Honda FK 2pc discs and BlueStuff pads: EBC product feedback

At Co-ordSport we are always keen for feedback on products and their use, from teams and drivers. To help with this, we often supply products at special pricing, or even on loan, for evaluation, testing and feedback.

Recently we supplied a set of EBC’s 2pc front discs for the Honda Civic Turbo FK2/8 cars, along with EBC BlueStuff pads, to our good friends at JRM Racing AB in Sweden, and here is their feedback:

JRM fitted the parts to an FK2 which we knew was going to do many trackdays. EBC discs and blue stuff pads in the front. Now that driver has done 3 trackdays and the car is back to JRM’s to check it over. The driver is around 60 years and an old rally driver, so fairly experienced. He says that setup works well, he is pleased with the braking performance. What we can see is that discs look good but the pads are almost done and they have quite uneven wear; top of the caliper is down to 3mm, whilst the bottom is approx.8mm. If I compare that with Endless ME20 pads, that we run on my FK8 they now have seen 5 trackdays and 6 races and they still have 9mm left and 100% even wear. I think the issue with the Blue stuff may be that it can’t take the heat and the material transfers to the disc and it starts from the top to shave off material from the pad.

Our assistant buyer, Liam M., is also a user of EBC’s BlueStuff pads, on his ST250, which has Focus RS Mk3 Brembo brakes as an upgrade, and he has noticed a similar wear rate on his pads, following a few track days and some fast road use.

As an EBC partner, reselling a wide range of their products, Co-ordSport passed the above feedback to them

 

Here is EBC’s reasoned & valid response from EBC

Some good feedback here and it’s clear he’s worked the brakes very hard, thanks for passing on his review. A few comments and explanations if I may:

BlueStuff vs. ME20

We’ve dyno tested ME20 here at EBC, it’s a good material with reasonably good wear properties, but its 3~4 times the price of BlueStuff, which must be considered. Also, BlueStuff is fully R90 approved and thus more ‘road focussed’, being road legal. BlueStuff is a great material for people who want to legally operate their vehicles on the public roads in the EU, but who also want to do a few trackdays, without changing their pads at the track…. This guy sounds like he’s purely doing trackdays so he’d be better off choosing our dedicated track pad RP-1, our dyno data also suggests this material has the upper hand over ME20 in terms of wear and performance, but is approximately half the price. We have done a lot of testing on the FK8 Type R with RP-1 pads and the 2pc discs, all feedback has been very positive. See this blog from most recently: https://ebcbrakes.com/ebc-news/ebc-brakes-racing-heads-to-the-ring/

Pad Taper

First thing to note, Brembo OE calipers and Brembo aftermarket racing calipers are worlds apart in terms of quality & performance. Their OE calipers, like every OE component, is built to a low price and as such on-track performance can suffer. Usually this means the caliper has higher flex, and it is this flexing of the caliper that causes pad taper. The key thing here is that this caliper is a ‘monobloc’ caliper thus it does not have any bridge bolts. Brembo and others market monobloc calipers as superior…. Don’t listen to them they’re talking rubbish, in EBC’s opinion. monobloc calipers are cheaper to produce, that’s why lots of OE Brembo calipers are monobloc it’s that simple. Look at AP Racing Pro 5000 series, they’re all 2pc calipers with bridge bolts. Reason being is that calipers don’t run cold at racing speeds, 160-200C is a normal caliper body temp. At this temp the modulus of aluminium halves, whereas the modulus of a high tensile bolt is unchanged (actually, the modulus of steel actually increases a bit, at moderate temps up to around 200C then starts to drop off). What this means is the bridge of a monobloc caliper loses roughly half its strength at high temps, which results in excessive caliper flex that then leads to pad taper. Basically the caliper bridge is running just 2-3mm from a brake disc at 600C+ thus turns to mush and the caliper flexes significantly, this is why we opted for a 2pc bolted design in our own calipers.

The other big factor in pad taper is the wear rate and the type of driving. If you do a trackday then follow up with several hundred road miles, you’ll find minimal pad taper. This is because, when operated under less severe loads, the caliper doesn’t flex as much and the pad tends to wear itself even again. However, if the vehicle is only driven on track then this ‘evening out’ phase never happens so the pads just get more and more tapered. I would therefore assume that these BlueStuff pads have done 3 trackdays back-to-back with minimal ‘normal’ road miles in between hence the severe pad taper.

My point above is actually demonstrated nicely here with Liam’s photos. Liam’s pads have some pad taper but much less severe, due to doing some road miles in between trackdays that allow the pads to wear back to even. Again, Liam is running the OE Brembo caliper off the mk3 RS…. A monobloc caliper with no bridge bolt reinforcement, I notice the same pad taper on my Focus RS too.

Just to add to that, monobloc calipers do have their place, as they do have better stiffness-to-weight ratios but they are typically only really used in racing. If a bridge is made of 100% aluminium then it needs to be much thicker to have the same strength as a bridge reinforced with steel bolts, simply this isn’t an option on road cars which are much heavier and thus need much bigger diameter brake discs…. Having a 25mm thick caliper bridge just makes the brake system too bulky and you run into packaging problems.

For road cars where space is tight and a big brake disc is required to manage brake temperatures, a 2pc bolted caliper is the best route as it gives good stiffness in a compact packaging…. The tradeoff being the caliper mass increases by 0.5kg or so (not perceivable in a road car anyway).