AlwaysInBoost

this is going to be a long one, so grab some coffee and a snack.

this past weekend I popped my cherry in the Z06 on the Pocono long course. I've been waiting to do this almost two years and it was a total blast ! My goals for the day were above all else to have fun and just get a feel for the car. If I felt comfortable I would try and push it a little but I also wanted to make sure I was able to drive home under my own power. i'm very happy to report that I was able to do them all.

My car is pretty highly modified in the power department, with a blower and all the bolt-on's, but not so much in the cooling or stopping department. I figured because of that, and all the research I've done on here, I would have some problems with overheating and my maybe my brakes. so I was determined to leave a large margin of safety on the table with my driving just in case I needed it.

I was fully expecting to see really high coolant and oil temps and having to cut my sessions short or take it easy out there because I have all stock equipment and a big FMIC blocking the rad. The temps & humidity yesterday were brutal, I don't know the exact numbers but my car was registering high 90's as the ambiant temp but I'm sure with the humidity it was a little higher.

To prepair the car as much as possible for the abuse I was going to put it through did a few preventive things before hand. I changed the oil on Saturday to M1 15w-50 and made the coolant about 20% dextrol & 80% water w/ a bottle of water wetter thrown in for good measure. I also wrapped the exhaust near the trans with some header wrap I had left over.








With that said, on track the oil temps I saw were in the 280 range on average. Highest I noticed was 295 once. Coolant temps were in the 240 range with the highest (i think) being 254. Never saw anything about the trans getting too hot on the DIC. This is all with stock cooling components because I really wanted to get an idea of how the car would behave "as is" before I started upgrading stuff that might not be needed yet.

Is Pocono long a hard course on teh car because of how fast you can go or does that speed and extra airflow help cool things down even more? and how do those temp line up with what others have seen on the course?

The other thing I was worried about, my brakes, did give me a little trouble but I can't blame them because I was trying to stop from 140+. I was running nitto 555rII tires, installed SS lines and was using Castrol LMA fluid. I have drilled/slotted/vented napa rotors with stock z06 pads. I think these are the original pads that came with the car when it was purchased new in 01! The rotors were replaced by the previous owner I believe for less weight in drag racing. ON the street doing sane speeds the car stops fine and there is no fade. On the track its a little different story.

Coming into the devils elbow, dropping down from 5th-2nd, it was difficult to get the car slowed down enough where i felt comfortable taking the tight left turn. the pedal was getting soft on me and at one point, coming off the tunnel turn, I must have boiled my fluid because I had to drive straight threw the cones when I couldn't stop. After that I made sure I wasn't going too fast on the straight to not be able to slow the car down.

The rubber I'm running might be too grippy for the stock pads, so I'm thinking to fix the brake issue I'll try some ducting to the front rotors, motul 600RBF fluid flush and new pads. What would others recommend?

The only issue I had all day was during the end of session 3 when I blew off my upper rad hose just as I was going around devils elbow. Lucky for me it didn't happen a couple hundred feet before I had to brake for the turn!

other then that yesterday was a blast. My McLeod street twin didn't miss a beat all day, no soft pedal or slipping of any kind that I noticed. My motor seems to be 100% also, even after the coolant insident. Plugs looked great and not leaking a drop of anything. I am sore as all get out though because of the seatbelt digging into my sholder and trying to hold myself in the seats while cornering. I can see how a proper seat is & harnesses should be the first mod and they are now on the top of my list. also feel like a burnt piece of toast from being in the sun all day.

sorry again for the lenght and if its scatter brained, I'd like to hear your comments...

John Shiels

Long course is not that hard on the car as you have long straights to cool the car. The worst course for my car is the south course and it is the shortest and slowest at Pocono. Skip Motul and do SRF and cooling ducts from LGM and DRM.

AlwaysInBoost

Is the SRF the silicone stuff that you're not supposed to run on the street at all?

so the long course is easy on the car huh, I guess thats why my temps weren't as bad as I thought.

AU N EGL

Nope

SRF is the good stuff. DOT 5 is the silicone stuff that you not supposed to run.

DOT five point 0ne is OK

95jersey

Sounds like you had a good time. With all the power you have, the problem with your brakes are the pads, they just can not stand up to the abuse generated by the long course. If your pedal remained firm the whole time, but you noticed that applying pressure just wasn't stopping you car, and it got worse as the day went on, you were overheating the stock pads. The long course is hard on brakes as you stop from very fast speeds lap after lap. The long straits help cool the pads, but from experience, I go through pads much more quickly on the long Pocono courses than I do on the shorter courses, which leads me to believe that stopping a 3300lbs car from 150+mph is just torture on the brakes compared to more repetitive lower speed stops. On the shorter courses and higher momentum road race tracks, I tend to just tap the brakes or only use a % of their power, vs stopping on the long course or double infield where you just mash the pedal and hold it down for several seconds.

Next time dump the stock pads and you will be in much better shape. I use Motul for 8 years now with good results. I also recommend you bleed every event or at least every other event.

Welcome to the new addiction

Wicked Weasel

congrats on your first day on a full track. most importantly no damage and you got home. Pocono Long was my first event years ago and I remember breaking the 150 mark with my H/C setup

AlwaysInBoost

Got ya! I've got a few bottle of Motul RB600 so I think I'll just try that next time.

As for the pedal feel; it was a little softer then usual coming off the straight, kind of spongy when you first press it, and it just wouldn't stop the car no matter how hard I pushed. would that be the fluid or pads?

Even after sitting for an hour after my last session, when I went to drive the car again, the pedal felt like it wasn't doing anything the first 1/3 of travel so I had to be real careful with my stopping distances on the way home.

AlwaysInBoost

bob, you have bigger ones then me. I wasn't really watching my speedo, or trying to hit a top speed, but Bobby Fisher who instructed me on my 3rd session said he saw 148 on the speedo at some point. I was pretty amazed how well the car felt at that speed.

Wicked Weasel

Do yourself a favor and get the motive pressure bleeder. If your brakes do not feel right many times it is the fluid. The fluid might have been burnt at the caliper and thus you would not see it in the reservoir. Using the pressure bleeder you can easily drain off the crappy fluid by the caliper and replace with better fluid and if you have to you can do a complete brake flush in no time.

It is one of the best tools that I carry with me. It has also saved other people at the track many times.

AlwaysInBoost

already got one

sothpaw2

Fluid is too hot--that's what the 1/3 of travel is about--that will make it hard for you to heel/toe downshift--ask me how I know. Motul should fix that--but use only Motul. I tried an off brand that was rated to the same temps as Motul and it got too hot to the same results.

I think pads were also overheated--unless pedal was to the floor the car will stop with too hot brake fluid--the pedal just goes a little low.

Wicked Weasel

It took all day but it happened in the last session for a bunch of laps. It was on stock runflats and HP+ pads and worse of all stock belts and stock seats. Thinking back now comparing it to the extra safety equipment that I now have it was foolish to say the least, but I survived and years later I am still going. Of course top speeds are much faster now and lap times are much quicker.....

Wicked Weasel

perfect - if for some reason you feel the brakes dont feel right then take your down time to bleed them again. I bleed off at the track sometimes when I feel the brakes are going a bit soft. Not sure if they were or not, but didnt want to find out either

are you going to NJMSP in August?

Last C5

I run the same tires and your braking will benefit from better fluid, ducting, and some Carbotech 10s in front and 8s in back.

MungoZ06

And then, because you'll generate more braking heat off your pads, you need to have a set of solid rotors to put on when your current ones spiderweb out from the holes to the edges ...

AlwaysInBoost

I don't think I'll make NJMP this year, too much stuff going on @ home. Should be able to do some more pocono events, shenandoah in October, and hopefully fit the Glen in there someplace.

Last C5, are you running 17f/18r sizes nittos? what pressures are you using? I was around 42psi hot, meaning right after I pitted I checked the pressure on all four courners. Started out with 36psi cold in all four.

alright, did some research and I think I'm going to go with the XP10 pads all around (I've had not so positive results with Hawk in other cars). I'll use the Motul 600RBF I already have and I still need to research cooling ducts. anyone have a particular brand they perfer for any reason? I have to double check but I think my charge piping *might* be in the way of running a duct on the driver side.

Going to pickup some NAPA rotors until these ones I have now are toast. I'll keep them and the stock pads with me for spares incase I destroy a set on track I'll still have something to drive home on.

I'm going to hold off on doing anything with the cooling system just yet until I get some more track days under my belt and start driving the car harder. I only used about 3/4 tank of gas the whole day so I know I wasn't all that hard, even though it felt like it.

AlwaysInBoost

my heel toe skills need work. In my EVO, since I drive it everyday, I can heel toe fine. I'm so used to it I actually find myself using my turn signal on track sometimes because I to it all the time on the street. In the vette however it feels unnatural still. Going from 5th-4th-3rd wasn't bad but the shift from 3rd to 2nd sucked. couple that with the fact that I didn't have a whole lot of confidence in my brakes and it makes for an interesting combo.

MungoZ06

I'll give you some free opinions ... worth what you paid ...

I run the same nitto's; started 32/30 and kept my hot temps when at rest in pit after cool down lap to 39/37 (prolly about 40/38 tops on track ... that's my upper limit.
CW seems to be one level less pad in rear for Carbotechs ... 10/8 or 12/10. 10/8 seem ok match for nittos ... but my next set will prolly be 12/10.
Most (including me) install the DRM ducts on a C5. I use Phoenix spindle ducts. LGM or ECS are more efficient, but require a little more installation work. I run SCAT silicone duct hose. Was running 3", which is a REALLY tight fit on the 3" duct and spindle mount; On my last set of hose, so just ordered some 3 1/4"

I went to RockAuto for AC Delco "Premium" ... made in China.
It *appears* as thos they're spider checking faster than the last set (made in Canada).
I have a set of Raybestos coming from RockAuto ... about $6 bux more a corner ... hopefully I'll get 20% more wear out of them.
After doing a LOT of reading, I decided that a radiator upgrade with an integrated EOC was right for my track use ... and have no regrets over my Ron Davis/DRM setup. MANY argue for separate oil coolers, esp for harder track use and FI engines.
YMMV
DennyM

AlwaysInBoost

thanks for the info Denny.

Last C5

:Last C5, are you running 17f/18r sizes nittos? what pressures are you using? I was around 42psi hot, meaning right after I pitted I checked the pressure on all four courners. Started out with 36psi cold in all four.

38 psi hot and sampled as you described seems to be the sweet spot for the Nittos. I am running the 17 / 18 combos 275 / 305s. Carbotech 10s all round will probably work too, I'm running SSBC Tri Force front calipers so the 10 / 8 combo works extremely well for me.