3DM TTX Öhlins Suspension for High Horsepower Applications

Rileyg

Specialist
Feb 6, 2019
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Wow, this is pretty awesome. Any idea on the pricing for such a kit?
 

[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
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What spring rates did you end up with for this setup? What were the target wheel frequencies? In my understanding it is hard to achieve flatride with the Z4. Because if you increase the front spring rate, even just slightly, you end up having to run a massively stiff rear spring. Apparently this is because of the position of the rear spring and the rear-biased weight distribution of the Z4.

Obviously the damper adjustments offered by TTX-series are world class, and I assume the go all the way up to 4 way? But how did you strike the right setting on the first go?

Not going for flat ride in this scenario. Flat ride is more suited for "grand touring" street oriented kits, we are applying that principle to the F10 5 Series we are working on. If you did flat ride in this Z4 setup it would be an over-steering nightmare, not what you want with a car that is going to be producing 600+ whp. Current spring setup is 70/120.

As for the right setting on the first go... I knew what force curve I wanted to obtain and set the valving so the rebound and compression were at click 10 each to get that force curve. TTX has about 25 clicks total so we have plenty of room to tweak. If needed when development/testing is done I will revalve and bring the adjustment back to the middle.
 

AzNdevil

Sergeant
Nov 4, 2016
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Hong Kong
@[email protected] is actually working on a setup that let's one run the F30 Öhlins R&T kit on the E8x/E9x, with F30 hub carriers up front. It is in flight I believe. Ostensibly you could purchase F30 front hubs (cheap, plenty in junk yards), swap hub bearings up front from the E90, use the bolts I mention, and everything bolts right up front. Rear you have to run the E9x M3 arm to have it work, but I doubt that disappoints anyone.

In the near future I don't think there will be a collar sleeve available to run the E8x/E9x struts with the F30 hub. You could certainly choose to have one machined, I suppose. It's not a particularly complicated piece.

Filippo

the sleeve is the biggest issue in my case since machine work costs more than everything else...
anyways i will wait and see there are solutions to this.... thanks :)
 

fmorelli

Major General
Staff member
Aug 11, 2017
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the sleeve is the biggest issue in my case since machine work costs more than everything else...
anyways i will wait and see there are solutions to this.... thanks :)
I think there is an F30-based solution coming, for the e8x/e9x, which gets the better hub carrier geometry. @ShockandAwe is running the F80 hub carrier, I think, which is similar (a bit more reinforcement and I don't remember if geometry is identical). Anyway yeah if you are willing to wait a bit, I suspect Barry will have a solution in SKU format, so to speak.

Filippo
 

Asbjorn

Lieutenant
Mar 10, 2018
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European, based in China
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Z4 N54 DCT
I'd love to see if there are others that are doing active suspension development work on these cars. Based on your comments above, @Asbjorn, do you happen to know of anyone?

Well define suspension development haha. If you mean adapting motorsport dampers to the E89 Z4, I can't think of anyone other than you. And afaik noone has done any actual damper logging with proper equipment on the Z4.

I had custom 1 way dampers made to spec for my own car. We got some stuff right and some other stuff less right. I might order a new revision at some point.

Today my custom rear sway bar should finish production. I was finding myself always running the stiffest position rear (HR), so I wanted to balance that out. Not sure if that falls under active suspension development. Of course we are also looking into the cost of having custom front uprights made to spec, but that is most likely not happening. Will see. I also calculated the wheel spring rates based on the springs I use and the work done by wranda back in the zpost days. That was why I wondered how you decided to go with linear springs as well as what wheel rates you were aiming for.

Everyone I know in China either goes for KW v3 or just lowering springs and call it a day. And I dont understand how KW came up with this setup for the Z4, it doesn't look ideal:

mmexport1594740748327.jpg
 
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fmorelli

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Aug 11, 2017
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Well define suspension development haha. If you mean adapting motorsport dampers to the E89 Z4, I can't think of anyone other than you. And afaik noone has done any actual damper logging with proper equipment on the Z4.
Hahaha ... well to be fair, I'm not doing the suspension development. That's Barry - he's the expert with the 20 years of domain chops I lack. On suspension, I'm just helping on the wrenching side. I don't have the background and make no pretenses I'm not the expert on the subject.

I just asked if you were aware of someone else, given what you said. I didn't know from your commentary (you mentioned some technical tradeoffs) if you had seen some suspension engineering guys doing stuff with any of these cars. There are various cars (ex GT3 etc) and I just didn't know if you had stumbled across some folks.

Filippo
 

ShocknAwe

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Jan 24, 2018
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A quick FYI on the rear mount on my setup...

I'm running double eyelets in my rear TTX, lower M3 camber link mount and upper Turner Motorsport solid RSM.

Using swift 10" rear coilovers springs with some generic TCK height adjusters I had laying around. Also have some custom spring pads in the camber link.

Formerly had Dinan RSMs.

If anything there's less NVH, no need to drill the frame, just make sure you have a 34mm socket on hand to install the Turner mount through the trunk.

-Alex
 

ShocknAwe

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Jan 24, 2018
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the sleeve is the biggest issue in my case since machine work costs more than everything else...
anyways i will wait and see there are solutions to this.... thanks :)

I'm running the F8xM upright with E9xM3 R&T front. @Hydra Performance makes a caliper bracket which allows this to work with the E46CSL 2pc front rotor. No sleeves required for the spindle clamp.

-Alex
 

AzNdevil

Sergeant
Nov 4, 2016
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Hong Kong
I think there is an F30-based solution coming, for the e8x/e9x, which gets the better hub carrier geometry. @ShockandAwe is running the F80 hub carrier, I think, which is similar (a bit more reinforcement and I don't remember if geometry is identical). Anyway yeah if you are willing to wait a bit, I suspect Barry will have a solution in SKU format, so to speak.

Filippo

i can see this become an interesting upgrade for guys that wants to take corners fast... i dont mind waiting althought i dont think its high on his priority list :p

I'm running the F8xM upright with E9xM3 R&T front. @Hydra Performance makes a caliper bracket which allows this to work with the E46CSL 2pc front rotor. No sleeves required for the spindle clamp.

-Alex

how much does the F8xM knuckle push the front wheel out? i have a custom AP Radical BBK already so i will need to plan for this as well...
 

fmorelli

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i can see this become an interesting upgrade for guys that wants to take corners fast... i dont mind waiting althought i dont think its high on his priority list :p
Well I can't speak for @[email protected], but given the discussions we've been having over the past several weeks, I'm not so sure I'd say it is not high on the priority list.

With the F3x knuckle we really did not notice any significant spacing change in the wheel well, if that is the question. I'm running a 19x9 ET35 front wheel with 245/35-19. I have a 3mm spacer up front though we might be able to run without it. With the R&T setup/stock E90 hub carriers on the prior revision, we needed a bit more space on the tire to spring clearance. It's not clear that we need it in this case. But given what I am seeing, I believe this will be a no-contact fitment as was the prior configuration, and possibly without the spacer.

Filippo
 
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AzNdevil

Sergeant
Nov 4, 2016
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Hong Kong
With the F3x knuckle we really did not notice any significant spacing change in the wheel well, if that is the question. I'm running a 19x9 ET35 front wheel with 245/35-19. I have a 3mm spacer up front though we might be able to run without it. With the R&T setup/stock E90 hub carriers on the prior revision, we needed a bit more space on the tire to spring clearance. It's not clear that we need it in this case. But given what I am seeing, I believe this will be a no-contact fitment as was the prior configuration, and possibly without the spacer.

Filippo

actually i am interested for both f3x and f8xM knuckles...how much camber are you running?

for reference i am on a e92, with a 18x9 ET31 wheel with 255/35 or 30/18 tire..and superpro adjustable camber/caster control arms so my control arm length can vary by a little

at -1.5 degrees of camber i have around 3-5mm of clearance
at -2.8 degrees i have around 10-12mm ish
 

Asbjorn

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Mar 10, 2018
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European, based in China
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Z4 N54 DCT
Not going for flat ride in this scenario. Flat ride is more suited for "grand touring" street oriented kits, we are applying that principle to the F10 5 Series we are working on. If you did flat ride in this Z4 setup it would be an over-steering nightmare, not what you want with a car that is going to be producing 600+ whp. Current spring setup is 70/120.

I calculated the wheel frequencies as below

1598952217400.png


This is based on the assumptions (from this source) that the front rate is 96% and the rear rate is 55% for E89 Z4. I do not know if these rates are correct.

The detailed calculations are found in attached excel sheet I got from @AzNdevil and updated with Z4 data.

fullsheet.jpg
 

Attachments

  • Z4-spring-tates.xlsx
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