[dsm_mikey]

It will be interesting to see your FEEDBACK on these brakes. For me, the PAD THICKNESS and EASE OF CHANGE-OUT out would be a HUGE benefit!

You MAY not find that much additional time on the track if you were comfortable with the previous brake set up, BUT I think the BENEFITS with the AP RACING products are HUGE. Pad thickness (More laps with 1 set of pads), SS Pistons, unsprung weight loss, not to mention a TRUE TRACK focused braking setup versus an OEM COMPROMISED road/track setup.

I would definitely LOVE a set of these! I would do this modification before ANYTHING else to the car other than track wheels. With the speeds our cars are capable of and the WEIGHT, it would be GREAT to have this upgrade!

Good LUCK and we will be waiting on your REVIEW!

Mike

Originally Posted by 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]

Originally Posted by sr71bb

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

I see, so better than the hawks on the street as well

[olblue75]

I didn’t realize that OEM brakes a were a compromised system myself.

[dsm_mikey]

Any FEEDBACK after your trackday with your new brake setup?

THANKS!

[sr71bb]

Originally Posted by dsm_mikey

Any FEEDBACK after your trackday with your new brake setup?

THANKS!

Well actually YES. First off, after inspection of the brake system, I found there were NO signs of any heat damage that you would normally see on a ZL1 1LE set up. Specifically I would basically COOK even the high temp piston boots even after just ONE hard track day on the ZL1 1LE set up.

The AP Racing set up as mentioned before DOES NOT use piston boots so that point of failure is eliminated. Secondly, I changed out to the FERODO 3.12 track pads from the 2500 compound track/street pads while I was at the track and that MAYBE took less than five minutes per side after the wheels were off (I drove to track with my street tires and changed out to MICHELIN slicks at track).

I was using anti- rattle clips and the TWO 6MM retaining bolts with the AP Racing calipers. I have since started using the quick change spring caliper brake pad retaining clip that eliminates those two bolts which makes the pad changes even quicker.

I noticed that the gray anodized finish on the AP Racing calipers showed absolutely NO SIGNS of heat damage since as color fade. They basically still look brand new. The rotors after track use were showing signs that the pads were tracking VERY evenly across the surface of the rotor. What this indicated to me was that the brake piston pressure was more consistently applied than on the ZL1 1LE set up. A part of that I think is that the AP Racing calipers while considerably lighter (10 pounds per side); are much more rigid AND that the springs that are BEHIND each of the brake pistons were doing their intended job of maintaining more consistent pressure against the brake pads.

Over the next few weeks I will post up whether or not the AP Racing set up results in FASTER lap times. I have an SCCA time trials event at ECR and an APEX time trials event at MOTOSPORTS RANCH Cresson Texas.

I had an issue my last track test day with some slicks that were heat cycled out so I couldnt determine the actual performance difference at that time.

[olblue75]

So could you get away with not running the dust boots on the Brembo’s???

[cdb95z28]

The dust boots help protect the piston seals. Yeah, one could run without them but they should be thinking about maintaining the piston seals more often.

[sr71bb]

Originally Posted by cdb95z28

The dust boots help protect the piston seals. Yeah, one could run without them but they should be thinking about maintaining the piston seals more often.

On the AP racing set up the clearances of the pistons to piston bores appear to be MUCH tighter tolerances than what you see on the ZL1 stock set up. I am sure that is one of the reasons they can get away with NOT using the piston boots with the AP Racing caliper.

BREMBO by the way as I mentioned earlier OWNS AP Racing. The issues with the piston boots melting on the ZL1 stock set up is that seal could and DID on occasion impede the smooth operation of the piston being applied against the back of the brake pads.

ON NORMAL conditions this WOULD NOT be an issue with the piston boots but under extreme temperatures as in aggressive tracking the car, this is definitely a known issue.

Which goes back to the fact that the stock ZL1 BREMBO set up was not really designed for aggressive or frequent track use.

[RUQWIKR]

The stock dust boots are an easy maintenance item to change and are only in the $40 range per caliper. I’d rather have them than not to help minimize fine dust particles getting between the piston OD and bore OD. For me, I only need to change them typically once per year even with lots of track time. That’s even with front CCM rotors on my main track car (same PN 19207044 dust boots / seals).

Typical “racing” kits are designed with very short / frequent maintenance intervals. Most / if not all, of the “regular” AP kits for various vehicles have dust boots with pistons machined with the retention groove in them. Enough dust in the wrong place will end up with sticking pistons, and if the dust tears up the ID of the pressure seal down in the bore, then you’ll start to see fluid leakage. I would clean the inner caliper surfaces well each time pads come out if not after each event to try to minimize the concern.

[sr71bb]

Ok this last saturday June 17th, I ran a time trials event at EAGLES CANYON RACEWAY on the short course (1.65 mile) that I have never run on before.

There were 56 time trial participants that day with there being just a HALF second difference between the top 5 fastest times.

I ran a 1.14.06 (P5) but wasnt particularly happy with that time because I felt like I should have been somewhat faster even with the 100 degree temps. I found after I inspected my tires that ONE of them was missing a fairly large portion of rubber in the contact area of the tire. These were TAKEOFFS but it was their first track session I have used them so needless to say that certainly was costing me some track time. I had a SPARE tire I could have mounted but I didnt discover the tire issue until AFTER the track sessions were completed.

The AP Racing brakes performed flawlessly and they were allowing me to brake ABOUT one track marker LATER.

This coming Saturday I will be at the APEX time trials at Motorsport Ranch CRESSON on the 1.7 (CW). Here I can see just how well these brakes work since I will have more comparable data.

[sr71bb]

This was the tire I was having issues with below. There was a layer of melted rubber that was hiding this damage. I knew though that my top speed was increasing with each session but my lap times were not improving

[RUQWIKR]

Originally Posted by sr71bb

Ok this last saturday June 17th, I ran a time trials event at EAGLES CANYON RACEWAY on the short course (1.65 mile) that I have never run on before.

There were 56 time trial participants that day with there being just a HALF second difference between the top 5 fastest times.

I ran a 1.14.06 (P5) but wasnt particularly happy with that time because I felt like I should have been somewhat faster even with the 100 degree temps. I found after I inspected my tires that ONE of them was missing a fairly large portion of rubber in the contact area of the tire. These were TAKEOFFS but it was their first track session I have used them so needless to say that certainly was costing me some track time. I had a SPARE tire I could have mounted but I didnt discover the tire issue until AFTER the track sessions were completed.

The AP Racing brakes performed flawlessly and they were allowing me to brake ABOUT one track marker LATER.

This coming Saturday I will be at the APEX time trials at Motorsport Ranch CRESSON on the 1.7 (CW). Here I can see just how well these brakes work since I will have more comparable data.

See you out there Saturday in the crazy hot and miserable weather. Says Heat Index of 110F towards the end of the event and Heat Index of 100F by 11am. Yep, Texas, yep summer.

[wakespeak]

Track temp at COTA today was 146F!

[sr71bb]

Originally Posted by RUQWIKR

See you out there Saturday in the crazy hot and miserable weather. Says Heat Index of 110F towards the end of the event and Heat Index of 100F by 11am. Yep, Texas, yep summer.

Good Deal, Dave!! I have no doubt we will see our best times before NOON and probably in the first 10 minutes of the session. I guess we are in GROUP B or what they call the PURPLE group??? I am going to start out with cold tire pressure of 23-24 but I may have to drop that slightly to allow for a 8-10PSI increase in pressure we normally see with 95+ degrees . I just replaced another starter that I have cooked and we put some additional shielding on it. I guess I am going to have to install some hood vents although I dont particularly like the looks of them.