Did my first DE in my C2 yesterday at Thunderhill. I have driven this track in another car before so have limited experience. There are some truths that have emerged about the car and my driving. I have read all of the recent posts about cooling issues, soft stock suspension and oil pressure issue on these cars but did not chime in as I had nothing to share. Now I do.
1. The stock suspension is truly soft on the track. I was astonished how floaty it was in long sweepers. I have wanted to lower the car but will now also focus on a moderate setup for DD and DE.
2. Oil pressure fluctuates on these cars in turns. Compared to driving on the street, I was pushing the car pretty hard. But I was getting passed by Corvettes, Camaros, Mustangs and Miatas so I was not tearing up the track. Running LN Spin on oil filter and M1 0W-40 with about 1500 miles on it. My impression is high temps and ariation are at work here. Looking in to additional oil cooling.
3. The Bridgestone S04 that feel so good on the track got greasy after 4 laps. Please note: I have mediocre driving skills on the track so maybe I overheated the tires. Pressures went up 3 psi in front and 5 in back. Car felt very squirrely. I suspect tire pressures have a lot to do with this. Also, alignment.
4. Car runs hotter on track than it has ever run on the street, even in stopped
traffic in 96F heat. Gauge went passed the 0 on 180. When I came in, car was puking coolant. Leak is on driver side and appears
to be coming from the expansion tank. Constant drip that stopped eventually. I added about a pint of coolant and drove 100 miles home without incident. System
holds pressure, no oil/water mix. Weird.
4. Did not have any AOS issues. Crankcase 1 bar from full when hot.
5. I'm not very fast (or experienced), but I do all my own stunts. Car doesn't have PSM so it was just me. Everyone else I talked to didn't dare turn off the driving aids. No apologies for my skills.

I won't return to the track until I get the known issues taken care of. This is my daily so that is alway in the back of my mind. And that was my goal: drive to the track, have fun driving fast (not racing), drive home, drive to work the next day. Until I get the maintenance issues addressed, I won't judge the cars on track ability.

 

Thunderhill in the summer is really hard on both man and machine! I did three of those events last year.

I don't think my car got quite as hot as yours, but it was definitely toasty. In the future I will drive around the grounds a bit before parking the car, so that it will have more time to cool before being shut down.

Definitely agree about the suspension. I'm on coil overs now but haven't been back on track with them yet.

Sounds like you had a good time and were able to drive home, so I'd call it a success!

And a video, just because. I'm not a skilled driver by any means...

 

That box that was in front of you the entire time , his head grew so big he ran off the road.

 

Sounds like a blast! If you are stuck on M1 I would recommend their 5w50 for track use. It will hold up better under the higher temps.

Just past the 0 isn't a concern for the water temp. But make sure you are clean between the condensers and radiators. You can also add a bottle of Water Wetter by Redline and drop the water temp 10-20 degrees.

Part of the floaty feeling will be your suspension but part of it your tires. I've run a US M030 suspension with Pirelli slicks and it was amazing how well it handled. Still some lean but little float. A great street/track tire if you are going to be doing much track time is the Bridgestone RE-71R. The only downside is they wear quickly.

As for the drop in oil pressure on the turns, usually this is because you are breathing the throttle. An X51 baffle or an accusump is recommended but most of the sp996 race cars aren't running additional oil coolers.

 

Congratulations!

I went to the track in my 99 C2 for the first time at high planes raceway near Denver yesterday. It was a blast.
Same observations, the stock "touring suspension" was very soft and did not give me confidence. Once I got used to it, I did not mind it to much. Turn in on high speed corners was hard to know what the car was going to do.
The temps ran ok, just past the 0. I was taking it easy on the straits to try and keep it cool.
I was not sure how much I should keep it running after my runs so I was just shutting her off.

Thanks for sharing.

 

The exciting part for me is that now I have some experience with the car. with that, I have uncovered some areas for improvement. Now I can start wrenching with some direction rather than just throwing time and money aimlessly.

Thanks for for the responses. Slakker, what does "breathing through the throttle" mean?

 

nine stone, same experience here. Especially on the high speed sweepers.

 

jandackson,

where you loosing oil pressure and the right hand sweepers too?

 

nine stone,
yes, pressure was getting as low as 2 Bar, though I wasn't studying the gauge for very long. It seems like the pressure fluctuated all over the place. Even above 4k on the straights it was at 3 Bar where it usually is at 3.5 to 4 Bar. After I came in and it sat for 20 minutes or so, the pressures were back to normal so it is clear to me that temperature has an impact here. As Slakker noted, the spec cars don't run extra oil coolers. I'm thinking a third radiator would be a good investment (after new water pump, thermostat, expansion and and cleaning of rad's).

 

I meant Breathing the throttle or letting up on it.