Thanks both
. Good question
@Jbrad94 on further mods, to address suspension - I'm leaving it as it is for now, as it drives and corners well from the factory in my opinion. Asethetically, it would be nicer a bit lower, but theres some pretty bumpy roads I have to traverse regularly which make me appreciate the stock height. If I were to upgrade, I'm tempted by full coilovers of some description rather than just springs (I have reservations about how well the dampers will work and last with lowered springs).
Regarding brakes, I agree, the big brake kits look lovely. I am particularly taken by the Reyland kits (AP Racing 6 Pots + 362mm floating rotors specifically), however I am conscious that I am not on an unlimited budget with this car - and am also very much aware that doing one upgrade can make another necessary (e.g. because I have added power, and am going to be using the car on track, I may need to improve my oil and/or water cooling), raising the cost even further.
With that said, I do think the stock brakes could be improved, and I needed to replace the stock pads anyway after taking them way outside of their comfort zone and destroying them at Oulton Park (above). Rather than go straight to a BBK, I have decided to see how the stock braking system can perform with some modest upgrades - all of the below has been done both front and rear
Ferodo DS2500 Pads
These pads (part numbers FCP4425H for front and FCP4697H for rear) should offer an increase in performance over the OEM parts, although choosing the right set was really difficult - and I won't know if I have got it right until I have fully utilised these ones.
The OEM brake pads are designed to work well from stone cold - and survive only standard road use. This allows them to be made quite cheaply and still perform adequatly for the majority of customers.
On the other hand, high performance brake pads are designed to survive the hot conditions created on track (with some being fine to 1000c+). The
problem with these are is that they are much more expensive, and most are not suited for road use - as they do not work optimally until they have been warmed up.
I needed to find a happy balance with my car doing double duty on both road and track, and so enters the DS2500 pad from Ferodo. This compound offers a better than OEM friction coefficient all the way from 20c to 500c (unfortunately, I dont have specs for OEM to compare - but this should be confirmed by their overall stopping power and resitance to heat).
Additionally, these come with a larger surface area to the OEM pads from the front, which should increase the amount the pads can clamp on the disc, and also
help the pad to last longer.
It is worth noting that these do not come with a wear sensor. To avoid a warning light on the dash, I cut the plug off the old pads and joined the wires by hand, then reconnected to the plug on the car - easy job. I also had to use Carista to fully release the rear electronic parking brake - which is important to avoid damaging the mechanism when replacing the pads.
To confirm, I am still using the original discs that came on the car, as they still have life in them. I have inspected them for wear/cracks, and cleaned them up - before bedding in the new pads.
View attachment 16903
HEL Braided Brake Lines
Braided brake lines (part number SEA-4-209 used here) are a nice mod to do for any car driven hard. Whilst the brake fluid runs in hard lines all the way out to each wheel, the final leap from the chassis to the caliper must be done by a flexible line for obvious reasons (the caliper can move up/down/left/right relative to the chassis).
The OEM lines are rubber, cheap for the manufacturer and perfectly adequate for most drivers. The
problem with this is that they can expand under hard braking, creating a softer pedal and reducing the pressure that actually gets transferred to the brakes.
Braided lines are still flexible, but a metal sheath stops them from expanding under pressure, creating a more direct braking feel, and allowing all pressure to get to the brakes. Their hard outer coating also improves durability over time vs rubber lines.
View attachment 16904
Motul RBF660 Fluid
The car is almost two years old, so it was sensible to replace the fluid anyway, but it was a necessity after replacing the lines and letting air in to the system. After doing a bit of research, I decided it worthwhile to replace the brake fluid to a more performance oriented specification OEM.
I'm not sure of the exact OEM specs, but to meet the DOT 4 specification, the dry boiling point (when the fluid is brand new) has to be at least 230c, and the wet boiling point (when the fluid has aged and absorbed water) 155c. Whilst I didnt boil earlier this year at Oulton, the ambient temps were cool and I may have been pushing them close to the limit. Boiling brakes are dangerous brakes (gas compresses, so when you press the pedal - all it does is compress the gas rather than press the pads against the caliper), stopping you from... stopping.
All of my research pointed to Castrol React SRF as the best, but it is very expensive. May be worth it in a BBK but with my stock brakes, I felt it overkill.
The next best seemed to be Motul's RBF range, available in a few different 'grades': 600, 660 and 700.
The key specs compare as follows:
Name | Dry Boiling Point (C) | Wet Boiling Point (C) |
Castrol React SRF | 310 | 260 |
Motul RBF 600 | 312 | 205 |
Motul RBF 660 | 325 | 204 |
Motul RBF 700 | 336 | 205 |
I opted for Motul RBF660 as it was practically the same price as RBF600, whilst 700 was a jump up in price (for a minor spec bump I probably wouldnt use) and Castrol SRF as mentioned above is way more expensive.
I used a pressure bleeder kit to bleed the fluid and found it both easy and efficient to use, well worth buying and will hopefully serve me well for many changes to come
.
As an overall comment for all of these upgrades together, I can tell you that the brakes now feel sharper in initial bite, and the pedal is firmer when stepping on them hard. I look forward to giving them a proper go at the track.
As a closing note, my car is currently making a strange noise - which I have posted details about
here. Hopefully It's nothing too serious and I can get it sorted soon