996 Carrera 4 suspension refresh options?

996 Carrera 4 suspension refresh options?

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Discussion

Dammit

3,790 posts

207 months

Wednesday 13th September 2017
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m444ttb said:
I'm looking to do a full refresh on my 996 C4's suspension come the summer (ties in well with the annual service and my bonus!) and wanted to get some opinions on here. I've already had Koni FSD dampers suggested from someone whose opinion I'd trust but that's only part of the package and I'm always open to alternative suggestions.

For some context I'm probably looking to replace everything that can wear out. The car is on 96k miles and I've seen nothing in the history to suggest any work has been carried out on the suspension. So it'll be dampers, springs, bushes, etc etc. All dependent on what the budget can take of course. I think my cap is probably £2k including fitting. Sadly that rules out XTC coilovers etc.

The car is unlikely to see much on track action so it's really road bias it needs. I wouldn't want to go any lower than say the M030 kit (think that's 10-20mm lower than standard?). I'm also keen to retain a nice NVH balance. I'm not sure if all of this simply adds up to 'replace with OE'.
It's not going to fit into your budget, but:


ATM

18,093 posts

218 months

Tuesday 19th September 2017
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Dammit said:
m444ttb said:
I'm looking to do a full refresh on my 996 C4's suspension come the summer (ties in well with the annual service and my bonus!) and wanted to get some opinions on here. I've already had Koni FSD dampers suggested from someone whose opinion I'd trust but that's only part of the package and I'm always open to alternative suggestions.

For some context I'm probably looking to replace everything that can wear out. The car is on 96k miles and I've seen nothing in the history to suggest any work has been carried out on the suspension. So it'll be dampers, springs, bushes, etc etc. All dependent on what the budget can take of course. I think my cap is probably £2k including fitting. Sadly that rules out XTC coilovers etc.

The car is unlikely to see much on track action so it's really road bias it needs. I wouldn't want to go any lower than say the M030 kit (think that's 10-20mm lower than standard?). I'm also keen to retain a nice NVH balance. I'm not sure if all of this simply adds up to 'replace with OE'.
It's not going to fit into your budget, but:

I see more love for Ohlins in the pork threads than anything else. Is that because they're great or is it brand snobbery or is it fashion or is it because we like Sweden? Genuine question. I mean you cant try before you buy right?

rival38

485 posts

144 months

Tuesday 19th September 2017
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Having been round the houses a few times, trying to decide what to replace the elderly shocks/springs on my 996.1 C2 with - I went with the Ohlins R&T for a variety of reasons. Not least, because CG said they were probably the optimum all round choice, and everything they have told me in the past has been 100% true! I decided the extra spend over the alternatives was `a wise investment` in that it would hopefully save any `if only I had` type thoughts. Perhaps my thinking is the combined result of marketing / forum chat / fashion...either way I am very happy with the result!

edc

9,231 posts

250 months

Tuesday 19th September 2017
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If you are less fussed about adjusting the ride height and fiddling with the damper settings but just want a good fixed height damper at a much lower cost then you can look at the Koni FSD. A bit like the Ohlins DFV these are sold along the lines of more firm and sporty when you want it and more supple and comfortable when you want it https://www.koni.com/Cars/Products/Performance/FSD...


skinny

5,269 posts

234 months

Tuesday 19th September 2017
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Koni FSD not available for C4 frown

mmcd87

626 posts

202 months

Wednesday 20th September 2017
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edc said:
If you are less fussed about adjusting the ride height and fiddling with the damper settings but just want a good fixed height damper at a much lower cost then you can look at the Koni FSD. A bit like the Ohlins DFV these are sold along the lines of more firm and sporty when you want it and more supple and comfortable when you want it https://www.koni.com/Cars/Products/Performance/FSD...
These seem spot on, the issue being from what I have read is that they are designed for standard ride height and not lowering springs / M030 springs. If they did a set of shortened ones they would be an excellent upgrade.

was8v

1,927 posts

194 months

Tuesday 26th September 2017
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mmcd87 said:
These seem spot on, the issue being from what I have read is that they are designed for standard ride height and not lowering springs / M030 springs. If they did a set of shortened ones they would be an excellent upgrade.
Kong do a kit that includes FSD dampers and lowering springs for the C2 at least not sure about c4

jkh112

21,889 posts

157 months

Tuesday 26th September 2017
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mmcd87 said:
These seem spot on, the issue being from what I have read is that they are designed for standard ride height and not lowering springs / M030 springs. If they did a set of shortened ones they would be an excellent upgrade.
The ride height with M030 springs is only 10mm lower than standard on the 996 so I would have thought that such a small difference would be okay with the same length dampers.

m444ttb

Original Poster:

3,160 posts

228 months

Friday 28th December 2018
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More than two years on and I have done absolutely nothing on the suspension. Ended up sorting the exhaust first as that was going to result in an MoT failure first, but I do need to get back on it with the suspension before it becomes an issues as there's a slight knock that becomes more noticeable as temperature increases.

I've decided to forget the budget (at least this side of Ex-TC suspension kinda money!) and try to find an optimal set up that will offer some longevity. On the spring/damper side I go round a loop of Ohlins R&T to Bilstein PSS10 to M030 and back to the Ohlins again. So I've kinda concluded I should probably bite the bullet there and go for the Ohlins and enjoy the better damping. The car won't be doing more than the odd track day so I gather a softer spring is available on request.

For the rest of the components I'm totally lost. I feel like I need to find a comprehensive list of components to begin with and go from there. I'm tempted by parts such as the Eibach rear arms but the overall cost of the refresh then begins to escalate rapidly and I need to work out whether I'd be gaining anything. Even using mostly standard parts to create a road car I could see it ending up at £5k plus fitting and set up, but it should at least be great to drive.

swtcar

12 posts

98 months

Friday 28th December 2018
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Hi Matt. It's been a long time! (Tommy from BMWOwner). Hope you're well and the Hartech engine is in fine fettle.

I'd suggest you try to get your car into Center Gravity for their discounted January Porsche clinic, should they have some spaces left. You'll get a meticulous assessment and understand afterwards exactly what needs replacing and what doesn't.

I went at the beginning of last year and only now am I refreshing the suspension. I went with Koni Special Active dampers, Eibach springs, new front top mounts, bearings, dust covers and bumpstops. All the suspension arms were in good condition and had plenty of life left in them. Ideally, I should have bought some adjustable toe arms for the rear but the jobs list is too big to be able to do everything!!

MrC986

3,481 posts

190 months

Saturday 19th January 2019
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swtcar said:
Hi Matt. It's been a long time! (Tommy from BMWOwner). Hope you're well and the Hartech engine is in fine fettle.

I'd suggest you try to get your car into Center Gravity for their discounted January Porsche clinic, should they have some spaces left. You'll get a meticulous assessment and understand afterwards exactly what needs replacing and what doesn't.

I went at the beginning of last year and only now am I refreshing the suspension. I went with Koni Special Active dampers, Eibach springs, new front top mounts, bearings, dust covers and bumpstops. All the suspension arms were in good condition and had plenty of life left in them. Ideally, I should have bought some adjustable toe arms for the rear but the jobs list is too big to be able to do everything!!
I was at Center of Gravity for one of their Porsche clinics today. It's a 2 hour slot they work to with an initial road test, shock absorber test, geo check and then full visual of the underside with a full report at the end & a discussion on possible options. My C4 runs an aerokit & I'm conscious of the ride height....l was slightly speechless when they said the ride height is marginally lower than an X74 kit. My shock absorbers were assessed as working satisfactorily for a 20 yr/80k mile car though they identified it had had a replacement NSF coffin arm previously (non OEM) & the recommendation was to replace the others due to the bushes failing (matching brand) plus top mounts & bump stops. The inspection was really thorough & also gave me some reassurance that it had been pretty well maintained before I bought it 16 months ago.

I now need to decide whether I go with B4 Bilstein shocks with H&R lowering springs (with no height adjustment) or whether I do a set of coil-overs (I'm not likely to track my car either) though have some flexibility on the ride height?

m444ttb

Original Poster:

3,160 posts

228 months

Thursday 8th August 2019
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Another update. I’ve ultimately decided to buy an M030 kit and keep it all OE. I bought it from Porscheshop for £1520, which is somewhat cheaper than everywhere else now. Prices have really escalated in the time I’ve owned the car. Neil Garner in Kemble will be doing the work so I’ll arrange the rest of the parts with them once the M030 kit arrives (I really want to check there isn’t something amiss given the price!). Broadly the plan is new arms on each corner, all the bushes, droplinks and top mounts.

fot0

101 posts

173 months

Thursday 8th August 2019
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I think you made the right choice with the M030 at that price point. I run a tired M030 on my C4, but that said fellow 718 passenger was surprised how the 20 year old still handles.

I bought PSS10 coil-overs last year and still waiting to be fitted myself. As already mentioned £2k is tight for a refresh - as new pair of top-mounts can cost ~£500.

On my 944T I went for OEM dampers with polybush, new tyres and 4 wheel alignment. Totally transformed the handling and well within my budget of £2k.

As a note, I tend to wait for big purchases with black Friday deals. More so with poor exchange rates.

Yourmumsmum

21 posts

55 months

Saturday 10th August 2019
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Strong vote for the M030 plus replacement of coffin arms, drop links etc with OEM parts from me. Did it on my ‘99 3.4 C2 5 years ago and transformed the car. Was going to go with Ohlins but the excellent Indy i use advised against- it was developed for the 997 turbo and needs careful choice of springs when used on another car.

I spent £4K plus but the result is a car that drives like new. Way more sensible than spending here and there as parts break - I guess suspension is only as good as its weakest part so do the lot and enjoy for 10 years rather than the triggers broom approach.

m444ttb

Original Poster:

3,160 posts

228 months

Sunday 11th August 2019
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I’m replacing everything that can wear pretty much. So should drive close to new. Looking forward to it... bar spending £4K or so! All part of using the car a lot more than I do now.

Engelberger

509 posts

66 months

Sunday 11th August 2019
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I have the original M030 kit with newish coffin arms done just before I bought the car.

Before you spend a silly amount on suspension or geo at CG (still not convinced - a laser geo is about £100) make sure you have replaced your engine mounts. Transforms the cars handling and will be the cheapest upgrade you will ever do. I don't understand anyone paying £5K for new suspension when they have that lump swinging around in the back on knackered old mounts.


ATM

18,093 posts

218 months

Monday 12th August 2019
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I have shiny engine mounts but not sure about the gearbox mount. Does this affect anything?

skinny

5,269 posts

234 months

Monday 12th August 2019
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Engelberger said:
Before you spend a silly amount on suspension or geo at CG (still not convinced - a laser geo is about £100) ...
A geo at CG isn't much more money, but what they offer over any generic alignment place is worth a huge amount IMO. CG will also perform objective test drives and continue to adjust until you are happy with the settings.
Porsche factory settings are quite wide and don't take into account anything to do with your driving style or your tyres. I would suggest if all you're doing is pulling the settings into the green for a standard geo, you aren't getting the best out of your car.

ATM

18,093 posts

218 months

Monday 12th August 2019
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I took my 996 to a Porsche Specialist. I asked them to check the alignment. They said they could not adjust the car as it was way too low. I took the car to a generic car alignment place with a good reputation. They had it aligned within about 30 minutes for £59 and it was great. I had some numbers all of the place prior but they got them all green within GT3 spec and the ones which remained red were matching left to right. When I paid my Bill I noticed a picture of a 996 race car on their ramps with full livery.

skinny

5,269 posts

234 months

Monday 12th August 2019
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anonymous said:
[redacted]
Well the range itself may be limited but the impact that differences within that range can haslve on your handling can be quite significant. I don't think for a second that alignment and geometry is a black art but the guys at CG have a lot of experience with porsche and can interpret how you want the car to behave into an alignment spec. They will adjust the car until you get the handling you want to achieve. That's why they are more expensive. But in my view, worth it. I don't think a normal alignment shop would offer the same. That said, i don't believe CG are the only place with the knowledge and experience, there are other specialists, but i don't expect much difference in price for a similar service.

My experience is that i had my car aligned following replacement of several suspension components and the handling was just not quite as i wanted it, a little unsure on entry with the rear taking a bit of time to settle down in hard cornering, and not quite the grip level i was expecting - even tho the alignment looked reasonable on paper, fairly safe settings, all in the green and very close left to right across the board. CG tweaked the settings and it didn't take much, from memory less than a quarter of a degree of camber front and rear to improve the footprint under lateral load and stop the tyre rolling, and a few minutes less of toe in especially at the rear to allow them to react quicker. Very small changes in number, (and ended up going slightly outside porsche recommended spec on camber) but a really noticeable change in handling. Even for my softly sprung standard C4, the handling is now exactly as i hoped it could be, it's perfection for me. A lot of that will be the stability i get from the new suspension components but i know for a fact now that these cars are sensitive to alignment.