Interesting. I've been through 2 sets of pads and my rotors weren't even 3/4 worn. I only replaced due to warping. A friend with the same car went through a rotor per set of st43s.

 

On the Z51, I went through 2 sets of ST43s with the same rotor, and only changed the rotor for the next season, since I wanted to start the new season without those 'hairline cracks'. Of course, YMMV, but I can easily say that ST43s do no rash the rotors like Hawk race pads do for sure.

 

Then maybe he had the same mindset or just thought because they looked bad then they were worn completely. Apparently, Min thickness = slots not showing at all.

 

Yeah, I love slotted rotors for that; visual inspection is all you need : ) I'm on the look for the next track day event. Here's hoping they setup something soon! With 593 whp on tap, I'd love to switch to R7s as soon as possible, but I'll have to use up my legacy track tires, first (R888Rs 315/335).

 

• Street driving traction:
  • A friend of mine who has PSS ZP tires on his 2017 GS is very unhappy with their traction, and my brother also told me that they felt like trash. My experience has not been that bad, but these ZP tires definitely don't warm up fast!
  • In my tests, tire pressures bumped up about 2 PSI (to 32 PSI) fairly quickly, by the time my 5 miles state road to the highway (from home) was finished at ambient temps of 45 degrees F and above. However, the display still shows them COLD, and and does not warm up to 33 PSI for a very long time, if ever, depending on my driving speeds.
  • I realized I should "help" the tire flex more. As such, I dropped the cold pressures to 28 PSI, and it did help! It come back to 30 PSI after my commute to the highway, and hits 31 PSI relatively soon, once I start driving at highway speeds. Once I gain that 3 PSI or so over the cold pressure, the tire starts prividing much more traction. It mostly holds on in second gear, and has good traction in higher gears.
  • Conclusion: If you don't care about tire wear as much, and can live it a little bit more fuel consumption, I think we should consider running low pressures on these PSS ZP tires, or else they don't warm up fast enough for any reasonable commute. I'm even considering 26/27 PSI cold, but have not tried, yet.
• Track preparation:
  • I've finally found some time to install the sharkbar, and I'm very much ready for a track day, as soon as they start throwing such events. Pacific Raceways here already started having events, but I no longer attend events there (since it is a bit too dangerous for high HP cars, in my opinion; it was built in the 30s, when safety was not a primary concern).
  • I'm also about to hit 1000 miles; yay! The closest track is another 100 miles away (if I don't trailer), so we're getting very close to the end of break-in period for track use.
  • I just installed the Sharkbar today. I'm also wondering if I should just swap to R888Rs even for street use, since I wonder if they would warm up fast and be a better tire for street use, even though they'd likely be much louder and not last as long.

Stacking up spares and parts/fluids during winter.


Ordered quite a bit of oil from Speedwaymotors.com when they used to sell it for $49.95/6-pack.


Sharkbar and BK harness tabs install


This is the BK tab for race harness (lap belts). Those edges, though not knife-edged, can still hurt you pretty bad as you get in and out of the car.


Used and angle cutter to sand it down a bit.


Then covered it with plastic tape to protect the seat cover from rash.


Used this with an angle cutter to sand/polish. I wish I had a finer paper as well, since with the angle cutter, it sands in no time, and finer grits would be fine. I love Diablo brand, though. Everything they make work great.


Surprise!!! The left side seat belt anchor on the seat was cross threaded, and likely over-torqued from the factory, with damaged threads. THANKS GM !!!


I've used a thread cleaner (M10x1.5mm) to heal the thread on the seat.


There was quite a bit of threadlocker on the bolts; I've used heat gun to soften it up.


Don't forget to pull the tabs a bit away from the seat to reduce chances of rash. That said, don't do it too much, or else it will damage the trasmission tunnel's carpet. We can't win : (


Seat installed back.


Sharkbar tabs by the B column (dome).


All finished!

 

Hi X25 - Some of the photos aren't showing up again, so you know.

Also, bummer Speedway motorsports doesn't sell the 0W-40 at $49.99 anymore!

 

Pics are hopefully fixed; thanks for the ping.

Indeed, They bumped it to $59.99. Looks like Amazon and uber are not the only companies with surge pricing practices : )

 

how do you route anti-sub belts through the seat bottom?

 

It's a bit hard, but you can use the same side anchors for the anti-sub belts, too. I do have the anti-sub belts as well, but to be honest, especially with this OEM Competition seat, I think 4-point with the ASM is sufficient.

ASM ensures that I'd not submarine, and that I would also lean forward with my inner shoulder during an accident, just like a regular seat belt would, which would help me survive if the car flips and the roof caves in. Considering I don't have a full cage or a real race seat, I think these are great compromises.

 

Brake system weight analysis
I wanted to do a quick analysis of unsprung and/or rotating weight delta anlysis between my iron Z06 brakes with Girodisc rotors, and the OEM CCB brakes.

• Calipers
  • Z06/Iron: Front 13.5 lbs (loaded) and rear 6.7 lbs (loaded). TOTAL: 40.4 lbs (27 / 13.4)
  • Z07/CCB: Front 15 lbs (???; loaded) and rear 10.4 lbs (loaded). TOTAL: 50.8 lbs (30 / 20.8)
• Rotors
  • Z06/Iron: Front 22.9 lbs (Girodisc) and rear 17.5 lbs (Girodisc). TOTAL: 80.8 lbs (45.8 / 35)
  • Z07/CCB: Front 13.4 lbs and rear 17.9 lbs. TOTAL: 50.8 lbs. TOTAL: 62.6 lbs (26.8 / 35.8)
• Total system
  • Z06/Iron (w/ Girodisc): 121.2 lbs (72.8 / 48.4)
  • Z07/CCB: 113.4 lbs (56.8 / 56.6)
  • Difference:
    • Total: Iron system is +16 lbs front, -8.2 lbs rear. Overall, iron system is only 7.8 lbs heavier with Girodisc rotors, but this doesn't tell the whole story.
    • Rotating mass: Rotating mass (rotors) has increased much more at 18.2 lbs!

Remarks:

• Front CCBs are lighter as a system, while rear iron brakes are lighter as a system, since the 2-piece iron rotor is about the same weight as CCB rotor at the rear due to iron hub CCB rotor comes with, while Girodisc uses aluminum hub. Just don't get into drift races with the aluminum hub : P
• If we used OEM rotors, the rear Z06 iron rotors weight 24.8 lbs, adding 14.6 lbs of more rotating mass to the system. Fronts are somewhat similar.
• As most people know, both unsprung and rotating masses are not good for a sports car. The rotors are both unsprung and rotating, so they not only make it harder for the suspension to work, but they also sap power during acceleration and braking (rotating kinetic energy; just like a flywheel).
• So on the surface, the weights are very close, and impact to suspension should be very limited, yet the added rotating mass will sap power (though not sure if it's significant enough, especially for a Z06).
• If you're wondering, AP kits' rotor weights are very similar, but they do have much lighter calipers. That helps when you sum up numbers, but the dynamic impact will be much limited, since calipers are not rotating mass (as long as you keep the caliper bolts tight : P ).
• One mitigation to the higher rotating mass of rotors is the wheels/tires. The track wheels I'll use (BC Forged 18" RZ39s) should save ~5-10 lbs per corner, more than offsetting the increase in rotor weights, especially considering weight in higher diameter is even more important to cut.

Overall, I think my setup will be more than competitive in weights. If I want to improve, for the money inspected in after market iron BBKs for little improvement, I could just get those real carbon brakes and see enjoy real carbon brakes, but I don't think I'll need it : )

 

 

You're right, there's a lot more to save, especially with the Pirelli scrubs; they're incredibly light. I just limited my numbers to wheels (and being conservative at that) due to people using different wheels/tires, but yes, there's even more potential!

 

 

The rings are $650/set FREE SHIPPING at xplosiveperformance.com (link). I think this is where I bought my spares, last time.

 

My brother stopped by tonight and we drove his Viper GTS and my car back to back to see how they compare. His car had 315/30/18 NT01 tires mounted up front, and 355/30/19 V720 ACR tires at rear, and I had the PSS ZP OEM tires. Long story short, I had no traction whatsoever during our back-to-back driving, while his car felt perfectly fine. I've been thinking about this for a while now, that a compound that needs little to no warm-up might be best for this car, especially for winter. I've used NT01 tires extensively, and they are such tires. I was able to make competitive laps even from the very first lap with NT01s, and their consistency throughout the session is also incredible. No wonder, my brother was also able to drive his Miata throughout the whole winter using NT01 tires without killing himself; a testament to the compound. Granted, you shouldn't drive it at/below freezing temps and under heavy rain or any snow, but the mild winter is not a big deal for these tires, and dare I say it, I think they provide amazing traction even in these conditions.After my brother drove my car as well, and slid around, telling me I have awful traction, I've decided to put on my track wheels and give R888Rs a try at the street!

• Conditions:
  • It was completely dry, and outside temp was around 38-40 degrees F during our tests at around 22:30, so not very warm at all.
  • That said, most of the winter passes by within a window of 35-55 degrees F in here (Pacific Northwest), and it's not too cold.
• PSS ZP:
  • These tires don't warm up fast, perhaps due to very stiff sidewall. I have decreased the starting pressure to 28 PSI, and it definitely helped. It comes to 30 PSI after a few miles, and provides some traction. but it's definitely not enough. I tip-toe the throttle. I did not need to do anything with my brother's Viper. It always had plenty of traction, as if I'm at the track with warmed up tires!
  • The road noise exists, but it is less with these tires.
  • Thread width (mounted; rough): Fronts measured ~11.5", rears measured ~13.25".
• R888R:
  • I later got back home, put the car on the lift, swapped to ST43 brakes, and put on my BC Forged RZ39 wheels with R888R tires: WHAT A DIFFERENCE!!! The car has transformed from demanding constant "handle with care" to "I dare you!".
  • I started with 28 PSI as with PSS ZP. It has also not warmed up much, and got to 30 PSI within similar times. However, unlike PSS ZP, it provided traction from the get go, even as I was leaving my garage!
  • On the highway, at 30-31 PSI, the screen stating "COOL" for tire temps, at ~40 degrees F, I was able to go full throttle in second and 3rd. This was not possible with the PSS ZPs.
  • Thread width (mounted; rough): Fronts measured ~12.5", rears measured ~13.5". Speedometer showed 70 MPH, when the GPS speed was ~68 MPH.
• Verdict:
  • I don't think PSS ZPs are adequate for street use at 40s-50s F ambient temp range. They just don't warm up enough. Granted, you can "survive", but what's the fun in just surviving, when you drive a car with so much potential? Looks like I should sell these tires to someone who could use them in warmer climates, or perhaps around here but in summer.
  • As such, now I need to figure out what I can do for my street and track setup.
• My options:
  • Current setup: I do have BC Forged 18" wheels shod with R888R tires 315/335, and Forgestar 19"/20" wheels with 285/335 PSS ZP OEM tires. My original plan was to finish up R888Rs at the track, and switch to R7s, which I would like to use for track.
  • Desired setup: I would like to start using R888Rs or similar for street use, since they allow me to actually enjoy the car, without fearing from it at all times. I'd also like to eventually switch to R7s (315/345) for track.
  • Options:
    1. Leave it as is: Use the R888Rs at the street as well as track until they are done. By that time, hopefully ambient temps would increase, and PSS ZPs would become fun.
       • $0.
    2. Get different tires for street: Find tires that fit on the Forgestars. As far as I see, R888R does NOT have a proper rear tire fitment at 20", neither does NT01s. I don't know of any other tire with similar cold traction.
       • Tires.
    3. Get another set of 18" forged wheels: Sell the 19"/20" set. My current 18" set becomes my street set since they already have R888Rs on them, and I get another set for track use with R7s.
       • Tires + $3500 (?) - (Forgestars + PSS ZP sale price).
    4. Get a set of 18"/19" wheels: Sell the 19"/20" set, but get rears 19" to install 345/30/19 at rear, which is almost perfect diameter. This also enables me to use R7 345/30/19, since it has much smaller sidewall than 345/35/18 R7s that I plan to use with my original 18" set. In other words, I could get those R7s with these new wheels, and use the current 18"/18" wheels for street.
       • Tires + $3600 (?) - (Forgestars + PSS ZP sale price).

What would you do? I'm thinking about 3 or 4. By the way, if I put one more wheel set on sale, people in the sales forum might start wondering if I am up to something : P



Front tires with PSS ZP on the left (~11.5"), and R888R on the right (12.5"). 285/30/19 vs. 315/30/18.


Rear tires with PSS ZP on the left (~13.25"), and R888R on the right (13.5"). 335/25/18 vs. 335/30/18.



The stock brakes are way too soft; even softer than my RAM EcoDiesel's. As such, I decided to switch to ST43s, too. The impact was major! Note the part number. This is not 1405, which is a tiny bit smaller than this shape, which causes the pad to "hit" the caliper a bit; not something you'd want to see happening. Girodisc sells these correct pads, and I also found them here (AFAIK, Z06 and Z07 use same shape: link).


I've bled the brakes, and also replaced the clutch fluid in the reservoir. The fluid in brakes looked like new, but the clutch fluid was still contaminated. I still see the wax contaminating the fluid. I'm guessing a few more changes will get there!


The rear hand brake hose was slightly rubbing on the shocks on both rear sides. I've bent the hose a bit to give it more clearance.


BC Forged RZ39s shod with R888Rs 315/30/18, 335/30/18. No, I was not parked in a disabled parking spot... and no, I don't care about the gap!



These wheels look beautiful in person.

 

I sold 2 sets of wheels on here last week, why not?

Some other ideas:

• Use PTM wet on the street or weather mode until the MPSS warm up. I drove this morning in a heavy rainstorm and enjoyed it. I've used PTM wet when it's cool here(not very often in south Florida). The technology is amazing.
• Switch to Michelin Pilot All season. Made in factory ZP and sizes. Cheaper too.
• Switch to Toyo R888R in 295/30/19 F and 325/30/20. The rear is pretty tall, but there's a thread on here where people love this setup. https://www.corvetteforum.com/forums...06-wheels.html

 

Well, I ended up picking none of the options. My friend, who has a '17 GS will come pick up my BC Forged wheels with the R888Rs this week.

• I am no longer interested in Pirelli scrubs, since the samples are not consistent (some come heat cycled out, some come in good shape, and tire shop becomes your second address). This means I don't need my wheels to be 18/18.
• I know most just do 18/18, yes I know, but I think 18"/19" wheels would be the best bet for our cars.
  • This allows me to go wider at the rear (19x13) with no interference.
  • I can also keep the profile of the tires small (345/30 vs. 345/35), and let the car's springs do most of the spring work.
• As such, I'm in the process of ordering two sets of 18x11, 19x13 forged wheels. One will be shod with R888Rs, the other with R7s, both at 315/30/18, 345/30/19. Talking to the vendors : )

 

Are you saying the R888Rs do better in the cold and wet than the OEM MPSS?

 

They did way better! We first tried the car with PSS, and after my brother laughed at me, saying my car has comical traction (while his Viper with NT01s did just fine), I immediately swapped to R888Rs, and we tested it out again about half hour, later. I had traction even as I was leaving the garage!!

People love PSS ZP, which leads me to believe that they work great at higher ambient temps, but during my time driving it since I bought the car, they never worked good enough (38-55 degrees F range). I'll either sell these PSS ZP tires, or keep them for when it's time to trade in the car, but I don't think I wanna drive my Z06 with them, at least not in this weather, especially after seeing how much better R888Rs are, even from the get go. I finally had quite a bit of fun with this car, yesterday. It was great!

 

What about in the rain? Would they hydroplane worse?
Any idea how they are in picking up little pebbles and sand? I assume about the same. I am in eastern wa so thinking all-seasons.