djm68

Hello,

I am about to install JRZ RS Pros I had built up for my 2012 Cayman R PDK. Car is largely stock . In addition to the coiI overs, I plan to install the following:
Tarett Camber plates
Tarett F/R swayers (26.8mm / 22/2mm)
Tarett swaybar end links F/R
Tarret toe control links
255/35/18 F and 275/35/18R Toyo R888R

Use case is HPDE with the intent to move up to formal time trials; I usually drive to the track, and very occasionally, I will do a fun road drive. My question is about spring rates; I had the coilovers built with 560lb F/ 672lb R. I've seen a lot different rates for the 987.2 chassis; before installing everything, I wanted to get some input on the spring rates.

Thanks,
DJM

rastta

What do you want to know? I run 700/800 on my Boxster S race car on Moton 2 ways. I run Ohlins R+T on my 987 Cayman S street car. It has 400/462 lb springs f/r. I've run R888's on numerous cars including the Boxster S - but don't like them as much as NT01's on the track. I also run Yokohama Advan race slicks on the Boxster S.
It's never just about spring rate - but how you set of the car, ride height, compression and rebound etc. Not sure what your question is.

Frank 993 C4S

djm68

Apologies if I was not specific enough: my main concern is if my spring rates were 'in the ballpark' for the use case I outlined. Too stiff? Too soft? I do realize there are a number of variables involved in setting up a suspension system, spring rates being just factor.

DJM

djm68

I agree it is a somewhat broad use case and, but based on recent visits to NASA HPDE/TT and PCA TT events, multi-purpose cars, similar to my configuration, are hardly exceptional.

DJM

rastta

Are they in the ballpark? Yes. They are going to be pretty stiff on the street though - although you can get away a bit with changing the dampening. As others have said - it's a compromise.

Apex1

I agree with the poster above, those spring rates are just too high for the street, especially with Tarett Cup LCA's. These new arms have absolutely no rubber. I have 400 lbs/in f and 458 lbs/in r and have changed my rebound/compression to 15 clicks from full stiff f and 18 from stiff rear to be able to drive around. However, you have already made your decision to install these from P9 website, so 6 months down the road you maybe wanting something else if you still use your car on the street. If its only a race car, you have gone the right direction. I would be interested in how you use your car after the install and impressions about the suspension settings. I started with the Ohlins, Tarett GT swaybars, down links first, then added the Tarett Cup LCA's later, so I felt the before and after, it was a big change, removing all the rubber parts and replacing with a solid thrust puck, and the two large monoball bearings made the Ohlin adjustments more noticeable, exposing the spring rates, especially for the street.

rastta

I have the Ohlins R+T as well - in fact just installed them about 4 months ago. I run 15/15 f/r on mine and stock upper mounts front and rear I was VERY concerned about the spring rates being that high on my street car. However - the Ohlins DPV valving makes a HUGE difference. My KW V3's in my old TT had much less spring rate - and felt much harsher on the street - and that's after messing with both rebound and compression. Not sure about the JRZ's but they aren't designed to be for the street like the Ohlins.

djm68

Rasta and Apex1:

Very much appreciate your thoughts and input. Very likely, I would have gone with the Ohlins R+Ts if they had been available when I bought my JRZs. The JRZ were an excellent deal (lightly used) and I could not pass them up. The install starts today, should have the car back by Friday -- I will post a follow-up after I have an opportunity to get out a drive a bit this weekend.

One bit of feedback I'd have, something that I find a touch humorous: the often cited 'compromise'. I wholly concur that my setup has some compromises, as does each of your setups, as do many other things in motorsports. Super sticky 'sprint' race slicks compromise longevity for ultimate grip, endurance racing engines trade off reduced power in exchange for extended engine life, etc. The question is, have I made the right trade offs? Time will tell and I very well maybe back here asking for help in taming my too-harsh suspension!

Thanks,
DJM

rastta

The JRZ's are great shocks - and I agree we all have to compromise at times. The nice thing is that you have the ability to change the spring rates down the road if they don't work for you. Curious to see your impressions of the ride as we all have a different perspective of "stiff and harsh" suspension.

Viperbob1

For a couple years I was running 1000/1200 springs on a street driven TT (and track with Yoko slicks) running triple adj Motons. People that rode in the car with me were always surprised how comfortable the ride is. all about setup. This stiff and hard for the street stuff is BS if done right. You can have the best of both worlds.......

dak996

hi everybody, I wonder if I can get a clean used JRZ to my 2012 cayman r ?

911ted

Whatever spring rates you use, knowing the corner balance front and rear ratios and having the ratio of the front & rear spring rates close to the same is a good starting place to set up the car from my experience.

powdrhound

You can run pretty significant spring rates if you have a quality 3 way remote canister shock. I've run 1000/1100 rates on a 996 and it drove better than stock. It's all about the set up. I currently run 1700/1800 on JRZ Motorsport 3-ways and it's fantastic at the track. Obviously not a street set up but the car gets trailored.