badhabit_wb

Looks great Bruno! I think your front end looks better than the zr1. If it's cooling that well you're good to go.

X25

Excellent results; thanks for sharing! If I decide to add more cooling in future, I will definitely consider adding the base LG kit. It would be nice to have a video with the temps overlayed, too, to see how they work out during your lapping; if you easily can of course!

BrunoTheMellow

I didn't log OBD2 data this track day, just relied on PDR. So the best I can give you is the graphs right now. Plus, unlike the results you saw, where the car cools down 1 half of the track and heats up on the other, this track either the temps settle or they don't. In my case they didn't settle yet but were increasing so slowly. Here's 23 minutes in before my cooldown lap.

Also, other good new is that even though it went from 80 to 95 throughout the morning, I still ran exactly the same top speed of 125 mph on the main straight every session.

MCK_Z06

That's awesome!
Im bummed that I could not make it today as my car is still down....

Yeah, Im really happy with the LG kit as well, I can't recommend it enough if you are having issues with temps.
Plus moving the intercooler out of the way of the oil and engine coolers seems to do wonders.

Hopefully we can meet in person at the next event.
Im plan on hitting the next The LIST event and going to try and go to the event in September @ ECR.

What car number do you normally run? Our cars look almost identical... lol!

BrunoTheMellow

for sure. i don't run numbers unless i have to. seldom. i dont remember my last one.

fatsport

Great results with the cooling!
Did you hit a time you're happy with?
Any idea how much weight your mods added to the front of your car, have you weighed it? I wonder at what point do the mods improving power outweigh(pun intended) the sacrifice in handling.

BrunoTheMellow

My goal was to beat my previous car's time without pushing the car. My last car was:
2015 z51, 570 rwhp procharged. Derates to about 500-525 rwhp at the track after timing pulled due to temps. Z06 springs, 295/305 r888r. Best lap of 1:22.5.

See below video of my best lap with c7z. I estimate the cooling added about 40 lbs and the iron rotors add another 40 lbs of rotational mass. Basically I'm driving with a child in the passenger seat.


In terms of data:
C7Z is 5-6 mph faster minimum speed on the big sweepers. My peak speeds on the straights are 6-8 mph faster than the z51.

Using the same timing app (Harry's laptimer) I've used for years. I ran a 1:19.98 hero lap with the z06 (and several 1:21.0-1:21.9 laps) and a best of 1:22.57 with the z51 (with several 1:22.5-1:22.9 laps). I tend to believe my actual best with the z06 on Harry's is 1:21.04 as I didnt see any 1:20.xx so that 1 second gap to the hero lap is odd.

PDR is showing a 1:21.85 best lap with a handful of 1:21.9x. That 0.75-1.0 second difference between PDR and harrys is within range of the different start/finish and measuring methods. Harry's start/finish line is in the middle of a braking zone so going slightly deeper or braking early could change the times.

I did not push the new car as hard. It has a 1:19 in it if I pushed as hard as I did with the z51 and the weather was better (ambient temps were some 20 degrees hotter and way more humid).

fatsport

Nice run. What a great track, technical with lots of runoff. I’d live there. Cheap too, Chin charges about half what I pay at Sebring.
Looks like you could use 2nd in a couple places.
Lots of great laps on YouTube to model after, Adam T is a beast. At Sebring I’ve been using Jade’s 2:16 lap as my target. I ran 2:26.2 in July heat, but I know I can do 2:23.

BrunoTheMellow

The longer configuration (3.1) is A HOOT. But not nearly as forgiving. I love the 1.7 as it's a perfect test track.

From my experience and from those that are much faster. I actually need to use 3rd less and shift up to 4th. The 3 big sweepers can be improved by going to 4th and using the smooth torque.

serpent

Bruno, can you post a comparison video if you have any of the old setup?
How much cooler is the car running? Are there any other things you can do to cool it down?

BrunoTheMellow

The car doesn't need any more cooling. I didn't do a before test but it was a stock 2015 Z which probably would have overheated in 10 min.

70 mm radiator. More oil coolers. I mean how much time and money do you want to spend ?

serpent

it was just a general question my man, lol. cant wait to see more track vids. imo GM didnt do this car justice, they did with the zl1 1le tho.

BrunoTheMellow

That's the point I am trying to make. There's a lot more cooling to be done but it's a money game. 1le has a lot more open frontal area and has:
Main rad
Aux rad
Main intercooler
Aux intercooler
Trans cooler

My car has:
Main rad
Aux rad
Intercooler 1
Intercooler 2
Trans cooler
Oil cooler

So I'm up 1 cooler getting airflow. But total area is still less.

Anyhow, on these cars you can get
twin oil coolers behind the intercoolers.
A more efficient custom made aux radiator (mine has pretty wide spread fins since it was a charge air heat exchanger first).
Another trans cooler as even the Z06 cooler eventually overheats the manual trans.
A better extracting hood or more vents

If you want coolant and oil at 200 degrees settled in 105 Texas weather you'll need all of the above and probably more. These cars just don't have enough nose area for how much they weigh.

All other sports cars have basically a fully open front bumper. How GM though this car could do it without that , idk.

BrunoTheMellow

Hottest track day yet!

Feels weird not having anything to fix with on this car. Ambient temperatures ranged from 83 to 103 from 8:30 am to 1:30 pm. 2.5 minute laps, About 25 minute sessions (or however long I lasted).

First, video of my best lap so you can gauge my pace and the kind of track, 25.3% on throttle if that helps any (best lap on 2nd session). Due to the car's gearing and absurd amount of torque, we tend to not wring it out in this track as that ends up being slower. This was a 2:22.96 lap and I was running consistently in the 2:24s with nearly zero traffic all day.


Now the data:

Session 1: 83 ambient


Session 2: 93 ambient


Session 3: 100 ambient


Session 4: 103 ambient


Session 5: 103+ ? it was hotter than a pigs butt.


Here's the graph for the above last session:


Not much to say except trans temp never stops rising. But it is rising so slow that it doesn't really matter. 70 degree rise in 20 minutes. Not worried.

Coolant and oil settle in early.

BrunoTheMellow

For ***** and giggles, here is my car vs my friend's stock ZL1 1LE. The coolant temp difference is definitely due to me having a 170 tstat as both cars have plenty of cooling capacity.

BrunoTheMellow

I am just going to start using this thread to log my track outings. This past Saturday was another successful day:




while sometimes not as accurate as other timing methods, I got my Harry's settings pretty accurate. Consistent laps all day even with some traffic.




Ambient temp was over 100 again. Max coolant temp of 215. Oil was hovering at 260. I was the only car out there during the longer sessions at times.

Here's the best lap, this time we ran MSR cresson 1.7CW (backwards). It's pretty neat this track can be ran in 4 different configs.


I was running 18" 305/315 pirelli scrubs for the first time (my first time on slicks ever) and running raybestos st45s. They felt better to modulate than carbotech xp12. Xp12s locked up my tires really easily. Wear seems better too. I hope it is, because the xp12s lasted 2 track days.

Slicks were at 29 psi hot. I was making sure not to go over the target 30 psi hot. Since the track was so hot I leaned towards the safe side. These felt great. Although the Max Gs were identical to stock cup 2s, I felt like I had more grip at corner exit.

I had one problem. I forgot to heat tape down my wheel weight and all of the 8ish weights on my left front wheel and 1 on my right front came unglued. A couple jammed into the calipers and scored my wheels. Sucks. Not deep enough to worry about air leaks, only a couple thousands of an inch deep. But now there is a big silver gash and a silver line on the barrel on my brand spanking new gun mental front wheels. Luckily my brakes are so huge it's only seen by laying down next to the wheel.

Does anyone know if should try and refinish or paint over this now bare section? Any sort of metal issues with weather, brake dust, etc?

Pacembellum

I want scrubs now! Thanks 🤣

Oh4GTO

Sucks about the wheels. I had one come loose as well and scored my caliper on the outside. Which tape is best to hold those down, I have a set of CF5s on the way for next season.

How much camber are you running with the scrubs?

I was originally planning on rubbing scrubs but running -3.0 camber on the street between track days is not appealing.

BrunoTheMellow

-2.2 front, temp was exactly the same across the tire. -1.8 rear.

3m high temp flue, get it on Amazon.

It was actually only 1 wheel after I cleaned them.

BrunoTheMellow

If you already have a way of moving them to the track and have 18s for r compounds. They are the obvious choice. But if you don't, here's your upfront cost and math:
$350 trailer + wood, wheel chocks, straps
$120 for trailer first time registration
$600 for hitch, mount, anti rattle, pin locks
+ Wheels of your choice.

Now I can resell the trailer for probably $250 since it's all built up. The hitch mount is removable, I can sell that for $400 probably. So I'll regain at least half of my expenses at the end so we will use $500 for the cost of trailering.

Scrubs are $750 shipped (+500 for trailer on first set). R compounds come out to $1300-1500 shipped so let's use $1400.

Scrubs would need to last half life of r compounds to not be cheaper. From my research scrubs last about the same as r compounds. If so, you break even by the second set.