Crown

track vid

0-300kph

chasing a 997GT2

Cannga,

I just wanted to thank you for your thoughtful, analytic and detailed comments on your TT suspension improvement program. I've been reading and re-reading it, since suspension work is the next (and first major) upgrade I have planned for my 997S Cab.

Many times I read forum entries from others that, no disparagement intended, presume a lot of insider knowledge such that there is not enough detail to unequivocally document the whole process. I've been left with the 'how did he get from 'here' to 'there?' ' problem.

You've been really helpful, and I'm now ready to pull the trigger on your step(s) 1,2 and 3. I've long been a fan of sports cars with a preference for excellent road feel and handling rather than hyper-power so that's why these enhancements appear waaay higher on the list than a (albeit highly desireable) VR supercharger kit (which will come - I hope - just not yet).

Really, many thanks. And have a happy holiday and a safe and healthy new year.

Verde

function_analysi:
Thx Cannga. Actually the link you've posted doesn't work, seems it's a bug of the new forum. Pls PM directly the appropriate url.
--

------- MY07 997.1 GT3White, CS, PCCB, Full Leather/Alcantara in Black

------- MY07 997C2S --GONE

You are welcome. It was my fault. I did not know how to use this odd Rennteam URL system and Eunice has just showed me how. Here we go:

http://www.rennteam.com/forum/thread/20064454/Pics_of_Shattered_Dymag_Wheel__Report_of_Problem/page1.html

At this point it might be a good idea to wait and see what the new HRE-Dymag combo wheel will be like. There have also been reports of air leak with some (not all) Dymag owners.

--

Regards,
Can
997 Turbo + Cargraphic Exhaust (Exhilarating Sound!) + Bilstein PSS10 (Review)

RLG:

Cannga,

I just wanted to thank you for your thoughtful, analytic and detailed comments on your TT suspension improvement program. I've been reading and re-reading it, since suspension work is the next (and first major) upgrade I have planned for my 997S Cab.

Many times I read forum entries from others that, no disparagement intended, presume a lot of insider knowledge such that there is not enough detail to unequivocally document the whole process. I've been left with the 'how did he get from 'here' to 'there?' ' problem.

You've been really helpful, and I'm now ready to pull the trigger on your step(s) 1,2 and 3. I've long been a fan of sports cars with a preference for excellent road feel and handling rather than hyper-power so that's why these enhancements appear waaay higher on the list than a (albeit highly desireable) VR supercharger kit (which will come - I hope - just not yet).

Really, many thanks. And have a happy holiday and a safe and healthy new year.

Verde

Hi Verde,

Glad to be of help and you are welcome. Credit goes to the many people whose past and present postings I read and learned from. And the patient folks at Bilstein -- I have reasons to believe both West and East Coast tech reps have some recollection of me.

I hope many amateurs like me have the patience to go through this thread. Even if one is not interested in upgrading, I think the explanation and empirically based information posted here by various people, even if only at a basic level, would make anyone understand and enjoy the 911 even more. BTW, I am not done yet, there are more to come, like shock dynos. In the mean time, thought you would be interested in a picture of Bilstein's test driver. LOL. It's only ad material and not sure how much "HE" is involved, but good to know the name is there.

BTW, if you are in Northern Cal., might want to give Alex at Sharkwerks a call as far as the work to be done on your car. I have no personal experience but his reputation is truly amazing.
You too have a healthy, happy, and prosperous New Year.

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

eclou:
recall that Excellence Mag took the Champion K1 car to the track and preferred the H&R springs with the stock coilovers vs the KW variant coilovers
--

eclou's post -- in short the magazine prefers the softer H&R spring to the stiff KW coilover -- brings to mind something I found to be interesting, and is a reminder of how complicated suspension tuning could be and why some call this a black art that is best left to professionals.

I once thought a stiffer suspension is unequivocally better with respect to handling, the only price to pay being loss of ride comfort. However, I then learned of a third and equally important parameter: tire traction. As the spring is stiffened, car actually loses tire traction. The gain in car dynamics (less sloppy handling, less weight transfer) from a stiffer spring therefore must be judged against the loss of road adherence from less tire traction. For example, around any given corner, depending on the speed and circumstances, a softer sprung car MAY actually be faster! Lastly here is another interesting picture.

(BTW, great memory eclou . I had to re-read the article to find out what it was you're talking about. Don't know if it's relevant or if it's the same coilover but I remember being a little surprised when someone on 6speedonline posted the spring rates for KW Variant 3-- 970 lbs/in in the rear, as opposed to Bilstein's 570.)

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

 tt surgeon

hey thanks gt,

i see you are from england, so basically the shock lasted 12 k  kilometers with techart springs i am assuming? and not 12 k miles.

cheers

ronnie

GT:
For cars with pccbs and lighter (or much lighter) wheels the effective spring rate will be noticeably higher (firmer) than those with stock wheels and standard brakes.

Very interesting observation.  Most of us don't have a chance to do controlled A versus B testing and will never know, but clearly the effect of unsprung weight on ride and handling is not to be discounted.

A guy who tests brake professionally told me one evidence of the effect of unsprung weight on ride/handling is to put your ear on the car's floor (while someone else is driving LOL) and listens as the car goes small bumps like railroad crossing, at 100 + mph. And he confirmed that he was NOT kidding. My wife has declined to participate in this test with me.

BTW, someone was asking on 6speedonline about REAR (not front) lower control arm. I rarely have read about replacing rear lower control arm, so re-read your posts and lo and behold, you seem to have changed that also?! I referred to you a couple times and invited him to post here but apparently he's got the answer from Ira at Tarett already (What a toy store that is -- check out this thing http://www.tarett.com/items/996-997-products/997-rear-swaybar-assy-detail.htm .

Pic for those not familiar - rear lower control arm:

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

Hey Guys,

Great discussion here. Eclou's comments about traction and softer suspension is RIGHT on. On most American tracks, European FIA/LMS setups look horribly difficult to drive, due to the loss of traction and the resulting loss of confidence. My guess (and it's only that) is that a U.S. racing setup would suffer less in Europe than a Euro setup in the U.S. This issue becomes MUCH more important when dealing with street cars, where tenths and hundreths don't matter but confidence and safety margins are everything. And, pleasure counts.

Been thinking about how good the H&Rs were with PASM lately, as two friends were looking to lower a 997 Turbo and a 997.2. Still "bugs" me to recommend a spring-only change, but then it hit me: PASM worked so well on the K1 because PASM adapts to conditions. It is not a fixed-rates damper, even though it must work with fixed-rate springs. And I feel PASM simply "works" "better" (IMHO and experience) with slightly stiffer springs with less effective travel.

 One of the two friends is a shop/tuner owner and tried the H&Rs. He was very impressed. I have no doubt that Motons or similar can be made to work even better than H&Rs/PASM, but the "getting there" won't be easy, or cheap. Or, if you pick the wrong "specialist," possible.

If I were doing a 997 Turbo, and based on my experiences, I'd do the H&Rs. That said, I'd sure love to try the whole range of possibilities out there. Just tried PSS10s on the loop, and they're good (far better than the stock setup), but that 997 Turbo didn't work out there as well as the K1 did, and a set of (VERY well setup) Motons on another 997 that day shredded them. Then again, it's not a fair comparison to K1: more power, but non-R-compound tires and no GT3 suspension bits or forged magnesium wheels.

The education continues... 

track vid

0-300kph

chasing a 997GT2

Sorry, Cannga!

Pete, I concur with  your findings on the H&R/PASM combo 997TT, it works very well on street and track. Thanks again for that great article, it and eclou's experience were big factors in my decision to go with the spring package. H&R and Champion definitely know what they are doing.

Keep up the great articles!

Doug

Houston, Texas USA 

997TT

(Wow is this really Pete?  )

For anyone not familiar, "excmag" is Pete Stout, editor and reviewer extraordinaire of Excellence Magazine, the preeminent US Car mag about Porsche. Great, great, great magazine about all things Porsche past and present, one that I read more than any others -- what I take routinely to the YMCA jazuzzi before and after my swims, and one I would recommend without hesitation. http://www.excellence-mag.com/

Pete/eclou/Doug and I are talking about an article Pete wrote on the Werks K1 Porsche in May 2008 Excellence Magazine.  I actually reported on it here. http://www.rennteam.com/forum/thread/426128/Champion_Turbo_w_Susp_Mod_Better_Than_GT3RS/page1.html

For me this article was the start of it all -- the first clue to me that the Turbo could be tweaked to anyone's preference, and in some way this whole thread owes its existence to this article.

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

Hmm

so are we saying the softer spring rate then the stock is better (h&r, that every body critisizes i, or are we talikng about the champion springs made by H&r?) , then stiffer then stock, like techart and gmg. i know everybody says go with the gmg spring becuase they are lot stiffer then the stock, this is contradicting above.

also i called champion motorsports, and they siad (not sure if i believe that because i think i was talking to a sales guy) that the spring rates are higher then the stock,and there is no difference between original H&r springs and champion springs they are the same rate etc, only colour diference, white verses black.

Doug

Houston, Texas USA 

997TT

doug

I totally understand the above , yes i see it, but i am merely refering to the main (stock) H&R spring rate verses the sports spring rate /h/r. which one did you get , the h&r or the champion H&R? also how is the ride, handling, and how much was the drop.

thanks

Ronnie

Ronnie, I have the Champion - H&R, the ride is very good and handling improved over stock. You will also need a good alignment shop, that is the other half of the equation. I couldn't tell you what the exact rates are but the car flat works. The drop is exactly 1" all around,  measured at the mid fenderwell it sits at 26" front and 26.5" rear. Most of the springs drop the car about the same amount. The only downside is your front lip will scrape a bit more, but that's not a big deal.

I was once a skeptic about using lowering springs but eclou and the Excellence article convinced me to try. I'm glad I did. Turns out  the PASM is a different beast and can't be compared to experience with  lowering springs in the past.

This is a great thread, lot's of info. Thanks Can.

Cheers and happy new year!

Doug

Houston, Texas USA 

997TT

GT:
Lol! Exactly! Pete its all your fault! If you go to the link that caanga posted you'll see how it all started.. So as I result I now like a lot a car that left me lukewarm at best when I first drove it.. Caanga the Werks setup has all those things we've been discussing with the addition of the front upper strut brace (what do those do anyway?) and the roll bar. However my setup has the damptronics and lighter wheels. Gmg told me that the K1 setup does not have the damptronics because of cost mainly..

LOL. I'll take the blame, happily. Makes my day to hear something we did/I wrote helped a reader in real terms. The K1 still buzzes around in my head, long after the fact. Mmmmn, K1. Good memories, like top 5-10 Porsches I've driven kind of good. Those mods took the 997TT, which left me lukewarm at best, and transformed it. I wouldn't, however, discount the contribution of the TOTAL system/package to my experience. Remember that car had a lot of other bits, like the bump-steer kit, the arms, the bushings, and, of course, the forged magnesium wheels and PCCBs. 

I continue to be surprised by how much better I like aftermarket-enhanced 997 Turbos. Same goes for regular early 997s, something I couldn't say in the 996 era. That said, just spent a few days on the loop in a 997TT with the PSS-10s and I wasn't anywhere near as crazy for that car as I was for the K1. It was a much milder suspension (essentially shocks/springs only), without R-compound tires, which the 997 Turbo very much benefits from, esp. with more power. In fairness, I have to say that having PERFECTLY setup Motons in another 997 for back-to-back comparisons didn't do the PSS-10s any favors. Those Motons can be silly, silly good. I'm sure they can be wretched, too.

Thanks for the kind words, makes a late night at the office (quite) a bit more bearable...  

All the best to you guys!

Yep. I think a lot of enthusiasts see Turbos these days and think "orthodontist" before they think "another enthusiast" in the way they do with a GT3, or even a Carrera, for that matter. Must admit I do, too. Maybe it's the chrome badge on the back? Maybe it's the shiny wheels? Or maybe it's because of the stance? But I suspect it's largely because of how Porsche is marketing the Turbo these days, and to whom.

It's hard to blame Zuffenhausen when you look at the sales numbers, but the K1 left me with the feeling that the factory needs to add an option group to the 997TT that restores some of the reverence once reserved for the 930s and 965s of old. Even if only a percentage of cars were ordered with it, there would be a rub-off effect. I think Porsche thinks the "911 Turbo" is still as big a deal as it always was in the minds of enthusiasts. I'm not so sure it still is, this despite its incredible specs and performance. I think a lot of people have written the Turbo off as an SL-ish car. I'm not saying I agree, but I catch myself thinking that way from time to time. The K1 made me think that a lighter, lower, louder, more extreme 997TT with back seats, AWD, and PSM would appeal to a core group of buyers who don't want a $200,000 GT2 or normally-aspirated GT3 but who DO want some attitude and are willing to pay $140-150k to get it.

Fortunately, you guys can (and have) built that car for yourselves. 

As to your track "experts," based on my experiences, I would NEVER underestimate a modified 997TT on track, even in merely competent hands. Especially if I was driving a GT3.   Hell, I wouldn't underestimate a *stock* 997TT on track in terms of speed, either. I just wouldn't envy the guy in it. Now, with a few good mods...

excmag:

 It was a much milder suspension (essentially shocks/springs only), without R-compound tires, which the 997 Turbo very much benefits from, esp. with more power.

Pete, surely you know this off the cuff remark is going to cost some of your compulsive read-between-the-lines readers dearly right?  Kidding aside, I already was scheming about Pirelli Corsa; you have just pushed me over the edge right there. 

I remember an interesting anecdote re. the Werks K1 review. At the time of its publication, I was new to this and had ZERO idea what these strange terms are. For example I was wondering what on earth a dog bone is doing in the back of my Porsche. So I called Champion, fully expecting them to have a package of suspension components, labeled something to the effect of "Champion  GT3 RS-Killer Complete Suspension Kit", READY to sell. After all, why else would a business send a car like that to be reviewed by you? And what else should a business do after such a spectacular review from the Editor of a well known mag?
To my surprise, and to this day I don't know if the guy answering the phone was kidding me, I was told that they were still sorting out to see exactly what all the components that were added to the Werks K1 are, and that they had no plan to sell a complete package.
BTW, not to my surprise, I was also told that I was not the only one who called because of what you wrote. That article did cause a stir.

Re. that PSS10 Turbo you are testing:  Nah, it's just like my car right now, still very much street oriented and I think it's too docile for your advanced-level taste (I have a good excuse: it's about as hard as I could take for my daily driving on LA streets!).
Of all the modded cars I've read about, I know of ONE PSS10-modded Turbo that will be a worthy competitor to that monster Werks K1. Amazingly enough, this car nearly mirrors all the mods on the K1: Tuned ECU, front & rear lower control arms, rear toe and upper control arms, aggressive alignment, cup tires, etc., etc.  It belongs to the person who has been talking to you: GT! Too bad he's in England; otherwise we just might have a fascinating suspension mods shoot-out, the first of its kind for the 997.

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

GT:
Pete if I may, the reason that maybe you did not like the suspension only modded tt is that no shock/spring combo can fix the second major issue the tt has; the geometry distorion under load because of the rubber suspension components.. And one question regarding those motons. I have heard that they are way better than any other electronic shock combo out there.. Are they though ok for the street? Ie can they be setup for hybrid road/track use or just track?

        Agree on your "if I may." It's why, when a suspension SYSTEM works, it's a good idea to try to replicate it as closely as possible. It is a bit crazy that the Champion boys have so much right, but don't offer this setup as a package.   Using Champion/H&R springs only would offset much of the cost of "real" coil-overs, allowing their package to transform a 997TT for not a LOT more than Penskes or Motons alone.

Motons CAN be better riding than PASM. Can is the operative word. You will need a genius to set them up that well. My personal belief, after driving and testing countless Porsches over the last 10-15 years, is that there are a handful of people out there who not only REALLY know what they are doing when it comes to shock valving, but have "the touch." I've driven cars with FAR stiffer suspension than the early 997 GT3 press car I drove and panned for its jiggly PASM (I've seen some evidence that later GT3/RSs got better, maybe/most likely via programming, but they still weren't good enough) that rode much better than that early GT3 and other 997s with PASM and relatively soft springs, which is of course tuned for Porsche's "mass" market. Last 997 with Motons I drove was set up by Synergy and was very, very good both in terms of wheel control and ride quality. 

I remember taking a guy who has "the touch" with suspension -- both successful race cars and HIGHLY enjoyable extreme back-road cars -- for a quick ride around the block in that early 997 GT3 press car. His eyes went wide and he said "I can't believe they let this car out like this" as we jiggled our way over lumps and bumps. And then I pointed out we were in PASM Normal. I know what he was thinking: He's built torsion-bar 911s with revalved Bilsteins and R-compound tires that ride better on the road, and would kill the GT3 on a race track. (a lot of people won't want to hear that. they can talk to Johannes van Overbeek if they don't believe me...)

I also believe there are a lot of people out there for whom stiffer = better. Some of them may be good drivers, but I suspect many of them don't realize the nightmares in terms of car control they're creating for themselves. You don't want the body to bob up and down (unloading the tire as it goes up, and compressing it perhaps too much when it comes down, not to mention what this does to geometry). Of course, you want the WHEEL to go up and down with the road. Thus, I think a lot of drivers write off cars that they think are "too soft" when they'd actually be faster in them, and potentially MUCH faster in them. And have more fun in them. The fact that some of the best people in the game don't all "get" this (or agree with my theory...) was never plainer to me than at Infineon, when watching a GT3 RSR fresh from winning Le Mans bob its way up the hill on the way to Turn 2. Every other RSR's body stayed flat while its wheels followed the road. The Le Mans winner (presumably still running Le Mans suspension, or a stiffer setup than the others) looked nearly undriveable. Or scary, at least.

When it comes to street cars, confidence and driving fun, not ultimate speed, is everything. I think damping is a big part of that, along with suspension that you KNOW what it will do as a driver. This is where bushings, geometry, and fixed-rate (or at least "invisible" changing-rate dampers as in new GT2) come in. You know it when you drive one of the "magic" setups. They don't come along often, even from the best manufacturers. So when a tuner gets it right, whether they stumble upon it or develop their way there, it's very impressive to me. Of course, they don't have to meet all the varied needs a manufacturer does.

Finally, while I know what I believe, I also know enough to know that ride is a VERY subjective thing. We see that here sometimes, where some testers like the way a car rides and others don't. So, my views on PASM etc. shouldn't be taken as gospel (not to suggest they were!). They're just ONE data point, and hopefully a useful one. Either that, or you guys, me, and a few others have very similar setup preferences. Well, that, or maybe there is some truth to them...

All THAT said, I think there are times when you have to call a spade a spade, and I think the 997TT chassis, in stock form, is far from one of Porsche's high points. I've said it, I've seen others say it, and I've heard plenty of owners say it. It seems there are some within Weissach who agree, too, so I am hopeful for the next version.

As for me, with a current 997TT I'd probably go for the H&R/PASM setup because it was plenty comfortable for street use here in the Bay Area (our roads are NOT great everywhere) and because it was SO good on back roads AND track. I like what I know works. And what more do I need? It was about the best compromise I've come across. Only concern was dealing with driveways, but I don't mind that concern so much. Would also be a LITTLE worried about how long those PASM dampers will last at the lowered ride height, but others haven't had problems so far...

Sorry for the book. Maybe some of it is useful.  

pete

I share your opinion regarding the Turbo in stock form: It is way too much to the luxurious side.  (Prior to installing the Bilstein, I nearly traded my Turbo in for a GT3, went so far as calling the manager.) I also have hopes, but  don't think PAG will have a sudden change of heart and give more sporting character to the next Turbo. To me, there are 2 reasons for this:
a. The current Turbo is selling too well -- at least before the crash, way too well, for the marketing guy to allow changes. It's making money, and we know $ talks.
b. There are enough people who like the Turbo as is. In other words, at the same time that I and many other owners are constantly talking about tweaking the suspension, a larger number, I suspect, are leaving the suspension as is. I don't agree but it's a matter of personal preference, and right now there seem to be enough happy Turbo owners for PAG to NOT change.
I don't know why, but starting around the 996 Turbo, there must have been a corporate decision to make the Turbo a luxurious GT type. On page one of this thread I posted the spring rates. The rear spring rate of the 996 GT3 is nearly TWICE (!!) the 996 Turbo. It the car continues to sell, I am afraid PAG is going to stick with this formula. US owners are NOT voting for a more sporty Turbo with their pocket book.

Your discussion of PASM and its interaction with the springs is educational for me. Re. PASM, for a long time now I have this idea: I think as currently implemented, that Firm setting of PASM is flawed!
Of all 3 cars I've driven: Turbo, GT2, and 997S, I've found that FIRM setting is too nervous & too firm but for the smoothest of road surface, with a bone rattling unacceptable ride on regular streets. I've speculated that the problem is the FIRM setting attempts to increase firmness by increasing compression damping to "killer" level. It's trying to do too much and ending up not doing anything well at all. Have you found facelift 2009 cars to behave differently with respect to PASM?

Regarding the Champion Werks1 package, I called several times and finally gave up after realizing it's not Champion's priority.  I could only speculate the car was put together and sent to you for reviewing as advertisement for the poseur (half kidding ) carbon fiber parts http://www.championmotorsport.com/werks1/. Suspension tuning/marketing was never the intention. But what do I know -- I am only an amateur.

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

GT:
Caanga, pss10=damptronics? I thought only the latter are pasm (i have those) and the former are only mechanical..

There has been some confusion regarding the nomenclature and I myself am guilty. Looking at my explanation below then look back up at the title of this thread, you'll notice that it is in fact wrong (damptronic, not PSS10) AND has a typo (damptronic has no s) .

Here are the correct terms:

The coilover is actually called B16. There are 2 forms to the B16:
1. Bilstein B16 Damptronic: This is the version most everyone uses. The 2 levels of Compression/Rebound damping are controlled by PASM button. Only 2 settings are available.
2. Bilstein B16 PSS10: This is the non PASM version. It has a knob at the bottom that has 10 settings of Bound/Rebound damping -- hence the 10 in PSS10. The bound/rebound curves are NOT independent of each other and how they are paired up are pre-determined by Bilstein.This could be a plus or minus depending on how "advanced" the tuner *and* owner are and whom you talk to (me, I am not about to argue with what Mr. Rohrl thinks is right -- LOL).
http://www.bilstein.com/mistore/ymm_productf.php?company_id=100484&year=2008&model_id2=2568&makes=PORSCHE&stored...

Basically, although PSS10 is in fact the wrong name for the coilover that we use, it's become more or less the standard because so many people refer to it that way.

BTW, this was going to be my next topic of "speculations" -- shock dyno curves of the Bilstein Damptronic and an amateur level discussion of what they mean. I put the posting on hold because all of a sudden excmag appears; I am too busy reading and responding to his posts .

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

hyper1:

Hmm
so are we saying the softer spring rate then the stock is better (h&r, that every body criticizes...), then stiffer then stock, like techart and gmg. i know everybody says go with the gmg spring because they are lot stiffer then the stock, this is contradicting above.

I think I was guilty of spreading the rumor about H&R spring so please allow me to right the wrong:

We do not know what H&R spring rate is -- I was guilty of spreading this rumor that it is softer than stock. Now that I think about it, I think there is a chance that I was wrong.

NOT everyone says to go with GMG spring because it is stiffer. We have a few users "happy" with that spring and we have GMG happy with that spring . But to date there has never been a comparison between H&R and GMG springs by a reputable source -- with the spring being the only variable. And in fact as you could see by excmag's (Pete Stout) posts, a H&R car, although one fully loaded with other components and cup tires, has hit the sweet spot big time.

I do believe GMG when they say their spring is the stiffest of all arfter market springs. But... all these springs being progressive in nature with variable rate (depending on the load), I even have questions about what it means when someone says one progressive spring is stiffer than another -- when is it stiffer?, and if it is necessarily better this way.  So until H&R and GMG could go head to head on a public forum (will never happen), or until there is a true shoot-out by a reputable source, I would most definitely reserve judgement on which spring is "better."

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

cannga:

I once thought a stiffer suspension is unequivocally better with respect to handling, the only price to pay being loss of ride comfort. However, I then learned of a third and equally important parameter: tire traction. As the spring is stiffened, car actually loses tire traction. The gain in car dynamics (less sloppy handling, less weight transfer) from a stiffer spring therefore must be judged against the loss of road adherence from less tire traction.

hyper1:
Hmm
so are we saying the softer spring rate than the stock is better ...

Your inclusion of the word "better" turns this into a loaded question! I guess my answer is, better subjectively or better objectively?

1. Objectively, yes, if it is tract time you are talking about, a stiffer spring is not necessarily better. I could imagine a track with less than perfect surface and sharp hill crests favoring softer springs, whereas one with smooth surface, tight space, and lots of combination curves favor a stiffly sprung car. (But what do I know, I am no race car driver .)

I remember vaguely reading (anyone could confirm if this is trure?) when the Turbo first came out, that the best time around the Ring was done in fact with the SOFT setting of PASM. I had a lot of difficulty with that and was very critical of Porsche engineers at the time -- imagine that, engineering a Sporty setting that is slower than the Comfort setting!! Now I think of a plausible and reasonable explanation: For this particular car, and this particular circuit -- because of bumps or crests or whatever, the dynamic advantage of the FIRM setting was not enough to overcome the traction disadvantage -- driver probably was having too many "holy s**t" moments .

2. Subjectively, I would say a stiffer car, within reasons of course, almost always feels more agile and less ponderous. In the case of the Turbo, because the stock setting is so soft, my opinion is ANYTHING stiffer will make the car feel better. But this does not mean you should go out and get the stiffest, because then comfort will be sacrificed.

BTW, for me (YMMV) 2 is VASTLY more important than 1. Subjective sensation is very much relevant to DRIVING FUN. And that, to me is the bottom line.

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

cannga:

hyper1:

Hmm
so are we saying the softer spring rate then the stock is better (h&r, that every body criticizes...), then stiffer then stock, like techart and gmg. i know everybody says go with the gmg spring because they are lot stiffer then the stock, this is contradicting above.

I think I was guilty of spreading the rumor about H&R spring so please allow me to right the wrong:

We do not know what H&R spring rate is -- I was guilty of spreading this rumor that it is softer than stock. Now that I think about it, I think there is a chance that I was wrong.

NOT everyone says to go with GMG spring because it is stiffer. We have a few users "happy" with that spring and we have GMG happy with that spring . But to date there has never been a comparison between H&R and GMG springs by a reputable source -- with the spring being the only variable. And in fact as you could see by excmag's (Pete Stout) posts, a H&R car, although one fully loaded with other components and cup tires, has hit the sweet spot big time.

I do believe GMG when they say their spring is the stiffest of all arfter market springs. But... all these springs being progressive in nature with variable rate (depending on the load), I even have questions about what it means when someone says one progressive spring is stiffer than another -- when is it stiffer?, and if it is necessarily better this way.  So until H&R and GMG could go head to head on a public forum (will never happen), or until there is a true shoot-out by a reputable source, I would most definitely reserve judgement on which spring is "better."

 

--

Regards,
Can
997 Turbo + Bilstein PSS10 (Review) + Cargraphic Exhaust (Heavenly Race Car Noise Review)

        thanks can for responding,

 i was actually confused thats why i bought it up, actually gmg is the one who also said that h&r springs are softer then stock, (on 6 speed)  techart is ~ 25 % stiffer then stock and gmg is ~ 50 % stiffer then stock, so that puts techart in the middle, which i am leaning on right now. so could this be misleading that h&r are softer then stock by some competitors, it has to be othewise the emag review would not be true then!

Ronnie