This weekend at Shenandoah Circuit I ran my Aim Solo DL as well as the PDR. Below is a raw cut and paste from yesterday's sessions with lap time, speed, coolant, oil, and intake air temp max. The high temp was 87F and sunny.

A couple interesting things. The first is that the vehicle speed is a little on the conservative side whereas most every other vehicle I've seen has been optimistic on indicated speed. I commented on this once before but folks comparing top speed indicated from say a C6Z to a C7Z need to realize that there is a combined error between the two that can result in 10 or more MPH difference.

The other is to look at the IAT. You'll see that when I pitted in and turned off the car the IAT shot up and stayed that way when I started the car back up until it got moving. Once moving the temps dropped rapidly. Usually my stops were pretty short and were enough to get gas, a drink, and use the facilities.

My lap times were all over the place. In some cases this was traffic, others is was the tires going off, or just me wanting to cool it for a lap or two.

Video of my fast lap.

Sorry for the horrible formatting but I don't see a way to insert a table.

Run/Lap Time GPS_LatAcc GPS_Speed ECU_VEH_SPD ECU_ECT ECU_IAT ECU_OIL_T
run 2 / lap 1 02.18.891 0.91 68.2 66.8 199 93 133
run 2 / lap 2 01.56.214 1.17 98.8 96.7 201 81 171
run 2 / lap 3 01.46.240 1.37 112.0 110.0 201 79 199
run 2 / lap 4 01.51.528 1.37 117.7 115.1 207 79 217
run 2 / lap 5 01.44.289 1.45 108.7 106.6 208 79 228
run 2 / lap 6 01.43.760 1.31 119.6 116.7 214 79 239
run 2 / lap 7 01.47.086 1.24 119.4 116.7 217 81 248
run 2 / lap 8 01.45.071 1.41 119.4 116.5 221 81 253
run 2 / lap 9 01.44.702 1.31 112.8 110.5 221 81 255
run 2 / lap 10 01.43.982 1.36 118.4 117.2 221 82 257
run 2 / lap 11 01.46.116 1.25 119.4 116.2 221 82 259
run 2 / lap 12 01.43.353 1.34 117.0 114.5 223 82 259
run 2 / lap 13 01.44.788 1.52 109.5 106.5 221 82 259
run 2 / lap 14 01.45.923 1.43 117.2 115.1 223 82 259
run 2 / lap 15 01.44.299 1.39 116.3 113.6 223 82 259
run 2 / lap 16 01.43.863 1.44 115.0 112.3 221 82 259
run 2 / lap 17 01.45.719 1.53 122.0 119.1 221 82 261
run 2 / lap 18 01.40.996 1.56 117.7 115.9 225 84 262
run 2 / lap 19 01.41.183 1.48 115.8 114.3 223 82 262
run 2 / lap 20 01.40.099 1.38 123.0 121.7 223 82 262
run 2 / lap 21 01.42.572 1.37 122.0 119.9 223 82 264
run 2 / lap 22 01.45.911 1.25 112.2 110.1 223 84 264
run 2 / lap 23 00.58.256 0.58 80.0 77.5 217 113 262
run 3 / lap 1 00.19.699 0.03 13.0 13.6 212 113 257
run 4 / lap 1 02.12.364 1.01 92.4 90.3 196 115 192
run 4 / lap 2 01.44.882 1.45 114.3 111.8 205 90 210
run 4 / lap 3 01.40.895 1.67 122.0 119.2 214 88 232
run 4 / lap 4 01.39.773 1.45 121.7 120.0 223 90 250
run 4 / lap 5 01.51.276 1.40 108.2 106.1 225 90 255
run 4 / lap 6 01.43.299 1.50 120.0 118.4 226 90 261
run 4 / lap 7 01.42.512 1.43 115.9 114.1 230 91 262
run 4 / lap 8 01.42.307 1.34 108.0 104.8 232 91 264
run 4 / lap 9 01.46.083 1.42 116.6 116.4 234 91 268
run 4 / lap 10 01.49.118 1.31 120.8 118.7 232 91 270
run 4 / lap 11 01.43.748 1.30 114.2 111.3 232 91 268
run 4 / lap 12 01.51.726 1.34 113.5 112.0 230 90 270
run 4 / lap 13 00.56.547 0.39 61.4 59.5 221 117 264
run 5 / lap 1 02.07.796 1.25 98.9 96.6 214 117 261
run 5 / lap 2 01.47.058 1.43 106.2 104.4 210 97 205
run 5 / lap 3 01.48.244 1.45 104.9 102.9 221 93 232
run 5 / lap 4 01.43.655 1.35 115.9 113.2 223 93 250
run 5 / lap 5 01.42.391 1.42 117.3 114.5 225 93 257
run 5 / lap 6 01.42.939 1.49 118.3 116.0 226 93 262
run 5 / lap 7 01.45.642 1.29 120.0 118.3 230 93 264
run 5 / lap 8 01.46.118 1.27 104.9 102.0 230 93 266
run 5 / lap 9 01.44.414 1.27 113.2 110.1 230 93 266
run 5 / lap 10 01.43.166 1.27 113.4 110.2 230 91 266
run 5 / lap 11 01.42.595 1.34 114.2 111.7 230 91 268
run 5 / lap 12 01.43.471 1.33 112.1 109.7 230 91 268
run 5 / lap 13 01.50.296 1.37 113.6 112.6 230 91 270
run 5 / lap 14 01.44.760 1.20 114.0 111.5 226 93 266
run 5 / lap 15 01.47.011 1.42 109.8 107.9 226 95 264
run 5 / lap 16 01.42.535 1.40 117.7 115.1 226 91 264
run 5 / lap 17 01.53.197 1.13 119.0 117.3 225 95 264
run 5 / lap 18 01.53.409 1.28 105.8 103.0 223 93 262
run 5 / lap 19 01.57.731 1.21 104.9 102.0 219 91 257
run 5 / lap 20 00.56.731 0.49 61.2 59.3 214 118 253
run 6 / lap 1 02.04.422 1.27 100.0 99.2 210 118 248
run 6 / lap 2 01.43.681 1.34 116.1 113.7 217 95 228
run 6 / lap 3 01.47.055 1.29 111.6 108.8 221 93 244
run 6 / lap 4 01.41.586 1.47 120.4 118.2 221 91 253
run 6 / lap 5 01.40.873 1.55 120.8 118.7 225 91 261
run 6 / lap 6 01.45.055 1.43 117.1 115.1 226 93 262
run 6 / lap 7 01.42.773 1.43 119.9 117.4 226 93 262
run 6 / lap 8 01.45.696 1.46 120.4 118.6 228 95 262
run 6 / lap 9 01.43.619 1.52 121.4 119.1 228 93 264
run 6 / lap 10 01.42.583 1.60 119.2 116.8 228 93 264
run 6 / lap 11 01.41.322 1.57 120.6 119.2 230 93 266
run 6 / lap 12 01.40.934 1.58 121.2 118.7 230 91 266
run 6 / lap 13 01.51.472 1.41 117.1 115.0 228 95 268
run 6 / lap 14 01.44.160 1.44 113.2 110.5 226 93 264
run 6 / lap 15 01.46.461 1.28 116.3 113.7 226 95 264
run 6 / lap 16 01.50.965 1.42 94.3 91.6 226 95 264
run 6 / lap 17 01.51.883 1.30 93.2 90.0 221 91 261
run 6 / lap 18 01.57.254 1.39 95.1 93.2 217 91 255
run 6 / lap 19 01.57.126 1.18 101.8 100.0 219 93 250
run 6 / lap 20 00.52.501 0.54 74.7 72.6 221 113 250
run 7 / lap 1 02.02.562 1.15 98.4 96.1 221 115 246
run 7 / lap 2 01.45.790 1.37 108.9 107.9 219 91 244
run 7 / lap 3 01.47.365 1.35 108.7 106.1 219 91 250
run 7 / lap 4 01.43.102 1.62 114.3 113.5 223 91 255
run 7 / lap 5 01.57.255 1.32 119.8 121.4 223 91 257
run 7 / lap 6 01.04.335 0.33 51.9 50.4 214 93 253

 

Let me try this.

 

Except why did those IAT's jump up only for a bit?

 

You may have demonstrated the anomaly here in your revision!

How about the new radiator cooling arrangement is causing some of those spikes?

Has anyone ever had this setup before in a SC? The Camaro SC has much more air going in all the way around:
http://www.chevrolet.com/camaro-zl1-muscle-car.html

 

Good Reporting Sean,

I've seen the same thing on my GS, especially in daily driving I can see a temp difference of about 30~40* at certain stop lights. After about 5mins of driving @ at least 30MPH my intake temps will settle at about +10* of ambient. My belief is that corvette hood lines are so low that the intake will heat soak in a couple minutes with without flowing air.

 

Anyway, I read guys are currently looking at trapped air in the SC as being the culprit in the latest MT thing.
Trapped heat would even jive with Tadges math and the air flow/aero scenerio!

 

Can you explain to us what occurred between run 5, laps 16, 17 and 18?

What i am wondering about is the ECU_oil_T delta between laps.

I guess what i see here is: Lap times and ECU_oil_T are not inversely proportional. Specifically with lap 17, why am i not seeing a corresponding drop in ECU_oil_T for that given lap time: 1.53.197?

 

I'm not sure what exactly you're referring to but I believe Truth clarified already. The cooling system is bone stock other that M1 15W50 oil. That includes the same coolant mix that left BG in December.

The IAT temp spike correspond to laps where I just started or stopped the car. If you look at the actual graph you will see it spike as soon as the RPM goes to 0 and then it starts high. Below is a capture of a restart and back out on track with a hot car.

 

 

Thanks for catching that. That is precisely why I wanted to post the raw data. It took me a bit to correlate this with PDR video but here is what was happening:

5/15 - normal other than being stuck behind a Miata for a bit.
5/16 - I caught a friend/student in his C7 Z51 and wanted to follow him around a bit to give him feedback on his lines. I was staying pretty close up behind him other than when he was offline.
5/17 - I passed but slowed so he could follow my lines.

 

Thanks. This is the info i was after. Could you please post more PDR video for these sessions? I am totally a PDR junkie.

PDR vids.....the more the merrier i say!

 

I think I can see why your car doesn't overheat while the car overheats in the hands of many others. It is not unusual to see a difference of 16 seconds between some of your laps in the same session. You are effectively running some cooling laps. Even if your fastest lap is fast by any standard the 16 second lags in some of the other sessions are more than enough to cool the car. At Laguna Seca which is a similar 1:40 track for the better advanced drivers, a 16 second difference puts you in the beginner group.

It is highly unusual for me to run a difference of more than 8 seconds. You guys must be getting a lot of traffic on track, similar to the lower groups. My car also would not overheat if I oscillated between advanced and beginner lap times.

 

Totally agree. M7 running 8/10ths should never overheat.

 

Where is there a 16 second spread here?
Lap 1 2:28.891
Lap 2 1:56.214
Lap 3 1:46.240
Lap 4 1:51.528
Lap 5 1:44.289
Lap 6 1:43.760
Lap 7 1:47.086
Lap 8 1:45.071
Lap 9 1:44.702
Lap 10 1:43.982
Lap 11 1:46.116
Lap 12 1:43.353
Lap 13 1:44.788
Lap 14 1:45.923
Lap 15 1:44.299
Lap 16 1:43.863
Lap 17 1:45.719
Lap 18 1:40.996
Lap 19 1:41.183
Lap 20 1:40.099
Lap 21 1:42.572
Lap 22 1:45.911

 

compare lap 20 with lap 2: 16 second difference.

If this is the same course, a near stock S2000 seems to do it in 1:40 too. Intake and exhaust is only good for 20 hp on that car and the rear tires are only 255s.

 

lol...what?
How does running a :56 warmup lap effect ECT and EOT ~20+ minutes later when he ran a couple of :40's and a :41 and the temps were 225/262?
S.

 

Wow talk about cherry picking information when most of his laps are withing 3-4 seconds of each other.

 

Comparing to this video, he is not running his Z no where near its potential, meaning that it should be over heating if ran to the limit?

 

To be fair, SBC ran his Z06 to nowhere near it's potential either (1:44 lap time at Laguna as I recall in cooler weather) and it overheated (in warmer weather).
I still think some issues are related to individual cars and some are exacerbated by driving method. SBC's car might be the perfect storm, as he has had numerous issues above what (I think) we've seen with any other car.
S.

 

Yeah, basically all but a few of his laps were on par with this ~260hp nearly stock S2000. No surprise it won't overheat. I bet Spec Miata records on this track are under 1:40.