[SCCAForums]

Looking forward to the results.

[sr71bb]

OK here a few pics of me and car at ECR!! LOL

I only ran ONE session of the four sessions because I cooked my starter. THAT run is in the YOUTUBE video in my signature below.

[sr71bb]

Originally Posted by SCCAForums

Looking forward to the results.

My next track time is MAY 6th at Motorsports Ranch 1.7 CCW so I will post up results. Weather permitting I am hoping for a personal best but I will post up either way.

[GunMetalGrey]

Originally Posted by sr71bb

Ok Guys,

AMP has just done a VERY Serious Brake upgrade on my car that really had a pretty substantial brake system on it to begin with but I thought THIS was necessary to push it to another level.

What you see here is an AP Racing (ESSEX) HEAVY DUTY (D62 width pad) with 390MM Rotor and YES it WILL FIT with my 18 inch APEC EC-7 ET25 19 x 11 inch wheels.

I will go into MORE specifics on the OPTIONS on this system and why it was spec out the way it was SHORTLY in some more posts that will follow.

Honestly, I don’t know what the heck I was thinking when I bought the Giro disc front rotors, for some reason I thought they were the only option for something that would cool better than stock OEM rotors, but I could’ve bought rotors from Racing Brake that were still 390 mm diameter stock OEM size also with directional vanes for cooling like the Girodisc

[sr71bb]

Originally Posted by GunMetalGrey

Honestly, I don’t know what the heck I was thinking when I bought the Giro disc front rotors, for some reason I thought they were the only option for something that would cool better than stock OEM rotors, but I could’ve bought rotors from Racing Brake that were still 390 mm diameter stock OEM size also with directional vanes for cooling like the Girodisc

YES but because the rotor hats are BIGGER on the GIRODISC rotors and made out of a lighter material resulting in it being 4.8 pounds LIGHTER, THAT is the advantage of the GIRODISC rotors over others. Its not just the cooling vanes. It takes LESS energy to stop a 4.8 pound lighter spinning disc.

[GunMetalGrey]

Originally Posted by sr71bb

YES but because the rotor hats are BIGGER on the GIRODISC rotors and made out of a lighter material resulting in it being 4.8 pounds LIGHTER, THAT is the advantage of the GIRODISC rotors over others. Its not just the cooling vanes. It takes LESS energy to stop a 4.8 pound lighter spinning disc.

Totally, but I think that would be very hard to measure the gains from, I am much more interested in the primary purpose of brakes; to repeatedly and safely stop a 4000lb thousand pound car with 800 hp when driving like a maniac! Hence I want thermal capacity and heat dissipation. Racing brakes says that they’re rotor only weighs 28.2 pounds so it seems like the best option in superior to both the stock OEM rotors as well as the Girodisc option.

[sr71bb]

Ok well THIS saturday I will be out at Motorsports Ranch Cresson TX on the 1.7 CCW to see if I can do a personal best with these FRONT AP Racing Brake set up.

A few notes at to WHY I chose this specific set up. First off I chose to get the CP9668 Caliper set up. This SPECIFIC caliper allows you to run the THICKER brake pads. To be exact 25MM brake pads (1 inch thick). This brake pad is almost TWICE as thick as the pads used with a ZL 1LE caliper as a comparison.

There are TWO versions of the CP9668 caliper set up and the HEAVY DUTY version which I opted for uses a D62 PAD (pad radial width is 62MM). The NON-Heavy Duty version uses a D54 PAD (pad radial width is 54MM)

WEIGHT Savings. This BIG BRAKE kit is 20 POUNDS Lighter than a stock ZL1 1LE set up. The CALIPERS DO NOT use piston boots (they are bootless). The pads can be changed out in a few minutes by loosening TWO 6MM Torx bolts. They also provided a spring clip that you can use INSTEAD of the two 6MM TORX bolts but THEN you cant use the anti-rattle clips.

I chose the 390MM rotor setup although technically you could choose to go with the 372MM Rotor (they use these on Corvette C8 set up).

I opted to get the anti-rattle clips for the calipers. These clips will keep the pads from making alot of racket as they shift as pressure is being applied to them. For a track car its NOT Necessary but for a street car, they are a MUST.

So the bottom line is I chose the largest rotor available, biggest caliper and widest PAD. I verified that THEY WILL fit inside my 18 x 11 APEX EC7 ET25 wheels. Essex offers a template which you can print out and then I transferred to a piece of poster board and then I checked it on a loose wheel.

Just to be on the safe side, I sent the template to APEX Wheels and their engineers CONFIRMED that the 18 inch wheels I currently have had enough clearance.

I purchased TWO sets of brake pads with the big brake kit. I got a set of FERODO 3.12 track pads which I will run saturday. The second set which is installed currently is a set of FERODO 2500 PADS. This is their high performance street pad and I have been pleased with them so far.

In case you were not aware, BREMBO owns AP racing which is a distributor for www.essexparts.com.

There is a WEALTH of information on their website regarding their offerings complete with videos.

Anyway, more to come later!!!!

[GunMetalGrey]

I had no idea Brembo owns AP racing.

That quick change brake pad option sounds great!

[sr71bb]

OK guys, one of the major selling points of the AP Racing Brake set up according to them is that the serviceability and maintainence is MUCH easier vs the stock setup. Another significant factor is that the AP Racing is 20 pounds LIGHTER than the stock ZL1 1LE set up in total by comparison.

I had chance to test that theory after I did some track testing the other day. The FIRST thing that happened towards the end of the day is that I broke a wheel stud and as you know that is pretty much a pain in the ass on the ZL1 1LE brake setup because it requires the removal of the brake caliper which is held on by TWO 18MM bolts. The problem with those bolts is that it is hard to get the proper torque on them when you reinstall them and they can easily strip out if you arent careful.

So below you will see that the AP racing caliper is actually attached to a SEPARATE BLACK Billett caliper bracket that you never have to remove and THAT bracket has TWO Studs that are actually parallel to the ground that the caliper slides over and TWO 14MM nuts attach the caliper to the bracket. So to take the caliper OFF the car, you just unbolt the two nuts and the caliper will slide off to the left (assuming passenger side).

Another issue that the AP Racing setup solves is pad changes are MUCH Easier and Much LESS FREQUENT because the pads are 25MM (1 inch thick - see pic). This assumes you are using the CP9668 caliper. In my PARTICULAR case I chose the HEAVY DUTY version of the CP9668 caliper which uses 62MM width pads as compared to the standard 54MM width pads. To change the pads you simply unbolt the TWO allen headed bolts you see in the pic of the caliper.

Another PIC of the inside of the caliper shows the brake pistons ; which of course AP Racing will tout as a selling point; is that these calipers DO NOT have piston boots. So the days of cooking the silicone boots SHOULD be over.

My NEXT track day I will be running DS 3.12 front pads on the AP Racing Caliper setup and I will run DTC60 pads on the stock ZL1 1LE rear rotors. The AP Racing system is designed to allow for the use of the stock rear brake system.

Of course the million dollar question is, '"Are these calipers worth the money?"

In the next few weeks I will try to determine that. Ultimately for me personally, if I can be significantly FASTER with this set up compared to the MODIFIED ZL1 1LE set up then that would be a YES. Is it worth it for the VAST majority of people probably NOT.

[sr71bb]

You can use as I mentioned the AP Racing Set up on the FRONT of our cars WITHOUT changing out the rear set up and it WILL NOT upset the brake bias that is built into our cars because they design the system to MATCH the brake torque characteristics of the STOCK GM set up. . The statement BELOW is DIRECTLY from the Essex parts website and contains some useful info:

Q: Is it okay to just buy your front-only brake kit? What about the rears?

A: Our front brake kits are designed to very closely mimic the OEM torque output on the front axle.That is accomplished by carefully sizing the discs and caliper pistons.For example, if we increase the disc diameter in our kit vs. stock, we decrease the overall piston area to produce the same overall torque output as the factory setup.As such, installing our front kit on your car will only have a negligible impact on brake bias.In most cases, the shift in brake bias is only in the 2-3% range.To put that in perspective, installing a more aggressive brake pad compound in your factory front calipers would typically have a greater impact on brake bias than installing our front kit while keeping the OEM front pad compound.

On most front-engine sports cars, the front brakes are taxed much more heavily than the rear brakes.That's why the front brakes are almost always larger, and why you go through 2-3 sets of front pads and discs for every set of rears you burn up at the track.The fronts do a disproportionate amount of work, and as such, they are the most critical component to upgrade.On many platforms, rear brake upgrades offer diminishing returns.The rear factory components tend to be smaller and lighter than the front components.As such, switching to AP Racing calipers and discs don't usually offer the dramatic unsprung weight savings that they do on the front.Since the rears tend to not run as hot, simply running good race pads and stainless steel lines on the rear will solve or prevent any rear brake issues.

On a rear-engine car, the rear brakes do a proportionately higher amount of work than on a front-engine car.As such, brake wear tends to be more balanced on the front and rear, and rear upgrades can be more relatively more important to the overall system performance.

Q: Will your brake kit mess with my ABS, stability control, torque vectoring, or disrupt my front to rear brake bias/balance?

A: No!Since our systems closely mimic the factory brake torque output on a given axle as described above, they have no noticeable impact on ABS, stability control, torque vectoring, etc.The brake pedal will feel much better due to lower compliance, and the brakes will take a far greater beating for considerably longer.You won't have any wonky ABS issues however.

Reference website (look under FAQ):
https://www.essexparts.com/ap-racing...m-camaro-gen-6

[JTRATX]

Originally Posted by sr71bb

I will be going with XP20 compound on the FRONT and XP12 compound on the rear.

How did you like those pads? Did they get a fair shake before the BBK?

[sr71bb]

Originally Posted by JTRATX

How did you like those pads? Did they get a fair shake before the BBK?

The XP20's DO NOT have the initial bite of the DCT-70's and they actually wore out FASTER than the DCT-70s'

The Xp12's wore MUCH better than the XP20's but they as well DID NOT have the same bite as the DCT60's did

These pads dust MUCH less than the HAWK pads did and they were easier on the rotors.

[GunMetalGrey]

Originally Posted by sr71bb

The XP20's DO NOT have the initial bite of the DCT-70's and they actually wore out FASTER than the DCT-70s'

The Xp12's wore MUCH better than the XP20's but they as well DID NOT have the same bite as the DCT60's did

These pads dust MUCH less than the HAWK pads did and they were easier on the rotors.

Wow those XP20’s are joke then because they also cost more than the DTC70s

[sr71bb]

Originally Posted by GunMetalGrey

Wow those XP20’s are joke then because they also cost more than the DTC70s

Well I also used these pads as my street pads as well so in that regard they were decent because they definitely were better on the street than the stock brembos were but just not as track capable as the hawks