Christer, I believe you and Joey are pretty much using the same springs...whether they are Eibach or H&R springs, we are speaking of the "street/sport/lowering" version, commonly used by Porschephiles to add performance and LOWER their ride??

I had H&R springs for a 965, they were only about 30lbs a corner stiffer than the H&R 964 street/sport/lowering springs.

Joey is changing out his shocks...a PERFECT time to get a set of custom-valved Bilsteins, the kind that Bill, I and others are using...a step above the "HD" version that I was using before, because they are "beefier" and easily re-valved to your specs...he (Joey) can still use his springs with that setup, if I'm not mistaken.

THEN, later on, if he wants more, he can go to the common 2.25" springs that most racers/track junkies use for ~ $100 a pair.

If he wants to go say...from his Eibachs to a stiffer setup, I believe his Eibachs, from memory are ~ 180lb front 260lb rear?? - or something in relation to that??

He might want to try 250 front 400 rear or better...if he makes that conservative "step-up" from his current springrates, a re-valve may not be in order...PROVIDED he gets a semi-aggressive valving done at first purchase of said shocks.

Okay, later on, let's say Joey wants to go to a 600f/750r springrate, he would then have to send his shocks in to get re-valved for an AGRESSIVE setup...so, hopefully one can see how this type of setup remains flexible?

YES, my setup is NOT ideal, whatsoever, for the street, but I gotta say, it's not that bad.

I would consider putting "tender" springs in, to add a 200lb progressive rate to the stiffer rate to improve the street driving comfort level, but for now I'm okay with my current dentalwork.

 

Jeff, previous posts by others would suggest that coilovers use different springs (i.e. stiffer but still progressive) to the normal lowering springs/sports springs etc - but I am not going to argue about that. From what I understand, the pss9 has this 'tender' spring or i think we call them 'helper' spring but that might be a misunderstanding by me. Anyway, the spring rates given for pss9's include the cumulative total of the main and tender spring and therefore give 'artifically' (for the want of a better word) high spring rates. Apparently the spring rate level on the pss9's are quite comfortable on the whole, and therefore may not be the best for the more serious track driver - despite the adjustable shocks.

Joey, it would be good to get some feedback from you how serious or far you want to go, or can you not get a post in sideways?

 

What I realized over the summer is that 90% of my p-car miles are track/autocross-related. On the occassional commute to work (16 miles r/t), the roads are in very good condition so I feel I'm in a good position to "push the envelope" a bit.

So yes Christer, I'm leaning toward the "extreme route" as you would say.

BTW, you're also correct regarding the effective spring rates of the PSS9's, but only to a point. Once the tender springs are fully compressed, the effective rate becomes that of the main spring.

 

Hi Joey, obviously I am always right to a point !

Well, I will repeat that I would definitely go with Jeff's route then - as he says if you get the right parts then you can just revalve to suit your springs. For track use I would recommend monoball mountings as well.

Look forward to hearing what you decide.

 

Here's something I'll share...just recently learned and have looked into quite a bit - the difference between the "helper" and the "tender" spring.

A "helper" spring is a low rate, maybe 10-20lbs that ONLY keeps the spring assembly seated in both the spring hat and perch at full suspension "droop" - whether you're "up on three" or jacking the car up to change tires/work on brakes, etc.

These prevent the malignment that usually occurs when the car settles again, usually causing a POP sound when the spring finds it's way back into it's "seat" again...NOT the most graceful way for your springs to settle back into your expensive CNC aluminum ($160 pr) hats!!

A "tender" spring is added to a linear spring to make it progressive, and Joey is right on when stating that the effective rate of the main spring kicks in once the tender spring is under full load. Again, these also effectively ensure full spring seat alignment when at full suspension droop and/or the "up on three" evolution that we, as 911 owners seem to enjoy having pics of.

Christer, a spring over a shock is a coilover, so whether you have a factory shock/spring setup or a Bilstein Supercup setup - both of those sets are coilovers.

The PSS9 setup uses a TENDER spring, so it is truly a decent street/track setup - but I'm sure most will find the springrate to fall shy of their expectations, the deeper they dive into being a trackhead.

What someone could look into is the length and I.D. of the mainspring, if it's say a 5"-6" spring that's 2.25" I.D. - you're set!! Buy a set to have the adjustable shocks AND the tender spring setup...when you need "more" - buy a set of springs from Eibach/H&R or Hypercoils to suit your needs and click those shocks up a notch!

I just wanted to clear up the tender/helper spring issue - again, I have just recently looked into this stuff, so while I'm not exactly a "GURU" on the subject, I have learned quite a bit regarding spring setups...and have MANY more ideas to try - as soon as that miracle grow kicks in on my $$$$$$$$ tree! ...right now it's a bit wilted.

 

Tom,
It might be useful to know what tires/wheels you use at the track. The Club Racer I referenced uses 8-1/2 x 18 front wheels with 245 Hoosiers. Those options alone will induce oversteer. He's also made every sway bar and "click" change he can think of but still can't get the tail to stay in.

Not looking for a debate, just an understanding of why your experiences may have varied.

 

Sounds like his front springs need more "UMPH".

The "RS" setup that Bill G. was using (the springs) had considerably soft front springs if I remember correctly, it seems the PSS9 may have followed suit with the same idea??

Yes, a fatter tire up front will induce some oversteer fer sure! ...but what width are the rears?? I would assume 275 if he's packin' that much rubber in the front??

If so, then he has a decent tire size combo...so I would either checkout the swaybar sizes, their adjustments and what the front springrate is...sounds like it might be a bit "soft" to me.

So, there you go...if he can figure out his mainspring length and I.D. - he can just get a set of stiffer springs, no problem...it does not matter if he uses Eibach/H&R or Hypercoil, although it seems the fan population for Hypercoils is growing.

I would still be curious as to his swaybar sizes and settings though.

Anybody know the springrates for the PSS9??

 

Yes, I realise that - I am sure though someone posted spring rates that were different for the various springs used. Ah, I have found it - please find pasted below. Not huge differences but I remembered something about it...

Ah, I found it (pasted below in bold):


Eibach 964 Pro-kit springs (like mine)
Front 82.6-250 lbs/inch
Rear 188-256 lbs/inch

H&R 964 springs
Front 190-255 lbs/inch
Rear 220-265 lbs/inch

H&R 965 (Turbo) springs (Jeff Curtis)
Front 250-270 lbs/inch
Rear 265-285 lbs/inch

H&R 964 Coil-over
Front 250-285 lbs/inch
Rear 265-285 lbs/inch

H&R 964 Super Cup
Front 455 lbs/inch
Rear 685 lbs/inch

Porsche Carrera RS springs (Bill Gregory)
Front 250-308 lbs/inch
Rear 375-508 lbs/inch

 

I was wondering what that was going to enter the discussion, as it is as important as springs, and much more important than shocks in terms of steady state cornering.

Shock tuning is where you go for transitional handling, turn in etc. But if you have a situation with steady state understeer/oversteer, then springs and sway bars are where you need to go, since its all about front/rear weight balance.

A shock will change the RATE of transfer, but once you are steady state, its all about front to rear weight balance, and sway bars would seem to be the cheapest, and easiest route to dial that in to suit the driver.

Of course, I have done nothing to my P car other than Bisltein HDs and H&R lowering springs, so take my words with the appropriate grain of salt. I do however follow the teachings of Fred Puhn and Carole Smith.

And all three pieces do have to play together nice. Most of the top dog SCCA Solo II guys I know do custom valve shocks as a matter of course. But those guys can also feel if a tire is 1/2 pound low in pressure. My butt-o-meter is no where near that good!

BGL

 

Joey,

I run 205/255 MPSC on 17" cup wheels (7 & 9"). I say the PSS-9 did not induce any oversteer on my 993 because I felt that when the PSS-9s were set similar to the stock suspension I replaced (full soft and with the same tires) the handling was about the same (and the car understeered like a pig). When I adjusted the set-up to make it more firm and firmed the rear swaybar, the car was reborn and is much more neutral. (That is inducing oversteer, but I think 95% of that came from the swaybar.) This handling was for both autocross and the track.

I concure that PSS-9s are not the ultimate track set-up (that would be Motons ), but for people like me who do 95% street and 4-5 track weekends, they are a nice solution (just not cheap).

 

Oh, the Club Racer I keep mentioning has ALL the go-fast goodies. His adjustable sway bars are 25/21 front and rear, with the front set near the max stiffness and the rear at full soft. He's also running 285 rear tires and uses a pyro to get the pressures right. I think Jeff may be right--that the difference between f/r spring rates may be too large for this particular car/driver.

FWIW, I've heard that many of the Club Racers are headed towards an 1,100/1,250 combo with JRZ's or Motons. The GT3 Supercups run 2,100/2,200 spings but with 500-lb tenders to keep it nice and comfy.

 

Thanks, Tom. Is it possible for you and Todd to meet somewhere along Hwy 1 and do some side-by-side comparisons and report back?
I used to live in SF and as a salesperson covered a lot of the Peninsula, all the way down to Santa Cruz. That drive over 92 must be glorious in a p-car! How's about a pic?

Thanks for your input!

 

2,100/2,200lbs?? AAAAAH!

Yup, the GT3 cup cars run ridiculous rates, incredible handling though...got to drive one a few weekends ago, just astounding.

I think we got everybody on the right track to thinking about what affects the other here, with spring rates, swaybar sizes and whatnot...good deal - great minds thinking together!

Good job on finding the springrate specs Christer!

NOW, as you can see, the Eibach "Pro" kit will probably induce some oversteer, with some GREAT turn-in qualities - why?? Because they initially start off soft, real soft, then get up to a more "sporty" rate.

You will notice that the H&R springrates, while progressive, span along a relatively smaller gap...the turn in won't be as precise, but the transition from soft to firm is less, providing a more balanced feeling through a turn.

Ah, the subject of swaybars, "black magic" to some, but purely simple math...trust me. I have spent the last two years really thinking about this and testing out different sizes, to where I finally think that I understand their use...as well as ABUSE!

You see, for those of you who are running a 24mm (RS) swaybar up front, with 19mm-21mm in the rear, BUT have one of the "sporty" spring/shock combos, not a racing setup - are effectively using your swaybars to stiffen up your spring setup.

I went that route for quite awhile, before realizing what was happening with understeer and all...then the SNAP!!

Yup, I broke my front swaybar, albeit hollow, that was still a feat that continues to baffle Weltmeister - probably because I didn't provide them with ALL the pertinent info.

I was using H&R 965 springs (rates above) with 25.4mm HOLLOW bar (effectivly 24mm) - so I was unintentionally using my front swaybar to increase my springrate, not good.

SO, we have to keep in mind, when keeping your shock valving synonymous (did I spel thit won ryte?) with your springrate, same goes for swaybars.

The guys that are changing out their wimpy rear swaybars with the larger factory ones are doing the right thing, the rear is a fairly easy area to improve on the 964, but anything with the front, beyond an RSA (M030) swaybar changeout requires some necessary consideration before embarking on some crazy upgrade to the "mumbo-jumbo" 24mm and above bars that are available.

If you do upgrade to 24mm in the front, surely you will have it on it's SOFTEST setting, or pay the price in UNDERSTEER...I know this all too well.

With that said, I'd better get back to work!

 

Plus, you get to exhibit that neat-o, three wheel, inside front tire up in the air thing that looks so cool, but would not normally be as fast!

One more "old adage" to pass along:

When you have a problem with one end of the car, work on the opposite end. Too much push? Stiffen the ***-end. Too much oversteer? Stiffen the front.

BGL

 

That, my friend is my "up on three" reference, and yes, while it IS oh so cool...it suggests you may have issues.

As for your last statement, that is a pretty accurate generalization...it works in most cases...but too much understeer usually translates to a front swaybar, or in some cases, too much spring in up front - if dialing neither of these in is an option, and you have an adjustable rear swaybar, tighten that puppy up a notch and go from there...but you will soon see that your adjustment "tongs" wind up pointing towards the ground under full load.