Over the winter we made a couple of upgrades; the brakes have always been a weak point and since getting rid of the booster, the effort required to push them was very high. However, the real problem was that due to the flex in the callipers the pedal wasn’t firm making them tricky to judge and not very reassuring.
We managed to get hold of a set of AP four piston callipers originally fitted to the circa 2007 Prodrive WRC Subaru Impreza. They’re quite fancy items being mono-block, internally ported with a single bleed nipple and titanium pistons. The additional piston area means we don’t have to push the pedal so hard and the stiffer calipers result in a nice firm brake pedal. To ensure we had a complete, unified system, we handed the calipers and hub assemblies over to Martin from Reyland Motorsport – https:/
Above you can see old vs new. This change has also been a really good weight save, with the new calipers weighing only 2.2kg each, vs 4.6kg for the old ones! Below you can see the final assembly.
Along with the much needed brake upgrade, we have also made a change to the gear ratios. On many a track, we have struggled when changing in to 5th gear, as it is simply too long of a gear. We identified another set of JC5 gearbox ratios which would shorten all of our gears and give us more acceleration in 5th which we were lacking a bit. So, we did this when the syncros and bearings got their annual refresh.