H&R Sport Springs vs. Bilstein Coilovers

Hello Everyone. I tried to find a thread on this topic before creating a new one, but had no luck. If one already exists, please accept my apologies and point me to it. I recently purchased a non PASM equipped '06 CS with <1,000 miles. I have always had 911 's but after driving a CS and experiencing the handling, I simply had to have one. The car is amazing! The one thing that doesn't thrill me is the stock ride height. I have a '92 America Roadster with the OEM adjustable suspension and H&R sport springs and when I park the CS next to it, it looks like a monster truck (OK, maybe that is a bit of an exaggeration ). Seriously though, I would love to get the groups feedback on whether to put H&R sport springs on the CS, (my experience with them on the Roadster with the factory dampers has been great) or bite the bullet, spend the extra $1200 - $1300 and go with a coilover system (PSS9 or PSS10). What are the key tradeoffs? Do you think the coilover setup is worth the extra dough? I am sure the ride height will be fine with the H&R springs so it really comes down to ride quality and overall handling. Any feedback would be greatly appreciated. Thanks!

I don't have first hand experience on the CS, but springs are maintenance free, put on and forget it. Also, because PASM is able to adjust compression/rebound within a range, the springs should work well. Coilovers... great if you will really use them, but they require a lot of maintenance IMO.

I am also debating this same choice. I had H&R sport springs and Beilstein Sport shocks on my 98 Audi A4 and really loved the handeling improvement it made. I am not sure I want to go the expense of the PSS9.

I installed just the springs (H&R), figured i'll sell them and do PSS9 if I'm not satisfied, so far so good with H&R, no complaints.

*begins tirade* :soapbox: Select a custom spring rate, DO NOT BUY A KIT. Kits tend to use progressive springs instead of linear ones, and generally give you much more limited results versus installing a set of springs with a specified rate. My brother used to run H&R Sports on his old Bimmer, before he knew any better. His current 325I mounts 550 lb front springs up front, and 700 lb rears, on Koni Yellows and Bilstein HDs, respectively. The difference is simply staggering. The old kit, while firming the suspension up noticeably, is FAR surpassed by his current "race car" setup, which remains streetable despite the relatively high spring rate. (Feels more comfortable to my tastes than Z51 suspension on a Corvette) Trust me on this, if you want to be blown away by suspension, go with user specified spring rates instead of a kit. Disclaimer: Using high spring rates may necessitate a damper upgrade.

That assumes you know what rates to specify, which in turn means you either are a suspesion engineer, or are willing to test a dozen different spring/damper setups, or are able to take a number off a list from someone who has done the testing, which to all practical causes is the same thing as buying a kit. I don't see why you view progressive springs as a negative, almost all cars nowadays wear progressives and by and large find significant gains in suppleness. Way back when the springs would bind on high deflection and cause a sticky sensation I could understand your point but that's ten years ago. First generation progressives also tended to have too much difference between the two rates the springs had, one way too soft that'd bounce like a 80-profile tyre and one too hard that'd only budge if the first one was bound. This however is long gone technology and progs are much more cohesive and effective now. I have no doubt that specifying your own rates tuned to your requirements and tastes is superior to any kit, that's like saying a tailor-made suit is better than one off the rack, however unless you have done the testing yourself it's about the same as advising "go into the tailor's shop, say 'I'm about yay high and yay wide' and get a suit made for you, you'll be more pleased than a suit off the rack"

Actually... It's not that much hard science, most people make changes in 50 lb increments. One user on the forum recommends 450 front, 600 rear for street/track duty, which sound pretty reasonable to me. As for linearity, the stock springs are linear, and in most applications linear springs will give you a more consistent response, I feel, and I'm not alone in this opinion. (Not aware of anyone with real suspension mods running progressive rate springs) IMO, that weird progressive spring rate/suspension geometry is one of the issues with Corvette handling. http://www.planet-9.com/cayman-modifications/13803-spring-rates.html

Personal experience only - Had H&R springs on my Merc Had PSS 9s on my Bimmer Both cars were Street cars although I took the bimmer out on track a couple of occassions. What would I do next ? Given that I would do limited trackwork with my 987 S (with PASM ) I would go with just the H&R springs and save the dosh. The springs only setup on my Merc C class transformed the handling tremendously and everybody commented how un-Merc like it handled and I agree.

Comparing a setup between cars is very, very patchy. Correct spring/damper rates have to do mostly with the car's natural primary and secondary frequency, it's vibration characteristics and the characteristics of all other spring-acting parts of it's suspension (ie: tyres and bushings). The only thing one can compare between car's in the same range is what the item was designed for. ie: a Billstein "fast road" kit for five different cars, if the first four were crashy, chances are crashy is what Billstein consider "fast road" and the fifth will probably be too. Assuming a same-name kit for a different car will have a similar feel to it is quite unlikely to come out a wise assumption. Having said that, the op's original question is one of comparison between a spring change and a spring/damper change. A chat with a competent suspension-setup specialist will help you quickly determine whether you're happy or not with the stock shocks. If you're not, no spring will help the problem and even so Billstein may not be the correct shock/spring combo for you.

excellent place for suspension parts Ground Control Suspension Systems I buy all my suspension stuff from them...they do custom too

Ugh, not ground control. Nothing against Jay, he is quite helpful but I've had quite a few products from them that were of sub par quality. Just my experience.

Just got off the phone with Ground Control. They have not done anything with the Cayman, don't have anything, and did not offer to provide any product or assistance.

Thanks for the responses. From the replies to this and what I have read on other threads, it seems that those who installed PSS9s have been thrilled and those who went with sport springs with the OEM dampers seem pleased also. Of course, it seems like the ultimate street/track setup would be the PSS damptronics on PASM equipped cars. Big bucks though and that option isn't available to me anyway since I don't have PASM . I'll continue to do more research as I won't be upgrading the suspension for another month or two. If anyone has any more input in the meantime, please continue the thread.

Hola Rodrigo; The KW-V3's are another option to the PSS9's, few CC members are using them and have good reviews.

Gracias Gilles. I hadn't heard of KWs, but after doing a bit of research here on the forums they definitely appear to be a viable option. I will keep them in mind as well.

I had H&R springs on stocks shocks for around 7000 miles, its cheaper then coilovers, drives better the stock, drops the car around 1.25. I just installed a set of JIC CROSS coilovers, haven't got it totally dial in yet, but with the wider camber adjustment and setting currently at middle point, the car already handle WAY better and sharper then with the H&R springs and shocks. If you track your car, then save yourself the installation fees and get the coils now, I learn the hard way .

Don't change to H&R springs if you have PASM . Many have reported problems after doing that. No problems reported for non- PASM cars.

Rodrigo, It is obvious that everyone has a opinion. But the question should really be "Looks" or "Handling"? The Bilsteins will give you superior handling, if set up properly, and the H&R's are really just going to make it look better. Increasing your spring rate without increasing rebound and dampening control can make it handle worse on bumpy surfaces. I have wasted 10's of thousands on suspension in all sorts of euro cars, and the one thing I learn't is that a adjustable coilover system wins in both the above categories. Be warned though you will sacrifice comfort no matter which route you take.

Fort - I did a search and found two instances of concern: 1. Ken had talked to someone who had talked to a suspension engineer from Porsche , who said don't put progressives on a PASM car - they had experienced a shock failure in such a scenario, supposedly. 2. Another member changed to H&R progressives and had a PASM shock failure but there seemed to be install issues on that one which contributed to failure. Were you referring to more failures than just those two? I've got H&R's (along with too much other stuff!) that I'll get around to installing some day and wanted to see what data quality was. I read a bunch of very happy individuals also so I'm not sure if the problem is isolated or is really a trend of sorts that one should really be concerned about. Thx for any further info.

Thank you all for the advice. From what I have heard and read, it seems like the best approach will be to bite the bullet and get the coilovers. Given the estimated cost of installation and alignment in Nor Cal running in the neighborhood of $1200, I might as well choose the coilovers and avoid the worry of having to upgrade later. A couple years ago I installed H&R springs on my '92 Roadster, coupled with the factory dampers and the handling definitely improved, but I must admit that the ride quality is pretty stiff. The one benefit of the factory dampers on that car is that you can adjust the ride height, which enabled me to corner balance the car. Not quite a coilover setup, but a bit better than most stock dampers. Having said that, I am sure that the handling would benefit from coilovers. The next step for me will be to go for a ride in a CS with coilovers to feel the difference. I am not far from Sharkwerks, and hope to stop by and check out the RS350 while it is there.

I installed H&R's on my ccs with no PASM and the drop is beautiful. The only thing is the other night i was driving an i noticed that my xenons reflecting on other cars seemed like it was bouncing up and down. I don't know if it was the freeway, or the xenons themselves or the fact that the springs are bouncy. I can't remember when i had my stock springs whether they were this bouncy because i dont' notice that it's bouncy. however, i will say, watching the lights shining on other cars makes it look like the car is bouncy. cab anybody with h&r's now or h&r's and then coilvers (or vice versa) chime in?

I have the H & R coil overs and sway bars on my 2006 Cayman S . The car handles great and there's more sensitivity through the Dallas custom steering wheel. The only problem is at 110mph I get a small scrap on the rear passenger fender well over a bump in the road up to my house. I used to be able to go over it at 130mph so I'll probably raise the rear by 3/4". The fronts seem fine.

Caymanis#1, You have three options, roll your passenger fender lip. Second have a shop give you -1.5 camber front and rear which will allow your wheel/tire will tuck up inside your fender lip. Lastly, change your wheel spacers from 25 mm to maybe 15mm in the rear, then try your speed bump with the smaller spacers. You may want to do all three. I have used a 23mm with the OEM 43 offset rear 18 inch wheel without tire rub but my Ohlins have a much higher spring rate of 458lbs/in in the rear. You could buy new rear springs with a higher spring rate as well.

There are litronic shims with a sensor that fit on your lower control arms to tell your your xenon lights their position that keeps your xenon lights level.