NineMeister

There is a difference between the left & right pressings for sure. However, since the window aperture, B-post and rear light frame dictate the position of the quarter panel on the shell, unless the car is bent the wheelarch just ends up where it ends and that's it.

Shamus964

Good stuff - thanks for the additional info - cheers!

Looks like I need to do some more measuring using the chassis and maybe some adjusting I'm about where you are in the front at an avg of 32.25 but I'm at 31cm in the rear which may be a bit low and could explain the feeling of riding the stops sometimes. Sure love the look though!

boxsey911

I'm actually not surprised by that because if you look at the side on pic of mine below, it's got quite a bit more rake (nose down) than yours.

NineMeister

Having a 964 too low at the back end reduces weight transfer onto the outer wheel and makes the car very nervous over undulations or bumpy surfaces. In simple terms, with the slight nose down attitude (like Steve's) you get more weight transfer under roll which plants the outer tyre more firmly onto the track.

Jimjacqmx5

One thing I've noted is my front springs are comparable to RS set up and KW set up but rear is about 60% as stiff. This would explain the feeling I've had and difficulty with turn in and eliminating understeer even when trail braking to the apex.
I have also noted some of the very quickest 964's here are running the same koni's as I am. So I'm thinking, stiffer rear springs and rebuild koni's ($400) vs $3K for KW. They will valve to suit.
I am hesitant to go for stiff bushes all around as it will have no compliance and buck on the street as well as transmitting a lot of noise. That said, I looked at Powerflex bush kit. Has any one used these? Comments?

Cheers again all for your input...

NineMeister

The Powerflex bush kits are good, we use them all the time, however do you mind me asking what was the point of the original question if you now want "gold standard" for $400?

Good luck with your upgrade, let us know how much faster the new springs are....

Jimjacqmx5

Happy to pay the $$$. Still looking at KW clubsport kit.
I was merely pointing out that it seems the Koni's if correctly matched with springs and then valves to suit appear to do an excellent job. As I already have these and can get them rebuilt and valved to whatever specs, it might be a good option.
With the powerflex, how noisy, how much transmitted road noise/ thump?
I haven't eliminated the possibility but dont want excess noise.

sml

I did some numbers on the KWs and I think they work out cheaper if you buy from the UK (excl VAT) rather than the US.

It's been a while since I checked the latest pricing, but from memory, I think they were cheap enough such that you can purchase x2 coilovers for under AUD$1k and hence have them shipped here under the $1k limit.

If you need a UK mail forwarder ... forward2me.com
If you need a US mail forwarder ... shipito.com

evoderby

And there's the big BUT...."Koni's if correctly matched-valves to suit".

Suspension design is something that can not be relied upon 100% from the drawing board and give spot on results in real life, it merely gives you a place to start with....

....when track testing it then comes down to having enough adjustment range to dial the dampers in to the form of least compromise i.e. personal preference and quickets lap times. The Koni's have bump and rebound linked in their adjustment, making dialing them in even more of a hit and miss affair!

I would either:

A) sample as many existing 'off the shelf' suspension setups as you can (riding the passenger seat already gives a wealth of information) and if one really seems to match your preference (and the car runs good lap times) buy this and be done with it.

B) buy a set up with a broad range of at least 2-way but preferably 3-way adjustability (slow bump, fast bump and rebound). Calculate required suspension frequencies (2 Hz normally considered for track cars without downforce, choose front frequency 10% lower than rear to prevent 'hopping'). Be prepared to play around with spring rates around this base setting, analyse RS and RSR spring rates including front rear frequency ratio and learn from this......don't forget the influence of sway bar selection/adjustment.

Option B is more costly, involves much more time, but can be very rewarding if you get things right to a level unobtainable with off the shelf kits. The fast bump option alone on Motons and JRZ's allows riding the curbs in complete control and win anything up to 1 second per minute.

I personally went this latter route (JRZ 3-way - best I've ever experienced) with my previous non Porsche car, currently I use OE RS supension....am talking from experience here;-)

What you need in any case, whether choosing A or B, is start of with a solid basis. This means changing suspension bushes to RS spec rubber or PU in the front, 9M rear trailing arm bushes are very much recommended as well. Perfectly suited for street use as well so don't worry....

Adjustable anti roll bars might also be a good investment, but keep in mind as with dampers and springs, what can be adjusted can also be adjusted totally wrong! Make sure you have got a good grasp of the theoretical impact of such changes and figure out a good testing protocol in which you change one thing at a time.

You might even go as far and change to 993 Evo hub carriers for reduced bump steer, or standard 993 items for better turn in (previously unknown to me but kindly shared by Colin recently).

Question; what wheels are you running (weight)?

Shamus964

I have the poly bushes (powerflex in the back and walrod fronts) with camber plates up front and I don't find it harsh or overly noisy - but I am running a B&B catless exhaust so who knows what noise is really occurring. The only way to really tell is to get a ride along w/someone who has them.

Barring that, it depends on what you want from the car I suppose - I wanted a sharper edged machine that was evocative of the earlier cars, something more visceral, so I did most of the 'warning too loud' mods (LWFW, catless header exhaust, RS motor mounts, camber plates w/poly bushes) and it's not too loud for me at all - long trips are just fine w/the Wife and the performance payoff has been completely worth it on each mod. The real noise makers on my car are the swiss cheesed airbox and lack of cat - when I run the stock airbox and cat it's a bunch quieter.

Good luck with your decisions!

Jimjacqmx5

All great advise.
My car is VERY loud exhaust so it sounds like a Powerflex upgrade mightn't bother me. Adjustable swaybars I already have and use the adjustability to suit different events. I have 24mm front and 22mm rear swaybars. 3 way adjustable both ends.
The guys here who valve the Koni's have extensive experience and presettings that have been tested at various tracks with 964's so I would think a reasonable set up can be achieved. That said, the KW Clubsports seem like a good out of the box option. So tell me about the 993 hubs, I believe the set up gives much better front end grip and reduced bump steer. What's required?

NineMeister

Bit late, but better late than never. Here's the Engineers top down approach to your conundrum:
1. Set objective for performance
2. Set objective for comfort & ride quality
3. Ballpark options and set budget
4. Buy parts based on best "bang for buck"
5. Fit & adjust parts
6. Quantify performance and evaluate results
7. Decide if you want to spend more to achieve more.....

In other words Jimjac, we can't actually help you with meaningful suggestions unless you tell us the whole plan, so it's pointless discussion 993 hubs if you only want to spend $400 on a set of springs.

Babalouie

I am curious about the 993 hubs though...how are they different to the 964 hub geometry?

NineMeister

Yes, they are. To fit them you would need 993 steering arms, lower ball joints and the ball joint fastenings - the lower a-frames are also different but you can easily convert from 964 to 993 specification. All customers who have fitted them reported an immediate improvement in turn-in and more positive steering feel. The other benefit is that the castings are designed for radial mount calipers so you can use the larger 993 calipers and discs without adapters.

Metal Guru

The chassis measuring points recommended by the factory are the bolt head holding the crossmember to the body for the front ( 125 mm to the floor) and the cast boss (218 mm to the floor) on the bottom of the trailing arm at the rear.
I wouldn't recommend going any lower than RS height as ride harshness and bump steer get very unpleasant below that point.