[-Eidos]

Hi gang,

I wanted to show the community another awesome option for coilovers.

They're from https://www.intraxracing.nl/en/ , a company with a strong motorsports heritage known mostly in the EU.

The front coils are upside-down, which gives you more direct feel, less camber and caster change from bending of the shock and therefore more grip and control. The rears are a true-coilover.

Both front and rear are equipped with a thermostat, which ensures that the damping characteristics stay the same throughout the race or session.

These are made to order and customized to your specific car, driving style, goals, and even color preferences.

For my set-up, I told Donald that my car will be:

- 75% track day car
- R-Compound tires
- Full kinematics
- Eventually will see about 100-200lb weight reduction
- Will get minor aero in the future
- Like to aggressively ride curbs on the track
- Seeing tracks that are in decent condition with the occasional rough spots. Big willow, Streets of Willow, AutoClub Speedway, and Buttonwillow.


I also requested to get their ARC (Anti Roll Control) option which allows you to run a softer spring and eliminate body roll if you want a true dual-duty car. It works independently of high and low speed adjustment so it works with their 2-way and 4-way option as well.

Their description:

Our ARC® system is developed by our current engineer and co-owner Niek van Sambeek and Henk Thuis (previous owner and founder of Intrax) with one thing in mind; a system that enables the engineers to use a softer spring and or setting with all the benefits (more traction, more grip, better handling, easier on the tires etc.) but without the disadvantages (extra body roll, pitch, squad or a collapsing system due to the softer spring and or setting).

They didn’t want to use any electronics because this will be seen as an active system which is still banned in 99% of all the competitions. And they didn’t want to connect the shocks with each other because this makes the system too heavy, fragile and difficult to install/maintain.

After lots of drawing, discussions, designing they started to test with a system which is purely hydraulic/mechanical and uses extra valves and pistons per shock. These extra parts react “intelligent” on the high and low speed of the piston connected to the piston rod without interfering with the normal adjusters of the high and low speed (so the ARC® can also be fitted on the 4-way system).

You can roughly say that the unsprung weight is the high speed movement and the chassis movements is the low speed.

For the high speed the system builds up enough pressure to keep the unsprung weight under control. Together with the soft spring/setting you will have a much more optimized constant pressure per wheel which ensures more traction, grip etc. When you brake and or corner the system will build up a lot of pressure. This way keeping the body roll/pitch/squad and dive under control. The extra great thing of this system is that when the high speed is there for a longer time it build up pressure very progressively, preventing a collapsing system. So when you drive high curbs, hitting big potholes or landing after a jump the car will still feel very much under control. Way more than with a regular system.

I also got their Black Titan coating.

Which is defined by them here:

Black Titan is a development that has been done for the military air force. They were looking for something that would make the engines more resistant to the various tortures that they are exposed to extreme temperature and condition. Black Titan was then invented. It is extremely hard, very low friction coefficient and resistant to corrosion. After using Black Titan on their aircraft engines, the maintenance interval was sometimes extended by 100%.

Intrax has thought, which is good for their engines, is also good enough for our shock absorbers. The coating is placed on the guide and piston rod, which is no longer prone to corrosion, but the friction with the other components is also reduced, which again benefits the damper's action.

All paired with their 1K2 system, which is their one way system that allows you to adjust the compression and the system will proportionally adjust rebound.

Intrax has a lot of other options like their 2-way and 4-way systems. They also have EMC (Electronic Magnetic Control), which allows you to adjust your shocks from inside your car. As well as EHC (Electronic Height Control) which allows you to adjust the height of your car from inside the car.

I've had one track day so far, and it was a huge transformation from my previous TCK Kline SA/DA set-up. Not to say that the TCK's were bad (They're actually great for the price), but the Intrax is on a whole different level.

Despite the Intrax set-up running stiffer springs because of my goals, on the middle setting (Front 15 of 40 clicks, Rear 26 of 50) the whole system feels much more compliant on the street than my old set-up (300#/600# on track settings) because of the quality of the dampers and ARC.

On these same settings, I get much less unwanted body roll, a more compliant chassis over curbs, and sharper turn in on the track. So a net positive on both fronts.

It was tough to find a distributor for these in the US. SD Garage in SoCal ultimately ended up helping out, so reach out to them if you're interested! They're working on a custom blue and silver color way that will look great.

[GtSport]

Hello,

Could you tell me more about it after some usage?
How is it on the street? How reliable is it so far? How many secods did you drop on your favorite track vs previous suspension?
I will mostly use it for trackdays and fun drives, but I’d still like to be able to drive it on some mountain roads and relax back home without braking my back.
I’m almost sure I will take the same one before the next season.
The only other could be MCS 2way remote, but I’m leaning towards Intrax 1K2 with ARC and BT.

Thank you!

[-Eidos]

Originally Posted by GtSport

Hello,

Could you tell me more about it after some usage?
How is it on the street? How reliable is it so far? How many secods did you drop on your favorite track vs previous suspension?
I will mostly use it for trackdays and fun drives, but I’d still like to be able to drive it on some mountain roads and relax back home without braking my back.
I’m almost sure I will take the same one before the next season.
The only other could be MCS 2way remote, but I’m leaning towards Intrax 1K2 with ARC and BT.

Thank you!

The suspension on full soft feels very compliant on the street despite my 150/120 Nm spring rates. I even daily drive the car on bad roads.

For a true dual duty car you can definitely ask Intrax to provide softer spring rates and they will revalve the dampers accordingly. ARC should help eliminate any excess body roll caused by the lighter springs.

If you have a big budget, I recommend getting their remote height adjuster as well as in car rebound adjustment. Those seem really nice.

In terms of performance increase I've seen anywhere between 3-4 seconds in improvement (plenty of more room to go if the driver improves...) over my previous set of aftermarket coilovers depending on the track. To be fair though my previous set of coilovers were under sprung and poorly dampened for any pace faster than intermediate HPDE.

[GtSport]

@-Eidos Thank you for taking the time to answer these questions. I’m more about the lap time than comfort, but I will also drive it on some mountain roads, mostly fun drives.
I’ve already talked to Donald and I think he will adapt it to my needs.
Now I can’t wait until spring and track season.
Do you run Intrax camber plates? Any weird noise with these on? I'm thinking if i should keep my Millway perfectly quiet camber plates or go with the Intrax. Millway have one big downside, maximum camber is -3.

[MR RIZK]

Originally Posted by GtSport

Any Millway have one big downside, maximum camber is -3.

Why not keep the Millways and add a set of adjustable SPL lower control arms.

[GtSport]

To get them in Europe I would probably have to pay twice their worth because of the transport and taxes.
I’d prefer the ones from Intrax or settling with Millway and run max -3 front camber.

[-Eidos]

Originally Posted by GtSport

@-Eidos Thank you for taking the time to answer these questions. I’m more about the lap time than comfort, but I will also drive it on some mountain roads, mostly fun drives.
I’ve already talked to Donald and I think he will adapt it to my needs.
Now I can’t wait until spring and track season.
Do you run Intrax camber plates? Any weird noise with these on? I'm thinking if i should keep my Millway perfectly quiet camber plates or go with the Intrax. Millway have one big downside, maximum camber is -3.

I run the Intrax plates. No weird noises at all

[GtSport]

I'm still waiting for my Intrax suspension, in the end I did spec-ed it for track and some very rare fast road so it will be pretty stiff. Hope that I will not use traction on some hilclimbs on soft rear settings.
Do u use also aftermarket ARBs? I heard that in some case true coilover rear springs catch the anti roll bar.

[noemon]

I'm about to push the button on the 1K2 with Arc and Black Titan.

Did it come with lower front control arms?

And if not did you just use the OEM ones or did you go for SPL?

[-Eidos]

Originally Posted by noemon

I'm about to push the button on the 1K2 with Arc and Black Titan.

Did it come with lower front control arms?

And if not did you just use the OEM ones or did you go for SPL?

It did not. I run full SPL.