Car Preparation for Track Event

[Kevin]

don't forget that prolonged running over 5000 (i think) rpms will cause the coolant to bypass the rad and flow back into the motor uncooled.


there's a fix around here somewhere but it involves changing the rad the stat...which I'm hoping to do in a few years...anyone have the how to?

[ZRapid-1]

Lots of good feedback. I really appreciate it.
Every little bit helps and provides a small edge.

Heating of the front brake rotors and pads is my biggest concern.
I tried a number of hard threshold braking stops and drove home. Really built up the heat.
The driving sessions are 25 minutes long and I’ll either be full gas or full brakes.

I have the painted top on already. The mounting screws are fully tightened. There’s a little less room for my helmet but I want the higher stiffness. I don’t have any windshield delamination and this will be a good test.

I’m bringing extra gas to top off at the beginning of the day. But I imagine most of it’ll be gone by the end of the day.

I have also added ZDDP Plus to the Mobil 1 oil to provide some extra wear protection.

Also need to remember not to use the parking brake once I get there. It’s a reflex that will be hard to break so I have to consciously think about not putting it on absentmindedly.

Keep the comments coming.

[Aurora40]

Originally Posted by Mystic ZR-1

Your wheels will be black from the brake dust.

http://www.zr1.net/forum/showpost.ph...51&postcount=3

The stuff is amazing, no lie. My wheels in normal driving would be really dirty in a week with factory pads. At the track I expected them to look powdercoated black. They were clean as a whistle with Armor All Wheel Protectant.

I'm interested to hear about the brakes at an HPDE, though. That would have been my main concern with the ZR-1. But I had no basis for it, they just don't seem big enough for a somewhat heavy car that pulls hard up top.

Did your '89 have J55's?

Originally Posted by ZeeAreOne

The driving sessions are 25 minutes long and I’ll either be full gas or full brakes.

Well, or cornering. As a percentage, I think you are on the brakes for not that much of the total time/distance, because the brakes work so much faster than the engine does. But obviously that stuff is really hard on brakes.

[Mystic ZR-1]

Yep, the car had J55, which uses the same crappy stock pads that fade big time. The only real difference between J55 and standard is the larger diameter rotor 13" vs 12" (I know, the caliper is different too, but it's the pads that do the work...)

[lbszr]

Hawk HT-10 pads have worked really well for me with the J55, and brake ducts.

Hawk HP+ did not have high enough heat range, they actually got the car stopped well, faded sometimes, but the biggest problem is a stack of warped rotors I don't know what to do with from the HP+'s overheating. They always burned the dust boots off.

HT-10 pads are about twice the price, but they have saved a lot in the long run with rotors and the pad lasts 5 times as long.

Oil and coolant temp is the limiting factor on mine at the track. Once it's heat soaked, I can only do about 3 or 4 hard laps before backing off. It did seem to help flushing, and adding straight water with water wetter. The big mouth scoop helped also. It was also above 90 degrees. High 70's, it will go a lot longer before backing off.

If heavier braking is used on the J55 from pads that fade, I think they would be more susceptable to spread as they aren't as heavy duty as like the C5 caliper.

[PhillipsLT5]

I think water pump cavitation is at 6200, do not run at that for more than 10SEC, coolant temp will not rise on guage but oil temp will, and then head gasket will blow on overheat

[lbszr]

Originally Posted by PhillipsLT5

I think water pump cavitation is at 6200, do not run at that for more than 10SEC, coolant temp will not rise on guage but oil temp will, and then head gasket will blow on overheat

That does seem to make sense, I shift at 6000 normally, but when I take it higher, it cuts the hard run time down fast.

Here's a link to a mod that seems to cure the heating issues.
http://www.cardomain.com/ride/418999...orvette/page-9

[ZRapid-1]

For those interested, there is a turn by turn guide to the track at:

http://www.limerock.com/images/stories/TurnByTurn_ClassicLimeRock.pdf

and

http://www.trackpedia.com/wiki/Turn_by_turn_guide_to_the_Lime_Rock_track

Car setup is mentioned in the small book in the pizza box. They cover removing the corner pieces of the front air dam, tire pressure recommendations and alignment settings.
Tom, thanks for mentioning that as a place to look.

[Tyler Townsley]

Originally Posted by PhillipsLT5

I think water pump cavitation is at 6200, do not run at that for more than 10SEC, coolant temp will not rise on guage but oil temp will, and then head gasket will blow on overheat

You are not seeing cavation. What is happening is the radiator bypass that starts at 5200 and all water bypasses the radiator by 5800. You can address by getting a better flowing aftermarket radiator and cutting the spring on the thermostat that closes the water flow through the radiator.

Tyler

[batchman]

Good tips all above. One more is the seat belt. If you don't already keep it all the way back, put it back all the way and push the "cinch" button on the retractor (on the floor). It will latch the belt. Suck in your gut, feed it as much belt as you can (it will ratchet), then use the power seat to push forward until it hurts. At that point it should be almost tight enough...

Have a ball, I've been an LRP fan since the annual pilgramage to see the GTP cars in the 80s. Finally got to drive a Skippy car around it - awesome - and that was before it got paved.

Best,
- Jeff