[biomed27]

anybody try this set up? https://www.bimmerworld.com/F8X-Fron...Assembled.html

[Polo08816]

Originally Posted by biomed27

anybody try this set up? https://www.bimmerworld.com/F8X-Fron...Assembled.html

Yes. I would order the parts of FCP Euro so you can lifetime warranty this later on.

[biomed27]

Originally Posted by Polo08816

Yes. I would order the parts of FCP Euro so you can lifetime warranty this later on.

How does this set up compare to the VAC monoball? I'm between the two options

[Logicoeur]

Originally Posted by biomed27

How does this set up compare to the VAC monoball? I'm between the two options

This is an f8x part meaning it's longer than the F3x arms. That's how the f8x gets more camber up front.

If you are AWD do not get the f8x arms. It's better to go VAC arms built for the F3x, unless you want to blow axles all the time. Get more camber using camber plates.

[biomed27]

My car is rwd. I'm more concerned with degrading ride quality/increasing cabin noise too much. Trying to find a happy middle

[alohasurftoad]

bimmerworld's are F8x for F2,3,4 series which adds 1 degree of negative camber, that's quite a bit. i haven't read a thread or post yet on anyone that has them. maybe you can "take one for the team" and let us know how it is...

i have VAC monoball UCA(only). the steering feel/precision improvement is substantial and because it's realized at all times you are driving, for me, it is one of the best mods i've done. VAC installs their monoballs in OEM arms, thus OEM geometry, plug and play, no alignment required after install.

thx @johnung for hooking me up with bryan@kiesmotorsports to get my VAC UCA

[biomed27]

Originally Posted by alohasurftoad

bimmerworld's are F8x for F2,3,4 series which adds 1 degree of negative camber, that's quite a bit. i haven't read a thread or post yet on anyone that has them. maybe you can "take one for the team" and let us know how it is...

i have VAC monoball UCA(only). the steering feel/precision improvement is substantial and because it's realized at all times you are driving, for me, it is one of the best mods i've done. VAC installs their monoballs in OEM arms, thus OEM geometry, plug and play, no alignment required after install.

thx @johnung for hooking me up with bryan@kiesmotorsports to get my VAC UCA

How does the noise and ride comfort compare to stock? Thank you

[alohasurftoad]

Originally Posted by biomed27

How does the noise and ride comfort compare to stock? Thank you

for me, there is no difference in noise or ride comfort. you can sort of feel the road more but in a positive way, where you can feel the position of the tires and tread at the pavement.

prior to VAC i remember the OEM electronic steering had no feel at all, the on center feel was non existent and i could never tell front tires position. sure it, would go where i pointed it. imo, with VAC steering feel approaches how it used to feel with "old school" analog steering.

recently, there was some member here that did not have a great experience with VAC. so you'll have to look for his thread. personally, i think VAC is awesome.
.

[Logicoeur]

Originally Posted by alohasurftoad

for me, there is no difference in noise or ride comfort. you can sort of feel the road more but in a positive way, where you can feel the position of the tires and tread at the pavement.

prior to VAC i remember the OEM electronic steering had no feel at all, the on center feel was non existent and i could never tell front tires position. sure it, would go where i pointed it. imo, with VAC steering feel approaches how it used to feel with "old school" analog steering.

recently, there was some member here that did not have a great experience with VAC. so you'll have to look for his thread. personally, i think VAC is awesome.
.

Do you also have camber plates?

[alohasurftoad]

Originally Posted by Logicoeur

Do you also have camber plates?

me? i have m-performance susp, a megan front strut tower brace(don't really feel it did much) and VAC monoballs in the UCA/thrust/tension arms.

johnung convinced me that the steering improvment with VAC UCA would be worth it and it is. i'm pretty much done with my car, so I didn't opted not to spend on the VAC LCA as well, but i'm happy with it.

[SuperLomi]

If you just want mono-balls there are better options out there, imo.

I've also read that monoball thrust arms provide a greater benefit than LCA.

The F8x arms seem to come with too many drawbacks. One of the bigger ones is having to use up a lot of the tie rod adjustment range to run reasonable toe, and caster changes (maybe this kit fixes that? My understanding was while the F8x thrust arm helped the problem, it didn't completely fix it)

[biomed27]

Leaning towards the VAC set up. Does anybody know if they use the genuine bmw part with the part number and bmw logo stamp? Trying to keep everything up to spec

[skier_du]

VAC uses the Lemforder arms. Lemforder are the oem supplier of the arms. So they're exactly the same arms as the oem BMW arms without the BMW logo and BMW markup.

FYI, if you wanted to get the f80 arms, you could get the Lemforder f80 LCA (f80 oem LCA has an inner mono-ball from the factory) and the have VAC put their f30 mono-ball into the f80 tension arm. They will do that. You'd have to call them though, and the sales guys may or may not know they can. But I've talked to Tony about this. He designed the mono-balls and can basically do just about whatever someone wants. So you'd just have to talk to them.

[alohasurftoad]

my OEM UCA are TRW with BMW stamp and the arms the VAC installed their monoballs in and sent to me are TRW as well.

both TRW and Lemforder seem to supply suspension parts to BMW, so either is fine and equal to OEM BMW.

[johnung]

Originally Posted by biomed27

My car is rwd. I'm more concerned with degrading ride quality/increasing cabin noise too much. Trying to find a happy middle

You won't get any added noise, vibration or harshness from the VAC Monoball thrust arms. But as Alohasurftoad alluded to- the driver will get enhanced road feel transmitted to his hands through the steering wheel. Basically it feels the way that a sports sedan should!

[Jvac]

I have a substantial increase in harshness when driving over bumps in the road, concrete joints etc after installing the Vac monoball thrust arms. I'm on stock m-sport adaptive suspension and 19" wheels from the factory. But I love the improvement in steering precision. It inspires so much confidence at the wheel of this car that I am willing to put up with the sharp ride quality and keep them.

[Logicoeur]

There's really no way to argue the case that they don't add NVH. The part transfers energy from the tires directly into the chassis. Now,
whether the driver notices or minds is another thing.

I have camber plates already, so I am guessing these will increase NVH for me significantly. Hoping someone with csmber plates who added these after can chime in though.

Road imperfections are pretty noticable for me as it is, so I believe a happy medium would be something like the Meyle HD arms. The bushings for those are just hardended rubber and not fluid filled like oe.

[Jvac]

Originally Posted by Logicoeur

There's really no way to argue the case that they don't add NVH. The part transfers energy from the tires directly into the chassis. Now,
whether the driver notices or minds is another thing.

I have camber plates already, so I am guessing these will increase NVH for me significantly. Hoping someone with csmber plates who added these after can chime in though.

Road imperfections are pretty noticable for me as it is, so I believe a happy medium would be something like the Meyle HD arms. The bushings for those are just hardended rubber and not fluid filled like oe.

I have a set of camber plates that I haven't gotten to installing yet. I will report back when I do. I figured the plates would add some more noise but it wouldn't be too drastic since I already have the noise from the monoballs .

[biomed27]

Thanks for the input. Hopefully more users can chime in regarding NVH with VAC set up.

[kilogram]

Originally Posted by Jvac

I have a set of camber plates that I haven't gotten to installing yet. I will report back when I do. I figured the plates would add some more noise but it wouldn't be too drastic since I already have the noise from the monoballs .

I added plates 2 weeks ago, monoballs 4 weeks ago. Plates (Millway street) added a lot more noise than the monoballs did, but it might be the design. I think the sandwich plate they use might be able to move enough to contact the housing...

[johnung]

Originally Posted by Logicoeur

There's really no way to argue the case that they don't add NVH. The part transfers energy from the tires directly into the chassis. Now,
whether the driver notices or minds is another thing.

I have camber plates already, so I am guessing these will increase NVH for me significantly. Hoping someone with csmber plates who added these after can chime in though.

Road imperfections are pretty noticable for me as it is, so I believe a happy medium would be something like the Meyle HD arms. The bushings for those are just hardended rubber and not fluid filled like oe.

Actually the engineering explanation that I've heard on monoballs is that their ability to move in almost all directions is what prevents them from transmitting NVH to the chassis. If you think about it, hard race bushings are the opposite of monoballs. They are stiff in all directions and are known for transmitting a ton of added NVH to the chassis.

I have both the upper and lower VAC monoball control arms. There was no added NVH at all. But the steering precision increased dramatically. The other difference that I noticed was added road feel transmitted to the driver's hands through the steering wheel, exactly what you'd expect from a European sports sedan.

[kilogram]

Originally Posted by johnung

Actually the engineering explanation that I've heard on monoballs is that their ability to move in almost all directions is what prevents them from transmitting NVH to the chassis. If you think about it, hard race bushings are the opposite of monoballs. They are stiff in all directions and are known for transmitting a ton of added NVH to the chassis.

I don't think that's a correct engineering explanation. The DoF the monoballs allow prevents binding in the suspension, but they absolutely transmit more impulse force directly to the chassis.

With rubber bushings, some of the impulse from suspension motion is consumed in deforming the bushing. This is part of rubber's natural damping properties, and as such some of the kinetic energy from the suspension impulse is dissipated. There is very little deformation in a spherical bearing (only the PTFE liner) to dissipate kinetic energy.

As an experimant, try hitting a piece of rubber with a hammer, then a piece of steel with a film of PTFE on it and see which one transmits more vibration and noise to the surface below.

The monoball is substantially stiffer than a rubber bushing in the direction it matters- the direction it's most heavily loaded. The suspension arm there is a two-force member, and although the bushing allows it to transmit limited moments, the moments involved pale in comparison to the designed load path.

Monoballs are most definitely higher NVH than rubber bushings. If they weren't, BMW would have used them there from the factory. And in the control arm chassis pickup as well. The monoballs used here are an existing part from the rear suspension, and it's cheaper to design the suspension to use existing OTS parts than to design it with a bespoke bushing.