In the market for a Z...

[kramard]

Hi guys,

I've been lurking here for months and am finally close to pulling the trigger on a Z/28. I've been tracking / DDing a 135i w/ tune and 245s on all four corners for the last two years. My 135i is great, but I'm looking for a NA car and more power .

Been between an e90 M3 or Z/28 and I just can't get over what a value the Z is. I'm a very performance oriented car owner.

My questions as follows:

- CCBs: How many track days would the rotors last? How many track days would a set of pads last? I run Summit Point 1 - 2x a year and in my 135i begin to slow from an indicated 135mph to 40mph on the front straight. When on the track I try to corner at 8/10ths+ but try to use the brakes at 6/10ths or less. I don't out right race, so lap times are less important than the experience. I'm very close to Group 2 (got all 5s on my last session but needed another instructor for a final check to solo).

- Trofeos: Are they down right dangerous in wet or cold weather? Obviously, no snow. But since I'd be buying this car going into winter and it would be my primary (while not my only, we have a Grand Cherokee) this car could see highway commutes in dry 20 degree winter temps. When the Trofeos wear I'd look at RE11 or Super Sports (have super sports on my 135i and Love them - I've had no issues at the track but I run a higher than average PSI). I live in DC so have to plan for a cold Jan / Feb.

- Mechanical issues? Any thing to be aware of when buying used beyond normal used car buying concerns? The car I'm looking at has a slightly discolored intake but everything else seems ok from my review today. The car has the hood vent insert so I'm not sure what could have caused the intake to have a whiteish discoloration. From a lot of the reviews I've read mechanical issues seem to be at a minimum but I've reviewed the engine braking thread and seen a few tuned LS motors go boom. Ultimately, part of me avoiding the e90 / e92 m3 is the ongoing rod bearing drama.

Would love your guys thoughts on the above.

Thanks in advance and here's to joining the club soon!

[Zslash28]

I would not drive on stock tires as a DD in those temps. Not saying I have not driven into work below 20*, but in the DC area, forget it.

Ive seen enough of these, and I have noticed the intake elbow having a white chaulky appearance. I think this is the material doing its thing, a quick wipe down should take care of it. (Ive seen pics of nearly 500 Z/28s)

[Schlok]

Originally Posted by Zslash28

I would not drive on stock tires as a DD in those temps. Not saying I have not driven into work below 20*, but in the DC area, forget it.

Ive seen enough of these, and I have noticed the intake elbow having a white chaulky appearance. I think this is the material doing its thing, a quick wipe down should take care of it. (Ive seen pics of nearly 500 Z/28s)

Negotiate the tire swap in your purchase, that's what I did. Don't drive on those tires in those conditions. I had a Z06 and it was dicey with the super sports sometimes.

[D2M]

From my experience I have gotten 6 to 7 days from the brake pads. My car wears both front and rear at an equal rate. I have spoken to a few Z06 guys and they get anywhere from 6 to 8 pad changes before the rotors need replacing, I will weigh mine on the 5th pad change. When the car needs 4 rotors it makes more sense to trade it in.

I have been to Summt before but not in my Z28. The Z is a brick and is not that fast on the straights, you will find Vettes and such pulling away on the straights.

For DD get rid of the Trofeos, the Z does well on a good street tire on track.

[Stephen12ZL1]

Originally Posted by kramard

Hi guys,

I've been lurking here for months and am finally close to pulling the trigger on a Z/28. I've been tracking / DDing a 135i w/ tune and 245s on all four corners for the last two years. My 135i is great, but I'm looking for a NA car and more power .

Been between an e90 M3 or Z/28 and I just can't get over what a value the Z is. I'm a very performance oriented car owner.

My questions as follows:

- CCBs: How many track days would the rotors last? How many track days would a set of pads last? I run Summit Point 1 - 2x a year and in my 135i begin to slow from an indicated 135mph to 40mph on the front straight. When on the track I try to corner at 8/10ths+ but try to use the brakes at 6/10ths or less. I don't out right race, so lap times are less important than the experience. I'm very close to Group 2 (got all 5s on my last session but needed another instructor for a final check to solo).

- Trofeos: Are they down right dangerous in wet or cold weather? Obviously, no snow. But since I'd be buying this car going into winter and it would be my primary (while not my only, we have a Grand Cherokee) this car could see highway commutes in dry 20 degree winter temps. When the Trofeos wear I'd look at RE11 or Super Sports (have super sports on my 135i and Love them - I've had no issues at the track but I run a higher than average PSI). I live in DC so have to plan for a cold Jan / Feb.

- Mechanical issues? Any thing to be aware of when buying used beyond normal used car buying concerns? The car I'm looking at has a slightly discolored intake but everything else seems ok from my review today. The car has the hood vent insert so I'm not sure what could have caused the intake to have a whiteish discoloration. From a lot of the reviews I've read mechanical issues seem to be at a minimum but I've reviewed the engine braking thread and seen a few tuned LS motors go boom. Ultimately, part of me avoiding the e90 / e92 m3 is the ongoing rod bearing drama.

Would love your guys thoughts on the above.

Thanks in advance and here's to joining the club soon!

CCB brakes are very good in the wear category. Thank goodness, as they are insanely expensive to replace. You have to be super careful when removing and reinstalling the wheels as not to chip the edges of the rotors. The pads last longer than steel counterparts too. I have many (14+) track days on a set of front pads and the rear pads are still stock after many more track days. The performance of a CCB isn't off the charts better than the ZL1 steel brakes with race pads, but the wear difference is incredible.

The driveline is very solid with only a few rare incidents of valve dropping in the LS7, but it has happened. My modified LS7 dropped a valve after 2000-2500 track miles. Transmission, clutch. rear, axles, etc. are very sturdy and up to the task of track thrashing. That white residue is on the rubberized part of the intake elbow and comes off with a little spray of armor all like protectant. Good luck with the purchase and go for it. $50k is a steal for a Z/28 considering the equipment you get for the $.

[XTREMZ]

My Z/28 has 10 track days and I just went through the first set of pads. The front rotors are starting to get somewhat rough, I expect the pads to start wearing out more quickly. My friend has 21 track days on his Z. His rotors now are very rough and he's going through pads much more quickly. My best guess is that you'll get 20 days at Shenandoah on your rotors, maybe somewhat less. My rear rotors are still smooth. They will last a lot longer than the fronts.

I live in Metrowest Boston. The day I test-drove the Z, it was about 45- 50 degrees outside. Went into a corner, added a touch of throttle and the rear end stepped out! Salesman was real quiet... The Trofeos are no good in the cold.

I bought that Z a year ago for $55k. 12 miles on odometer. I decided to use the savings to buy a second set of wheels and winter tires. Made a big difference.

I put the Trofeos back on in the Spring. They lasted 4 track days. Great grip, but not much communication.

Using Nitto -01s now. Very satisfied with them.

Have 7,000 miles on the car and zero issues so far, knock on wood!

Go for the Z!

[kramard]

Thanks guys. Appreciate the guidance - definitely encouraging insight.

Does anyone know what the cost to change the CCBs is? Is it simply changing rotors and pads or is there more I need to price? Also, both cars I'm looking at have 5K miles on them and are in the 45K neighborhood. One's from a Chevy dealer, the other is from a Ford dealer. What's the best way to check wear on the CCBs? Want to make sure I'm not getting a car w/ 10 track days already.

Stephen12ZL1 - do you know why your LS7 failed?

Thanks again.

Dave

[D2M]

OEM pads will be around $420 per axle.

Rotors will be around $1200 / $1300 per corner give or take.

If the pads have a white chalky look to them then they have been tracked if they are black then they have not gotten hot enough to burnish. The more white the more heat they have been exposed to. As for the rotor if the area where the pad rides looks like the inner part be the mounting hat then they have not seen rough use. It you have a hard time seeing the carbon weave like on the inner part then they have been used on track.

[shadowhunter66]

Originally Posted by D2M

OEM pads will be around $420 per axle.

Rotors will be around $1200 / $1300 per corner give or take.

If the pads have a white chalky look to them then they have been tracked if they are black then they have not gotten hot enough to burnish. The more white the more heat they have been exposed to. As for the rotor if the area where the pad rides looks like the inner part be the mounting hat then they have not seen rough use. It you have a hard time seeing the carbon weave like on the inner part then they have been used on track.

Does anyone have photos to compare the two differences?
Would love to see for future reference!

[hjdca]

Originally Posted by shadowhunter66

Does anyone have photos to compare the two differences?
Would love to see for future reference!

Hello, Here is a picture of my front passenger rotor and pad. 2015 black Z/28 with 550 street miles, not tracked. I did not burnish the brakes and I do not think the dealer who owned it did either. It had 300 dealer owned miles on it when I got it.

Gotta love those Z/28 rims. No problem inspecting the pads and rotors with the rims on. Cool ..

Speaking of Brakes, today, on the way to the DMV, I see a yellow light, so, I hit the Z/28 to make it, but, I am feeling kinda late on the light, then I see a police car facing the other way on the other side staring at me. So, I hit the brakes hard, the Z/28 stops fast, but, I am still in the middle of the intersection... So, I sheepishly let off the brakes and coast through.. thinking I am toast... Surprisingly the Police car let me go. I could not believe it. No license plate, nothing, just a red permit tag on the front of my windshield. I am on borrowed time today !! Yea !

[D2M]

That is a perfect example of what a non raced, not burnished brake looks like. Notice the pad material is completely black and you can see the actual carbon weave on the rotor face. The brakes will look like this until you track the car.

[backtotintops]

to add here...the oem pads pagid and textar actually come up on amazon occasionally for way less and rotors too. Drive it in all weather with street tires...it is so much fun and and has no problem in the cold she can put out the heat for sure...but snow is a bit tricky even on streets. Trofeos I have run in the rain on the track but I have great reverence.

[hjdca]

It's a great ride. It got lots of attention.. If you can get a clean one, jump on it, you will love it. No Regrets !

[D2M]

Here are some guideline pictured for reference to brake wear and what to look for.

In the pic below is a brand new 50 miles brake assembly. I got the car home and removed the wheel to get a better look at those cool looking brakes. Notice the still visible carbon weave on the rotor face and completely black pad material. If a car is strictly street driven the brakes will look like this for a very long time.




In the pic below is what a properly burnished brake pad will look like. Notice the white chalky ring around the pad material contacting the rotor. This means the CCBs are able to provide maximum performance. This does not necessarily mean the car was tracked. There are people crazy enough to do the burnishing procedure on the street. This pic is after 1 track day of moderate use.



This next pic highlights the difference between a new rotor face to a track used ( NOT worn out ) rotor face. Notice how the carbon weave looks compressed and melted on the face where the pad rides. If you see this the car has seen track time.



In this pic you can see the carbon weave is no longer visible. This rotor has seen a lot of track time and heat. There is still plenty of life left however.



This next pic highlights a brake pad that may have been over heated. Notice the extreme white color and chipping away of the pad material around the edges. This pad has 2 track days of heavy use. It may have gotten too hot as I was experiencing some slight fade towards the end of the day.



Brake wear will vary from driver to driver.