Monday, March 17, 2014

Wilwood Ultralite HPS 32 Vane Brake Rotor Finally Installed

More than a year just to install a pair of brake rotors? Even by my king of procrastination standard this sets a new precedent :) At one point I even bought a can of high temperature paint to paint the (unplated) rotors myself but eventually decided I wanted a new (properly plated) rotor. Took me quite a while to order one as I had to sell of my unplated set to help with the funding (of the new plated rotors). Luckily Bro Peter came to my rescue. As usual got royally sc*ewed by customs tax.You can read up more on the cost here. Picture below of the zinc plated rotor.

Not sure what this cut out at the side of the rotor is for. Balancing the rotor?

Part number still visible despite the plating.

The newly arrived rotors sat in my store room gathering dust for a couple months while I worked on other mod projects. Self poisoning set in and I decided I was gonna go the whole hog and ordered a set of ARP brake hat bolt kit. The bolts used on my Coleman Racing rotors are just plain aircraft grade stainless steel type. Remember, brake hat bolts should only be used once as they are stretched during install and subsequent heat cycles impacting their strength. I only need 16 sets of bolts + washers but the minimum quantity sold by ARP is 32 for a kit. Again Bro Peter came to the rescue reserving half my fasteners. Thanks Bro! Cost including shipping came up to USD 168.96. Picture below of the ARP kit.

Material is 8740 chrome moly steel and each bolt features an exclusive 12-point cap screw design. Each bolt is also drilled to permit safety wiring and is rated at 200K psi tensile strength. Here's how safety wiring looks like from Wilwood's website. Close up shot below including part number and size of the bolt. Like everything American, size is in British Imperial size or what the Americans call SAE.

Being non-metric gave me an excuse to buy a set of spanners from ACE.

But Tao already had a set of even better non-metric socket wrenches. I then also decided to order a new pair of Wilwood centre hats just in case. Picture below of my Wilwood centre alloy brake hat. Part number is 170-10200. Centre hat needs to be re-drilled for the Sentra's PCD 114.3 4 lug pattern. Cost me USD 375 for a pair of centre hats including shipping. Tax is another story :(

I also decided to weigh everything. The previous Coleman brake rotors + Wilwood centre hat + fasteners were about 6 kg+. Wilwood claims the HPS 32, part number 160-12206 weights 13.6 lbs or ~ 6.18 kg. Weight of the Wilwood alloy centre hat in picture below.

Weight of the total number of ARP fasteners per side.

This means total (rotor + centre hat + ARP fasteners) rotor weight is 6.181 + 0.721 + 0.116 = 7.018 kg which is heavier than the Coleman rotors but since I did not yet have a digital scale when I had these (Coleman) rotors I cannot say specifically how much heavier but should be in the range of 0.5 - 1kg heavier. 

After much fondling of the rotor and ancillaries, I proceeded to assemble everything. Again I decided to use Permatex High Temperature/Strength (Red) thread lock vs safety wiring. Have had no issues with the centre hat bolts coming loose despite tens of thousands of kms of driving using the Permatex so can vouch for its effectiveness. Picture below of the assembled rotor + centre hat + ARP brake hat fasteners. 

Close up of the lovely ARPs. Shame these can't be on display being in a place where the sun don't shine.

The brakes squeal quite a bit especially when cold so I bought the below from Hard Brakes to hopefully reduce/minimize the squeal.

The Permatex Ceramic Extreme Brake Parts Lubricant is applied between the pad backing plate and the titanium heat shield shim. You can read up more on it here. Total time including assembling the rotors, cleaning and install was bout 2 hours. Tao did most of the spannering. Picture below of the installed rotor.

Took Sharkie for a drive/blast to bed in the new rotors. Happy to report no judder and less brake noise with little to no squeal. Brakes are now near perfect and the only area left to improve would be slight shorter brake pedal travel via a larger master cylinder. As usual my rims were coated with zinc dust during bedding. This (black dust) will eventually go away with more use/bedding. Picture below of the rotor post bed-in.

With the HPS 32 being a straight vane rotor I would expect the heat dissipation capability to be less than curve/directional vane rotors. I did inquire with Wilwood on a better rotor (increased number of vanes or directional vanes) for my size and spec but got the expected response "Unfortunately it will not be possible for us to make this custom rotor". Wilwood only has this rotor in slotted or plain faced version and the bling SRP cross-drilled rotors in the size (12.2" diameter 1.1" thick rotors) I want. Most of their trick rotors are at least 1.25" thick or in bigger diameters.  On hindsight I should have gotten a more "popular" sized rotor. More self poisoning at work?

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