Intrax Four-Way Coilover Replacement Suspension

[Trackrat]

My GT3RS project car now has the Intrax 4-way overs installed and tested over four track days. Result- AWESOME!

The more I tracked my 2010 GT3RS the more I knew I wanted a more track oriented suspension set-up. Upon replacing the monoballs, drop-links, caster pucks, toe-control arms and top shock mounts with solid bushings, the car was much more precise but still too mushy on track. Trying to research a new coilover solution was tedious and time consuming and I looked at a lot of choices, and talked to a lot of people.

Bottom line I selected a supplier most USA folks have never heard of - the Dutch company Intrax. Located in the Netherlands, Intrax has a LOT of Porsche GT3 set-up experience. I chose the 4-way with spring adjusters on the rears and "Black Titan" piston coatings to help reduce stiction.

Intrax required me to specify my suspension set-up, primary use of the car and current handling and then built the system to my specific needs. I requested track performance with the ability to still be street driven if desired.

Many smart people shook their heads poo-pooing my decision and warned me that I was was about to ruin my car. That only Porsche could properly chose spring rates and dampening. That 4-way adjustable would be a tuning nightmare.

WRONG!

The result, upon replacing the PASM OE system was amazing to me and quite simply a transformation. Installation was by Jess Lattin, a talented Master Tech I work with, was straight forward and problem free. Out of the box, with Intrax recommended set-up settings, the car was transformed to go-kart like handling. Turn-in, track-out, steady state, stability under braking, trail braking, all were greatly improved.

Over the course of 4 track days at two very different tracks I was able to experiment with various compression and rebound settings and was able to adjust for very bumpy and then very smooth tracks easily and quickly. With the car on the ground.

I will update the thread as things progress but so far I could not be happier with my Intrax coilover solution.

[FTS]

I hadn't heard of Intrax, but they look superb. Since these are custom valved, did they provide you damping vs frequency chart as the baseline build?

[Trackrat]

Originally Posted by FTS

I hadn't heard of Intrax, but they look superb. Since these are custom valved, did they provide you damping vs frequency chart as the baseline build?

Is that the same as a (shock) dyno chart? If so, no. They did provide laminated set up sheets with suggested settings and how each should affect the handling.

[FTS]

Yes, the shock dyno charts. I am sure they'll provide a copy to you if you ask them, they most likely maintain a copy for themselves for their records. It may be useful later on if you want to rebuild and/or revalve them. It also would have been interesting to see it

I could not quite tell which knob is what, e.g. how do you adjust the high/low-speed settings for rebound and compression. As you went through the adjustment ranges, how did the attitude of the car change, could you tell the difference between minor changes, or mostly 2-3 clicks at a time?

This looks like a very sophisticated system, that's why I am asking the questions, very attractive

[TRAKCAR]

Looks very nice. Spring and shock setup is still a black art.

Pete, how do you find these guys?
If it ain't Dutch, it ain't much ;-) Koni is Dutch too, so I guess there is know how there.

i thought jrz and moton are also dutch, no?

[FTS]

Originally Posted by TRAKCAR

If it ain't Dutch, it ain't much ;-) Koni is Dutch too, so I guess there is know how there.

So true. Most shock manufacturer's founder either come from Koni originally or Bilstein; KW, Ohlin, Moton, even several Penske engineers

[PJS]

4 way intimidates me :-)

[Trackrat]

Originally Posted by FTS

I could not quite tell which knob is what, e.g. how do you adjust the high/low-speed settings for rebound and compression. As you went through the adjustment ranges, how did the attitude of the car change, could you tell the difference between minor changes, or mostly 2-3 clicks at a time?

This looks like a very sophisticated system, that's why I am asking the questions, very attractive

I am setting them up tomorrow for my upcoming weekend and will take pics and update this thread. The rebound on rear is on top in the cabin and on front on the bottom of the strut. High speed compression is the big red knob. Low speed compression is another red knob that fits over the 4mm male hex you see sticking out. The entire curve of both is adjusted by loosening a locknut on the low speed adjuster and the whole "barrel" moves in/out.

You can go from perfect throughout, to twitchy and super loose, to mushy turn in, to loose on track out and very firm overall to very cushy for street ride.

Notebook, pen and towel to lay on are required!

The suggested default setup is truly superb, these guys know what they are doing. So neutral, so taut and controlled.

Originally Posted by TRAKCAR

Looks very nice. Spring and shock setup is still a black art.

Pete, how do you find these guys?
If it ain't Dutch, it ain't much ;-) Koni is Dutch too, so I guess there is know how there.

Indeed but the key is to find smart people to set it up 95% and then you can play with the other 5% for smooth tracks/bumpy tracks/ dry/wet. I knew you would enjoy the Dutch origins of it

Originally Posted by FTS

So true. Most shock manufacturer's founder either come from Koni originally or Bilstein; KW, Ohlin, Moton, even several Penske engineers

An incestuous business for sure. Read the history of Intrax on their site...lol.

Originally Posted by PJS

4 way intimidates me :-)

No need! Last year I was intimidated as well and now I cannot imagine not having them and the adjustability. Either learn how to tune them or find a shop that has experience and let them help you. Porsche should offer an adjustable suspension as an option for the trackrats.