Anatomy to getting the perfect 997 Turbo suspension
What is the perfect suspension? That is the age old question, how do you create something that will fit everyone's tastes?
By Jason Tang

The 997 Turbo was designed essentially as a "GT" touring machine with a somewhat cushy ride adjustable with a push of a button intended to firm up things a bit. When I first drove my Turbo after taking delivery, I set out to analyze the way the car felt under varying road conditions. From that I determined that the stock setup was a bit too soft for my tastes especially with the rear "jiggle" around undulating sweepers. I knew I needed to find a way to tighten things up as well as improve the overall steering feel. I had no way of knowing that this was the beginning of a man's 3 year journey in finding perfection.

http://vimeo.com/28721791

Step 1
Parts list of parts acquired over the span of 3 years.

Billstein B16 Damptronics


H&R adjustable swaybars


Tarrett swaybar droplinks


Metal balls/connectors instead of rubber or plastic balls/connectors


2nd step:
RSS lower control arms for both the front and rear


RSS adjustable rear link kit


RSS adjustable rear toe steer kit


3rd and final step:
Mode Inc Camber Plate Kit


The process
In the beginning, there was the stock form and then one day, the Car Gods deemed it was necessary to banish these into the great parts graveyard nestled in the dark corner of the attic


Damptronics and H&R sways


Manufactured by Bilstein


Part numbers


Rear subwoofer removed


Rear PASM wire connector


View from under rear shock opening


Marking the mounting points for the sway bars


Installing the H&R sway bars


Side view


New coilovers from underneath


Damptronic coilover


Comparing the stock non adjustable droplinks with the new fully adjustable droplinks


New swaybar droplinks are installed


Rear Tarett droplink


Rear


H&R rear swaybar


Massive rear RS wheel


Final adjustment before putting everything back together


Corner balancing


4 wheel alignment


A few months down the road, it was deemed necessary to install rubber boots to insulate the droplinks from the weather elements to prevent corrosion and binding.

Rubber boots in place


Installed


GT3 RS alignment specifications that was used:
Front
Left camber: -1.0
Right camber: - 1.0
Left caster: 7.5
Right caster: 7.5
Left toe: 0.4mm
Right toe: 0.4mm

Rear
Left camber: -1.8
Right camber: -1.8
Left toe: 2.0mm
Right toe: 1.9mm

My first impressions were that I was very impressed with the changes in handling I’ve experienced so far! It feels much more neutral and compliant over most roads. There are times when it does feel a bit stiff (really rough roads) but for the most part, it’s a must-have upgrade. The suspension motions are very well controlled especially around sweepers. It no longer “jiggles” over slight adulations/bumps mid-turn and is now very flat. It’s now just flat and very easy to control. It also feels much lighter on its feet which I didn’t think was possible. I’d say that it handles/feels more like the 997 GT3 I drove. This upgrade is relatively inexpensive compared to most out there and highly recommended! The differences in ride height between stock and lowered form is less than I thought it would be. ½” lower in front from the ground to the bottom of the wheel opening on top. ¾” lower in the rear. But the most important one of all is the front lip which was less than ½” lower on mine. No major worries about additionally scraping the front end. The shop that did the install did adjust the coilover height for me. I believe it comes set to be a bit lower from the factory. Bottom line is, if you were on the fence about doing this upgrade, my advice is “DO IT!” The last note is, yes, there’s a difference between the “normal” and “sport” PASM mode. Both feels very compliant but I’d say that the “sport” mode is a bit too harsh for daily driving. I’d save that for those “spirited” runs where it really shines.

 

Step 2

Fast forward a few years, I made the mistake of driving a friend's 997.2 GT3 RS that had just gotten a number of modifications done to it. And let me tell you guys, it was a revelation! I'd driven a number of other GT3/GT3RS before and it just does not compare to the way this example felt. The way it handled felt almost telepathic to the point where you literally could think where you'd want it to go. I was impressed and far from it for me to think that it'd be possible to make my Turbo handle exactly the same way but I knew I probably could get close. And so, I decided to order the same kit for mine. My Turbo was already in the shop because the front coilovers needed to be rebuilt for unrelated reasons so I figured I might as well get the new bits installed. I had them installed by the very capable techs from Motoring Unlimited whom also installed my tailights last year too. The next step was to get the new RSS parts.


Lower control arms




Control Arms in the rear




Specs



Afterwards, the Turbo was delivered to my home where I had a chance to try her out briefly because of rush hour traffic. A real drive would have to wait until a later date.

Step 3

It was determined that further modifications would be needed to ensure that the front coilovers worked properly with the mounting points. As it stands now with the stock mounts there were a fair amount of spring binding due to the fact that the mounts were not "turning" with the coilovers as steering inputs were made. We needed to find a type of mount that would allow the coilovers to properly "turn." A "pillow shock mount with ball bearings were found that would allow proper spring adjustment as steering inputs were made.

Bilstein Damptronic with stock shock mount



Stock mounting cup. No fitting issues initially but later I discovered that there are binding issues with the mounts and springs.



Top view of new vs old shock mounts



New vs old shock mount



Bottom view



Top view



Comparing coilovers with old vs new shock mounts



Final alignment and corner balancing



The view most will see now that the handling has been perfected



Many thanks to the team at Cantrell Motorsport and Motoring Unlimited for their hard work in making my Turbo the perfect handling machine.

997TT at Cantrell Motorsport



Motoring Unlimited



Now that I've managed to soak it all in and think about my impressions since these new bits were installed, I can share them with you. First off, I can't stop raving about the change then and now because of these simple modifications. It really did go a long way in improving the overall feel/handling of my Turbo. I already had Bilstein damptronics, H&R sways and Tarret droplinks previously which definitely improved handling from stock form but these new RSS bits took it one step further. My car feels almost much more assured around the corners and the steering feel has especially been taken to a new level. I was also very impressed at how compliant this setup was. Not quite bone jarring but hardly Cadillac smooth either. Have I managed to discover the holy grail of suspension perfection yet? Time to hit the track to find out!

At ORP, ready to go!



My impressions after multiple sessions around ORP is that the Turbo has achieved near 100% perfection. Not quite like the GT3 RS that served as its inspiration but about as close as one can get given the fact that the Turbo has extra weight and AWD hardware. The Turbo handled very well around the corners and was well planted. I received plenty of road feedback from the varying road surfaces and was able to make adjustments accordingly. I'm very pleased with the overall feel and this is the anatomy to this man's perfection suspension setup for the Turbo.

 

What a great write-up! Your Turbo is as good as it gets Jason! Thanks for sharing!

 

I think you have one of my favorite turbo's out there, Jason! I'm sure it's a dream to drive!

 

wicked post mate

 

A W E S O M E
thanks for sharing

 

Great write up!

 

The anatomy is to buy a GT2.

 

GT2 doesn't fit my needs...no AWD. Thanks for your suggestion though.

 

I cannot say for the road, but as you ramp up your speed at ORP, you would be well suited to dial in additional negative camber up front.

it will improve turn in and dial down understeer and allow you to get on throttle sooner.

Love the car and the mods -- excellent write up.

I have bascially all of that stuff on my car and can attest to the improved feel (RSS hardware, sway bars, motons, etc)

Love seeing the car at ORP!