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Endurance Spec front brake kit (champcar, WRL, etc)

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    Endurance Spec front brake kit (champcar, WRL, etc)

    This is a bit of a "backwards" group buy since I already have parts in hand. I asked around the endurance racing groups and got some interest, but bit off more than I was expecting. If this needs to be moved please accept my apologies.

    I campaign two E30's in the "champcar" series.
    Click image for larger version  Name:	PinkiesVIR.jpg Views:	0 Size:	71.8 KB ID:	10037634

    While we have found success on the OE brakes (My old setup was Stock Girling calipers with Zimmerman rotors. Condor supplies my brake lines, and I use PF08 or ST43 pads), the setup does have weaknesses:

    1. Rotors - The rotors last about 14 hours at most tracks, even with 3" custom cooling ducts. We have cracked rotors on many occasions, leading to some pretty hairy moments having to finish a race with a terrible braking vibration. Luck kept us from "exploding" a rotor and having a big issue
    2. Consumables Costs - The rotors get changed after ever weekend on the track, including doing "testing" or "DE" days. Pads are good for 1 Race weekend, and the left overs get used for testing and DE. The rotors are $30 each (FCP helps with this), and the front pads are $200/set.
    3. Component Sourcing - The Caliper brackets are NLA new. The guide pins are currently NLA and have been for a year or so, and I just used up my last NOS set of those plus swapped my last set of good brackets from left to right (One pin wears faster than the other). The calipers require frequent rebuilds to replace the seals, which have been intermittently available. At least this stuff is cheap when it is available.

    Looking to improve upon this, and minimize risk of rotor failure in longer races, I have designed a custom kit to fit the E30 front and work with the stock E30 rear.
    The kit is designed, as much as possible, around off-the-shelf Wilwood components. It's primary concern was minimizing ongoing consumables costs and maximizing ease of service.
    In addition, No modification to the strut is necessary. This was a critical parameter for our team since we end up replacing strut housings on a (much to often) regular basis due to damage.

    Off the shelf items:
    Wilwood Caliper 120-13232. Forged Superlite 4 Radial, 4 Piston, 1.25" Pistons
    Wilwood Rotors 160-2898 (RH) and 160-2899 (LH). 11.75x1.25 with a 8x7 mounting pattern. Many other rotors will also work (for example HAWK HR8002R and HR8002L). For longer events I recommend Wilwood 160-13499/160-13500 Rotor (GT 48 SPC 37 11 .75 x 1.21)
    Wilwood Bobbins and Bolts 230-14845 (qty 2 required). 5/16 x .750. Locktite and Safety Wire recommended.
    Wilwood Caliper Mounting Studs/Nuts 230-13273 (qty 2 required).
    Pads - Any '7420' pad shape, which is an extremely common shape. Almost any compound can be had for <$200 in this shape.
    Lines - The Wilwood caliper is supplied with 1/8-27 NPT female threads. This means adapters are necessary.

    Custom Components, Made in USA:
    Hats, Machined from 7075-T6 Aluminum, with black anodize Type 3
    Click image for larger version  Name:	IMG_5527-Medium-rotated-e1624233792895.jpg Views:	0 Size:	99.5 KB ID:	10037638
    Adapter Brackets, Machined from 1018 Steel, with black powder coat
    Click image for larger version  Name:	ORVI2796-Medium-rotated-e1624233550351.jpg Views:	0 Size:	79.3 KB ID:	10037635

    I had 20 kits made. I hope I can pass enough on to recoup my investment.

    $350 for the pair of brackets
    $250 for a pair of hats

    From Me, the cost would be $620 shipped to US.

    Fixed Costs are for the Wilwood components, which you would buy direct from your preferred source:
    Calipers - $500
    Rotors - $100
    Bobbins - $100
    Hardware - $40
    Pads - $200

    Lines - $100
    Adapters 03122ERL - $15

    All in, you are looking at ~$1600

    I have 10 sets of "custom" braided adapter brake lines that I had made that I can sell for $100. Includes 8 brake lines (4 for the rear, two "stock" fronts (not needed) and 2 M10-NPT adapter fronts)

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    Technical Details:

    Brake Bias:
    With stock brakes, the torque bias (assuming equivalent pad compounds) is 67.6% front.
    With this kit in the front, and stock rear, the torque bias is 66.8% front.

    The rotor is 9.6 lbs per Wilwood
    The caliper is 5.4 lbs per wilwood
    The adapter bracket is 1.2 lbs
    The hat is 1.2 lbs
    Total = 17.4 lbs per corner

    Stock Rotor = 10.5
    Stock Caliper and Carrier = 8.8 lbs
    Total = 19.3

    With Pads, the weight is basically a wash.

    This is the biggest downside to the kit. It was designed as a no-compromises kit for our race team. We run 15x10 Jongbloed wheels. This is what the "fast" endurance teams are using.

    If you run a normal 16 or 17 inch wheel its very likely to clear.
    I race on XXR 530 16x8.25 +0

    If you run a 15 inch wheel less than 9.5" its very unlikely to fit.

    15×7 TRM = does not fit, even with 20mm spacer.
    15×8 TRM = does not fit. Would be close with a 25mm spacer.
    15×8 Team Dynamics = fits with a 15mm spacer, but with VERY little clearance. Would not recommend.
    15×8 Kosei K1 = does not fit even with 20mm spacer.
    15×8.5 Konig = does not fit, even with 20mm spacer. Hits drop center (just barely, but too close to run safely)
    15×10 Basset Steel = Does not fit. Caliper hits mating face of wheel near lug holes.

    This is a to-scale diagram you can print to check different wheels.

    The team has competed in two events on this setup so far. In June we ran a 7 hour event at CMP in South Carolina (result: P1) using ST43 pads. In August we ran a 24 hour event (shortened to 19 due to a fog delay) at VIR in Virginia (result: P1) using Ferodo DS1.11 pads.
    Click image for larger version  Name:	CMP_Win.jpg Views:	0 Size:	83.5 KB ID:	10037636

    The $43 dollar "ultralite" rotors were on the car for CMP. For HPDE and mid-pack cars, these are sufficient.
    The $100 "spec 37" rotors were on the car for VIR. They survived 19 hours and will go again at the next event.

    If you want annual brake maintenance on an endurance car the Spec37 + ST43 is the setup.
    Last edited by redneckvtek; 11-22-2021, 04:03 PM.