to have a large affect on Primary ride, but very limited affect on handling and steering characteristics in relation to the other factors. "

[ornicar]

Originally Posted by freedomfries

Just want to clarify that the figures you quoted are for the E46. The same source you used lists the following the the E9x:

E90: 22,500
E93: 15,750

http://youwheel.com/home/2016/06/20/...ehensive-list/

There are no figures for the E92 but journalists reported that the E92 is 25% stiffer than the E90. It is not known how much of the increase in stiffness is due to the chassis itself or the additional bracing BMW added to the E92.

This is possibly true if the E90 and E92 were equipped with the same bracing. I still believe that the E90 does not have the E92 bracing due to cost cutting. MSRP on the E92 was $1700-2700 more than the equivalent E90 model:

https://www.e90post.com/forums/showthread.php?t=78473

I have found this excellent document on the cars reinforcement effects.

https://publications.lib.chalmers.se...391/219391.pdf

One of the conclusions is that local lateral stiffness may have more effects on handling steering and ride characteristics than the global torsional rigidity.

" The results presented in Section 4.2 show that the largest factor affecting handling and steering characteristics is lateral stiffness for front and rear, whilst camber stiffness front is shown to be the third largest factor. Global values for torsional and bending stiffness is shown to have a large affect on Primary ride, but very limited affect on handling and steering characteristics in relation to the other factors. "

[CalvinNismo]

Originally Posted by ornicar

So you were 100% right @ [Phil325i] (contact: 157271) I did a dry fit, and the M3 brace is bumping into the steering motor in a large area

Photos will follow.

I'm afraid that opening the plate to such a large area will weaken it too much and that in the end it has no interest.

in addition the 2 fixing points at the rear are slightly offset.

Are you satisfied with the 2 bars solution from an NVH reduction point of view?

I may also consider fitting the E88 bars again.

The M reinforcement plate will be for when I mount my M hydraulic rack one day maybe

The brace does in fact fit the 1 Series with a hydraulic rack. It requires 10mm spacers for the front and 20mm spacers for the rear and slotting of the rearmost holes. You cannot however fit the standard undertray with the brace mounted, which would be fine if your car is a track slag. Thanks ornicar for selling me the brace and for the advice! I have ultimately gone for a front only brace though, similar to Biginboca and I can notice the increased stiffness. I may look into a custom/secondary plate for the rear section of the subframe in the future.



I have done a 'how to' on BabyBMW which I am more active on.

How to Fit the E9X M3 Belly Pan to the E8X 1er

[Biginboca]

Originally Posted by CalvinNismo

The brace does in fact fit the 1 Series with a hydraulic rack. It requires 10mm spacers for the front and 20mm spacers for the rear and slotting of the rearmost holes. You cannot however fit the standard undertray with the brace mounted, which would be fine if your car is a track slag. Thanks ornicar for selling me the brace and for the advice! I have ultimately gone for a front only brace though, similar to Biginboca and I can notice the increased stiffness. I may look into a custom/secondary plate for the rear section of the subframe in the future.



I have done a 'how to' on BabyBMW which I am more active on.

How to Fit the E9X M3 Belly Pan to the E8X 1er

Nice job! Your brace came out great and the write up is perfect. Interesting to me that on the 1 you can use the puck for jacking the car too. On the 3 series we have to remove that plastic puck and instead have to stick with a stupid metal rectangle that gets bent to hell in short order lol

[bimmermech123]

Originally Posted by Guy Fieri

The "upgrade" is the solid panel that reinforces the subframe:




It won't fit non-M subframes but I replicated it by using the same mounting points for my own bracing. It reinforces the tension strut and wishbone mounts. It was more of an experiment but I couldn't believe the difference it made. Biggest surprise was the reduction in NVH gained from the M3 arms. The factory underbody panel still fits too.

What material did you use for the custom bracing? Aluminum or steel? Also, can you confirm the dimension of the bracing? It looks like 1" wide, 3/4" high, and 1/16" thick.

[e30h26]

I ended up doing this with the original strut braces since I upgraded to the M3 one. Had to shorten them slightly and repaint them after flattening the ends to drill a new hole, but it worked out really well.

[Biginboca]

Originally Posted by e30h26

I ended up doing this with the original strut braces since I upgraded to the M3 one. Had to shorten them slightly and repaint them after flattening the ends to drill a new hole, but it worked out really well.

Nice work man! Did you notice any difference after? I modded the Aluminum M3 front subframe plate/brace to fit my car and felt a noticeable improvement after installing it:

https://www.e90post.com/forums/showp...&postcount=276

[335i54n]

heres mine, i made the mistake of using 7075 al bar which after the fact I learned is not really weldable or bendable. so I had to use spacers since theres a height difference between front and back of sub-frame.

already have monoballs in front with m3 and other strut bars but these bars added a ton of feedback. not sure if it help handling but any increase feedback on a front strut suspension is appreciated but most dd probably wont like it

[Shoooter_j]

Originally Posted by e30h26

I ended up doing this with the original strut braces since I upgraded to the M3 one. Had to shorten them slightly and repaint them after flattening the ends to drill a new hole, but it worked out really well.

Nice, gna have to try this out!

[rbryantaz]

Originally Posted by Guy Fieri

I fitted the E9x M3 rear subframe brace onto my E90 and it helped the chassis feel much more solid:



Info here: https://www.e90post.com/forums/showp...postcount=4300

Good info.

I did this recently and on my 335i.. I didn't realized that there is a slight interference with the gas tank on the 335i. The gas tank has a "well" (which extends down by about 3/8") that interfered with the rear passenger bar. I thought my bar was bent at first but realized that it is because the 335i has a different gas tank than the M3.

The well is actually visible in your picture. It is probably fine to just tighten up the bar and let the gas tank flex but it is something to be aware of.

I ended up installing 3/8" spacers between the cross brace and the bars so that it didn't flex the gas tank too much. I believe that 1/4" spacers were enough and only lightly flexed the gas tank but 3/8" makes it a non issue.





Given that it is a simple spacer and longer bolts I think it is worth adding for a 335i. As a side benefit it also allows the original bolts to be installed in the outside holes so that they are plugged.


-Rich

[335i54n]

the e84/e92 x brace is a better fit/design imo, the m3 brace is like that to clear the resonators on v8. e92 brace fits, no issues

[rbryantaz]

Originally Posted by 335i54n

the e84/e92 x brace is a better fit/design imo, the m3 brace is like that to clear the resonators on v8. e92 brace fits, no issues

Yes the e92 brace does fit without any changes.

It is described well here: https://www.e90post.com/forums/showthread.php?t=165246

I have to think about the single bolt point on the rear of the e92 bars where they bolt to the subframe attachment. That seems like it could pivot slightly where the M3 version is one piece in the back so it won't pivot. I know there is much debate about this with front strut bars... Can this have the same issue?

-Rich

[335i54n]

not really, both bars are weld to the center plate and the way the bar are setup it make more sense as braces, the e92 way. the m3 way is only cause they could Not route the bars the same way due to the resonator. part of me wishes i too went m3 brace to match and maybe will need extra room for exhaust

[autoart]

The M3 version looks to be made out of larger/ thicker metal also. The previous post also says that the M3 version has different designs for the e92/e93/e90. Maybe you were sold the wrong one, just a thought. So is this even a worthwhile mod in your opinion?

[rbryantaz]

Originally Posted by autoart

The M3 version looks to be made out of larger/ thicker metal also. The previous post also says that the M3 version has different designs for the e92/e93/e90. Maybe you were sold the wrong one, just a thought. So is this even a worthwhile mod in your opinion?

I haven't driven it much after putting it on and sadly haven't had time to take it out to throw it around corners.

It seems a little thicker. I think the only place it "could" be really better than the e92 version is that the e92 version just has a single bolt hole on the rear as I mentioned. There probably isn't enough movement in the body to allow that to pivot but it is more likely to pivot than the M3 version is because it is welded in the rear (rather than front) and the front is a 2 bolt point connection.

e92 picture from ecs:



This is probably not a significant difference and the spacers are a disadvantage. There are however usually more used M3 braces around so they are often cheaper used. I think I only gave $100 for mine.

Note there is also another ear brace that goes in the rear of the e93:

https://www.realoem.com/bmw/enUS/sho...88#51618045988

I have one but didn't realize that I needed to add mounting points to the body of the car that are only really reachable when the rear subframe is out so I haven't installed it.

-Rich

[tylerhart_21]

I have a small question. Would using similar hardware to the m3 strut tower brace be better or similar to using rivnuts. Marked in red.

[335i54n]

you mean a nut and bolt through the subframe? nope, rivnut imo is best and easiest way