997 GT3.mk1 PASM re-valve begins
07-28-2011, 07:14 PM
#31
Drifting
Thread Starter
I spoke with a German guy (Udo) at Bilstein regarding my re-valving today - the PASM ecu controlling the tiny increments of change - each .1 milli-amp causing tiny changes in valving (I'm now convinced PASM like center lock wheels sounds good on paper but not so good in the real world)
Anyways, the Bilstein Damptronics came up over and over in our conversation. As an aside, and somewhat scary, Udo was entirely convinced that Bilstein just improved Porsche's implementation of PASM (the valving) but that the spring rates were THE SAME. I had to correct him, he did not believe Porsche would have used a 230# spring on the GT3 "It can't be - ours is 340/570 - that is what Porsche used - we just improved the internal valving - made it softer in many places, firmer in others"
So, this is not new news, it has been listed long ago, but the Bilstein Damptronics are 340 front and 570 rear.
My shocks are now done, sitting in Califormia waiting to be shipped. The shocks were dynoed after the revalving as a check - the compression / rebound charts more firm, as they should be, than their own 340# front Damptronics.
Udo and I then had an interesting conversation about how the PASM ECU may interpret the feedback from the firmer springs and then how the computer would then make it's tiny adjustments to valving that PASM does in the background all the time - this led to interesting guesses by him about the computer thinking small bumps may be larger bumps because the springs will be giving firmer feedback to the cars sensors that are involved, etc, etc
Hope to have the car up and running by the end of next week.
Terry,
On the Damptronics, he stated that the German's all drive the Ring on the Firm B16 Damptronic Setting. I found this somewhat implossible given what you have said about the Firm setting and the fact that I believe that Porsche claims the NRing is faster on the Soft OE setup.
It was hard to understand 1/4 of what he said between the German accent and my lack of understanding of internal shock construction and the PASM ECU's milli-AMP tiny changes that it is making constantly to the shocks, but on the Damptronics I did get that they believe they improved the too harsh customer complaint about the mk1 shocks and thus to back what you have said it seems their Soft setting seems to work for you around the track at WG.
For my front shocks, they made their best estimate based on their re-valving experience, how the scale the settings up to work with a 450# shock. I will report back how it feels.
On a final note, he said if I didn't like the 450#s, he encouraged me to even put the stock springs back in to see, as a test, how the re-valve would make them feel. I re-iterated again that stock was 230#, and not 340 like the Damptronics, he still encouraged me to try the 230s and then a bunch of other rates between and above.
Paul
Anyways, the Bilstein Damptronics came up over and over in our conversation. As an aside, and somewhat scary, Udo was entirely convinced that Bilstein just improved Porsche's implementation of PASM (the valving) but that the spring rates were THE SAME. I had to correct him, he did not believe Porsche would have used a 230# spring on the GT3 "It can't be - ours is 340/570 - that is what Porsche used - we just improved the internal valving - made it softer in many places, firmer in others"
So, this is not new news, it has been listed long ago, but the Bilstein Damptronics are 340 front and 570 rear.
My shocks are now done, sitting in Califormia waiting to be shipped. The shocks were dynoed after the revalving as a check - the compression / rebound charts more firm, as they should be, than their own 340# front Damptronics.
Udo and I then had an interesting conversation about how the PASM ECU may interpret the feedback from the firmer springs and then how the computer would then make it's tiny adjustments to valving that PASM does in the background all the time - this led to interesting guesses by him about the computer thinking small bumps may be larger bumps because the springs will be giving firmer feedback to the cars sensors that are involved, etc, etc
Hope to have the car up and running by the end of next week.
Terry,
On the Damptronics, he stated that the German's all drive the Ring on the Firm B16 Damptronic Setting. I found this somewhat implossible given what you have said about the Firm setting and the fact that I believe that Porsche claims the NRing is faster on the Soft OE setup.
It was hard to understand 1/4 of what he said between the German accent and my lack of understanding of internal shock construction and the PASM ECU's milli-AMP tiny changes that it is making constantly to the shocks, but on the Damptronics I did get that they believe they improved the too harsh customer complaint about the mk1 shocks and thus to back what you have said it seems their Soft setting seems to work for you around the track at WG.
For my front shocks, they made their best estimate based on their re-valving experience, how the scale the settings up to work with a 450# shock. I will report back how it feels.
On a final note, he said if I didn't like the 450#s, he encouraged me to even put the stock springs back in to see, as a test, how the re-valve would make them feel. I re-iterated again that stock was 230#, and not 340 like the Damptronics, he still encouraged me to try the 230s and then a bunch of other rates between and above.
Paul
07-28-2011, 07:30 PM
#32
Rennlist Member
I spoke with a German guy (Udo) at Bilstein regarding my re-valving today - the PASM ecu controlling the tiny increments of change - each .1 milli-amp causing tiny changes in valving (I'm now convinced PASM like center lock wheels sounds good on paper but not so good in the real world)
Anyways, the Bilstein Damptronics came up over and over in our conversation. As an aside, and somewhat scary, Udo was entirely convinced that Bilstein just improved Porsche's implementation of PASM (the valving) but that the spring rates were THE SAME. I had to correct him, he did not believe Porsche would have used a 230# spring on the GT3 "It can't be - ours is 340/570 - that is what Porsche used - we just improved the internal valving - made it softer in many places, firmer in others"
So, this is not new news, it has been listed long ago, but the Bilstein Damptronics are 340 front and 570 rear.
My shocks are now done, sitting in Califormia waiting to be shipped. The shocks were dynoed after the revalving as a check - the compression / rebound charts more firm, as they should be, than their own 340# front Damptronics.
Udo and I then had an interesting conversation about how the PASM ECU may interpret the feedback from the firmer springs and then how the computer would then make it's tiny adjustments to valving that PASM does in the background all the time - this led to interesting guesses by him about the computer thinking small bumps may be larger bumps because the springs will be giving firmer feedback to the cars sensors that are involved, etc, etc
Hope to have the car up and running by the end of next week.
Terry,
On the Damptronics, he stated that the German's all drive the Ring on the Firm B16 Damptronic Setting. I found this somewhat implossible given what you have said about the Firm setting and the fact that I believe that Porsche claims the NRing is faster on the Soft OE setup.It was hard to understand 1/4 of what he said between the German accent and my lack of understanding of internal shock construction and the PASM ECU's milli-AMP tiny changes that it is making constantly to the shocks, but on the Damptronics I did get that they believe they improved the too harsh customer complaint about the mk1 shocks and thus to back what you have said it seems their Soft setting seems to work for you around the track at WG.
For my front shocks, they made their best estimate based on their re-valving experience, how the scale the settings up to work with a 450# shock. I will report back how it feels.
On a final note, he said if I didn't like the 450#s, he encouraged me to even put the stock springs back in to see, as a test, how the re-valve would make them feel. I re-iterated again that stock was 230#, and not 340 like the Damptronics, he still encouraged me to try the 230s and then a bunch of other rates between and above.
Paul
Anyways, the Bilstein Damptronics came up over and over in our conversation. As an aside, and somewhat scary, Udo was entirely convinced that Bilstein just improved Porsche's implementation of PASM (the valving) but that the spring rates were THE SAME. I had to correct him, he did not believe Porsche would have used a 230# spring on the GT3 "It can't be - ours is 340/570 - that is what Porsche used - we just improved the internal valving - made it softer in many places, firmer in others"
So, this is not new news, it has been listed long ago, but the Bilstein Damptronics are 340 front and 570 rear.
My shocks are now done, sitting in Califormia waiting to be shipped. The shocks were dynoed after the revalving as a check - the compression / rebound charts more firm, as they should be, than their own 340# front Damptronics.
Udo and I then had an interesting conversation about how the PASM ECU may interpret the feedback from the firmer springs and then how the computer would then make it's tiny adjustments to valving that PASM does in the background all the time - this led to interesting guesses by him about the computer thinking small bumps may be larger bumps because the springs will be giving firmer feedback to the cars sensors that are involved, etc, etc
Hope to have the car up and running by the end of next week.
Terry,
On the Damptronics, he stated that the German's all drive the Ring on the Firm B16 Damptronic Setting. I found this somewhat implossible given what you have said about the Firm setting and the fact that I believe that Porsche claims the NRing is faster on the Soft OE setup.It was hard to understand 1/4 of what he said between the German accent and my lack of understanding of internal shock construction and the PASM ECU's milli-AMP tiny changes that it is making constantly to the shocks, but on the Damptronics I did get that they believe they improved the too harsh customer complaint about the mk1 shocks and thus to back what you have said it seems their Soft setting seems to work for you around the track at WG.
For my front shocks, they made their best estimate based on their re-valving experience, how the scale the settings up to work with a 450# shock. I will report back how it feels.
On a final note, he said if I didn't like the 450#s, he encouraged me to even put the stock springs back in to see, as a test, how the re-valve would make them feel. I re-iterated again that stock was 230#, and not 340 like the Damptronics, he still encouraged me to try the 230s and then a bunch of other rates between and above.
Paul
reading this, makes me wonder about the feasibility of playing with springs/shocks in the presence of PASM ...
good luck!
07-28-2011, 09:02 PM
#33
Drifting
Thread Starter
Just to confirm my seats of the pants experience over several days back when I took my 7.1 to the ring, it was very noticable how much better the car handled on OE "normal" vs "OE sport" PASM settings on the ring ... it may not have been faster but it was much more composed...
reading this, makes me wonder about the feasibility of playing with springs/shocks in the presence of PASM ...
good luck!
reading this, makes me wonder about the feasibility of playing with springs/shocks in the presence of PASM ...
good luck!
The reason I chose to revalve the front up to a better range is so that from here I can tinker if I would like and the shocks would be in the right neighborhood of valving.
The entire PASM thing is what it is - I view it as a secondary effect - magic fairy dust so to speak that most of us all would rather be without but it doesn't really kill the deal - get the valving in the right range and 50-100 spring range adjustments will be no problem - outside this it won't be 'optimal' but it won't not work either - I know for certain it has been done to at least 400#s in the front without revalving and without issue.
What I would like to see is someone sell a cheap kit to convert the rear spring as a DIY to a matching 60mm ID spring to make changing the rear to a higher rate - easy.
07-28-2011, 09:34 PM
#34
Paul - this is making me think a little harder about PASM. It is undoubtedly true that the stiff position makes the car turn in better and not roll over as much, so it is much better on a tight , technical course, especially with quick alternations between left and right turns. At the Glen, where there are no such turns and the car has lots of time to settle, stiff is worse. I would have thought that the 'Ring is more like the Glen but there may be areas where stiffer would be better. The big problem with stiff comes when there are bumps - it seemed to me that Motons with 6-800 lbs springs (a friend's car I drove once) ate up the bumps a lot better than the B-16s, even though the spring rates were much higher.
07-28-2011, 09:38 PM
#35
Race Director
I have the GT3 control arms on my C2S and will convert those over the the GTS. I also have ordered the Mono-Ball ends and Eddie @ AWD has me using his Thurst Arm Bushings. This will make the GT3 control arm all solid. That along with AWD's rear toe links (FK ball ends) and I'm set.
07-28-2011, 10:06 PM
#36
Drifting
Thread Starter
Paul - this is making me think a little harder about PASM. It is undoubtedly true that the stiff position makes the car turn in better and not roll over as much, so it is much better on a tight , technical course, especially with quick alternations between left and right turns. At the Glen, where there are no such turns and the car has lots of time to settle, stiff is worse. I would have thought that the 'Ring is more like the Glen but there may be areas where stiffer would be better. The big problem with stiff comes when there are bumps - it seemed to me that Motons with 6-800 lbs springs (a friend's car I drove once) ate up the bumps a lot better than the B-16s, even though the spring rates were much higher.
Why I think revalving is worth a try is because having the 2 modes built into the computer, especially the street soft bumpy track mode, is that as long as you revalve for your spring rate, the soft mode should be a good fit for tracks with bumps - they are absolutely never going to rival an Ohlin suspension however. I can remember the day when I first drove on my Ohlin suspension on the street, and this was after replacing an already very good after market KW Clubsport suspension, I remember taking the same onramp that I drove everyday to work and the car just sucked up every single bump like it wasn't even there and the stiffer springs, properly dampened, held the car perfectly - that was 10 years ago and I remember it like yesterday. To this day, I have never driven in any car whose suspension was better - 10 years ago, in the non Pcar world that was a $5k suspension - today that is a $7k setup.
07-29-2011, 03:31 PM
#37
Rennlist Member
I have the GT3 control arms on my C2S and will convert those over the the GTS. I also have ordered the Mono-Ball ends and Eddie @ AWD has me using his Thurst Arm Bushings. This will make the GT3 control arm all solid. That along with AWD's rear toe links (FK ball ends) and I'm set.
07-29-2011, 03:33 PM
#38
Rennlist Member
I am pretty sure this is going to work (yet to be completely defined) - others have put more spring on the front with no re-valving and the car is fine. Bilstein themselves have said to me that the shocks would have no problem at all handling 15% more spring without any noticeable effects at all. I had a set of Ohlins remote reservoirs on a previous car and can tell you after much tinkering that a set spring can work with a very wide range of compression and rebound settings - clearly you want to find the settings that make the car to your liking but another driver on the same spring may use a very different setup.
The reason I chose to revalve the front up to a better range is so that from here I can tinker if I would like and the shocks would be in the right neighborhood of valving.
The entire PASM thing is what it is - I view it as a secondary effect - magic fairy dust so to speak that most of us all would rather be without but it doesn't really kill the deal - get the valving in the right range and 50-100 spring range adjustments will be no problem - outside this it won't be 'optimal' but it won't not work either - I know for certain it has been done to at least 400#s in the front without revalving and without issue.
What I would like to see is someone sell a cheap kit to convert the rear spring as a DIY to a matching 60mm ID spring to make changing the rear to a higher rate - easy.
The reason I chose to revalve the front up to a better range is so that from here I can tinker if I would like and the shocks would be in the right neighborhood of valving.
The entire PASM thing is what it is - I view it as a secondary effect - magic fairy dust so to speak that most of us all would rather be without but it doesn't really kill the deal - get the valving in the right range and 50-100 spring range adjustments will be no problem - outside this it won't be 'optimal' but it won't not work either - I know for certain it has been done to at least 400#s in the front without revalving and without issue.
What I would like to see is someone sell a cheap kit to convert the rear spring as a DIY to a matching 60mm ID spring to make changing the rear to a higher rate - easy.
07-29-2011, 03:36 PM
#39
Rennlist Member
Paul - this is making me think a little harder about PASM. It is undoubtedly true that the stiff position makes the car turn in better and not roll over as much, so it is much better on a tight , technical course, especially with quick alternations between left and right turns. At the Glen, where there are no such turns and the car has lots of time to settle, stiff is worse. I would have thought that the 'Ring is more like the Glen but there may be areas where stiffer would be better. The big problem with stiff comes when there are bumps - it seemed to me that Motons with 6-800 lbs springs (a friend's car I drove once) ate up the bumps a lot better than the B-16s, even though the spring rates were much higher.
07-29-2011, 07:13 PM
#40
Race Director
I asked and asked around and everyone I know that has done this says I'll be fine. Everything else in the suspension still have the rubber so it's not really hardcore.
07-29-2011, 07:55 PM
#41
Three Wheelin'
The only place I notice anything remotely negative is at idle, where I feel slightly more engine vibration making it into the body shell - nothing dramatic to a GT3 owner.
The monoballs seem to soften the effective spring rate (the loss of the rubber bushing's resistance to twist?), but allow quicker suspension movement - changing PASM a little. The ride is better, and there are more places I can use the Sport setting (but I'd still really prefer a Spyder type analog suspension). My alignment now seems to be holding and (to me) the car is finally predictable enough that I am able to tell what the rear end is doing, instead of just trusting the car.
Oh, yeah, that's with all Sharky's RSS links, too.
07-29-2011, 08:22 PM
#42
Rennlist Member
Larry, I've got about 5K mostly, street miles (in LA) on them and I can only wonder why the cars didn't come this way.
The only place I notice anything remotely negative is at idle, where I feel slightly more engine vibration making it into the body shell - nothing dramatic to a GT3 owner.
The monoballs seem to soften the effective spring rate (the loss of the rubber bushing's resistance to twist?), but allow quicker suspension movement - changing PASM a little. The ride is better, and there are more places I can use the Sport setting (but I'd still really prefer a Spyder type analog suspension). My alignment now seems to be holding and (to me) the car is finally predictable enough that I am able to tell what the rear end is doing, instead of just trusting the car.
Oh, yeah, that's with all Sharky's RSS links, too.
The only place I notice anything remotely negative is at idle, where I feel slightly more engine vibration making it into the body shell - nothing dramatic to a GT3 owner.
The monoballs seem to soften the effective spring rate (the loss of the rubber bushing's resistance to twist?), but allow quicker suspension movement - changing PASM a little. The ride is better, and there are more places I can use the Sport setting (but I'd still really prefer a Spyder type analog suspension). My alignment now seems to be holding and (to me) the car is finally predictable enough that I am able to tell what the rear end is doing, instead of just trusting the car.
Oh, yeah, that's with all Sharky's RSS links, too.
I have the RSS toe-in & dogs (woof) on the rear from Sharky also, really makes a noticable difference to the stability of the back end ...
07-29-2011, 08:38 PM
#43
Three Wheelin'
Hey Steve, did you just do the rear control arms (monoballs) or the fronts as well? - what about thrust arms and also the strut mounts/camber plates?
I have the RSS toe-in & dogs (woof) on the rear from Sharky also, really makes a noticable difference to the stability of the back end ...
I have the RSS toe-in & dogs (woof) on the rear from Sharky also, really makes a noticable difference to the stability of the back end ...
I have the monoballs and thrust bearings front and rear. I have the rear toe/bump-steer and lock-out kits, and the rear links.
I do not have the strut mounts/camber plates.
It was the rear that was driving me crazy. Once I started, well, you know how that works...
07-29-2011, 09:47 PM
#44
Rennlist Member
Hi Larry,
I have the monoballs and thrust bearings front and rear. I have the rear toe/bump-steer and lock-out kits, and the rear links.
I do not have the strut mounts/camber plates.
It was the rear that was driving me crazy. Once I started, well, you know how that works...
I have the monoballs and thrust bearings front and rear. I have the rear toe/bump-steer and lock-out kits, and the rear links.
I do not have the strut mounts/camber plates.
It was the rear that was driving me crazy. Once I started, well, you know how that works...
07-29-2011, 09:58 PM
#45
Three Wheelin'
I did it all at the same time, then had them corner-weight it, so I can't say what it would be like with the stock front and the modified rear. I really like the total results, though.
To me, the rear is an absolute necessity. I'd still do the front, though, since I've only noticed positives from the front after the change (no negatives), and the cost delta to do the front after buying the monoball set wasn't that much..
To me, the rear is an absolute necessity. I'd still do the front, though, since I've only noticed positives from the front after the change (no negatives), and the cost delta to do the front after buying the monoball set wasn't that much..