[Alpina_B3_Lux]

19. M3 strut brace

This is part of my extended review thread that you can find in its entirety here: 335i E90 LCI - Experiences and review of various modifications (long!) but that I reposted here in order to make this part easier to find.

• Why?

As you may have read in my previous review (see here: REVIEW: M3 suspension parts & Quaife limited slip differential ), I've been in the game for improving the stock suspension of my 335i for some time. The M3 pieces that have been installed so far have already had a considerable positive effect and made me think of adding another piece that is transferable from the M3 to my car: the strut brace (or tower brace, as it is sometimes called).

Now, you may say "but the 335i already has a strut brace", and you would be correct. However, the brace that the 335i comes with from the factory is rather flimsy: The bulkhead end is just a loose slot in the end of the brace, so it only braces against compression, in extension it is unsecured. Also the standard single bolt attachment at the strut tops will be subject to flex and distortion, whereas the diecast ring arrangment of the M3 item gives a very solid and rigid attachment to the strut top.

Again, you could argue: "Why the M3 part? Isn't there a strut brace from the BMW Performance line as well?" Well, the Performance strut brace still is only a two point brace, just like the OEM one that comes on the 335i. The M3 brace, on the other hand, is a three point brace that also connects the struts to the firewall, and not only with each other. By definition it is therefore stiffer. This V arrangement also gives open access to the engine and maintains pedestrian impact regs clearances between bonnet and rigid parts.

• How?

First of all, you will need to order the parts - either from your BMW dealer or through an aftermarket provider. Here's the link to the part catalogue at RealOEM: BMW E92 M3 strut brace installation on 335i

The components look like this:


To make it easier, here's also the list of the parts with their respective part numbers you need:

• 51617900821 Ring, dome cross-brace, left
• 51617900822 Ring, dome cross-brace, right
• 51618044553 Strut brace (you need two of those)
• 51618045860 Mount for strut brace
• 51617891281 Covering cap (you need two of those)
• 51618046445 Stud (two of those) *
• 51717898374 Stud (4 of those) *
• 07119904401 Hex bolt (2)
• 07146954965 ASA-Bolt with circlip (not needed, can be re-used from existing brace)
• 07146963730 Torx bolt (2)
• 51717895241 Hex nut (6)
• 31316769731 Self-locking collar nut (6)

You will have to replace the items marked with an (*) as otherwise the brace will interfere with the microfilter assembly. Item 51618046445 can be replaced with two 07119904401 hex bolts.

As I wanted to avoid any hassle at the time with bolts or nuts that don't fit, I ordered the whole package through Harold at HP Autowerks who has already been of great help in the past. Here's the link for the M3 brace package (which already includes all correct pieces to install it on a 335i):
HP Autowerks / link to shop for M3 strut brace - everything costs around 250 EUR in total.

As I've no problem admitting that I'm not too much manually inclined, I didn't do the install myself (although it probably is rather easy for someone with a bit of skill). I had it installed, as many of my modifications, by Daum Motorsport that did the job very well, as usual. Here's an extensive guide with photos on how to install it: BMW E92 M3 strut brace installation on 335i

Here are some photos of how it looks installed on my car:

View of the engine bay / right tower (see the red arrow):


View of the engine bay / from the front (see the arrow):


View of the engine bay / complete view (see the two red arrows):


• Improvements?

After picking up my car from my garage, I took it for a spin on some curvy back roads, and the difference was noticeable immediately. Compared to other modifications, the difference is not probably immense, but I confirm that it has made a marked difference. The intial steering response is much sharper and more direct, and when you're in a bend, even tiny steering inputs result in the front just tucking in even more. It allows you to drive the car with more precision and is, to say it plainly, even more fun to let it rip on some curvy backroads.

• Problems / disadvantages?

None at all from my perspective. Of course it is not cheap and you have the hassle of installing it in replacement of the OEM brace - but at least for those like me that are already on the slippery road of multiple suspension modifications it is certainly worth the money.

Alpina_B3_Lux

[tres]

Those m parts really transform the car. I just have the subframe bushings left, I getting the delrin subframe bushings. Good review

[HP Autosport]

Excellent review!

[cvc 22349a]

You can feel that the strut towers are tighter? I can't, but the M3 brace does make it easy to adjust strut dampening. Nice review though..

[tibra1]

These all but eliminate cupping..very cool review Alpina.

[lito]

great review as always

[Freelo]

Great review, many thanks.

There have been others who've felt the change from the M3 brace was not very perceptible.

I have all the other M3 suspension pieces including subframe bushings. Hadn't felt it was worth to do this one. You seem to have had all the other M3 bits also. In your situation, how would you rate the change you felt from this relative to the other M3 suspension mods?

Am I reading your review right that you're saying you think it's well worth it for people with all the other M3 pieces? Even for street-only drivers like me?

Again many thanks.

[Alpina_B3_Lux]

Originally Posted by Freelo

Great review, many thanks.

There have been others who've felt the change from the M3 brace was not very perceptible.

I have all the other M3 suspension pieces including subframe bushings. Hadn't felt it was worth to do this one. You seem to have had all the other M3 bits also. In your situation, how would you rate the change you felt from this relative to the other M3 suspension mods?

Am I reading your review right that you're saying you think it's well worth it for people with all the other M3 pieces? Even for street-only drivers like me?

Again many thanks.

As mentioned in my review, I already had all other M3 pieces installed before installing the strut brace, too. I did feel a noticeable change, although of course this change was not as big as when I installed all other M3 pieces around 18 months ago.

On the other hand, I would wager to say that as the other M3 pieces already give you a much more direct feeling for the road and for the steering input, the change is more perceptible than when installing the strut brace without having the other M3 pieces in the car.

Of course, in the end you will need to decide for yourself whether a rather small change in the car's behaviour is worth the money; for myself, I can say that it is, but YMMV.

Alpina_B3_Lux

[tres]

I have the m bits installed also and in my opinion the biggest difference was the swaybars and the lsd. I had a chance to really push the car in the corners and I now feel the difference. the front/ rear control arms guide rods etc, strut bar ,MR toe arms made. I'm still on the stock springs/shocks and sub bushings. Once winter is over I'm going to install the delrin sub/diff bushings and the ohlins kit from harold.

[Alpina_B3_Lux]

Originally Posted by tres

I have the m bits installed also and in my opinion the biggest difference was the swaybars and the lsd. I had a chance to really push the car in the corners and I now feel the difference. the front/ rear control arms guide rods etc, strut bar ,MR toe arms made. I'm still on the stock springs/shocks and sub bushings. Once winter is over I'm going to install the delrin sub/diff bushings and the ohlins kit from harold.

Great, let us know your thoughts on the Öhlins kit once you have it installed. I'll have mine in next spring probably.

Alpina_B3_Lux

[tres]

I will

[BlueLion]

+1 on all of the OP points

-Harold is a great vendor to deal with, I bought my strut bar from him

-I installed this after installing my KW to be able to adjust them without dealing with the OEM bar. I wasn't expecting it to change much on the car but after driving, you can def feel a difference in steering response.

-After taking out the OEM bar and comparing it to the M3 and seeing out it installs you can see why it cost more and handles better.

[intensee92]

great review!

[Alpina_B3_Lux]

Originally Posted by intensee92

great review!

Thank you! Much appreciated.

Alpina_B3_Lux

[chrisw335i]

hey, i am curious if you guys still have these in stock and can give me a pricing shipped to 31909. thanks!!

Originally Posted by HP Autowerks

Excellent review!

[Alpina_B3_Lux]

Originally Posted by chrisw335i

hey, i am curious if you guys still have these in stock and can give me a pricing shipped to 31909. thanks!!

Why don't you shoot Harold a PM? On the website of his shop they're listed as being in stock:HP Autowerks Shop - M3 strut brace

Alpina_B3_Lux

[ciomas]

Great read and a solid review as always, Marcel

[Alpina_B3_Lux]

Originally Posted by ultra_racing

great

Thanks! BTW I've been to Malaysia this year and liked it a lot.

Originally Posted by ciomas

Great read and a solid review as always, Marcel

Thanks a lot!

Alpina_B3_Lux

[DaFish]

Originally Posted by Alpina_B3_Lux

As mentioned in my review, I already had all other M3 pieces installed before installing the strut brace, too. I did feel a noticeable change, although of course this change was not as big as when I installed all other M3 pieces around 18 months ago.

On the other hand, I would wager to say that as the other M3 pieces already give you a much more direct feeling for the road and for the steering input, the change is more perceptible than when installing the strut brace without having the other M3 pieces in the car.

Of course, in the end you will need to decide for yourself whether a rather small change in the car's behaviour is worth the money; for myself, I can say that it is, but YMMV.

Alpina_B3_Lux

Awesome review as usual thanks

A couple more questions pls

Can you describe the differences in initial turn in? Is it sharper and can you enter turn quicker with the bar?

2) what about mid corner longer turns like a 270 degree onramp? I would expect there is benefit here

Pls advise

[TurboBimmer]

Originally Posted by DaFish

Awesome review as usual thanks

A couple more questions pls

Can you describe the differences in initial turn in? Is it sharper and can you enter turn quicker with the bar?

2) what about mid corner longer turns like a 270 degree onramp? I would expect there is benefit here

Pls advise

Turn in is definitely precise than before. And in long fast turns the car is more stable in the front, less floaty.
This strut brace is definitely a worthy improvement over stock.

[Thumperx]

Originally Posted by Autobahn335i

Turn in is definitely precise than before. And in long fast turns the car is more stable in the front, less floaty.
This strut brace is definitely a worthy improvement over stock.

Cannot wait to get mine in.

[mjollnir19]

I just ordered the M3 Suspension kit from tisher and I had second thoughts about the M3 Strut Brace Kit. This is because I already have the Dinan CF Strut Tower Brace or whatever it's called. I really figured I wouldn't know the difference or whether it would even improve the handling.
After reading Alpina's review I assured that it would be a beneficial addition to my suspension set-up. Thanks Alpina!! (read your thread and wow GJ)