The Evolution of Brakes:Essex/AP Racing Radi-CAL Pro5000R Comp. Kits, must see!

[jritt@essex]

Originally Posted by skru_fase

These look too good to be hidden behind wheels!

Thank you sir! They are indeed pretty. Anybody who has any interest in technology, machine work, or racing always gets a big smile when you drop one of these bad boys in their hands!

[d0o0fy]

Originally Posted by jritt@essex

AP has pushed back delivery on their new four piston rear Radi-CAL calipers several times. No need to worry though, they are indeed coming! Based on our most current information, we expect to start shipping rear e90/e92/e93 kits by April 1st. We have added the new rear kit to our website. The standard hardware that typically comes with our Competition Kits is included: Calipers, two-piece discs, mounting hardware, Spiegler brake lines, detailed instructions. It will shave 16-17 unsprung lbs. from the rear of the car, and parking brake function is fully retained!

As with most new caliper launches, AP has told us that we'll only be receiving a limited number of the new calipers. Since demand for these rear kits has been growing dramatically, we're a bit concerned that we may not have enough calipers in the first shipment to cover all demand. Therefore we are opening pre-orders starting today.

• Customers who already purchased our front kit will receive priority for a matching rear kit.

• We will ship kits out in the order in which the reservations are received. If you definitely want a rear kit, get your order in ASAP!

• To reserve your kit, please call one of our sales associates at 704-824-6030 and give them all of your information. We will not be collecting credit card numbers at this time. When the kit is ready to ship, we will call you back and get your payment info.

• Please note any accessories that you'd like with your kit...race pads, autox pads, fluid, pad tension kit, disc burnishing, etc. Also, if you already have our front kit and will be needing more pads for those, please let our sales people know.

• If you ordered your front kit through one of our authorized resellers, you can have them call and reserve your rear kit.

Thanks so much for your continued support gents! The new rear kits are going to be killer, and a beautiful complement to the front kits you've all been enjoying. Below are some fresh family pics of the Pro5000R caliper range.

























temporary image hosting

Pre-order's in. Thanks!

[Pistonheed]

Hi,

Does anybody know if there is any disadvantages to running the 25mm CP9668 calipers compared to the 18mm CP9660 calipers?

I'm not sure why anybody would opt for the 18mm pads when the price difference between kits is so small (only 10%). 25mm pads will last longer, obviously, and offer ~40% more pad life at only a ~12% price increase.

Below is a direct quote from Essex parts website. https://www.essexparts.com/essex-des...668372mm-e92m3

"the CP9668 caliper: It is about a pound heavier (including the difference in pad weight), and roughly 14mm wider than the CP9660. You will lose that 14mm on wheel spoke clearance vs. the CP9660 kit"

I appreciate if you are serious about weight loss then the CP9668 calipers and 25mm pads will be heavier but I'm happy to sacrifice that weight.

What I'm confused about is wheel clearance. I appreciate the caliper will be 14mm wider but I would have thought the caliper will only poke out 7mm more than before?? If it was to poke out 14mm then surely the disc would need to move to keep it central??

Thanks

[merakulous]

Originally Posted by Pistonheed

Hi,

Does anybody know if there is any disadvantages to running the 25mm CP9668 calipers compared to the 18mm CP9660 calipers?

I'm not sure why anybody would opt for the 18mm pads when the price difference between kits is so small (only 10%). 25mm pads will last longer, obviously, and offer ~40% more pad life at only a ~12% price increase.

Below is a direct quote from Essex parts website. https://www.essexparts.com/essex-des...668372mm-e92m3

"the CP9668 caliper: It is about a pound heavier (including the difference in pad weight), and roughly 14mm wider than the CP9660. You will lose that 14mm on wheel spoke clearance vs. the CP9660 kit"

I appreciate if you are serious about weight loss then the CP9668 calipers and 25mm pads will be heavier but I'm happy to sacrifice that weight.

What I'm confused about is wheel clearance. I appreciate the caliper will be 14mm wider but I would have thought the caliper will only poke out 7mm more than before?? If it was to poke out 14mm then surely the disc would need to move to keep it central??

Thanks

Probably the wheel clearance is the biggest disadvantage. According to the website, the narrower one can accommodate the stock wheels. The wide caliper is going to stick out more and could hit the back of the wheel spokes requiring spacers etc.

[Pistonheed]

Originally Posted by merakulous

Probably the wheel clearance is the biggest disadvantage. According to the website, the narrower one can accommodate the stock wheels. The wide caliper is going to stick out more and could hit the back of the wheel spokes requiring spacers etc.

Thanks for your reply.

Not sure I like how they word this. Surely the wider calipers will fit behind the stock wheels if you run a spacer? And if I'm right about the caliper only moving by 7mm then you will only need a 10mm (common size) spacer to make everything fit.

Hopefully jritt@essex will be able to answer the queries.

Also, I managed to go off on a tangent and wasn't very clear on my main question. So...

Does anybody know the pros and cons to running 25mm pads compared to 18mm pads?

Will the 25mm pad take longer to get up to temperature?
Will the 25mm pad last longer before overheating?

[VictorH]

Does anybody know the pros and cons to running 25mm pads compared to 18mm pads?

There will be no difference in time to operating temp. The kinetic energy to heat converter is the rotor which should reach operating temp in the same amount of time irrespective of the pad thickness.

Advantages of thick pad option
Longer life
Possibly less heat transfer to the caliper when new or partly worn

Disadvantage of thick pad option
Wider caliper to hold thicker pads
More expensive, though cost to life of pad might be equivalent
Heavier (slightly)
Bigger fluid shift in your brake fluid reservoir when you retract the pistons to put the new pads in particularly if you run your pads all the way down

Some people argue that when the piston is way out running a thick pad that has worn down there's more possibility of movement of the piston (not as much is in the sleeve at that point) but with good modern calipers I don't think that's an issue.

What did I decide? I'm going with the thick pad option. Fewer pad changes, less hassle and equal performance.

[Pistonheed]

Originally Posted by VictorH

Does anybody know the pros and cons to running 25mm pads compared to 18mm pads?

There will be no difference in time to operating temp. The kinetic energy to heat converter is the rotor which should reach operating temp in the same amount of time irrespective of the pad thickness.

Advantages of thick pad option
Longer life
Possibly less heat transfer to the caliper when new or partly worn

Disadvantage of thick pad option
Wider caliper to hold thicker pads
More expensive, though cost to life of pad might be equivalent
Heavier (slightly)
Bigger fluid shift in your brake fluid reservoir when you retract the pistons to put the new pads in particularly if you run your pads all the way down

Some people argue that when the piston is way out running a thick pad that has worn down there's more possibility of movement of the piston (not as much is in the sleeve at that point) but with good modern calipers I don't think that's an issue.

What did I decide? I'm going with the thick pad option. Fewer pad changes, less hassle and equal performance.

Brilliant, exactly what I was looking for. Thanks

[jritt@essex]

Victor H covered the pad issues pretty well, thank you.

The CP9660 caliper body itself is 163.1mm wide, while the CP9668 is 188mm wide, a difference of 24.9mm. However, Radi-CAL calipers are inherently asymmetrical (the inner caliper half is a different width than the outer half), so you can't just divide the total width by two to compare spoke clearance across calipers like you would with an older style of caliper. If you look at the top left pic in the installation drawings below, you'll see the dimensions for the outer caliper half. The CP9660 outer half sticks out 91.21mm from the disc center line, and the CP9668 sticks out 102mm, a difference of 10.79mm. The shape of the outer caliper halves is slightly different on the two calipers along its arc however. That means they will fit behind wheel spokes in slightly different ways along that path (also keep in mind that a wheel spoke is typically curving along its path as it moves away from the hub to the barrel). At any rate, you really must check the wheel fitment templates to be certain on any wheel you plan to run (links below). That's why we provide them! So with regards to fitting behind stock wheels, you'll need a spacer with the wider CP9668's, and longer bolts or wheel studs to make sure you have enough thread engagement to hold the wheel securely.

The offset is the same on both calipers at 42mm (distance from the center of the mounting holes to the center-line of the disc), which is what allows both calipers to be run on the same bracket and disc.

You can see the installation drawings in the links below:
CP9660 installation drawing

CP9668 installation drawing

Front wheel fitment templates are here:

Front CP9660/372mm e92 M3 wheel fitment template

Front CP9668/372mm e92 M3 wheel fitment template

ps I believe I got that 14mm number from my engineering director for a specific wheel application quite a while back...it may have been in reference to a Corvette application.

[jritt@essex]

Hello Gents,

Just an FYI...pre-orders for rear Radi-CAL brake kits will start shipping out today! One of our sales staff will be calling to collect your updated payment info. Please let them know if you need any extra pads, fluid, pad tension clips, etc. Thanks so much again to all of you who pre-ordered, and we hope you enjoy your matching rear brakes!

[slicer]

Originally Posted by jritt@essex

Hello Gents,

Just an FYI...pre-orders for rear Radi-CAL brake kits will start shipping out today! One of our sales staff will be calling to collect your updated payment info. Please let them know if you need any extra pads, fluid, pad tension clips, etc. Thanks so much again to all of you who pre-ordered, and we hope you enjoy your matching rear brakes!

Excellent! I'm looking forward to getting my set.

[Chuck's M3]

Few contribution photos for the thread. Thanks again Jeff!








More personalized photos (including installation notes) on my daily driver thread. Start Post#34.
http://www.m3post.com/forums/showthr...0#post21665490

[jritt@essex]

Wow! The car looks stunning! I'm extremely jealous right now!

[Dreamer99]

Has anyone tried this Ap Racing Radi Cal Competition Brake Kit Front Cp9660372mm package with their 219M wheels? I'm just wondering if spacers would be required.

Also, does the Pro5000R rear kit have a 365x30mm rear disc?

[slicer]

A few pics of the front and rear kits installed. I love them so far. I will be giving them their first track use in a few weeks at Sonoma

[Dreamer99]

OK I got a little impatient waiting for someone to reply to my 219M fitment question so I pulled my front wheel and used the AP Racing CP9660 wheel clearance template. Looks like it works. The pictures below show the gap is about the thickness of the wheel weights. I may just have to get them moved a little further out. What do you think?

Also, I assume the rear would have more clearance so did not check it.

[Chuck's M3]

Originally Posted by Dreamer99

Has anyone tried this Ap Racing Radi Cal Competition Brake Kit Front Cp9660372mm package with their 219M wheels? I'm just wondering if spacers would be required.

Also, does the Pro5000R rear kit have a 365x30mm rear disc?

Assuming you are shopping for the e9x m3...
https://www.essexparts.com/essex-des...49-34028-e90m3
"One pair 340x28mm AP Racing CP3864, 60 vane, J Hook racing discs, with fully floating 6061 hard anodized aluminum hats and attachment hardware"

It is a 340x28mm rear disc.
Cannot help test fit 219m (front or rears) unless someone near Seattle wants to test fit on my car... I only have the 220m and m359 wheels and dont require any spacers for wheel or suspension clearance. When inquired for arc8 squared18 and staggered 19), recall response was spacers to clear my ohlins r/t, not brakes (for selected offset). Decided to stick with known m359 - despite the weight.

Good luck!

Btw, looking good slicer!

[jritt@essex]

Originally Posted by slicer

A few pics of the front and rear kits installed. I love them so far. I will be giving them their first track use in a few weeks at Sonoma

Looks awesome! Thanks for sharing the pics.

[jritt@essex]

Originally Posted by Dreamer99

OK I got a little impatient waiting for someone to reply to my 219M fitment question so I pulled my front wheel and used the AP Racing CP9660 wheel clearance template. Looks like it works. The pictures below show the gap is about the thickness of the wheel weights. I may just have to get them moved a little further out. What do you think?

It's really tough to tell from pics, but our recommendation is that you have at least 2mm of clearance from everything surrounding the caliper. Everything flexes a little under load, and you want to make sure the wheel won't deflect into the caliper.

Below is a good example pic of a tight fitment that has been working for our customers. It's a CAD model of one of our kits fitting into a Corvette OEM wheel. It gives a relative idea of just how tight you can get without issues. Once you mount the wheels, you just need to slowly rotate the wheel and make sure there are no weights in the caliper path, etc.

Hopefully that helps!

Also, I assume the rear would have more clearance so did not check it.

You are probably correct on the rears. We never seem to have any issues on rear wheel clearance. That said, my advice is never assume anything!

[Dreamer99]

I'm seriously considering the CP9660 front kit and a rear CP9449 kit as it looks like they will fit behind my 219M 18" wheels without the use of spacers. The question I have is what combination of pads should I consider? One set would be for daily and winter usage so don't want noisy pads and a second set to swap in for track days but have to be able to drive to and from the track with the pads in.

On the track sometimes I feel like I'm too aggressive initially on the brake pedal so maybe a pad with a progressive bite. If I stick with the same brand would it take less bedding?

[Dreamer99]

Looks like some "branded" options are:

CarboTech 1521 and XP8
Hawk HPS and DTC60
Stoptech 308 and SR?

I'm not sure about Ferodo as I think the DS2500 would be too noisy as a daily pad

[roastbeef]

Originally Posted by Dreamer99

I'm seriously considering the CP9660 front kit and a rear CP9449 kit as it looks like they will fit behind my 219M 18" wheels without the use of spacers. The question I have is what combination of pads should I consider? One set would be for daily and winter usage so don't want noisy pads and a second set to swap in for track days but have to be able to drive to and from the track with the pads in.

On the track sometimes I feel like I'm too aggressive initially on the brake pedal so maybe a pad with a progressive bite. If I stick with the same brand would it take less bedding?

Originally Posted by Dreamer99

Looks like some "branded" options are:

CarboTech 1521 and XP8
Hawk HPS and DTC60
Stoptech 308 and SR?

I'm not sure about Ferodo as I think the DS2500 would be too noisy as a daily pad

i might be able to provide some feedback. i have the 5060 kit up front and oem rear rotors/calipers. with the 5060 kit up front, i ran ds2500 pads. felt great, just like oem. no more noise/etc., even when cold. with the oem rear and ds2500 pads, i got a little bit of screeching. they never seem to get up to operating temperature. with one of these kits, its going to be easy to swap pads, and i'd go for the softest street pads you can find just to keep noise down.
i have been told that if you stick with ferodo pads on the same rotor and swap them (like ds2500's for the street and dsuno's for the track) that you don't have to bed them each time.
if you're aggressive on the brakes, you might actually like a higher bite pad. i use dsuno's at the track, and when i recently tried ds1.11's, i found myself missing the initial bite. the uno's are a little more expensive, and they last about the same amount of time.

[Chuck's M3]

Originally Posted by Dreamer99

Looks like some "branded" options are:

CarboTech 1521 and XP8
Hawk HPS and DTC60
Stoptech 308 and SR?

I'm not sure about Ferodo as I think the DS2500 would be too noisy as a daily pad

Sent you a PM with video links of track session cabin view(windows down). First min or so should give you an idea what the ds2500 sounds like as i make my way through the paddock at low speeds. amteur driving is boring so dont watch the rest! otherwise you might see how ths ap racing stopped me from going off track in the second video

-Charles