[Nezil]

Originally Posted by drledford93

I was asking about the rings that go between the aluminum strut brace and the shock tower itself. They are $160/pair. Not terribly expensive but if not necessary...

Like I said, it’s your call. If you want the most stiffening, do it, if you want to save money, don’t. None of this is necessary.

I found that the M2C's top hat and the M3/M4's are different part numbers. They look identical from what I could tell in close up pics, hence the confusion.

Not sure what you mean by this... the part number for the 3 hole top hat required is 31307853702. This is a common part for the M2C / M3 / M4.

The part number list on page 8 was created by comparing all the differences between the OG M2 and the M2C on RealOEM. I then actually did the install and corrected the quantities of fasteners and any incorrect part number. I’m pretty confident it’s accurate.

[drledford93]

I saw some used top hats from the '15-16 M3 and compared the pics to the M2C's and found them to be identical (from the pics that I could tell). But, the part # listed on the Ebay auction was different. That and something that I thought I read somewhere (Lord only knows where I saw it, now) that there was a different top hat for the early M3s vs M2C. I could (and probably am) waaaaay off base here, I fully admit that...

The part # is 31302284702 and here is the listing I mentioned.

[Nezil]

Originally Posted by drledford93

I saw some used top hats from the '15-16 M3 and compared the pics to the M2C's and found them to be identical (from the pics that I could tell). But, the part # listed on the Ebay auction was different. That and something that I thought I read somewhere (Lord only knows where I saw it, now) that there was a different top hat for the early M3s vs M2C. I could (and probably am) waaaaay off base here, I fully admit that...

The part # is 31302284702 and here is the listing I mentioned.

Woah, I'm really sorry, I've mis-quoted the part number in my post above, and will edit that before anyone makes a decision based on that.

Around 2015 I think, the M3 / M4 changed to a 5 bolt mounting arrangement from 3 bolts. The threads got thinner, but more of them (5 x M8 vs 3 x M10), and this necessitated a different top hat - that is the difference. I should have said that you need the same top hat as the M2C / Late model M3 / M4. The part number is 31307853702.

Here is an image of the 3 bolt top hat, part number 31302284702:

And here is an image of the part we need, with 5 bolt holes, part number 31307853702:

Interestingly, the eBay post you linked appears to show an image of the 5 bolt with the 3 bolt part number!

[drledford93]

Woah, interesting. I thought they were the correct ones.

BTW, ended up getting the CF brace for less than advertised! A true bargain!

[nothingman]

I was always on the fence about this mod until this thread convinced me the upgraded brace is the missing link making the OG handle like the Comp.
I'm just starting to acquire parts, and want to give a special thanks to Nezil for putting together such a comprehensive parts list. I took the liberty of importing it into Google Docs and adding average prices in $USD so we can all easily print it out or modify / update it if parts change:

https://docs.google.com/spreadsheets...7e8/edit#gid=0

[2020M2Competition]

Originally Posted by Nezil

[*]Stage 1: Strut reinforcement rings

You could eliminate stage 1 and save yourself some money. The M2C doesn't have these rings, but the M3 and M4 do; your call. If you do skip Stage 1, you'll still need 10 of the stock bolts that hold that strut top hats on because they're single use (torque + angle). These are listed in the 'return to stock' section; the part number is 31306869931.

Any thoughts on why the M2C doesn't come with the strut reinforcement rings?

I'm wondering if it's worth adding these if and when I get around to upgrading my suspension

[PLF69]

I think these rings are a little ''over engendered'' from the F80 development and they realised later is was worth saving the cost at no risk on the M2 Comp.

I just bought a used aluminum OEM brace for my OG M2 and I know I'll be skipping the rings.

[Bee Pee]

Originally Posted by PLF69

I think these rings are a little ''over engendered'' from the F80 development and they realised later is was worth saving the cost at no risk on the M2 Comp.

I just bought a used aluminum OEM brace for my OG M2 and I know I'll be skipping the rings.

Agreed - black rings are optional add-on.

Bmw chose to omit these on F87 and also the strut extensions that connect end of CFRP to firewall.

[David.m]

Originally Posted by Bee Pee

It reads like it might be worth you trying to cut down rear bump stops (aka 2nd dampers in BMW speak). If rear wheel travel is limited by hitting the b/stops the damping response will be more intense. Trimming b/stops down will allow rear dampers more stroke to work more effectively.

Plus its a relatively easy DIY

Trimmed b/stops and perhaps a proper rear brace might allow rear suspension to be more effective for little outlay...

I've installed Ohlins R&T which has dramatically improved suspension behaviour, springs are firmer than oem but the ride is a lot less bouncy, I guess a combination of better dampers and less bumpstop.

Shortening the oem bumpstop may improve in some instances but not sure about the big hits at speed, you'd still be bottoming out hard and having the same violent rebound that the oem damper can't cope with.

[Bee Pee]

Originally Posted by David.m

I've installed Ohlins R&T which has dramatically improved suspension behaviour, springs are firmer than oem but the ride is a lot less bouncy, I guess a combination of better dampers and less bumpstop.

Shortening the oem bumpstop may improve in some instances but not sure about the big hits at speed, you'd still be bottoming out hard and having the same violent rebound that the oem damper can't cope with.

You point is valid and with everything- moderation is the key.

Having seen how much shorter oem bumpstops are for e series 5 series compared to the ones that came with my m2 MPerf coilovers, I have zero concerns after 8 months of trimming 10mm off my rear bumpstops.

[M Fifty]

Originally Posted by Bee Pee

You point is valid and with everything- moderation is the key.

Having seen how much shorter oem bumpstops are for e series 5 series compared to the ones that came with my m2 MPerf coilovers, I have zero concerns after 8 months of trimming 10mm off my rear bumpstops.

You mean the "Auxiliary damper w.protective tube rear"?

[Bee Pee]

Originally Posted by M Fifty

You mean the "Auxiliary damper w.protective tube rear"?

✅

[3t3p]

I have the rings they help with placebo effect

[Bee Pee]

Originally Posted by 3t3p

I have the rings they help with placebo effect

Ditto I have the strut tower rings add-on as part of my m4 alloy+CFRP brace retrofit.

My rationale was I have coilovers and take the car on TDs seemed logical to include these OEM parts too.

Probably overkill esp for a car that stays on standard suspension and used as DD only....

[3t3p]

seriously they are hefty steel rings, totally believe they could stand to reinforce something. If they do or not I have no clue.

All I can say is love the car with the brace and very sure this is what 'fooled' the journos into M2C has new suspension. Not been in an M2C other than to check out the seat in a showroom though

[M Fifty]

The first generation Mini used to suffer from deformation of the shock towers where the strut tops bolted on, when driven hard on bumpy roads. Maybe the extra weight of the M3/M4 is enough to do similar, compared to the M2.

[Bee Pee]

Compared to F2x/3x/8x, new G2x cars have more localised re-inforcement built in around the strut top hole - see about 1min into YT clip below

Am even more glad I chose to add-on strut top reinforcement rings during alloy CFRP retrofit onto my OG M2...😎

[3t3p]

I think you may as well do it? They're cheap

[M Fifty]

The R53 Mini used to bend it's strut towers on US roads. I remember being impressed at just how hard you would have to keep on in to do that, as doing it to both sides it wasn't a one-off, overcooked it on a bumpy bend, moment.

[3t3p]

went on a good old B road blast today in the Peak district with lockdown restrictions eased (it was busy!)

The GF definitely noticed the cars' improved compliance over undulations. We would normally be expected to be thrown up and down a whole lot more and there was one sharp undulation I had forgotten about that was taken at speed. We felt it sure but the car stayed nicely composed.

On original suspension we would have been fine also no doubt, but it would have been a lot more 'exciting' shall we say!

The car does less of that weird side to side rocking that it used to do. Suuuuch a good upgrade that's why i'm a broken record about it on forums.

[David.m]

After 18mths of patiently searching I have these on the way to me Being an island in the southern hemisphere not only reduces the numbers of covid 19 but also totalled F80/82's with surviving front braces.

[PLF69]

Originally Posted by David.m

After 18mths of patiently searching I have these on the way to me Being an island in the southern hemisphere not only reduces the numbers of covid 19 but also totalled F80/82's with surviving front braces.

Is this the one from Australia!? I already baught the aluminum part but was still eying the it, totally worth it !