993 Faq Frequently Asked Questions about the Porsche 1994-1997 993

04/11/2003

H&R Coilover systems

Filed under: Suspension — admin @ 4:45 pm

There are two coilover systems which we will cover here.

1. The Normal H&R coilover:
Spring rates: 295 front, 360 rear
This system will transform your 993 to a fine handling machine that it deserves to be. I have personally used this system on my cabrio and I have tracked it regurarly. The system paired with either RS or M030 sways can lower the car to RS specs and be aligned, corner balanced properly to tailor your needs.

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Suspension Upgrades

Filed under: Suspension — admin @ 3:39 pm

This issue I think is probably the most popular upgrade and the best money that one can spend on a 993.
There are two facts when it comes to the stock 993 suspension.

1. The shocks are not of good quality and they wear very quickly. What this does is that when you drive at anything over 7/10’s you feel the suspension not controlling the car very well. Especially the back end where the most weight lies.
There have been many descriptions of the feelings that one get. Double sets, wiggling, loading and unloading of the suspension, wobbling, all are common descriptions describing unsettling feelings that get communicated by the suspension to the driver. So while the fan factor is certainly low the car does not inspire any confidence to be pushed.

2. The stock suspension is inadequate for the track and while one can track the car in stock form, at the end of the day they will move to a coilover system which is a quantum leap in performance. Also the US ride height which was mandated by the government, is visually bad and has been described as 4×4, track height etc. The stock shocks do not provide height adjustments so there is not much you can do.

On separate chapters we will analyze each suspension coilover system available separately and you can be the judge according to your budget and driving preferences. You will see that we will stick with coilover systems ONLY because we do not believe that adding just springs to the stock socks will have any profound impact in handling besides a visual improvement. The common opinion is that just springs are not matching the socks therefore they may create worse handling accompanied with a rough ride.

12/15/2002

Strut tower brace

Filed under: Suspension — Jeff 993TT @ 5:13 pm

All strut braces offered all use the same basic design: to tie together the shock towers during corerning.

The several options include:
a) Factory brace in aluminum
b) Factory brace in carbon fiber ( as on the Turbo S )
c) Brey Krause brace in aluminum
d) Brey Krause brace in carbon fiber
e) Other aftermarket bars, ie Rennline, etc.

Given this, and comparable cost of the different options, many elect to stick with the factory offering.

How to install

Pull the carpeting in the truck forward by unsnapping the three retaining snaps, to expose the gas tank and strut towers.

Remove the forward two nuts on each strut tower. You won’t affect the front end’s alignment by doing this.

Slid the bracket onto the exposed strut bolts on each end, and retighten the nuts to NO MORE than 24 lb-ft. More than one person has stripped these threads by overtightening.

Install the rod onto the two brackets. Rotate the bar until there is no slop in the brace and brackets and rotate just 1/2 turn more to pre-load the brace against the strut towers, pushing the strut towers outward. Now use the hex nuts to lock the brace in position.

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Wheel alignment

Filed under: Suspension — Jeff 993TT @ 4:58 pm

When do I get an alignment?
Any time your car does not go straight down the road when the steering wheel is pointed straight. Note that 2 lane roads are generally “crowned” and this will induce your car to head off the road to the right (or left if you drive on that side). Best to make this test on a multilane freeway with a good surface.

Any tiime you change your shocks or ride height.

If you get uneven tire wear. Too much negative camber will result in the inside edge of the tires wearing out much faster than the outside edge.

You must *always* do a four-wheel alignment on a 993. Changes made at one end of the car alone will adversely affect the other axle.

Kinematic toe: an attribute of the 993 rear suspension which helps to stabilize the tail-happy tendency of a rear engine car. The toe value changes dynamically while driving, depending upon the forces acting on the car. This is a critical value, and the vast majority of garden-variety garages will have never heard of this parameter, let alone have the tools or knowledge to address it. Kinematic toe is your litmus test to identify these shops and take your alignment work elsewhere. The factory tools to set the kinematic toe are quite expensive; unless the garage does a lot of 993 alignments, they will *not* have the tools in-house.

After your alignment you should always get a printout of what the actual alignment settings are for your records. The Porsche recommended settings are:

For USA For RoW Sport RS
Front Rear Front Rear Front Rear
Toe +5′ +10′ +5′ +10′ +5′ +15′
Camber -0.33 -1.17 -0.33 -1.17 -1.0 -1.33
Caster 5

993 Suspension FAQ

Filed under: Suspension — Jeff 993TT @ 4:34 pm

This page contains information about common suspension changes and their effects.

993 suspension FAQs

Here is some generic suspension information:
The Car Suspension Bible

What are the differences between USA and ROW suspension?

Filed under: Suspension — Jeff 993TT @ 4:32 pm

The US agricartural ride height for most belongs to a 4X4 not the 993. Our ROW brothers and sisters do not really have to deal with this. In order to lower the ride height read below.

Replace the springs to alter the ride height. Cutting springs is bad — you change the spring rate and it’ll no longer match the shock valving. It’s also very difficult to remove the right amount to achieve the exact ride height you want.

All alternative springs will result in a lower ride height than the US-spec factory suspension.

Porsche RoW (rest-of-world, i.e., not US-spec) M030 (sport suspension): 1-1.25″ lower
Eibach: 1-1.5″ lower
Bilstein PSS9: this is a kit which includes 9-way adjustable shocks, threaded strut bodies, and dual coilover springs. The threaded strut housing allows a great deal of adjustment to the ride height {someone insert actual range here?}
H&R: {???}

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How long do the stock shocks last?

Filed under: Suspension — Jeff 993TT @ 4:31 pm

The stock suspension does not last long, some have reported 15-20K miles with shot shocks.

I did about 15 track weekends (and about 25k miles overall) with my ROW M030 shocks over the course of 2.5 years. They definitely failed at the end of that period. The failure was, frankly, unnoticeable on the street. If you don’t track your car, you may be perfectly happy w. those (Monroe) shocks for an extended period. On the track, the car had become quite scary to drive at the limit. You only have so much time to load up the suspension when committing into a corner, and the worn shocks meant it took much longer to transfer the car’s weight onto the outside wheels.

The current consensus is to run, don’t walk, from Monroe shocks and use Bilstein shocks. They are considered to have substantially longer life {80-100k miles??}, and can be send back to Bilstein to be rebuilt for $50/shock when they *do* wear out.

Note also that different third party suspension vendors will often use Bilstein shocks, simply relabeled and custom-valved per the vendor’s specifications. So you shouldn’t feel amiss for not buying a Bilstein-branded suspension.

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