[430Scud]

Originally Posted by 23109VC

What was the total cost to install this M5 sub brace? All parts? If I had someone install it for me what would I expect to pay at a reputable shop?

I'm also thinking of getting hard races rear sway bar… I read another review from a different BMW for him or a guy installed it and said it made big improvements and turn in and cornering

Thx

Its all in my various posts in this thread...but I will save you the work
Parts is just under $700 with some careful shopping online. Use the seller I used mybimmerparts.com
It is an easy DIY if you have basic wrenching skills...just remove some stuff and install the new stuff. Very basic. If you are paying a shop, it will take them one hour on a lift. If they milk it some, one and a half hours tops. I don't know what the prevailing shop rates are in your area.

[430Scud]

Originally Posted by choppedliver

I’m thinking to do the following;
1) mono ball… I expect this makes a massive difference to the steering as others mentioned.
2) Hardrace rear brace
3) Hardrace rear sway bar
4) Hardrace front brace
5) X-brace
6) M5 strut brace - need to research this

I gather with AWD you can’t add a front sway bar or it seems Hardrace don’t sell one. Does one exist?

I’m in Australia and might grab the Hardrace stuff as it’s pretty cheap here.

I am suspect that this rear brace will do anything....
https://www.hardrace-europe.com/rear...ace-q0479.html

Look at where it attaches, and what it is attached to. It attaches to an already rigid structure. Am I missing something here??

[430Scud]

Originally Posted by Lancelot

This one is the secondary part from strut tower to front, it's got a hole in the middle to fit the admission pipes, the 530hp m550i has it, and it doesn't fit the 462 hp m550i.

I fitted the main strut brace from m5 however which fits very well on all m550is

When you state "main strut brace", do you mean "strut brace, bulkhead" as listed #1 in this diagram? Did this replace the existing M550i factory brace with M5? Is the M5 version more robust or substantial to necessitate the upgrade? I know the M550i brace is made from stamped and folded aluminum sheet. The M5 strut brace appears to be made from thick aluminum stock, perhaps water jet cut?
https://parts.bmwsydney.com.au/showA...sembly=9052513

M550i factory brace:
https://www.realoem.com/bmw/enUS/sho...diagId=51_4339

[choppedliver]

Originally Posted by 430Scud

I am suspect that this rear brace will do anything....
https://www.hardrace-europe.com/rear...ace-q0479.html

Look at where it attaches, and what it is attached to. It attaches to an already rigid structure. Am I missing something here??

I don't think you are. I think it's pointless.

[choppedliver]

Looking at the rear sway bars again the M5 and M550i.

M5 - https://parts.bmwsydney.com.au/a/BMW...r/33_2234.html

M550i - https://parts.bmwsydney.com.au/a/BMW...r/33_2097.html

The M550i has a rubber part (#10) that requires different brackers (#3 and #4) to the M5. Or to put it another way the M5 doesn't have part #10 and the brackets that come with it don't allow for it (they actually seem flimsier).

If the above is not an issue I was wondering if you can re-use the swing supports from the M550i. They aren't cheap and weirdly the M550i only lists 1 as needed, which isn't correct.

At least with the Hardrace rear it bolts directly up using factory brackets with thinner rubber/whatever to allow for that. Would be a lot cheaper than going the M5 route even if it can be fitted.

On the front sway bars I can't find the difference between the front on the M5 and M550i so would be tempted to go hardrace rear and then see how that works out.

Here is a positive reference for hardrace rear sway bar.

https://www.n54tech.com/forums/showthread.php?p=689617

[430Scud]

My 2 cents on anti roll bars. Most cars from the factory (in fact almost all cars) are set up with a lot of understeer. Increasing the roll stiffness in the rear through a larger rear bar can really bring things a bit closer to neutral. Increasing the front and rear at the same time is better, but (to me) only if the rear is increased more than the front. Otherwise you are still keeping all that understeer. I guess car manufacturers feel it is better (safer) to crash front first, versus rear first...

[430Scud]

Originally Posted by choppedliver

Looking at the rear sway bars again the M5 and M550i.

M5 - https://parts.bmwsydney.com.au/a/BMW...r/33_2234.html

M550i - https://parts.bmwsydney.com.au/a/BMW...r/33_2097.html

The M550i has a rubber part (#10) that requires different brackers (#3 and #4) to the M5. Or to put it another way the M5 doesn't have part #10 and the brackets that come with it don't allow for it (they actually seem flimsier).

If the above is not an issue I was wondering if you can re-use the swing supports from the M550i. They aren't cheap and weirdly the M550i only lists 1 as needed, which isn't correct.

At least with the Hardrace rear it bolts directly up using factory brackets with thinner rubber/whatever to allow for that. Would be a lot cheaper than going the M5 route even if it can be fitted.

On the front sway bars I can't find the difference between the front on the M5 and M550i so would be tempted to go hardrace rear and then see how that works out.

Here is a positive reference for hardrace rear sway bar.

https://www.n54tech.com/forums/showthread.php?p=689617

My suspicion is because the two anti roll bars use different support brackets, the bushings will not interchange. Meaning the M5 bushing will not fit the M550i bracket. Plus it appears the length of the endlinks that attach to the end of the anti roll bar are different too...all in all, until someone has done this change and answered your questions adequately, the hardrace seems the better route to go, unless you are prepared to buy the M5 bar, bushings, brackets and endlinks as a complete set.

Hardrace is 28mm rear bar. What is the M550i and M5?
I'd go measure mine with my digital caliper, but I have DHP so no point.

[choppedliver]

Originally Posted by 430Scud

My 2 cents on anti roll bars. Most cars from the factory (in fact almost all cars) are set up with a lot of understeer. Increasing the roll stiffness in the rear through a larger rear bar can really bring things a bit closer to neutral. Increasing the front and rear at the same time is better, but (to me) only if the rear is increased more than the front. Otherwise you are still keeping all that understeer. I guess car manufacturers feel it is better (safer) to crash front first, versus rear first...

Good advice.

[choppedliver]

Originally Posted by 430Scud

My suspicion is because the two anti roll bars use different support brackets, the bushings will not interchange. Meaning the M5 bushing will not fit the M550i bracket. Plus it appears the length of the endlinks that attach to the end of the anti roll bar are different too...all in all, until someone has done this change and answered your questions adequately, the hardrace seems the better route to go, unless you are prepared to buy the bar, bushings, brackets and endlinks.

Hardrace is 28mm rear bar. What is the M550i and M5?
I'd go measure mine with my digital caliper, but I have DHP so no point.

You are on point...according to that hardrace reference the standard M550i rear is 24.5mm. No idea what M5 is yet. I've not seen a reference. I also don't see any aftermarket or failing to find it.

[430Scud]

Originally Posted by choppedliver

You are on point...according to that hardrace reference the standard M550i rear is 24.5mm. No idea what M5 is yet. I've not seen a reference. I also don't see any aftermarket or failing to find it.

I suspect the Hardrace bar is larger than the M5, only so they don't eliminate a potential customer. I bet the M5 is 26 or 27mm then.

That is how the Eibach bars I bought for my E39 540 M-Sport.
540 25mm F 15mm R
M5 27mm F 16.5mm R
Eibach 28mm F 18mm R

[Lancelot]

Originally Posted by 430Scud

My suspicion is because the two anti roll bars use different support brackets, the bushings will not interchange. Meaning the M5 bushing will not fit the M550i bracket. Plus it appears the length of the endlinks that attach to the end of the anti roll bar are different too...all in all, until someone has done this change and answered your questions adequately, the hardrace seems the better route to go, unless you are prepared to buy the M5 bar, bushings, brackets and endlinks as a complete set.

Hardrace is 28mm rear bar. What is the M550i and M5?
I'd go measure mine with my digital caliper, but I have DHP so no point.

Look at my ebay links, they come with full bushings and brackets, if it were me i'd just get a set of these for front and rear, or find the m5 competition flavour if wanted to go a bit further.

Rear diameter is listed as 30mm for m5 ; now that doesn't say much as many roll bars are hollow, so the real info would be both inner and outer diameters in that case.

My view:
Be careful with sway bars, Hardrace, eibach and the likes have none of the testing capacity of BMW, and i tried multiple combinations of sway bars on my f30, none were satisfying, some were dangerous on normal roads.

Unless you're doing a dedicated track car, compliance is a desirable aspect of a suspension - to stick to the road, absorb imperfections of your normal road, be predictable and safe. The M5 is engineered to be a bit sharper with this compromise, so that's still OK but aftermarket are usually for smooth track surface, nothing else.

[430Scud]

Originally Posted by Lancelot

Look at my ebay links, they come with full bushings and brackets, if it were me i'd just get a set of these for front and rear, or find the m5 competition flavour if wanted to go a bit further.

Rear diameter is listed as 30mm for m5 ; now that doesn't say much as many roll bars are hollow, so the real info would be both inner and outer diameters in that case.

My view:
Be careful with sway bars, Hardrace, eibach and the likes have none of the testing capacity of BMW, and i tried multiple combinations of sway bars on my f30, none were satisfying, some were dangerous on normal roads.

Unless you're doing a dedicated track car, compliance is a desirable aspect of a suspension - to stick to the road, absorb imperfections of your normal road, be predictable and safe. The M5 is engineered to be a bit sharper with this compromise, so that's still OK but aftermarket are usually for smooth track surface, nothing else.

Agree you cannot do a direct comparison on paper between a hollow or solid anti roll bar, not without actual deflection numbers.

I disagree that you can have dangerous combinations of anti roll bars, UNLESS one went to unreasonable extremes between the front and rear sizes. That could cause gross oversteer or understeer. No one is advising of such an unreasonable combination.

I have never heard of Hardrace until this thread, but Eibach has been around for decades and a well respected brand. Their products are certified and meet many quality standards, including ISO 9001 certification. You can go to this page and scroll to the bottom for their various certifications in different countries. https://www.eibach.de/en/company/eibach-awards

I have installed various combinations of anti roll bars and strut bars on several cars I have owned, and never found any of them to detract from compliance of the suspension, if only in a subtle/minor way. Versus shocks and springs have a very direct impact on compliance. Just try a Bilstein PSS kit and see what that does to compliance...even on the lightest rebound damping setting.

For that very reason, I am more interested in chassis braces and anti roll bar changes than I am spring and damper changes. But I will admit that firmer springs and dampers have always made for a more confident and inspiring drive on a twisty road. But the sacrifice is most assuredly compliance.

[Lancelot]

Originally Posted by 430Scud

I have never heard of Hardrace until this thread, but Eibach has been around for decades and a well respected brand. Their products are certified and meet many quality standards, including ISO 9001 certification. You can go to this page and scroll to the bottom for their various certifications in different countries. https://www.eibach.de/en/company/eibach-awards

I know that well I ended up with their kit which was OK indeed.
But bad experience with H&R, with rear wheel lifting unexpectedly when you need grip. Anyway, we all have different experiences.

Originally Posted by 430Scud

Versus shocks and springs have a very direct impact on compliance. Just try a Bilstein PSS kit and see what that does to compliance...even on the lightest rebound damping setting.

100% with you on this.

[PetieD 7]

Originally Posted by choppedliver

I’m thinking to do the following;
1) mono ball… I expect this makes a massive difference to the steering as others mentioned.
2) Hardrace rear brace
3) Hardrace rear sway bar
4) Hardrace front brace
5) X-brace
6) M5 strut brace - need to research this

I gather with AWD you can’t add a front sway bar or it seems Hardrace don’t sell one. Does one exist?

I’m in Australia and might grab the Hardrace stuff as it’s pretty cheap here.

Did you end up getting the "engine bay suspension brace" for your vehicle? I am thinking about it b/c I will be installing MSS sport spring (height adjustable) kit and thought it would be a good idea to install that at the same time!

[choppedliver]

Originally Posted by PetieD 7

Did you end up getting the "engine bay suspension brace" for your vehicle? I am thinking about it b/c I will be installing MSS sport spring (height adjustable) kit and thought it would be a good idea to install that at the same time!

Ah no...I'm getting MSS next week assuming they've turned up. I was planning to do the MSS first and then do the other changes after. I suspect MSS will make a massive difference so may not bother.

[Mach550]

Does anyone know how much camber the uppers allow?

https://www.hardrace-europe.com/fron...ies-q0664.html



Also, wouldn't you want to ensure that the car is in a neutral position or on a rack where the tires are still making contact before bracing the body? Probably talking about millimeters but this could matter.

[choppedliver]

Originally Posted by Mach550

Does anyone know how much camber the uppers allow?

https://www.hardrace-europe.com/fron...ies-q0664.html



Also, wouldn't you want to ensure that the car is in a neutral position or on a rack where the tires are still making contact before bracing the body? Probably talking about millimeters but this could matter.

I was told elsewhere in a related thread there is no front camber adjustment.

[Mach550]

Originally Posted by choppedliver

I was told elsewhere in a related thread there is no front camber adjustment.

correct, but that's why I linked some camber arms

[Boosted_8]

Originally Posted by Mach550

Does anyone know how much camber the uppers allow?

[url]https://www.hardrace-europe.com/front-upper-camber-kit-bmw-5-series-6-series-q0664.html.

I'm at -1.6 (chosen on recommendation of the shop) using these items and there is still some adjustment left in the bolts. I would say depending on your stock starting point (usually around -0.25/0.5) -2 should be possible.

[Boosted_8]

Originally Posted by 430Scud

Agree you cannot do a direct comparison on paper between a hollow or solid anti roll bar, not without actual deflection numbers.

I disagree that you can have dangerous combinations of anti roll bars, UNLESS one went to unreasonable extremes between the front and rear sizes. That could cause gross oversteer or understeer. No one is advising of such an unreasonable combination.

I have never heard of Hardrace until this thread, but Eibach has been around for decades and a well respected brand. Their products are certified and meet many quality standards, including ISO 9001 certification. You can go to this page and scroll to the bottom for their various certifications in different countries. https://www.eibach.de/en/company/eibach-awards

I have installed various combinations of anti roll bars and strut bars on several cars I have owned, and never found any of them to detract from compliance of the suspension, if only in a subtle/minor way. Versus shocks and springs have a very direct impact on compliance. Just try a Bilstein PSS kit and see what that does to compliance...even on the lightest rebound damping setting.

For that very reason, I am more interested in chassis braces and anti roll bar changes than I am spring and damper changes. But I will admit that firmer springs and dampers have always made for a more confident and inspiring drive on a twisty road. But the sacrifice is most assuredly compliance.

I put the base M5 roll bars on. With -ve camber and 255/285 sportcontact7 she grips and rips

[Junebug85]

Originally Posted by Lancelot

I'm glad it's useful

I also retrofitted the front strut bar from F90, it really is bolt-on, except you need to remove the wipers to access the bolts on the firewall, which requires a specific wiper removal tool (~$10) to access below the plastic trims.

It made a slight improvement; I'll post some pics later.

Apologies to dig up this from 2 years ago. When you fitted the F90 strut brace, did you use the bolts that are for the F90 or re-used/got new G30 ones?

I've been looking and found the F90 bolt part numbers are different from the G30 ones.

F90:

51648076922 (4 bolts near the wipers) M10X25-SW18
07148076410 (4 bolts that go in the strut towers) No size listed on realoem

G30:

07119905147 (4 bolts near the wipers) M10X25-10.9ZNS3
51716966566 (4 bolts that go in the strut towers) M10X45

This thread has given me some insight for some mods on my 540ix

[Lancelot]

I think i just reused the ones from the original strut bar;

If you go by the book
1/ the f90 bolts are probably a bit longer as the strut bar is significantly thicker
2/ you’re supposed to use new bolts each time with torque to yield

But to be honest i don’t think it matters that much in that particular situation,