Braking in BTCC (also, largest wheels to fit 1990 200)

[Gerard <gerard@poboxes.com>]

Hi!

Well, waiting for companies to get back to me about interviews and
stuff, I seem to have plenty of wastable time on my hands. Two options,
could go look at the electrical fault on the 200t, or could read a car
mag and look at BTCC braking systems. Well, still waiting for some info
on the electrical fault and places to check from a fellow lister. So
BTCC braking it is!

The car in question here is the Nissan Primera. They race a local
motor here in South Africa in the local touring championships which
are much more restrictive than BTCC. First of all, some info on the
car. Both are the 2-litre unit. The BTCC car has the engine lower in
the bay and further back, while the SA version must remain stock
layout. The BTCC car has the head turned around with the exhaust at
the back, unlike the local one with the exhaust in the front. BTCC
car has a damn nice intake system. Local touring regulations say they
all have to use Racetech engine management system. BTCC has 225kW, local
has just over 200kW.

Now the brakes. The local car is running 4-pot single caliper units
up front on something like a 320mmx28mm ventilated disc. The BTCC car's
braking system is what I'm interested in. The regs there have more
to the wheel story, the locals use a smaller wheel. The BTCC car has
19inch wheels and use something along the lines of 368mmx28mm ventilated
discs. The disc looks real interesting, there is a brownish cover over
the hub section, makes the grip area look real narrow. Now the calipers
are the best part. Up front the Primera is running two 4-pot calipers
by AP Lockheed. A lovely setup for anyone interested in bumping up the
wheel size to put in a larger disc and calipers. The braking must be
phenomenal with such a setup. How often do they redo the discs on the
BTCC racers? After every race?

The big question is can something like this be done to someone's Audi
if that person is really serious about racing the thing? Does anybody
know what sort of mounting bracket the BTCC car uses in order to
hold the 2 calipers? Does anyone know if AP Lockheed make adapters?
Anyone using AP Lockheed as apposed to ATE or Brembo brake systems?

I also saw that Brembo make 8-pot calipers in aluminium cast single
piece units. No doubt for F1 use.

This is just me doing some "stirring" as usual. Reason I'm putting this
out here is that my entire braking surface units are shot (rears are
4mm below minimum!) and I believe my calipers to be shot as well.
At least last time I had the front units turned they put the calipers
on with a air wrench! Deep grinding noises come out when braking in
a moderate fashion. Normally the car will shake like mad. So, needless
to say a complete brake replacement is on the list for sometime in the
future, so I might as well do a brake system upgrade. I'd therefore like
to know what lister's have to say about AP Lockheed systems and if
anyone knows of someone who runs a 2-caliper-per-disc setup.

Also, the car in question is a 1990 200t and I'd like to know what the
largest wheel and tyre combination is that will fit in place of the
BBS mesh units that came as stock. I think these units are 15x7.5,
don't know much about things like "offset" (wozzat?)Correspondingly,
what would be the largest unit brake disc and caliper that fit with the
wheel. Currently the wheels are 205/60ZR15 (should be 205/65VR15). Don't
go by the "1-2-3-up principle", I'm not thinking of maintaining the same
wheel diameter/width. Let's also assume the front has been dropped
30-40mm and the rear 30mm and we're running Bilstein gas shocks. So,
what would be the largest diameter wheel and tyre combination to fit the
wheel arch perfectly on the 200 and what would be the corresponding
disc/caliper sizes that would fit without a problem? I *am* looking to
still be able to turn and take a average size pothole/bump without
losing my fenders! ;)

Stir, stir, stir.

Thanks.

Ciao.

G.
-- 
"a thousand miles from here, there is another person smiling"
1990 Turbo (200t, MAC13A ECU, 1.4-1.6 bar (1.8 bar with faulty WGFV!),
FWD auto)
name   : gerard van vught
tel    : +27-21-696 0331 (h) / 082 923 9609 (cell)
url    : http://www.poboxes.com/gerard/
e-mail : gerard@poboxes.com  / han.solo@galaxycorp.com