The 993 suspension was claimed to be 80% new compared to the 964. The Porsche engineers certainly did a good job of hiding all those new part but if you go down on your knees and look under that fat backside of your 993 then you will see an organized mess of aluminum rods, frames and other interesting stuff.All these parts together form the new multilink suspension that killed the scary oversteer issues. (Well not quite but it did help).
Compared to the newer watercooled 911's with the endless abbreviations like PTV,PASM,PDCC,PCCB etc. the 993's suspension options were clean and simple: standard,sport or lowered. Porsche themselves described them as: "The sportsuspension improves handling with a minimal sacrifice on comfort, a small price to pay for performance". ( The real price was about 1300 Deutschmark by the way).
If the first owner was willing to pay that price can be found on the option sticker in the maintenance booklet or on the sticker under the front bonnet.
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| Option code sticker of 993 with 030 option ( sport suspension ) |
FACTORY SUSPENSION OPTIONS ( ROW models, USA models differences in brackets)
Standard suspension: no optioncode on sticker (will show up on VIN check as M029 or M032 touring suspension)
- Standard Boge or Monroe shocks
- Swaybar front 20mm rear 18 mm [ USA rear 17mm ]
- Standard springset M029/M032
- Standard Boge/Monroe shocks
- Lowering Springset M033
- Swaybar front 20mm rear 18 mm
- Lowering 10mm front, 20mm rear
Sport Chassis: optioncode 030
- Stiffer Boge or Monroe shocks
- Stiffer lowering springs M030 ( 14% stiffer front / 30% rear) [ USA same spring rate as M033]
- Swaybars 22 mm front, 20 mm rear
- Lowering 10mm front, 20mm rear
Exceptions:
Porsche turbo and 4S : Factory option M030
De Porsche 993 S (2S): Factory option M033, optional M030
Porsche 993 RS: Factory Bilstein adjustable suspension Lowered 30mm front, 40 mm rear compared to Standard Carrera 2. Swaybars: 23mm front, 20mm rear.
UPGRADING YOUR 993 SUSPENSION
Lowering your Porsche 993, (or any vehicle).
Contrary to what a lot of people think, lowering is initially achieved by using lowering (shorter) springs and not by a shorter shock absorber. The adjustment on the shock collar is only to be used for minor height adjustment and corner balancing. All Bilstein sport shocks have adjustment collars on front and rear. Koni FSD's only on the front shocks.
Since the KONI shocks are not adjustable I have asked the KONI technical department their opinion on using lowering springs in combination with FSD shocks. They advise against using springs that lower the car more than 30mm as the FSD system may not work properly and roadhandling may suffer. Basically that means that any Porsche spring is ok, the H&R springs are oustide of the design parameters of the Koni FSD shocks.
ROW and USA model 993's
US Porsche 993 models had to conform to US government ride height legislation ( amongst other things like emmission laws ). Due to these laws US models have a ride height that is higher than ROW ( Rest of World ) 993 models ( 20mm front, 10mm rear). If you want a Euro like ride height you will need Euro-spec springs. A USA sport suspension is just stiffer not lower!
Lowering = less comfort?Not necessarily true. In fact, a lowered 993 with new shocks and matching springs will be more comfortable than one that is still on factory suspension. The original shocks are a 20 year old design and shocks have improved a lot. If you want total control over the comfort level and be able to change it on the spot ( ie for trackdays or DE events) buy the Bilstein PSS10 and never look back....
Springs are just springs
As described above, the spring will determine ride height but also the comfort level. A higher spring rate means a stiffer and thus less comfortable suspension. Original Porsche springs will have a colormark on them to identify the spring rate. Aircon, tiptronic, targa, these options increased the weight of the car and asked for different spring ratings.
A good alternative to Porsche springs are the german made H&R or Eibach Springs. I would use Porsche springs unless you want to lower to a RS like ride height.
SUSPENSION OPTIONS
| Lowers your car: | ||||||
| I want: | Shocks | Springs | ROW | USA | Comfort | |
| Just new shocks | Bilstein B6 HD / Koni FSD | standard | n/a | n/a | 10 | |
| Euro Sport ride height ( ROW sport) | Bilstein B6 HD / Koni FSD | M033 | F-10/R-20 | F-30 / R-30 | 9 | |
| Bilstein B6 HD / Koni FSD | M030 | F-10/R-20 | F-30 / R-30 | 8 | ||
| RS ride height + 10mm | Bilstein B6 HD xtr thread | M030 | F-20/R-30 | F-40 / R-40 | 8 | |
| RS ride height or lower | Bilstein B6 HD xtr thread | H&R | F-30/R-40 | F-50 / R-50 | 7 | |
| The holy grail for my 993 | Bilstein B16 PSS 10 | n/a | up to -60mm | up to-70mm | 2-10 | |
Notes for this table:
- Bilstein B6 HD xtr thread are special made B6 shocks with extra thread on the front shocks to allow the use of shorter springs.
- Comfort rating is just an indication compared to baseline standard suspension
- Bilstein B16 PSS10 is a fully adjustable coilover set. The holy grail for the 993 with adjustable rebound and compression.
General disclaimer: all shown data is based on own research on actual springs and shocks and various publications like the Essential Companion, Porsche training manuals and factory workshop manuals. I do not claim to be 100% correct as even Porsche's own manuals contradict on many data.
Copyright Guido Strobl 2012. Distribution allowed if website is mentioned: http://www.flugplatz911.com