GunNam

I'm looking to upgrade my brakes and have been researching the AP Racing Brake kits (based some great reviews on here and personal referrals from friends that use them).
From what I've researched so far, the kit that includes the 330mm rotor, the rotor is 28mm thick (Stillen AP7820SR) while the kit that includes the 299mm rotor is 32mm thick (URGE Designs/Essex).

What's the benefit of the rotor diameter vs thickness differences?

Also, one of the reviews on here (rhouck) shows the pad thickess as just under 16mm. I have a friend that has the Stillen 330mm kit and he says he also has a pad that is 16mm. How is that possible? Both kits use the same caliper, but the rotors are different thickness? Am I receiving bad info?

Urge

GunNam, the kits are completely different and use different shaped pads.

The original AP kit was made from their Street Line and only use an AP Racing Street Caliper. The rotors are not AP Racing, simply a generic outsourced unit.

We speced out our kit and Essex designed it using AP Racing Competition Catalogue parts. Both the Calipers and Rotors are used in Stock Car, Rally Car and Touring Car racing. The Calipers are forge aluminum with a Natural Colored Anodized Finish. They use Steel Pistons for less heat transfer and anti Knock Back Springs so you don't have to double pump brakes when the pistons slide back. These calipers are lighter than the Street kit by a few pounds. They do take 20mm pads (thickest on the market) at the same or lower price points vs other pads (due to common shape) so you always get much longer lasting pads with our kit.

As far as the rotors, again our kit uses AP Racing Competition rotors with Hats designed by Essex. The AP Street Kit uses generic (Non AP) outsourced rotors. AP Competition rotors use a proprietary alloy that is more durable than typical iron. Also, our Competition rotors use AP Racing proprietary J-Hook designs which provides better heat distribution and more leading edges than slots or curved slots, improving longevity, bite and pad deglazing. Finally the these rotors are 32mm wide and have 60 Vanes, widest and highest count on the S2000 market. This provides more surface area to move air through and transfer heat away from the rotor, providing excellent cooling for a smaller diameter rotor.

We chose 299mm as it is the same diameter as OEM and would not change the brake bias. Also, this diameter is the same used on 500 HP, 2800 lbs stock cars on short, brake abusive oval tracks. If they can handle 500 HP, why go bigger? In fact are rotors are lighter than OEM, saving more overall weight vs the other AP kit or any other track kit.

I hoped we answered your questions. Bottom line, 2 completely different kits, using different levels of AP parts.

thomsbrain

The Urge/Essex kit seems peerless if you're not looking for a brake bias change. I have no doubt the performance is fantastic. That said, I'd be hard-pressed to think of an S2000 track setup where you wouldn't want to increase front bias, due to the fact that nearly all of us run wider-than-stock front tires and stickier-than-stock rubber, both of which benefit from increased front bias. In addition, most rear-brake upgrades involve larger-than-stock rear rotors, which further increases the need for additional front brake torque.

Urge, it would be cool if you offered a version with 328x32 rotor and a spacer for the caliper so it would fit over the larger rotor. Nothing else in the kit would need to change. It wouldn't be for increased heat capacity, but just for increased brake bias.

GunNam

Thank you for the detailed reply. Just for clarification, the Stillen AP7820SR kit uses the same AP part number for the caliper (8350) as your Urge kit. It just happens to use the larger diameter 330mm, but thinner width (28mm) rotor. It looks like Evasive has a similar 330mm kit now, but with the J-hook rotors (AP7820J). I guess I was hoping there was a kit like what thomsbrain mentioned.

Urge

It would add about 3-4 lbs of rotational weight, $200 more replacement cost per Pair and $300 more in upfront cost. We knew there was some compromise, but too much in favor of the 299mm rotor.
Wouldn't be easier to simply go with higher friction pad to get the brake bias you want?

We have noticed with our rear vented rotor, you can put more bias on the rear and get less overall wear and endurance longevity. Some of our customers were seeing the OEM rears completely fade after 5+ laps significantly burdening the fronts. Our rear kit improves front wear by 50-100% as the rear brakes can take a beating and don't start over heating putting more and more pressure on the fronts.

Can you post the part list?

The Calipers look different from the pictures I see. Different Bolts, lengths, etc. Similar, but small differences. To my knowledge, no competition parts are made with vanity colors, all are natural Anodizing. Also, ours accepts 20mm pads and as noted theirs does not.
https://www.stillen.com/ap-racing-ho...-ap7820sr.html
http://www.essexparts.com/shop/compe...0-caliper.html

Again our kit has thicker pads, which reduces replacement costs and our rotors are the lowest cost in the industry.

GunNam

My apologies Urge, I must have mixed something up, you are right, the calipers are different part numbers. Stillen Hook Slot Sport Rotors on the site also start at $250.

Urge

Yup, our rotors are $165 to replace..

SakeBomb Garage

For a third option, there's also now a 325x32mm Competition AP Racing setup. Similar to the 299x32mm Essex kit but with increased thermal capacity. We designed this kit using the same components as the current AP Competition kit but with a larger 325mm rotor to increase brake torque and thermal management.

https://www.s2ki.com/s2000/topic/115...big-brake-kit/

https://www.s2ki.com/s2000/topic/114...per-conversion

Urge

To date, we have sold 50 Front BBK with our 299x32mm rotors and not one person had exceeded the thermal capacity of our rotors. These are these same rotors that are used on our 500 HP, 2800 lb Stock Cars, which is ironically the same weight as our S2000, actually slightly more if you have any weight reduction.

Our philosophy is why go bigger? Bigger cost more, weigh more, negatively effects suspension dynamics, acceleration & deceleration.

Our URGE/ESSEX front BBK replacement rotor cost are $170 per rotor, which is over a $100 less per rotor or over $200 less per pair of front rotors than other larger rotors.

We applied this same lightweight, cost effective philosophy to our rear rotor kit. To date we have sold 33 rear kits in less than a year and have 100% positive feedback on improved track durability, reduced rear pad wear & reduced front BBK wear (due to the rears never overheating). Again, why go bigger? Why spend more money to add more weight and change the brake bias you are already accustom too?

Our Front & Rear Combo kit is under $3000, reduce rotor weight across all 4 rotors and have adequate cooling for endurance racing.

Here is a link to our cost effective, lightweight & professional and S2KI race proven Front and Rear Brake Kits.

SakeBomb Garage

No offense meant whatsoever with this post, and we do highly respect the engineering work that you guys do! We just looked at your website and you guys do some really great stuff from your unicorn header, to scavenger exhaust system! So in no way is this meant to diminish what you've accomplished.

With that said, we've sold (and still sell) the Essex 299mm kits to our S2000 customers, but have seen thermal issues with them on track. 299mm is pretty darn small to be honest (that's the stock S2K and Miata rotor diameter). For the record, we have nothing against the 299mm AP disc, and we are close to releasing our Turbo Miata kit using the same 299 disc and AP caliper, however we do feel that for a 2800lb car with high power potential, the disc is simply undersized.

For some perspective, we've sold countless sets of our SBG Designed AP 325mm FD3S/RX7 brake kit for competitive use for years now, but originally we played around with a more budget-oriented 299mm setup. In testing the 299mm discs simply couldn't take the abuse. We were forced to run much more aggressive pads, and we found high rotor wear, high pad wear, and drastic temperature fluctuations, so we abandoned the project. The FD and S2000 are very similar in weight and power potential, and the results we saw on our customers 299mm setups (and on our own shop car) verified our initial testing results from years ago, (in our opinion) the disc is simply too small.