To begin, I do not intend to own the ZO6 for more than a few years. I will very likely trade it in when something quicker/hotter comes out. Hopefully that will come in the form of a Corvette of some sort. Further, because I intend to keep trading up, I lease the car. This makes doing any mods problematic, especially those that are somewhat intrusive.

I track the car, but not race it. I enter as many HP driver schools as I can get into a year, roughly 7 or 8 depending on available time. These do not void warranties (they are not timed events, or preparation for timed events), and are covered by insurance. I auto-cross and enter time trials in an owned BMW, and a team Porsche 914/6, and practice road racing in karts between Vette outings. I run stock F1's on the track, as their grip limitations do not stress suspension tuning or brakes to the point of needing upgrades. I am even running stock brake pads, and have only chaged the rotors to increase cooling and reduce warping risk.

My approach to oil temps and trans temps, is to change the oil prior to each event, run the extra quart recommended by Chevy, and change it after the event (Mobil 1). I do not allow the oil temps to reach 300 (cut sessions short if needed). I shift the car a little short and rpms between 3500 and 6300 on the track, to keep input shaft speeds lower in the trans and gear reduction to the lowest level to still be fun. This keeps trans temps down (never had the high temp warning come on yet.) We're on track to enjoy the car, not set track records. A lot of times I'm running third/forth gear, even if I can go quicker by shifting down to second in some places. Even so, I have yet to be passed by anyone in A run groups, including BMW M3's, Vipers, NSX's, M coupes, etc.. even on race tires... so I'm not running that much slower.

I did an experiment in one school: For two sessions I ran the car in 3rd and 4th gear only and kept revs below 6400. I focused on running smooth clean laps, but running the car at about 85% of its capacity. Then I ran two sessions flat out, dropping into second on tighter corners, running the engine nearer redline between shifts, etc.. ran the car to 95%+ of capacity.

First two sessions, oil temps stayed below 280, no smells from under the car, and it cooled quickly at the end of the sessions to 235. Second two sessions the oil temps spiked 295, and I could smell hot gear lube from under the car. In all four sessions I was passing the same cars, and was not approached by anyone (including race tired M3's, M coupes, NSX's), so did not seem to be running that much slower with the conservative approach. I was enjoying the drive in every session just fine.

I have found the deep well of torque on the LS6 can be tapped easily, and does not require the engine be revved to produce the desired handling effects (throttle steering.)

So, the dilema comes down to: Exercise some discipline at the track, focus on line and cornering technique, while being careful with the equipment. Or: Install an oil and trans cooler and run the car flat-out any time its on the track and risk run-ins with warranty and lease turn-in problems.

My current feeling is to keep the car stock, exercise some discipline, enjoy the car for what it is, practice better driving technique and equipment conservation (except tires, which just get eaten up when running quickly on any decent road course.)

Any comment on this approach? Anyone else taking a similar approach?

 

Makes sense! Your times on a road course are going to be more dependent on your driving skills than power to weight ratio. Getting the braking points and lines right is going to drop your times. Shifting at 6500 versus 6000 isn't going to make much difference.

As one learns a course and gains experience, you often find that second gear turns become third gear turns. I always use the lowest revs possible, and as you say, the deep well of LS6 torque means you can go a gear higher than necessary much of the time, which will reduce oil temps without having a significant impact on your lap times. Such is not the case with a smaller displacement engine such as the NSX. To keep up, you have to keep the engine in the high rev sweet spot all the time.

If you develop your driving skills you can usually turn quicker times than the guy who is pounding his car into the ground - kinda like the difference between Mark Donahue and Parnelli Jones!

Using the least engine revs will lower the engine oil temp, and using fourth gear as much as possible will reduce gearbox oil temperature. Since fourth is direct drive - no torque goes through the countershaft - less heat is generated.

Duke




[Modified by SWCDuke, 9:32 AM 5/29/2002]