997 gt3 suspension

[cook3471]

What's the thoughts on changing the suspension on a gt3 ? From my older days of motor bikes ohlins suspension has always been the dogs I've got front and rear on a gsxr and rm and looking at what's available for gt3 there's lots to choose from so let's have some thoughts before I buy road use only not interested use

[cook3471]

For a 997 gt3 gen 1

[noneedtolift]

Was faced with the same predicament on my 997.1 RS two years ago - then drove a car on KWs and have never looked back since. Is it faster against the clock - no it is not. Does it drive nicer and is it more confidence inspiring - yes it is. (I am referring to track driving)

If you go for it, make sure you go for a proper piece of kit and have it set up by an expert.

[Cunno]

If your going for road use only I'd look at these:

http://www.exe-tc.co.uk/porsche-suspension

CH installed a set of single adjustment on his old gen 1, there is a mag write up on it somewhere.

[Slippydiff]

here : http://www.exe-tc.co.uk/images/porsche/gtporsche_a...


I run a set of custom built and valved Ohlins 3 way adjustables on my Mk1 996 GT3, they're superb (and I hope I'll be forgiven for saying they're a few rungs up the ladder in comparison with KW's)

But for a road going 997 GT3 ? Personally I don't think a standard 997 GT3 is exactly hamstrung by its suspension on the road (on the track yes, but not on the road)

At no point during the ownership of either of my 997 GT3's did I think "Some decent dampers would make the car more planted and quicker from A to B". If ever there was a case of diminishing returns, this I suspect would be it.

I've no doubt the fitment of some KW's, Motons, JRZ's, Ohlins or ExeTC's would improve the cars composure (and no doubt compliance) but the 997 GT3 front end is a lot better resolved out of the box (for road use) when compared to the 996 versions.

If you haven't already done so, make sure all the suspension is in rude health and get the corner weights, ride heights and geo set up correctly (and accurately). Google search the usual suspects to establish those best equipped to carry this out.

[fioran0]

For road use (and the odd track day) Bilstein PSS10 is a solid upgrade that everyone ignores bizarrely. Its my favourite street use upgrade for the GT3. You get all the benefits of a better shock without just screwing up the extra compliance that the 997 GT3 offers.
Spending more is a waste if you aren't going to track hard.
I am not a fan at all of KW.

[Steve Rance]

Agreed. For road I'd go that way although the standard active set up is very good on the road. Passive definitely better on the track but I'd question the need to go that way for road only

[fioran0]

Bilstein offer both PASM and non PASM options so it can be kept if you have it on.

[noneedtolift]

Hi Fioran,

the reason I went for a KW is that I drove it and liked it - paired with the fact that I can get excellent track side support from there here in Germany, and funnily enough next to none from Bilstein. Very interested to hear from a knowlegable guy like yourself why you don't like them! Not a KW "fanboy" btw and have never driven a Bilstein car as, like you say, there don't seem many cars around running them.

[Harris_I]

This may not be relevant for a 997, but I found the 996 on PSS9 to be no better than OEM, and the Manthey KWs to be excellent for the price (coupled with solid bushes).

[keep it lit]

noneedtolift said:

Hi Fioran,

the reason I went for a KW is that I drove it and liked it - paired with the fact that I can get excellent track side support from there here in Germany, and funnily enough next to none from Bilstein. Very interested to hear from a knowlegable guy like yourself why you don't like them! Not a KW "fanboy" btw and have never driven a Bilstein car as, like you say, there don't seem many cars around running them.

Hi,

Which KW's do you have fitted, the street V3/Clubsports kit or the Competion equipment ?

[adamb]

Harris_I said:

This may not be relevant for a 997, but I found the 996 on PSS9 to be no better than OEM, and the Manthey KWs to be excellent for the price (coupled with solid bushes).

I'm somewhat out of the loop on this stuff having sold mine 2 years ago, but I seem to remember that Manthey charged a hell of a lot more than others for KW equipment which they seem to brand as their own?

[fioran0]

The OP was wanting shocks for road use only, and I presumed simply asking if there was anything out there by way of a better shock that he could be running for his car instead of the factory units given his experience with ohlins on his bikes.

Given the compliance of the 997 GT3 on the road is what many enjoy over the 996 GT3 then putting something on that doesn't just destroy this is important.
The Bilstein PSS10 is an excellent shock upgrade. You gain from having a better quality shock over the stock unit but avoid getting into the track use compromise trade off sweepstakes. Ride is fundamentally unchanged but now takes place on a better quality shock.
As Steve said, PASM can be advantageous to keep on (I personally think its better to bin it even on the road and put on something passive that when set is comparable to PASM in regular mode but this is definitely a case of each to their own on this one.) Bilstein offer shocks that enable this to be kept too.

In these circumstances I really like the Bilstein shocks (on all 996 and 997) over the factory units and above everything else. Of course if you start tracking with any fervor you will find the car wallows much too much just as you will in the same cars with the regular shocks. You aren't running upped spring rates and the factory rates are simply not enough in these conditions. It is possible to revalve the Bilsteins of course to use harder springs but there are better options to use instead when this is your goal.

So in short; looking for a car that will respond on track markedly better than OEM and you are willing to compromise your road manners then PSS10 (or PSS9) is not the answer. Looking for a way to improve the car that the factory delivered for road use (and help if you do go near a track once in a while), PSS10 is definitely the way to go IMHO.

So to KW. If they are working for you then thats all that matters at the end of the day. If you are getting positive support when you need it then thats a massive plus. It matters when you are racing a car thats for sure.
I dislike them for reasons of design, quality and philosophy from a technical perspective. I also dislike how they feel from the drivers seat (which isn't surprising given my tech issues).

[cook3471]

Thanks for all the info and replies iam taking it that like most things you cannot have the best of both worlds ! You either go for road use which I do or more track geared which is then not as good on the road? My car is a 2007 (57) with 25 k on so I suppose it all will be getting tired if not through miles age alone. Just out of intrest if iam doing this is there anything else I should be looking at or changing before it was geo,d up I'd would try and do it all in one go I hate doing things twice

[TB993tt]

I think retaining the PASM and using the Bilstein B16s is the way to go, a better shock but retains the variable damping which Porsche developed with Bilstein (this is what I have on my 7GT2 together with solid links) There is also an aftermarket PASM computer available which claims to work much faster and "better" than the factory system at controlling the valving - I have one on order so can't comment on it yet.

If you are ditching the PASM I think the new Ohlins kit in the link below looks a great bet, Ohlins at a Bilstein price.

http://www.fvd.de/de/en/Porsche-0/997_GT3-141-34/-...

[Slippydiff]

cook3471 said:

Thanks for all the info and replies iam taking it that like most things you cannot have the best of both worlds ! You either go for road use which I do or more track geared which is then not as good on the road? My car is a 2007 (57) with 25 k on so I suppose it all will be getting tired if not through miles age alone. Just out of intrest if iam doing this is there anything else I should be looking at or changing before it was geo,d up I'd would try and do it all in one go I hate doing things twice

On the contrary, I believe you can have the best of both worlds, but it will cost you. The ExeTC dampers are peerless, If I were to do another 996 Mk1 GT3 road "project", they'd be on my wish list.

But I do have to agree with Neil on the Bilstein PSS9/10 set up, they are often overlooked and KW seems to be the default go to for 996 GT3 owners, I suspect a large part of that is down to a certain UK KW dealer telling every 996 GT3 owner that "It's not worth trying to adjust the ride heights and set the corner weights on your car because the spring seats will be seized" they go on to say that "for not much more than the cost of a new set of OE Bilsteins and springs, you can have a set of spangly and "better" KW V3's fitted"
Many fell for it, and hence there are plenty of 996 GT3's fitted with the KW's.

Ruf work/ed closely with Bilstein, some years ago I bought a Ruf/Bilstein PSS9 equipped 996 Turbo. Compared with the standard wallowy barge suspension, the Ruf kit was a huge transformation, yet still retained everyday civility and compliance.It made the Turbo and far more engaging and safer car to drive.

Furthermore, a fellow PH contributor decided to build his own Bilstein kit to use on his 996 GT2 a couple of years ago, he bought a set of PSS 9/10 dampers from bilstein and chose his own spring rates before purchasing them off Eibach. The results were excellent, I don't think I've driven a more usable, biddable, compliant 996 GT2 on the road.

Back to back at Bruntingthorpe, my Ohlins suspended 996 GT3 felt more in it's element, but part of that would have been down to the Cup tyres rather than the MPS2's the GT2 was running.

[fioran0]

• soapbox time* feel free to skip!!

I have long ranted, to anyone who is unfortunate to stand still long enough, that I suspect that an average track day car is more likely slower because of adjustable suspension than is faster because of them. Adjustable shocks are wonderful things BUT they need proper setup to work most effectively.

Given the time and effort required to set adjustable shocks up properly (except MrD who can just dial them in instantly of course for any condition); running lap after lap doing small adjustments of one parameter then the next while taking notes to get them to an appropriate baseline (and being able to feel/feedback on changes) is something few people are doing. Putting a pro driver in your car for the day to set it up is a very good shortcut but I am not seeing the average car having this done either. (Steve, I am about to set myself up as your pimp)

The result is that most are running on a shock that isn't operating at its best. I have lost count of the number of GT3s in particular I have driven on fantastic suspension setups where its just all over the place and I have plenty fingers left for counting the ones where they were adjusted properly.
The water is made cloudy by the car now running on harder springs which imparts an immediate improvement on track over the wallowing that occurred on factory rates. The package is thus felt to be wonderful (since separation of spring and shock doesn't take place in the mind) when the reality is that the same uprated spring paired to a non adjustable shock that was matched to that spring rate (out of the box) would be both better and faster (than the maladjusted 3 way)

The Exe-tc thing is an interesting one. They aren't adding tons of travel WRC style to the GT3 (which is the real solution killer) and there are limits with things new that can be done with a damper and a spring. It seems like the progressive spring rate coupled to giving good set up support on a quality damper are their ingredients. There are plenty quality dampers about so that leaves spring and setup information. See above for setup and a window in to why it matters. That they know their package on various cars and can tell you exactly what its baseline setting needs to be is a big help to owners. As a side bar this is also the reason Moton were great when they first came out. They offered good quality components of course but they had tested their package properly and could tell you out of the box where your baseline would be on a GT3.

The use of a progressive (and a soft) spring is counter to the way most aftermarket stuff operates. I presume that the thinking is all about wheel control. Keep the wheel on the ground over bumps and the car feels better and can be driven faster.

What may be interesting for you to hear is that this approach to wheel control is also used in high level sports car racing but its done without using a progressive spring (for reasons you can all google). Instead linear springs are stacked giving wheel control over bumps or in slow sections (depending on how you set up and what your goal is) but leaving everything else to happen on the normally linear hard rate. The obvious hurdle to applying this setup is that rate and length are critical and car specific. Change pretty much anything and you need to calculate everything out again and replace at least one set of springs. It makes it impossible to sell as an off the shelf package.
The 997.2 RS (lauded for the way it eats the road up) is using stacked springs at the rear. It lacks the precision of the racing set ups but its on there and the main reason it feels so different across tarmac than previous cars.

As a final point, not every suspension setup looks enough at what happens when the wheel is moving in the negative direction. Failure to do so results in some weird features and a car that rather suddenly feels like its falling over under certain conditions.

Edited by fioran0 on Wednesday 2nd July 12:29

[F40GT346]

I also have a 997.1 GT3 that I use for road driving and track days. I personally like the standard set-up with the option of firming the dampers via the button on the dash for dry track days, and normal for road or wet track days. On bumpy british roads it often feels too stiff and on track it feels like it could use slighly stiffer springs, but overall I think its a really good "compromise" set-up to cover road and track use. The geo set-up seems to have a bigger influence on track handling. If I had a track only GT3 I would consider changing the suspension - but then I'd probably look for an ex-cup car instead.

[mrdemon]

2 springs were on the Audi TTRS mag ride upgrades :-) nothing new
gave better on road ride comfort and better on track performance, win win.

strange we don't see it very often.


1 or 2 way shocks are not hard to set up.
takes a track day then you have a starting point to fine tune from there.

full 3 ways are tricky.

but most shocks are 1 way any way which I would avoid, why have adjustable shocks which are not adjustable for bump and rebound separate !

great way to learn about car control and how a car handles for a novice like me.

Edited by mrdemon on Wednesday 2nd July 13:59

[fioran0]

Those springs are not working in the same way at all. That's just a regular stack of springs.

Edited by fioran0 on Wednesday 2nd July 14:19