[M1500Z]

Preface
This is a story/review of my experience with a 3DM custom TTX setup for my M2 Competition. I'm in no way a shock master and sometimes my ADD gets the best of me—happy to correct anything that's unclear or misstated. I'll be updating this as I get track experience and photos of the car on the ground (it's dirty yech).

3DM TTX for M2 CSR (most applicable link)


Introduction
When I first received my original M2, way back in September of 2017, I knew I wanted to put coilovers on and take it to the track at least once. It would be a couple of years, but eventually I would select an Öhlins Road & Track kit and get to my first weekend tracking that car. Fast forward to moving that same kit onto an M2 competition and getting into the track experience more heavily, I was getting a bit faster and adding some more grip.


COTA April '21 prior to APs and 275s

With the wider wheels and tires came limitations of the R&T kit, mostly:

• fitting wider wheels and tires is difficult due to the spring perch location on the strut.
• the spring rates and damping are unsurprisingly a compromise between street and track use.

While being a fantastic option for the platform and mixed use, the R&T kit does what it says on the tin—road and some track. I’d seen people reference 3DM Motorsport on these forums and the good experience they’d had with revalving the R&T, so I called them up hoping I may be able to solve some of my issues by adapting the kit to my use-case. I ended up speaking to Barry at 3DM for quite a while regarding the options I had, but ultimately we agreed that making the R&T kit work for me would be difficult and not guarantee a solution. It made more sense to sell it and move to a setup that is more track oriented. At the time, I felt the Öhlins TTX were too expensive and overkill so I thanked Barry for his time and went on to looking at other options—mostly MCS, AST/Moton, etc, but also Nitron and a few other more boutique options.


Learning
After speaking with 3DM, I began to dig in and research these other brands (even reaching out to a few members here). It seemed like MCS was the likely winner and I was put in touch with Bimmerworld (who were excellent to speak with). They recommended I go with MCS 2-way remote and had some sound reasoning behind that recommendation. When I looked over the quote, the price was higher than I’d anticipated, but by now I had basically talked myself into a certain tier of suspension. I told myself if I’m going to spend the money, I should educate myself further.

Now, when it comes to dampers, a large swath of what’s available are monotube dampers and they mostly do things in a similar fashion (especially the various 3-letter brands). There are many different flavors of monotube damper available but they all work pretty similarly. I’ll avoid going into the details of how they function because I’m not a subject-matter expert by any means, but I’d recommend utilizing the resources out there to learn for yourself before buying into any particular system.

When I really dug in and tried to learn about the various dampers on the market, I found that many of them don’t go into the details of what sets them apart from their competition. There’s a bunch of marketing speak generally that, in some form or another, shows they provide the best grip or control and knob adjustments the driver can feel. It’s all relatively hyperbolic or vague or both.

I don’t want to imply that those dampers aren’t good—that’s obviously not true—just that it didn’t really sit well with me why one brand seemed to be top dog for a few years before being replaced by the next hot brand.

This frustrated me because I naively wanted some sort of data—something that quantified why a particular brand might provide more grip or control the vehicle better. Most people don’t go testing with shock pots and then provide that data online for every platform, but I just wanted something I could buy into.

Frustrated, and a little fed up, I went full circle and took a hard look at the Öhlins TTX—after all, I was really happy with the quality and performance of my R&T kit (within it’s realm of expertise) and by this time I’d convinced myself I needed really nice suspension. What I found is that Öhlins actually has some great information online in the form of various manuals and interviews about the TTX dampers. In addition, I’d come across some videos of through-shaft dampers from Doug Brenner in CA. I’d highly recommend reading/watching these:

• Ohlins TTX40/46 manual
• TTX40 tear down

Again, I won’t go into all of the details myself as I’m likely to misspeak, but take a look at those. The TTX46 front strut is a through-shaft damper and these through-shaft dampers are really interesting, differing in many ways from a monotube damper. They are a twin tube design that uses a solid piston that acts as a pump to push oil through a compression or rebound circuit and are inherently balanced, requiring significantly less gas pressure to prevent cavitation. This leads to basically no “nose pressure” and should lead to a more supple quality. This also completely separates the compression and rebound circuits. Again, I’d recommend reading and watching for yourself as I found it very interesting.

If you look around, you’ll find that many high-end motorsport designs share some of these qualities, whether twin-tube or through-shaft or both.


Coming back to Öhlins
After spending a while educating myself, I decided I really liked the idea of the TTX dampers.

• I appreciate how Öhlins is very thorough with the information they provide.
• The TTX engineering was very neat to me, seemed incredibly well thought out, and many GT4 teams have used them, BMW included.
• The price difference was a lot smaller than I’d anticipated.

My previous interaction with Barry at 3DM left a very good impression on me—he was very informative and willing to spend the time discussing my issue without pushing me to buy anything. I decided to give him a call to discuss the TTX setup. Now, it’s worth noting that Barry has a mountain of experience with Öhlins, has personally run cars on Öhlins’ shaker rig for data (including an M2 CS Racing), has helped Öhlins develop some of their kits, and is a BMW guy himself. Seemed like a no-brainer to me.


3DM customer M2 CSR on the shaker rig

Barry and I discussed all the various aspects of my car, target ride height, tires run, tracks, etc. and decided on a TTX46 strut with the TTX36ILX (in-line reservoir) rear. I’m sure many of you know that Öhlins is also selling a kit that will be available soon—this is not that kit(it's not even available yet). Working together on a more customized solution allowed Barry to

• provide valving for my criteria with his existing knowledge of the M2 on track.
• spec our own springs/lengths etc.
• run a true coilover rear with more spring options should I need them in the future.
• use Vorshlag camber plates to Barry’s spec to achieve a low stack height.

We settled on 14kg/mm front and 12kg/mm rear Swift springs and helpers. Coming from the R&T, I was thinking these might be too stiff, but Barry was confident they would be streetable and that the TTX damping properties would be suitable to driving to and from the track (more on this in a bit). I know a lot of people will be curious about spring rates, but the TTX can run whatever spring rate you'd like within reason—I'm not sure how low you can go, but you can go much higher than the rates I've selected.

Once everything was assembled (dynoed, balanced, etc), Barry and I hopped on a zoom to discuss the dyno charts for the dampers. He provided me with all the dynos so I can revisit them should I have questions or want to make any changes.


Hands-on thoughts and installation
The dampers themselves are exceptionally made and quite lightweight. I don’t think this is any different in the expectations from other motorsport-grade suspension. The adjustment knobs can be turned by hand or by tool and require enough effort as to not make any errant clicks.


TTX dampers, left TTX46 strut, right TTX36ILX rear coilover


Left TTX46 adjusters, right TTX36ILX valve body

Installation is pretty straightforward and the same as most any other damper on F8X chassis. The front TTX strut is a bit different in that it uses machined aluminum spacer rings to adjust the knuckle height. The bottom cup is machined to bottom out within the knuckle—just the same as the R&T kit. The lower spring perch and locking collar are used to fine-tune the ride height. The dampers shipped with 3 spacer rings up front, and I only needed 2 to pretty much nail my targets. The mounts for the swaybar are threaded onto the damper body, height adjustable, and locked with a pinch-bolt.


Left TTX46 strut, right TTX36ILX rear coilover

Sadly, I need to run a little additional height to get out of my driveway. With an 18” wheel, the ride heights are 575mm front and 577mm rear measured wheel lip to fender (I'll add some photos once the car is clean). A quick trip to my local shop, Soulspeed performance, and the car was aligned and corner balanced.


Experiences
This is probably what most people will want to know and sadly, it's the smallest section at this point, but I'll update it as I get more acquainted with the dampers and more seat time.

On the street
I almost couldn't believe how the car drove the first time. I was expecting a pretty stiff or heavily damped ride until about 30mph, but they honestly feel about the same as my R&T setup (with 550lb front spring) at 7 clicks, but there’s an additional suppleness to it. If anyone here is a cyclist, it’s similar to switching from a Gatorskin to a Vitoria Corsa—you don't lose feeling, but little ripples and road imperfections seem softer. The drive I took had some choppy sections of road, but nothing miserable. The one thing that I did intentionally was drive on a long elevated section of highway where the road was repaved above the expansion joints—lots of da-dunk... da-dunk... da-dunk. The car handled the joints in an exceptionally composed manner. Right now I'm in the dead middle of the valving, but will tinker with them more to see how comfortable I can get the ride without it being bouncy.

On track
Updated June 1, 2022

May 21 and 22, I had my first experience on track. This was at Circuit of the Americas—my home track and somewhere I’m pretty familiar with. I went out first session on base settings to feel the car out. This would be 10 R 10 C from stiff, or right in the middle of the adjustment range. Once the car is up to speed and tires are warm I’m noticing a few things:

• The grip—both corner exit and the ability to put the car where you want it on turn in.
• Neutral setup that really allows you to rotate the car with throttle inputs.
• Steering felt more precise and inputs and corrections could be minimized.
• The car was much less likely to be upset by undulations in the track—something COTA is unfortunately becoming known for.

The ability to get on the throttle earlier and harder is something I’ll continue to get used to, but I was very impressed with how much easier it felt to drive the car with the right pedal.

Throughout the first day, I tinkered with the settings just to feel how they effect the car and I can say, the clicks are noticeable. I pretty quickly was able to find where too much compression was and then used the rebound to play with how the car felt in transitions as well as working to make the brake release smoother. Day 2 I again started from baseline and then made some aggressive changes with rebound to see how it would affect the car. I think I’ve found a good setting for rebound at COTA and will concentrate on compression next time I go out. After that, I think I can start working on individual axles.

Qualitative results are great, but how does that translate quantitatively? With driving being a bit of a physical activity with the ultimate measured outcome being laptimes (there’s lots of other data of course), I think confidence and precision translates into times and consistency. And that was what I was shown:

• I set a new PR of 2:31.1, a whole 1.5s off my previous time that was set in much better (cooler) weather.
• Instead of having a flyer here or there, I laid down successive laps that were within 1 tenth of that lap, later in a session, with the tires beginning to go off.

I’m not sure what else I could ask for with this bit of kit. I think it provides a very high performance ceiling and tons of adjustability that I’m just scratching the surface of.

Oh, and I hit a few turtles —they were the smaller ones, but they were still almost imperceptible in upsetting the car. With the previous R&T setup and the dampers set where I liked them, you could say that hitting a turtle was an experience you'd rather not repeat.

Some notes and thoughts

• The TTX46 I am running is a 2-way adjustable with a cast valve body—4 way valves as well as a billet valve body with an optional blow-off valve are available.
• The TTX36ILX I specced is not a through-shaft damper like the TTX40 and 46. Should you desire it, the TTX40 is available as rear damper.
• The Öhlins Advanced Track Day kit for our cars uses a Millway camber plate that adds caster and camber at the same time (BMVMU20 manual, pg 5)—I believe these cars add caster with a normal camber plate and do not think this is ideal.

[to_riffic]

If you were closer, I'd ask for a ride in your car to see how it feels!

[MR RIZK]

Curious why not run TTX46 front and rear so the rear also has the external canister?

Otherwise congrats on the purchase..

PS: the spring rates should be 14/12kg

[mike@x-ph.com]

Thank you for the review

[M1500Z]

Originally Posted by MR RIZK

Curious why not run TTX46 front and rear so the rear also has the external canister?

Otherwise congrats on the purchase..

PS: the spring rates should be 14/12kg

Thanks for the catch. I was thinking Newtons when I typed that—changed :P.

The TTX46 is only available as a strut. The TTX36 I have in the rear is available with a piggyback or remote reservoir. The ILX has packaging and weight advantages by packaging the reservoir "in-line," or internally. Another bonus is that you can use these in series that don't allow remote reservoirs—something that's not important to me.

The real upgrade in the rear would be to use the TTX40 since it's a through-shaft unit like the 46 front, but it's a significant cost increase to do so and past the point of diminishing returns for a HPDE guy such as myself. You could argue I passed that point a while ago ��.

[///393]

Dang. That’s fancy. Interested in feedback once you get some track time.

[Yadadameans]

TTX is like top notch stuff. It is up in the price range though. You get what you pay for. Never cheap out on coilovers.

[Remonster]

The TTX technology is really incredible, we put a set on our shop E36 M3 as a demo vehicle because it's great for people to feel what they can end up with before they think about spending this kind of money for anything. I believe the very low gas pressure they're able to run is responsible for the very high levels of grip they can generate as well as the supple ride quality. We're at 45psi for our kit vs. 260psi for some other brand recent remote reservoir kits I've installed.

[MR RIZK]

[M Fifty]

Originally Posted by M1500Z

This frustrated me because I naively wanted some sort of data—something that quantified why a particular brand might provide more grip or control the vehicle better. Most people don’t go testing with shock pots and then provide that data online for every platform, but I just wanted something I could buy into.

A thread from a few years ago that may still be of interest:

https://f87.bimmerpost.com/forums/sh...highlight=dyno

HTH

[MR RIZK]

M1500Z to aid in the comparison with other brands would be great if you provided the PVP plots of your setup.

[M1500Z]

Updated with initial track thoughts. Ask me questions—it's been a few days so I've likely forgotten some things.

[lzhmax]

Nice, one of the best shocks if not the best ones.
I'm currently running nitron r3s with 12 and 13k spring rates, still streetable and on track they are the best shocks i've ever experienced after using Ohlins r&t, KW cs and Bilstein cs.