TT Gasman

Looks great Alex! What are the measuring points for your ride hieght?

Dr_KarlB

Alex,
What wheels are those ?

They are stunning :-)

Alex (UK)

Unsure, whatever these points were I suppose:

Alex (UK)

I think I have to be a member here to have a signature, but on other sites I have:

MY2008 997 Turbo - Cargraphic stage II powerkit (544PS/798Nm) | HRE P40's | Bilstein Damptronics | GMC Sway/Toe-steer/Dog-bone kits

So HRE P40 in 19" and silver powder finish. Very pretty and save 5kg (total) over OEM wheels.

Alex (UK)

I've done it!! With the help of Chris I have found 997 Turbo driving nirvana for 'all-road' driving...

These were the tests we did yesterday:



Please note the REVISED PORSCHE FACTORY SETTINGS. There was some confusion over numbers Chris initially gave me, but yesterday I checked them for myself and revised my tables. This principally meant all the ride heights I was basing my initial calculations on was wrong!!

The other thing of note is that in 3000 miles since I fitted my Damptronic kit the car has sagged a LOT. This means though that by raising the car back up higher the dampeners/springs have more travel and them and the ride becomes softer and more importantly makes the wheels touch the ground more when on rough terrain GIVING YOU A MASSIVE AMOUNT MORE TRACTION ALONG WITH BEING MUCH MORE PLANTED.

The other major change I made was setting the front sway bars to full soft (note still a little stiffer than the stock bars). The allowed the front end to lean and twist more. Again this helps with traction and stability over public roads.

So the car does roll a bit more through corners but the extra compliance is staggering. The car is so much more confidence inspiring now. As Chris says in the world of geometry tuning "compliance is king"!

I would HIGHLY recommend everyone with the Bilstein Damptronic kit to go back to your tuners after a few thousand miles after the car has done most of its sagging/settling, and check you ride heights, and adjust the Bilstein's to match mine. You will be amazed at the difference! Please note that ride heights should be measured at the Porsche official locations under the car. Using fender measurements is WILDLY inaccurate according to Chris.

Any questions then let me know.

TT Gasman

So how much did the damptronics sag? I'm still on the fence about them.

Alex (UK)

@0 miles: stock suspension (bottom of the range Bilsteins)

Factory front = 132 mm +/- 10mm
Factory rear = 153 mm +/- 10mm

@7500 miles: B16 Damptronics (top of the range Bilsteins)

Front: 134 mm
Rear: 140 mm (bigggg sag, and huge change in rake ie. the nose should be pointing downwards and it was nearly level!)

Reset to 119/132mm F/R

@10500 miles: B16 Damptronics (top of the range Bilsteins)

Front: 112 mm (sagged 7mm)
Rear: 128 mm (sagged 4mm)

Reset to: 117/138mm F/R (-15mm stock)

@17000 miles: B16 Damptronics (top of the range Bilsteins)

Front: 115.5 mm (sagged 1.5mm)
Rear: 135.5 mm (sagged 2.5mm)

Reset to: 117/138mm F/R (-15mm stock) - shouldn't be any more sagging now

The sagging is worse with stock Bilstein's than the B16 Damptronic kit. I'd say it takes between 3000-5000 miles before the suspension fully settles.

The really important thing is the front to rear ratio as you need to get that nose pointing nicely downwards! I think Chris measured the angle of the car at 1 degree in this regards after we adjusted for the revised factory setting baseline numbers.

Alex (UK)

Wow - I have just been out for a 2 hour spin down some countryside roads and I am delighted to say that sport mode is BACK on the menu!

Now that my Dampeners have been raised up to -15mm from OEM after they spent the last 3000 miles dropping even the Mrs can't believe how much smoother the car is now even over rough potholes at slow speeds!

If you do now find some flat-ish fast roads and engage sport mode then the car immediately sharpens up and leans less through the corners (countering the soft front GMG sways I have set now), all without knocking out your teeth like it use to with the Damptronic kit. ie. it's tolerable again, and not only that, it's fantastic!!


So I repeat once again to anyone who has Bilsteins fitted... After 3-5000 miles go back to your suspension specialist and get them to adjust the dampeners ride height to either -15mm (or I think -20mm would be fine now for those who track a lot). And please please please insist they measure from the Porsche official ride height places under the car (several times for consistency) as described earlier in this thread, and NOT from wheel arches!!

Boy I love my car now!! It is now perfect for me in every way

ET997s

Hi, Alex,

Just wondering if you have any "magic numbers" handy for 997 C2S? I am about to install the PSS10 (the non-Damptronic one) cuz my car doesn't come with PASM.

Currently I am running on the Euro -20mm Sports Suspension. It's a bit too stiff for me. I think I will go for -15mm as my initial setting for the PSS10. Am curious how I should start with the 10 adjustments too.

Thanks!

Coochas

Tremendous post Alex! Very useful writeup. Thanks.
If I ever decide to upgrade the suspension, I'll keep this in mind.

Alex (UK)

I would find out what the stock settings are from PIWIS (which your tuner should have access too). Then find out what Bilstein recommend for the range of front/rear drops. Then set the ride heights (based on points indicated under car - NOT fender which a lot of tuners do!) depending on what the factory setting are minus the minimum drop.

More info can be found on my Rennteam thread:

http://www.rennteam.com/forum/thread...GMG/page1.html

ET997s

Thanks a lot, Alex.

Alex (UK)

Chris has been busy annotating many of the pictures taken in this photo journal. I have started to upload some of them to picasa:

http://picasaweb.google.com/alex.997tt/CenterGravity1
http://picasaweb.google.com/alex.997tt/CenterGravity2
http://picasaweb.google.com/alex.997tt/CenterGravity3

Alex (UK)

Had my final ride height adjustment the other day (in order to counter the last of the sagging) at Center Gravity.

Ride heights in were measured at:

Front: 115.5 mm
Rear: 135.5 mm

Final settings (shouldn't be any more sagging now):

Front: 117 mm
Rear: 138 mm

As mentioned before, raising the ride height (still aiming at -15mm from stock) increases the dampener travel and gives a smoother, more compliant ride over rough terrain. I test drove the car today and on local (really) bumpy b-roads I was getting an extra 10-20mph, just with an extra 2mm dampener travel!

One of the downsides of raising the car though is that it naturally lowers the amount of negative camber (more = better grip in corners) available to the front wheels especially. However, in the winter months lots of negative camber is pointless anyway. It does mean though that I can get more castor (more = better stability at high speed). So what I lost in front camber I gained in front castor. Of course there is a solution to all of this... GT3 lower adjustable control arms and adjustable thrust arm bushings. About £500+ though for parts. Hmm, maybe if I do some more track days I will go down this route.

Two very interesting posts from Cannga over on 6speedonline regarding Bilstein B16 Damptronics vs 997.2 suspension:

http://www.6speedonline.com/forums/2592158-post167.html
http://www.6speedonline.com/forums/2631906-post168.html

So it looks like the Bistein B16 Damptronics may still be a good addition to the 997.2 Turbo.

NineEleven

Alex, these are tremendous effort to put together & I am intrigued. Would you mind sharing how much the suspension parts cost? I would be interested in a similar set-up.