Tech Tip 10 - Worthwhile mods especially brakes
see also FAQ3 - Power Output
see also FAQ12 - Chips and Hot Film
Items which may be of interest to you. I've owned a C2 1992
for over a year now and absolutely love it.
The first modification I made to the car was replacement of the steering wheel.
I'm rather tall so I needed a slightly smaller wheel than the original to accommodate
my knees! However, I wanted to keep the airbag, so after some phoning around
I got a nice three-spoke wheel from Stuttgart Connection. Looks better than
the original...
My first track night was last year at Brands Hatch and was a great experience.
However, only when I did more track nights at Knockhill, I realised something
had to be done about the brakes. Knockhill is well known to be heavy on the
brakes, and after several laps the brakes started to fade and didn't come back
unless I left the car alone for more than half an hour. I started to ask about
Turbo brake upgrades etc. Unfortunately, this would set me back some £2000,
so I decided to go for something more simple. Other tracknighters advised me
to change the brake fluid to racing brake fluid (I took AP600), change the pads
to Pagid Orange pads, and to replace the hoses to metal hoses. All acquired
from Phil Hindley at Tech9. The brakes feel good on the road, but the real test
will come in two weeks time at the next track night. I'll keep you informed.
Another worthwhile modification is a strut brace. Also to be tested in two weeks
time but I can already feel the difference on the winding Scottish country roads.
The car feels much more precise and confident in fast corners. I'm looking forward
to the track night! More later, keep mailing. regards, Reinoud B
The standard 964 brakes are already phenomenal and I had no
problems with them on Brands Hatch (the Club circuit unfortunately, PCCB end
of last year). Knockhill is a totally different circuit though. Short straights
and slow corners mean that virtually everyone's brakes will overheat. Most people
will stop after 10 - 12 laps because their brakes are "gone". Someone took me
round in an 964 speedster RS, with the famous "red" brake calipers. The stopping
power of these brakes are amazing, you are literally hanging in your belts with
your nose against the screen. Therefore I checked how much it would cost to
have these fitted but that was a bit over the top. However, also these brakes
fade to some extend on Knockhill, although much less than my standard. General
advice on Knockhill is to not put your hand brake on after you come in, otherwise
you will find your discs warped...
The change to Pagid racing pads has made the pedal much firmer, and I guess
you need some more pressure for the same braking but this hasn't disturbed me
to date (I'll ask my girlfriend, maybe she?) On brake fluid, it is clear that
on Knockhill the brake fluid overheats and starts to boil. Pedal travel is much
longer and becomes very "spongy". I will have to see how the AP600 fluid performs.
Most people at Knockhill have changed their fluid. Castrol SRF seems to be best
(silicone) but is £36 per liter, and needs to be changed every year (two liters)
as the silicone absorbs water. AP600 is £18/liter.
Tyres I use Pirelli P0's. On the "N issue", I understood that different N numbers
indicate P0's for different cars. There is only one P0 for Porsche, and Checkpoint
here in Aberdeen said they know about this and gave me the right ones (I think
it is N0, I need to check). Price for four was ca £580, incl. VAT and fitting.
On track days I'm still experimenting with tyre pressure. Last track day I kept
the pressure at 35 psi (some advised me to drop to 28, but I found that a bit
too drastic for now). After the first round (15 minutes) all tyres had increased
to ca. 42 psi, but the front left (who gets all the beating) to 45 psi. Dropped
it all to 35, and after another round most had increased again to some 40 psi.
Dropped them again, and then they remained stable. This was of course on a dry
track.
Oil Generally, the engine used a lot of oil over the last year, but that turned
out to be due to a leak. The repair took 20 hours, but luckily it was still
under the warranty as I bought the car from a dealer last year. I used Shell
Helix to top up, not sure what the garage has put in. I've participated in three
track nights to date (one BH, two Knockhill) but I'm booked in for all this
year at Knockhill (unfortunately only three!). I'd love to do more, but there
is not much else here up north. Spa would be great, who knows in the future.
Regards, Reinoud.
The rear hubs contain a small pair of brake shoes which act as a handbrake. This is why the handbrake is so fierce if you apply it while reversing! - Winston B