utkinpol

that is the key, highlighted. theoretical perfection is unachievable anyway.
450/600 is how KW v3 comes and how damptronics come. racers and tuners seem to make faces at it but you know, a lot of people track their cars on such setups and do not complain.

i did not realise you had stock big springs - in my setup they are all same size, 7" springs so i can move them around relatively easy.

997gt3north

I actually didn't know that was the KW V3 spring rate - I'll have to check as that seems odd that the V3s would use a higher front rate that the Clubsports. The Damptronics for the 997 use a 340/570 spring rate. The 600 number I think is used as an approximation what I have that from Bilstein directly - your 450# may come from another Damptronic kit that you may be confusing for the 997 chassis - again, this is from Udo, the German dood I have spent about an hour on the phone with over the last week.

Paul

997gt3north

I actually just checked, the V3 spring rate is 285/970 for the 997s 2007-2010. I was going to say that but wanted to check first. KW for the longest time has had 900# springs on the rear of 911s. Your 600# may be a Cayman / Boxster spec.

utkinpol

450/600 is quite a 'standard' for street/track coilovers kits. i saw it a lot when I was shopping around for my setup. it all changes when you start pricing out PRO class motons and JRZs with external canisters.

Regards, Paul
(yes, it is also my name as well. Nice to meet you, Paul. )

997gt3north

Yup just checked

KW
Cayman V3s 230/400
Cayman Clubsport 400/685

Larry Cable

I now wonder if there is a "cheap" upgrade here by a la carte ordering of B16 components (minus the PASM shocks themselves) that might be an improvement?

997gt3north

If you can do your own labor and alignment then it will be cheap. Given you will pay for labor and alignment with new shocks then you just have to forget this part - or tell your wife not to count it. I think you can make some change, without revalve, that would be noticeable and maybe useful for some to do. If we take what Bilstein said to me as true, then up to a 15% spring increase can be done without any noticeable effect at all. The problem is that the stock front spring on mk1 997s is 230#s - so 15% higher is only 260 which isn't much help in my opinion. Now, there is at least one shop out there selling this type of solution using a 350# spring without revalve and said it works - I also know of someone who has tried a 450 without revalve and said it is ok. 15% more in the rear lets you try a 700 but there is no point raising the rear without doing the front.

For the front shocks, you don't need any B16 Damptronic parts - all you need is 2 60mm $80 springs that are 8 inches and #340s to give it a try. The Swift Spring part number to give this a try is (Z60-203-060 - this is Metric for 203mm length and 60N/mm - or 8 inches and 336#s)


The total cost of doing this properly in parts is

Fronts
2 x $150 - for revalve ($300)
2x $85 - Swift Springs ($170)

Add Labor for removal, install and shipping to/from California for shocks. If time is on your side then surface shipping is very reasonable.

Rears
Re-valve and Spring = $470
Bilstein Parts (not sure yet but my guess is $100) = $570

So, $1040 in Parts and Re-valve + shipping to / from Cali = $1400 gets you Damptronics at your custom spring rates with a Soft and Firm setup.

To be able to do this, you have to be able to do this yourself or have a shop that can hold your car while the shocks are being sent out and sent back - so for people in a winter part of the world it is a good winter project and the shop will more likely be accommodating.

Mvez

I got a hold of them, but Wes said you decided to do something different. Any news?

997gt3north

Sent you a pm - going to be months to get those tiny parts - going to try another route

tcsracing1

Suspension is just one of those things..... very scientific. Cup teams are constantly tweaking.

My 997 has the tarrett catalogue thrown at it along with GMG sways. Everything. Corner balanced, bump steered. you name it...

It is paired with B16 Damptronics.

I have raised these shocks as high as possible for rallying and i also have used them slammed to almost CUP level for track.

The lower you go, the harsher the ride but nice on a track when you mean all business.

I am now in the process of having a custom set of shocks made just for tarmac rallying and adjusted for higher then stock ride height so i have no idea what to expect at this point. Dont ask me about valving or springs because it is all foreign to me now

I will post some pics and specs soon as i get them.

It is going to be wild.

What will be interesting is that at stock ride height, they should handle the street/bumps better then stock due to travel, droop and rebound.

They are remote res. and like all serious suspension upgrades, not PASM compatible.

The idea is to be able to run over bumpy pot holed filled roads at over 100MPH with little to no upset. Jumps are also welcome.

997gt3north

Mini update

I decided to go a different route as getting the tiny Damptronic pieces was going to prove a timely affair and there was no guarantee from a big corporation that they would ever arrive.

So, to make a 60mm linear spring work, there is really 3 options to make them fit:
1) Fudge it - put a 60mm spring top hat on the spring, place it in the OE funky spring perch and make it work - I actually was told by a very smart person that this can be done, it will work.
2) Remove the OE spring hat, send it off to a machining shop with your desired new spring and have them make an entire new spring perch, matching the OE part everywhere but have the spring seat area fit a 60mm spring. If you know a machine shop that can lathe aluminum (basic stuff for them) this is an easy solution that should not be too expensive
3) Buy a Rear Monoball Shock Top Mount from Tarret, TRG, or other and then figure out what Spring Top Hat will work with the OE shaft sizing and spacing and the mate it to your new Monoball Top Mount.


I have decided to go with #3. I purchased from Rennline a Tarret Engineering Rear Monoball Shock Mount and now I'm searching for the correct spring top hat.

I would like to put out a public thank you to Dan Jacobs who runs a well known Porsche shop in CT who spent a little time on the phone with me and will be sending me out some top hats to see what will fit the stock Bilstein shock shaft with correct spacing. I also have a call into Ira from Tarret so see if he knows of a possible Bilstein or Porsche part number that may work - there may be a Porsche 993 RS part that might work. Either way, I hope to have a part list shortly that would allow an easy conversion for the rear.

I will first be trying, without re-valving the rear shocks, a 130N/mm (728#) spring in the rear to see if it better matches my new re-valved front 450# front and if the stock valving works with a 728# shock. If it feels good, I then plan on hitting the track to test things out. I then plan on possibly upping the front to 500 to 550 to again see how it feels.

I have also ordered a Swift 160N/mm spring (896#s) that I want to try with a re-valved rear spring. 900#s seems to be the consensus upper limit (KW Clubsport excluded) for a rear rate that can still be driven on the street.

More to come


Paul

trophy

Paul, just sent you a PM, i have some parts you can borrow for testing if you like... and I am in Canada so makes life a little easier.

PS: I have spoken to KW suspension techs in the past and have been told that for the clubsports on my car (993) I could go up approx 150lb and still be in the range for damping (stock fronts are 340lb could go to 490) . It is all dependent on where your shocks are set etc,.

997gt3north

Another mini update.

Spoke with a known after market parts supplier today to discuss the rear upper hat.
Looks like he is interested in making up a part that will work for our 997 car's to hold a 60mm spring so that the stock hat can just be removed as is and this identical part, except for spring width, could be installed to accommodate a 60mm spring. In order to do this properly, he is going to order a stock rear hat to make sure he has all the dimensions correct so that the existing hardware can be removed and re-installed and fit properly. I mentioned this in an earlier post, but this is entirely doable on your own if you have a local machine shop near by that can lathe aluminum. Having this part available would effectively allow all 997s with Bilstein PASM shocks to quite easily make a rear spring rate change (this doesn't have anything to do with re-valving but should allow for easy spring rate tinkering).

Do 997 non GT car's that have PASM also have the lower part of the spring being 60mm? If so, then their lower spring perches will work for 60mm linear spring sizes and this rear hat, if / when available, will also allow those car's to easily try higher spring rates.


More to come

Paul

997gt3north

For those that are following or care about this rear spring hat that we have and what we are dealing with, I found a few pictures that people may find useful.

http://www.truckspring.com/installat...M4-Y612A00.pdf

The above link (turn to the last page with the picture of the B16 Damptronic shock) and you can see what internal pieces would have to be removed if you happened to have the exact spring top hat from the B16 Bilstein Damptronics - ie it would be pretty easy - you would just remove 2 pieces from inside the spring perch and with the proper 60mm spring top hat it would be easy.

Here is a YouTube video showing the actual B16 shock - this is our exact shock but setup with a linear and helper spring and then with a spring hat on the top - this, as is, fits up into our rear spring perch after removing two internal pieces.

If someone could find a very similar type of Damptronic top hat then this would be cheap and simple way of swapping out the rear spring and yet keep the funky Porsche designed spring perch intact.

I may have found a possible piece while surfing the TRG part site from their racing part list in their suspension section - it isn't exact but it is close to what the Bilstein Damptronic Hat looks like (sorta). TRG calls the part a Spring Hat Upper Monoball

http://store.trgparts.com/spring-hat...all-p4900.aspx

This type of hat would if available be the easiest and simplest way for this to be done - no need to mill / lathe a new aluminum Porsche Spring Perch or swap out the spring perch and replace with a Monoball Strut Mount and then find another spring hat to mate with a Bilstein shock shaft.

If all this is boring please stop clicking on this thread.


Paul

Mvez

I am waiting on this same part. It looks like from the bilstein brochure, that a 7" rear main spring with a helper spring will work fine, or just go with an 8-9" main rear spring and skip the helper.