X74 spring rates?

I�ve been waffling for a while trying to decide on a suspension upgrade. X74 seems like it would be great, but I still have nagging worries about the ride height. Reannimator�s hybrid suspension idea sounds interesting � Bilstein sport shocks (X74) with ROW M030 springs. I�m not versed well enough to be able to render a judgment as to whether this is completely technically sound, but it would seem so as long as the M030 spring rates were in the ball park of the X74 rates. I know the M030 rates are roughly 170 front and 260 rear vs. roughly 145 front and 200 rear for stock. Anybody have the X74 spring rates for comparison? Is there any other spring that would lower somewhere between X74 and ROW M030 and would be compatible with the Bilstein sports? Or am I playing with fire and I should just bite bullet and go with X74 or ROW M030?

x74, 20-30mm drop. Re-animator put a lot of effort into his setup and it seems to work, unless you're willing to do alot of trail and error I would recommend the x74 for a >'02 car and row 030 for pre '02. The factory has already done the work for you.

Bilstein engineered the Sport shocks to match the stock spring rate with a 40% tighter range. Those shocks are technically specific to the dampers used in the X74. Without knowing the exact spring rate of the progressive springs in the X74, they are automatically in the same range by design. Just $.02. RoW M030s are linear and more consistant throughout the compression range. Food for thought.

I'd personally be a little wary of mixing & matching. Reanimator has a setup that works well for him, which is great. I'd think about the fact that the x74 shocks are matched to the x74 springs, which are both softer and stiffer depending on where you are in the shock stroke, i.e. they are progressive. I'd think that shock tuning is done a little differently with a progressive spring than it is w/ a straight-rate spring. In particular, the low(shaft)speed damping would probably need to be softer, whereas the highspeed damping would be stiffer. that, and you don't simply make a shock "40%" stiffer when you increase spring rate by 40%. You typically decrease compression damping, while increasing rebound damping. Net: just because a shock works well with a stiffer spring, doesn't mean it's "right" for a softer spring. IMHO, the short answer is that both the ROWM030 and the x74 were engineered as a system by Porsche. I personally wouldn't screw with that system unless you like to tinker. You just need to pick how much ride height you're willing to sacrifice. Based on the hockenheim numbers I saw, the delta from stock->row030 is roughly equivalent to row030->x74, from a track time perspective.

Believe me, I *am* leary of mixing and matching. However, if the x74 shocks are the same thing as Bilstein sports, then people are mixing and matching everyday when they use all kinds of different springs with the Bilsteins. I sould still like to know the x74 spring rates to know how close they are to the M030 spring rates.

Understood. Realize that (if you can get the rates) since the x74 springs are progressive you're going to get a range of rates for the springs, based on the "depth" of the compression. In other words, they start out soft and get stiffer once the narrow coils stack. Reanimator: are both the front and rear springs on the x74s progressive?

The X74s must be mismatched to the Bilsteins that they come with via that logic. The Bilstein aftermarket Sports are exactly the same valving and rod dimensions of the dampers that come in the X74 per Bilstein technical. So, if Weissach matched the progressive springs to the Bilsteins, they made them progressive to lessen initial spring rate for the already stiffened dampers to make them more palatable to the Porsche driver. Overlapping of ranges is standard across the auto industry. I liken it to my warranty safe Porsche Short Shifter Kit. It is technically specific to the B&M shifter which was the original design. Porsche repaints the B&M SSK and voila, Porsche engineering at its finest.

I can only say that they rears are progressive. The GT3 street car from Porsche comes with progressive springs in back just like the X74; however, the GT3 Cup Car comes with linear springs all around like 986, 996, and 997 variants. When switching lateral Gs in opposing directions, the progressive springs are less reliable in delivering a consistant spring rate than linears by design.

I agree re: the behavior of progressive springs. Every time I've tried progressive springs (in aftermarket kits) I've hated them. They compromise predictable response for a fluffy ride. My guess is Porsche did a decent job with them, however

I got to ride in a GT3 Street on the street once. Based on that experience, must agree 100%.

Thus far we have been discussing shock and spring rates....but does anyone here have the exact specs as to the height "drop" front and rear of the X74 kit for the 02'-up 996's ?? (compared to stock) I'm looking to upgrade my suspension as soon as I learn what option is most feasible for me....I'm looking for significantly stiffer and more stable shocks + springs over stock* I'm also looking for a noticable 1inch-to-1.5 inch drop. in ride height as well....obviously if porsche has already done the homework for me, id prefer that route if the X74 is up to snuff* ?

-40mm front, -30mm rear, delta from non-sport European model. I believe that means it's -50 and -40mm delta from US.

It's -40mm front, -30mm rear, from US specs.

...then out of curiousity, why do the europeans call it the -40mm sport suspension? Aren't we (US) about 10mm higher than they are?

They refer to the x74 as the -30mm sport suspension, the ROW M030 is the -10mm sport suspension. If I knew how to upload an image here, I could post a table I have that gives all of the ride heights.

Here are the instructions to post pics . Items in bold are buttons If you want to attach a picture you must be in the Advanced Message mode, which is the mode in which you can attach the Smiley Faces to your post. When you start a thread you will automatically be in the Advanced Message mode. If you do a Quick Reply you have to click on the Go Advanced button below the text area. Down below the text area and below the Submit Reply and the Preview Post and Spell Check buttons, there is a Miscellaneous Options section followed by an Attach Files section. In the Attach Files section, click on the Manage Attachments button. You will now get a pop-up window. There are 3 buttons - Browse , Upload , and Close this Window . Click on Browse and now (in a different pop-up window) you can search on your PC to locate the pic you want to attach. Click on the name of the file you want and then click Open button (you will automatically go back to the initial pop-up window) Now click on the Upload button. After the file has been uploaded, click on the Close this Window button. You will be back to the original "message" or text screen. Your file name should be listed just above the Manage Attachments button. If you click on the Preview Post button you will NOT see your pic. You will see it only after you submit the post. When you are finished typing the text, you can Submit the reply and everyone will be able to see your great looking P-car! I hope this helps!

OK, let me try this out..

[Image-only post; no author-written text. Original image references:] https://rennlist.com/forums/graemlins/thumbup.gif

Before I decided to go X74 for my previous 996 (traded it before doing X74), I had a long talk with Gert at Carnewal, and came away convinced to go X74. I don't have any info re putting together a system mix and match, but I do know the spring rates for X74 differed with each model - I had a Targa and the springs with the X74 were specific to the Targa. Gert has a wealth of information and I would recommend calling him for some input. I think he also has X74 on sale and the Euro rate is getting better.

That diagram is great/informative, thanks for posting ...I need you guys opinion on something, is the drop for the X74 suspension too extreme ?? Is there any rubbing on stock 18inch porsche wheels ? (at full compression) How does it look ? A 40MM drop in front is nearly 1.6 inches and 30MM in the rear is nearly 1.2 inches drop in the rear. How stiff/track oriented is the roW Sport* suspension compared to the X74? Which one is better for the track ? Thanks.

In short, based on what I've read (and my ROW030 experience), the X74 is better at everything except ground clearance. I've heard a few accounts of people saying it may even have better ride characteristics than the 030 (which is somewhat harsh). Since my car was at the time a daily driver, I went 030 for the ground clearance. since it's no longer a DD, I'm considering going x74 (which is a simple upgrade, by the way, just swap out the pre-packaged struts). Anotehr thing to keep in mind is that an honest install shop should charge less to install the x74 since it comes with preassembled struts/springs. You can do a simple swap and not have to rebuild struts / compress springs. My guess is it saves 1-2hrs. Oh, here are some track times I had stashed: " In a german magazin they had a comparison of a C2 with stock suspension vs. 030 vs. X74 on the track (Hockenheim) and on a 36m (100ft) Slalom: Hockenheim: 1:16.9 min stock 1:16.2 min 030 1:15.7 min X74 Speed Slalom: 123.0 km/h stock 126.1 km/h 030 127.2 km/h X74 "

If the x74 is anything like the x73, you won't be dissappointed!

The ride height is the only thing keeping me from pulling the trigger on the X74. If you read all of the threads on the message boards, you can get every conclusion you want by picking the right response as the answer. Some will say the scrape all of the time, some will say they never scrape, others are somewhere inbetween. Clearly, if you have an aerokit, you will have more problems up front than if you didn't.

when I asked for his oppinion on the X74 setup being installed on my 02 NA: Subject: 2002 996 X74 suspension Question: Would you have the part nos. for the X74 suspension to include the anti-sway bars? Thank you. Answer: X74 will also lower your car more than a safe amount, just like your previous question about lowering 1.5" with the PSS9. You will need to be ready to stop the car any time you approach any obstacle higher than an inch or two, or risk bottoming out and damaging the engine or something else under the car. Also, we have reports of 996 GT2 and GT3 street cars twitching while cornering when you don't hold constant throttle. This is NOT a problem for the Cup cars. So far there is no confirmed solution for the street cars. Many things have been tried. All I am saying here is, you should expect to have this problem if you go with X74. My best guess as to the ultimate fix for this problem will be some fine tuning of the ride height, and an increase in front toe as some of the German tuners have found necessary to run good times at the Nordschleife of the Nurburgring (without the car going into the woods). To order the X74 kit, just call your Porsche dealer or local tuner, or go to http://www.carnewal.com and click on suspension. There are several versions of the X74 kits. Pick the version of the kit that you need for your car. Also click the Carnewal link to "Read what customers had to say about the X74." It goes into all sorts of useful detail, including the engine protection plate, the costs, the benefits, people's experience and feedback, and more. OK now on to the part numbers. You know what I often say, if you call and they don't know the part numbers, keep shopping until you find someone who does. You may even offend a qualified seller by trying to tell them the part numbers. Also note the part numbers are subject to change, and they do. With your dealer, if you (or I) made a mistake, it will be your problem. If you let them look up the part numbers for your order, then any mistake is their problem. Withstanding the foregoing, for the C2 (but not C4), cars after 2002 (but not 2001), here are what appear to be correct part numbers (unless it's Tuesday or raining): Front: 996.343.980.20 front shocks 2002+ (qty 2) 996.343.980.08 supporting mount (qty 2) The front springs depend on the car's VIN. 996.343.980.07 504 qty 1 set for cars up to 992S6 03565 996.343.980.25 504 qty 1 set for later cars Then there is a helper spring 996.343.980.09 qty 2 Sway bar 996.343.701.04 for C2 (703.02 for C4) For the rear: Shocks 996.333.980.24 qty 2 (.10 supercedes to .24) Springs 996.333.980.07 504 qty 1 set for cars up to 992S6 03565 996.333.980.11 504 qty 1 set for later cars Helper springs, 2002 & later 996.333.105.03 qty 2 Sway bar 996.333.701.17 (.13 supercedes to .17) Again, these are only for a C2, 2002 & later model. Double check them with your seller, in case I made a mistake. Joel Reiser - PCA WebSite - 1/23/2005 and Follow Up Regarding lowering the car in the future, I was thinking of getting the X74 kit now vice the PSS-9. Reading the archives, I believe it lowers the car 1.5" front and 1" rear. The roads here in SoVa are not bad. Except for bad freeway 64 expansion seams in the Norfolk area, most of the roads are ok. I've read about your warnings about cracked engines. That will be the only fear I would be afraid of, like running over unexpected debris on the freeway. I am very carefull approaching ramps/speed bumps and curbs. Any thoughts? Answer: Yes for a street car if you really want to run low, I would get the factory X74 kit. It should give you better resale value later on. People drive the GT2 and GT3 on the street with this height and it is OK, just take it easy whenever you might encounter something that could challenge the ground clearance. Steep driveway entrances should be approached at an angle if possible. An engine protection plate is probably a good idea. They make them for the front of the cars as well, but I would protect the engine first. Joel Reiser - PCA WebSite - 1/23/2005

Geez! Thank you all very much for the last sequence of posts. Those were the answers I was looking for....I AM going to purchase the full X74 kit with the sway bars Where would be the best place to purchase this kit for my 02' carrera coupe ? Dealership ? Carneval ? How much is a good price? Thanks again!

<when I asked for his oppinion on the X74 setup being installed on my 02 NA: > What did you end up with, x74 or something else?

Best deal is with Gert at Carnewal: http://www.carnewal-europe.com/main.htm . X74 is currently on sale I believe.

Settled with the Bilstein Sports Shocks and H&R Springs... and very happy with the ride. NOT harsh and not too low.. Since the H&R are progressive they still corner well behave and keep the car from jarring ride. I only do DE's maybe once every 2 years.