Hey guys,

Looking to improve handling on my 08 TT. I have seen many people go with just springs instead of a coilover system. What are the advantages/disadvantages one should be aware of when making this decision? Thanks.

 

i had springs only on my 997 TT and it was good, and then i switched to full coilover system .... from my experiences, springs will give you the lowered look for your ride but not ride quality ..... on the other hand , coilovers will give you much better ride quality and you can adjust it the way you like ....... so its better to spend little more cash and get coilovers instead of just springs ....

 

What he said ^ you can also adjust the ride height which you can't do with springs only,only downside i see is cost compared to springs, make sure you get ones that are compatible with pasm if you want to maintain the ride stiffness adjustment function of the sport mode button.

 

What about harshness?
I have a B16 Coilover which is quite harsh. Aren springs more comfortable?

 

Do you have the B16 PSS10 or the B16 Damptronic? I assume Damptronic? The harshness could very well be caused by your after-market sway bar. What are you settings of the sway bar? Any other suspension mods on the car?

While each of us varies in our taste - a setting that is soft by someone might be considered too harsh by another - the Bilstein Damptronic by itself is not harsh at all, per most users' taste. A little bouncy because of the stiffer springs but this could be reduced by using Tarett rear drop link. http://www.tarett.com/items/996-997-...lnk-detail.htm

 

If your coilovers are harsh, you probably have the ride height set too low. The Bilstein B16 Damptronics are really not designed to have their height adjusted a great deal, since ride height and preload adjustments are done with only one adjustment. Try raising your car 20mm and seeing how that helps. (yes, you will need another alignment)

 

Advantages of lowering springs are simplicity, and lower cost. For very little cost you could have a significant improvement in handling and fantastic result. Of the lowering springs available, I would probably prefer the stiffer ones, like Techart, or GMG, which I suspect are stiffer than the H&R spring. With the GMG, I would recommend the complete system of lowring springs, sway bar, metallic joints (rear upper and lower control arms, etc.), but I know, the cost and complexity have now increased.

The disadvantages of lowering springs are the height drop is a fixed 24mm, and this could be too low for some people. Also, the stock dampers are designed neither to operate at lowered height, nor with the stiffer springs, so damper failure is a risk, seemingly very very rare though. Some users, NOT everyone, have reported a floaty sensation in high speed curves with lowering springs, possibly a result of, and typically seen in, an under-damped system (the stock damper is not really designed to work with much stiffer after-market springs). Lastly if you read enough users' reports, you will see that a number of people who started out with lowering springs end up eventually moving to moving coils, negating the cost factor, actually nearly doubling it.

Advantages of moving coils are a more complete system with damper and springs designed together as a system; this is the way it should be. The height is adjustable for those afraid of scraping. The springs could be interchanged to stiffer springs allowing more flexibility for track junkies.

Disadvantages are cost, and while a majority of people have no problem for years, (very) few people have had electronic failure related to the PASM system. The way out of this is to replace with non PASM system, such as Bilstein B16 PSS10 (versus the PASM-compatible version, which is Bilstein B16 Damptronic). FWIW, despite of the potential problem, my vote is still with the Damptronic version because this retains best the features of the stock Turbo (Bilstein also makes the stock OEM suspension and uses Porsche's test driver as consultant, as close a relationship as you could wish for.). Mine has been flawless and perfect the 4 years that I've had it.

I think both lowering springs and coilovers are excellent solutions and both could TRANSFORM the stock car's soft & imprecise handling. The key is to buy from authorized dealer and at all cost YOU MUST USE AN EXPERIENCED TECH to work on your car. I cannot emphasize enough how important this is (this of course applies to all mods in your car, not just suspension, but it is PARTICULARLY important for suspension work). It's my humble opinion that an overwhelming percentage of suspension failure is related to improper installations, including aggressive lowering and *other* components of the suspension system (stiff frozen sway bar, aggressive lowering, wrong-side drop link, wrong washer, etc.).

 

Yes, I have the Damptronic. I put the swaybar on the cars after the the Dampronic; no difference in harshness.
Thanx for the rear drop link, is this item also working wiht aftermarkets swaybar or only with stock?

 

Thanx, but my shop told me that ride height has nothing to do with stiffness; nevertheless since my car is too low anyway for my garage, I will adjust the height hoping it will also affect stiffness. U never know until you try .

 

I couldn't agree more with CAn's last paragraph. I have also suggested to people here the most important component (particularly when it comes to suspension) is the shop.

You can't swing a cat without hitting a "porsche shop" around here. Unfortunately most of these shops are "installers" of parts and that's pretty much about it.

Most cars are slammed waaaay to low. might look cool but you won't be getting the desired result.

 

Your shop is wrong. If the car is too low, it will ride terribly, like I said, preload and ride height are NOT adjustable separately on the Bilsteins.

 

Cannga, ur info is as always invaluable. U mentioned Tarrett drop links to rid the "bouncy" with just springs. Could u elaborate?

Ken

 

Remember Ken...a sway bar is essentially a torsen spring that connects the left and right sides of the car. The drop links can add or remove some pre-tension on the bar to help curb the "bounciness" that some people feel.

And I agree, Cannga's input on this top is always unbiased and spot on.

 

Hampi, sorry I caused some confusion. If your car for whatever reason feels unusually harsh, I would NOT add any metallic-joint links like the Tarett drop link. Metallic links limit free play/slack in movement and impart precision, but increase harshness - law of physics.

Regarding the harshness, it's nearly impossible to correctly guess over the internet (!) but the first thing I would do is to establish a frame of reference. Is your car abnormally harsh, or is it working fine and is just harsh for *your taste*? See if you could drive another 911 with Bilstein, or let your professional tuner drive the car and give his opinion. Without knowing your definition of harsh, we could be chasing something that is "normal" to begin with.

Suspension tuning must be considered as a system, and therefore anything in the system could contribute to stiffness: tire wall's stiffness, tire pressure, suspension links (rubber vs. metallic), the sway bar, and finally the coilover, so that's why you might want to have an experienced tuner look into the issue. Some examples: Sway bars almost by definition increase stiffness if they are to work effectively (think about it, sway bar works by reducing the "independence" of our independent suspension) so I remain suspicious of the FVD sway bar. After-market sway bars in addition use Poly-urethane bushing, that must be lubricated once every 1-2 years at most, or the joint might freeze and cause stiffness. Good luck and hope this helps.

 

Hi Ken/Tom thanks for the kind words, I am merely repeating what I learned from others, and observations from my own experiments.

Regarding the bounciness, the Turbo has a lot of undesirable movements in the rear, particularly in curves and with acceleration out of curves, etc. (Turbo's rear end likes to mambo, both vertically and laterally. Just drive a GT3 back to back at limits vs. Turbo and you'll know what I mean.) The way to counter movements is to add links with metallic joints; these could be the drop links, the rear upper control links (dog bones), the rear lower control arm, etc. These links obviously serve different functions, but they will do one thing in common: limit slack/free play in joints. The rear lower control arm is particularly important, but I always mention as a start the Tarett drop links Web Site Here because they are cheap, totally reversible, and could be an easy DIY. (See Bob/bbywu's excellent DIY thread.)

In particular for those of us with Bilstein Damptronic, which because of its stiffer linear springs could feel "bouncy" to some (NOT all), the Tarett drop link does wonders to stabilize the rear. I know well because I have switched back and forth many times to compare. The trade-off is, of course, increased noise and harshness; ride vs. handling, nothing in suspension tuning comes free.