SP's new brakes

Its been 6 long months since I last updated the blog. Apologies, a lot has happend since. Thought that I should update the blog with one of the last mods that I have done on SP. I have been using the Wilwood 4 pot caliper and DBA 276mm discx 25mm thick disc, which is the standard EVO3 disc size btw which came with the car when I purchased it. The brakes were good and offered good pedal pressure and bite. However, the Polymatrix E pads which I was on initially was sometimes a little vague especially on cold days and under hard use. I cannot judge when it was going to give away especially at the track. I also experienced a couple of occasion where I lost the brakes completly esp one on turn 14 doing about 180 kmh, and I generally used to brake close to the 50m mark. It was not a good experience, let me tell you. I was told this could be pad knock back or too much heat.

SP with the old Wilwood 4 pot and DBA single piece disc setup

So I experimented with a different brake pad, Polymatrix B compound, which was really good and helped with the feel, but it was so noisy, almost unbearable, and trips back to the house after mamak sessions made my neighbours shriek. Coming to a traffic light, motorbikes and other cars would look at me wondering why this idiot hasnt got his brakes fixed. But on the track they were marvellous, once they get some heat, the shrieking is less and the bite phenomenal. But I still had cooling issues. So ordered some custom dry CF brake cooling ducts from the UK, and silicon cooling hoses, to mitigate the heat, but this too did not help much.

Dry CF brake ducts with silicon hose

Close up of the dry CF brake duct

Talking with a brake supplier in the US, it was finalized that bigger and thicker discs will be necessary to combat this. The problem with the thicker discs are that my calipers will not fit, so again this had to be upgraded to a 6piston caliper, which also has a larger pad surface area compared to the 4 pots. This will also help to minimize heat transfer to the brake fluids. I took some measurements to design the brake hat and to include a spacer as well and my idea was to try and fit the largest disc possible under 15in rims. This is so that I can use my slicks for track days. So in the end a 305mmx32mm Wilwood two piece disc with aluminium hat was ordered along with my 6 pot Wilwood SLR radial mount calipers. When I received the parts, a couple of things were different, firstly I was expecting a black caliper, but somehow I got the more expensive and bling bling version which was in red and the grooved disc ended being a solid disc. So some emails to the supplier to complain and we ended up with an agreement for future replacement discs.

The 6 pot caliper side view

Another angle, note the staggered pistons

Another view

Bigger and thicker disc, shown without the aluminium hat/bell

Another view, from inside the rotor

Polymatrix B compound pads

I also decided to continue use with the Polymatrix B compound as I was quite happy with them except for the noise factor. This meant that everybody knew I was coming, not by the engine or exhaust noise, but by my brakes! Installation was fairly straight forward as the caliper bracket for the 4 pot Wilwoods could be reused, with the addition of some spacers. Well, after everything was fixed, I also decided to try out the Neo Synthetic Race brake fluid, which has been pretty good so far, thanks GT Auto! After the brakes were bed in, decided to try out the stopping power, and boy it was astonishing, the brakes were a lot better maybe up to 30-40% improvement over the previous setup. This was also confirmed on the track, as the brake did not fade, and I could really stand on the brakes and haul the car down, braking power was fantastic and so far did not experience any fade. However, I did have some problems, this is due to installation rather than the product itself. On the first track session, one of the fitting for the bridge pipe was not tightened properly and brake fluid started to leak from the loose fitting. This resulted in uneven braking pressure on the fronts, and we managed to tighten the fitting with some difficulty. The second problem that I faced was more serious and by luck or Gods grace, we pitted in time before it became even worse. The bridge bolt on the LHS caliper somehow managed to work out loose and was sheared by the spoke of my rims. This then resulted in the brake pads to dislodge itself from its position in the caliper, and started to grind itself on the inside of my SSR type C. The RHS caliper bridge bolt has also started to work out loose, but it wasnt as bad as the LHS. That ended my track day and managed to put the pads back into the caliper and made a temporary repair to hold the brake pads in place. New replacement pads and bolts were ordered from Wilwoods.

As this was part of R&D project, I have made an error on the caliper overall size and due this I am unable to fit the 15in wheel as the caliper is too large to clear the internal dimension of the 15in wheels. So I am now stuck with 16in rims and tyre combo for track day and road use.

Caliper and disc installed

Another view, brackets are machined from 7075 Aluminium

Side view after installation, cant really see the larger rotor here

Another shot of the newly installed brakes



A different view



Other upgrades will be blogged soon.  Watch this space!