Henry964

Yesterday - in a track meeting - some friends told me that when I was braking hard my car was shifting its weight to the front much more than the other competitors.
One of them recommended changing the springs to Eibachs, (my car was canadian originally) and keeping the Bilstein sport shocks that I have installed when I bought the car (the springs where never changed)
I was loosing about 2-3 seconds per lap ( 2 minutes lap) to my nearest competitor and I was wondering how much of that difference can I recover lowering my car (most cars sold here came from Germany)

I was always reluctant to lower the car because of the bad shape of our roads but I think its about time to do it

ilko

There is a joke among track guys: "A real racer will sell his first born and ***** out his wife for a clear second per lap improvement." So you have ways to go

Eibachs are fine for the road, but a little on the soft side for the track. I'd use H&R green or red (even stiffer).

joey bagadonuts

I agree with Ilko. Eibachs are too soft (they will make your car less responsive on track) and H&R's would be a little better. Linear springs, however, would be the best choice versus these progressive-rate kits.

As for lap times, I would look at the car's handling through different phases of the corner and place more emphasis on exit characteristics. How your car exits a corner (understeer, oversteer, neutral) will have a greater impact on lap times than entry or mid corner handling. It's also difficult to say whether your braking is costing you time without being in the car with you. There are too many variables to offer an informed opinion, i.e. suspension, brake pads, tires, technique, road surface, corner design, etc.

I would recommend that you read "Speed Secrets" and "Speed Secrets 2" by Ross Bentley (if you have not, already). These books not only cover technique but, also, handling issues and how to get the most out of you and your car. You should also use an instructor to ensure you are developing proper fundamental skills and utilizing them on a very consistent basis.

http://www.speedsecrets.com/PRODUCTS...9/Default.aspx

Henry964

Thanks Ilko and Joey!!!

I agree with Joey in that I need to improve the nut behind the wheel... I am planning to get personal instruction ASAP....

Regarding the spring issue my car is not a track toy, it is a 95 % street car and some streets and roads are really in bad shape here so I need to improve handling without too much lowering and hardening, remember that my suspension is standard except for Bilsteins.

joey bagadonuts

You're welcome, Henry! Yes, a good instructor is almost always a good way to find better lap times.

Developing a good car for street and track is very challenging. Perhaps the best alternative is the adjustable coilovers, PSS10 or CROSS. In my experience, it is the shock valving which determines whether a car will be comfortable or harsh on city streets / responsive or slow on track which is why adjustability is desirable in a dual-purpose car. I think if you switch only springs, you will not realize much handling improvement at the track while making city driving less comfortable.

Here is a chart from anto1150 which provides details for various options, including KW and PSS. With CROSS, you have various spring combinations but I think any one of the adjustable kits would be your next upgrade as opposed to springs only.

boxsey911

To echo the thoughts of the other guys, driver training is the most productive way of spending money on your car to go faster round a track. On my own local track (2:15 ish lap) I'm now about 10 seconds faster than when I first started due to the tuition I've received. And I've got a long way to go yet because the pro can get my car round nearly another 10 seconds quicker!

Through experience I would put a second set of wheels with track tyres (e.g. Toyo 888s) above suspension as a go faster upgrade. Then probably better brake pads and fluid - knowing that you have good brakes gives you the confidence to use them less. And when you get to suspension, I would agree with Joey to go for adjustable coilovers because you can set the balance of the car for the track. Having them set as hard as possible is not always the right answer....fine tuning the bump/rebound so that the car changes direction through the slow bits is key to getting an overall faster lap (I got that last tip from Joey a while ago )

joey bagadonuts

anto1150

sacred words!

sundog

I've got the Bilstein and H&R Reds on my C2. It is much more fun and responsive. I can't imagine having it on the track with softer suspension.

IrocMan

The front suspension is very important indeed. Some old racers (I heard Ickx saying that) joke that the rear just pushes or follow, but front always drives the car.
You can find some pretty cheap racing 993 dampers (for instance Penske use to sell their older stuff for a good price) fully adjustable with serious springs. The car will be totally transformed.

Be careful if on the other hand you put springs and absorbers which are not done for working together - front will dribble, dive and/or bump, which is terrible.

IrocMan

Joey,
Very interesting chart you have here.
Note how the Cup springs work in a wide range...

joey bagadonuts

It's as if they have built-in helper springs. My guess is that travel in the softer portion is virtually maxed out while standing--before applying lateral/longitudinal force on the car. On track, then, the suspension would operate at the higher rates.

The softer rates come into play (like helpers) when all load is removed. Basically, they keep the springs in place when shocks are fully extended, like when the car is raised on a lift. Again, just a guess.

Nader Fotouhi

Are the RS or Carrera cup springs available?

IrocMan

Yes they act like kinda double springs.
I think they keep preventing the wheel from dribbling on low loads, for instance interior wheels in a fast curve. That's what I didn't like when my car was using eibach springs and was still 4WD: absorbers were too hard for the springs... which were actually too soft when loaded, and too hard on low loads. They were perfect on the rear however once the absorbers were adjusted...

Suspension and train is the hardest point to setup on a car. Most people spend time and money tuning the engine, they'd better learn how to use a pyrometer

IrocMan

The RS are not so interesting actually. I think the H&R in that case are more interesting.
I know that you could still order the Cup ones few years ago in Europe. I hesitated in 2005; a contact at motorsport told me they had some cups available... and the idiot I was bought some Eibach for a fraction of the cost, but I quickly regretted it !

The Hyperco were the springs which made me happy.
On my car I have some '98 RSR shocks with Hyperco springs like the ones you can find on ebay and other sites for about $2000. They fit the 964. The front drive train is transformed !
Then you need to upgrade the rear wit the same stuff... and lighten it seriously with a polyester hood and quarter panels for instance. That's all you need to get a fast car.

Personally I like to get the rear a bit softer (and higher of course) than the front and then adjust an aggressive setup on the trains. The car oversteers but keeps a very good motricity which is important especially on a club car, you want to keep grip even on wet track rain. Hyperco were too hard for the rear of my car which is too light.