Gauging Interest:New for 2017 Essex Designed AP Racing Radi-CAL Competition Brake Kit

[JRitt]

Originally Posted by dave-

@JRitt did this ever go anywhere? Have considered the Endurance kit but really like the idea of the new radi-cal design and benefits.

Have been looking at a CP9440 front kit which seems to have appropriately sized pistons for our cars but they're limited to a rotor size of 330x28mm. Not sure that will offer sufficient thermal mass with sticky R comp tyres on a boosted car and long track sessions?

We have investigated this option several times, and it's not going to happen. Frankly, the cost difference is so great that we can't imagine we'd sell many of them at over $3,000. Our least expensive Radi-CAL option is for the ND Miata, which retails at $3,249. That is a tough sell when our $2,099 Sprint Kit does the job in style for 99% of our customers. Heck, a group of Toyota engineers leveraged our Sprint Kit to win an endurance racing championship in 2018, and it has been proven all over the world. It's cheap to run, incredibly effective, and fits a million wheels. People have even run it with swaps and tons of boost.



The Endurance Kit is a beast. We've had a 600+ WHP Evo customer winning Time Attacks with it, including the 2018 Gridlife Trackmod title. They set a couple track records along the way. The Endurance Kit is more than any 86 will ever need, regardless of what is done to it, stuffed under the hood, etc.

[Pat]

I have been very happy with the Sprint kit. If I had a nit to pick, it would be replacing rotors due to heat stress cracking well before the thickness becomes an issue. The first rotors lasted me two years.
If I wanted to make them last longer, that would just mean getting them to run cooler, right? Are there any GOOD ducts for this kit? I don't remember ever seeing any. I know the Endurance kit has them as an option, and the APR kit blows air on the face of the rotor.

[BatStig]

Originally Posted by Pat

I have been very happy with the Sprint kit. If I had a nit to pick, it would be replacing rotors due to heat stress cracking well before the thickness becomes an issue. The first rotors lasted me two years.
If I wanted to make them last longer, that would just mean getting them to run cooler, right? Are there any GOOD ducts for this kit? I don't remember ever seeing any. I know the Endurance kit has them as an option, and the APR kit blows air on the face of the rotor.

The kit from Verus has worked great for me and my Sprint kit.

http://www.verus-engineering.com/pro...oling-kit-ft86

[Pat]

Their website says, "Using the OEM fog lights as the inlet to the kit..."
I don't have fog lights. Does that matter?

[churchx]

Pat: one can purchase insert with opening for duct inlet. You can search on ft86sf or check which ones are suggested/linked in velox's duct kit thread.

JRitt: i'm sure that sprint and endurance kits are more then capable. Just that sometimes, when one reads all those nice technology bits in higher end stuff, there is some urge/itch to get no compromise (even if placebo compromise) best

[kch]

Sad to hear the radical isn't going to work out, but at the same time, that saves me quite a bit of money that i didn't need to spend

[JRitt]

Originally Posted by Pat

I have been very happy with the Sprint kit. If I had a nit to pick, it would be replacing rotors due to heat stress cracking well before the thickness becomes an issue. The first rotors lasted me two years.
If I wanted to make them last longer, that would just mean getting them to run cooler, right? Are there any GOOD ducts for this kit? I don't remember ever seeing any. I know the Endurance kit has them as an option, and the APR kit blows air on the face of the rotor.

Disc Cracking

Glad you're enjoying it! Just about all of our customers across all platforms crack their discs before they wear them thin. That's because they're all tracking their cars! There isn't anything abnormal or unusual about that, and why we don't even bother to publish a minimum recommended thickness for our discs.

How many track days are you getting out of your discs? Most of our customers are getting double, triple, or five times the track miles out of our discs vs. their stock ones.

Also, what tracks are you running? Disc life can vary greatly depending on the tracks you run. Disc cracking is due to expansion and contraction. In the ideal world you would take your discs to 1000F on the track and then they would stay there the entire time. If so, they wouldn't crack much. The problem is, every time you hit a brake zone and the following straight, you're running them through a expansion and contraction. On some tracks there aren't a lot of long straights, and corners come rapidly one after the next. On such a track, the discs maintain a more constant temperature, and you won't see as much cracking. The temps aren't swinging wildly from searing hot on huge brake zones, followed by huge blasts of cool air on long straights. On a track like Watkins Glen or Road America however, the layout is conducive to brake destruction! Long, fast straights lead to high speeds, followed by heavy brake zones for tighter turns...followed by more long straights. The disc temps have huge swings, and that expansion and contraction kills/cracks them more rapidly.

Finally, are you following our guide on disc replacement (When is it time to replace my iron disc rings?)? Many people prematurely replace them, even though they have lots of life left in them.

Brake Ducts

In our experience, aftermarket brake ducts on a production car aren't typically very effective for a couple reasons. 1) Air collection location- You may not be pulling the air from a good pressure spot on the front of the car. 2) Moving all that air- Even if you are pulling from an area on the front of the car designed to provide cooling air, there is too much junk in the nose to get a large enough hose from the front to the inside of the disc without pinching it down. Even if you get it through the nose, you then have to route it past the wheel without pinching it down and cutting off the flow as it passes the tire on the inner fender. 3) Directing that air- As noted, you don't want that air blowing on the disc face. That creates a temperature differential between the inner and outer disc, which will actually lead to more cracking vs. if you had no duct at all! 4) Trapping heat on the inner face- Many of the plates and attachment mechanisms for duct kits have some type of plate that covers part of the inner disc face, which is a no-no. That simply traps heat on the inner disc face, and causes the same temperature differential as above...except this time the inner is running hotter than the outer.

Many of the duct setups we see on purpose-built racecars at the pro level are multiple 4" hoses...in some cases as many as three of them leading to the discs and calipers. That's the type of air required to effectively cool, and it's just not attainable on a production car in most cases.

Hopefully that is helpful.

JRitt: i'm sure that sprint and endurance kits are more then capable. Just that sometimes, when one reads all those nice technology bits in higher end stuff, there is some urge/itch to get no compromise (even if placebo compromise) best

We totally get it. The Radi-CAL calipers are bad@ss, and they are far more advanced than any other caliper on the market period. That goes all the way up to NASCAR Cup, IMSA, F1, etc. They are the best, period. Sometimes want is enough justification!

[ZionsWrath]

I no longer have my car but I plan to buy another one in a couple years.


I had sprint kit and loved it. I will definitely buy a radical kit on my next car.


Your last post, I had heat checking like the second picture in the link. I had no issues with the brakes. No vibrations. Went through several sets of pads. And ultimately sold my AP sprint kit when I sold the car.

[Pat]

Originally Posted by JRitt

How many track days are you getting out of your discs? Most of our customers are getting double, triple, or five times the track miles out of our discs vs. their stock ones.

Also, what tracks are you running? Disc life can vary greatly depending on the tracks you run.

Finally, are you following our guide on disc replacement (When is it time to replace my iron disc rings?)? Many people prematurely replace them, even though they have lots of life left in them.

Thanks for the thorough response. While I don't keep track of tracks days, I would guess I get about 16-20 per year. Which means 32-40 for a set of rotors.
Most of the time I am driving High Plains Raceway, but also Pikes Peak International Raceway, Pueblo Motorsports Park, and La Junta. Once in a while I'll make it to other tracks like Motorsports Park Hastings, Miller, or Heartland Park, but have not driven those with these brakes yet.
Yes, I followed the replacement guide. I had cracks extending to the edges of my discs.