Let's Talk Suspension Stuff

[Bulldog9]

I'm trying to keep most of my build actions in my "I am a Wet Head" thread, but will break out for specific questions and discussion, especially if can help others.

At some point, I will replace and refresh my suspension bits. As I see it I have a few options. Would love to get some collective wisdom on the benifits and drawbacks of each, as well as see what others have done.

1. Go with all OEM or Porsche Struts and Shocks. This should be straight forward, but can be confusing with all the options. I am tracking the M030, but I also see options for with or without Sport Suspension. Is the Sport Suspension the same as the M030? Or is that different?

2. Koni Cut a Strut and Koni Sport Rear Shocks - This looks pretty straight forward, simple and cost effective.

3. Bilstein Cut a Strut that is more involved and requires welding a threaded sleeve to the cut strut.

4. SPAX Coil Over - Looks interesting, but is farthest from OEM.

I want to stay as close to OEM as possible and am leaning towards Stock or Koni, but not if there are superior options.

There are also several Pricey options on Lindsey and Paragon, but seem to be pointed towards racing. I am looking for stock/street/pleasure, so not considering these.

[djnolan]

I read there are differences between the rebound damping between Koni and Billstein, I can't remember which one may have it or not.

[walfreyydo]

1) going with OEM is going to cost you substantially more than Koni/Bilstein as well as not giving you the performance and adjustability of those shocks/struts - not recommended

2 and 3) Koni's/Bilstein IMO are a better option, are suitable for OEM+ applications and rebound adjustable, but without coilovers on the front you will have zero height adjustability (important for corner balancing and tweaking the car's handling by swapping out spring rates)

If you already have M030 thats going to be the way to go, but as I understand M030 only entails bigger brakes and bigger sway bars - possibly a front coilover as well but I cant recall.

What I did with my car (also a S2) was move to a full coil over setup, with a torsion bar delete, Koni yellows on all four corners and full poly bushings (Powerflex). The car is 75% autox/hpde and 25% street. I understand that this may not be the right combo for you, since you really want to stay closer to OEM type setup. I went with the Paragon Coilover kit for TB-delete (which is very similar to the Ground Control kit as well).

I think the best middle ground would be to go with Koni or Bilsteins, consider front coilovers (maybe a #250 spring) - or at least stiffer front springs, and go with a slightly thicker torsion in the rear (maybe a 28-30mm bar or so). That will give you adjustability for height, while still retaining a close to OEM system.

If you do not go with the front coilover, you are going to be stuck at OEM ride height and a large amount of body roll and less responsive handling if you keep the stock springs (regardless of sway bar) but it really depends on what you personally want. Also do not neglect the benefit that updated/upgraded bushings bring (even rubber OEM), as well as something like the urethane trans mount diy (a cheap and fantastic upgrade) - your axles will thank you.

I know I am pushing the front coilover thing pretty hard but the height and spring rate adjustability benefits they bring are far and away worth it for the track (and street), especially since you are already needing to modify the front strut for Koni/Bilsteins - its just a matter of adding the sleeve at that point. Unless this is some sort of collector car (but I might question why you would want to track it if thats the case, since thats a good deal of abuse).

Also note that with the rear coilovers, there are mainly two systems: retain the torsions or remove the torsions. Retaining the torsions will mean you cannot lower the rear unless you re-index the torsion bars and mainly the purpose for this is to have spring rate adjustability. If you remove the torsions you MUST make sure you have a coilover system designed for this purpose - spherical bushings on the upper and lower shock mount as well as a reinforced lower shock bolt (that mounts to the control arm). The giveaway is when looking at the rear shocks, do they have that solid spherical bushing or are they rubber? If they are rubber they are meant to keep the torsion.

I think the best option as close to OEM as possible is a front coilover with a rear torsion. If I recall, some 944s actually came with front coilovers, so going that route could actually still be classified as OEM - but make sure you match whatever front spring you go with to a rear torsion of appropriate/matching wheel rate.

Hopefully that makes sense.

[944 S2]

I did the OEM option. I shopped around and found a good deal on the struts with an online Porsche dealer. I wanna say around $375 each. I didn’t want to mess with cutting and welding and don’t own a welder. It’s obviously a lot easier too. I think it’s likely that the insert is a heavy overall option also. My car is in pretty good shape and I’d like it keep it stock as these cars are getting rare. Yes I’m interested in resale valve! The rear shock were not available so I went with the Bilstein as I understand them to be close to OEM in performance. I wasn’t looking to race or change my suspension ride.

[924RACR]

I'm now 20 years or so on my Bilstein HDs... different product as it's the early chassis, but the durability has been amazing. Also use them (in full race spec, not the HDs) on our 924 racecar, and just an excellent, incredibly durable product.

I haven't had the same good results with Konis, race or street trim.

But I wouldn't see any great motivation to just stick with stock, whether or not you do a coilover upgrade...

[Bulldog9]

Originally Posted by walfreyydo

..................

I think the best option as close to OEM as possible is a front coilover with a rear torsion. If I recall, some 944s actually came with front coilovers, so going that route could actually still be classified as OEM - but make sure you match whatever front spring you go with to a rear torsion of appropriate/matching wheel rate.

Hopefully that makes sense.

Great Info, thanks. I am leaning towards front Koni Coil Overs or cut a strut and matching Koni rear shocks. I don't want to eliminate the rear torsion bars or load the rear shock top/mount area by putting coil overs there. Sport Shocks will work well I think.

Will also swap out bushings, etc.

[Bulldog9]

Originally Posted by 944 S2

I did the OEM option. I shopped around and found a good deal on the struts with an online Porsche dealer. I wanna say around $375 each. I didn’t want to mess with cutting and welding and don’t own a welder. It’s obviously a lot easier too. I think it’s likely that the insert is a heavy overall option also. My car is in pretty good shape and I’d like it keep it stock as these cars are getting rare. Yes I’m interested in resale valve! The rear shock were not available so I went with the Bilstein as I understand them to be close to OEM in performance. I wasn’t looking to race or change my suspension ride.

Originally Posted by 924RACR

I'm now 20 years or so on my Bilstein HDs... different product as it's the early chassis, but the durability has been amazing. Also use them (in full race spec, not the HDs) on our 924 racecar, and just an excellent, incredibly durable product.

I haven't had the same good results with Konis, race or street trim.

But I wouldn't see any great motivation to just stick with stock, whether or not you do a coilover upgrade...

I have had great experience with Bilstein, none with Koni, but my impression is they are not as durable as the Bilstein.

I'm trying to stay as close to stock and OEM as possible. I see Paragon not only sells the kits, but sells the Koni Kits in pre-built units with core charge.

How would new OEM/Sachs compare to the Koni's or Bilstein? I am not going to track or auto cross, just looking for a great handling stock ride.

[walfreyydo]

Originally Posted by Bulldog9

Great Info, thanks. I am leaning towards front Koni Coil Overs or cut a strut and matching Koni rear shocks. I don't want to eliminate the rear torsion bars or load the rear shock top/mount area by putting coil overs there. Sport Shocks will work well I think.

Will also swap out bushings, etc.

I think you will be happy with that route, but you should upgrade the rear torsion so the spring rates match the front (if you are going stiffer springs in the front). Also keep in mind that lowering the rear will require removal and re-indexing the torsion bars anyways, so this would be a good time to upgrade them as well.

There is adjustment in the spring plate but its very minimal and youll still potentially have the issue with mismatched spring rates if you dont upgrade the torsion, but thats ultimately up to you and what you are comfortable with.

[Bulldog9]

Decision Made. I'm going with the Prebuilt Koni front struts and matching Koni Shocks in the rear. Also doing new bushings and caster blocks. Also considering new Sway bar bushings front and rear.

[Stoneguy]

I also did some suspension work on my 86 na a couple of years ago. Like you, I didn't want to stray too far from stock. What I ended up with was all new Powerflex bushings front and rear. ball joint rebuild , rack rebuild. tie rods, caster blocks and "Koni cut a strut" inserts. On the rear I chose "Ground Control" Eibach coils over Konis without torsion bar delete. I kept the stock ride height. I'm happy with the results.

[bgarner]

I went with Konis this past year when I did my suspension rebuild. They made a crazy difference in the handling. I'm sure you'll be happy with your decision!