MarkDFW

It is a balmy 97 degrees in Texas, and I'm at Eagle's Canyon Raceway today. My car is a 2012 grand sport A6 with cam, headers, CAI, and tune. The cam required an aftermakret torque converter be put in for drivability, which also meant I had a big tranny cooler put in. I have an aftermarket radiator with integrated oiler cooler. During my afternoon session, a couple of weird things happened:

1 - Part way through my last session, I hit the paddles to downshift to second (in turns where I always have downshifted to 2nd) and see an "xx" where I would normally see the gear I'm in. Car made me stay in 3rd. My tranny temps hit around 250 and oil temps were 295ish.

2 - The weirder issues was my fuel gauge. It kept reading 3/4 of a tank through the entire session. I chew up 1/3rd tank through a session. Once I shut it down after the session was over and started it back up, I was at 3/8th of a tank.

I can see #1 as limp mode if tranny temps got too high, if that is in fact what happened? #2 has me really shaking my head.

Drove the car home from the track about 55 miles, and it runs fine.

Any ideas?

froggy47

nassaubluecoupe

Possibly. I ran an autocross today and after a few sessions my car went into reduced power mode, even though the temps were fine and it has never done this at an actual track, where the temps are higher. I turned the car off and let it sit for a few minutes and it's fine now. I have a friend that is running with The Drivers Edge at MSR Cression this weekend, and he said the heat was doing strange things to some of the cars out there today also.

bdanyluk

Yeah...on a hot day around 100 degrees my 2006 does weird things sometimes.

Somtimes, at a HPDE day after a few good sessions, like my ABS light coming on. I just shut it off and turn it back on, and it ran fine.

froggy47

Do you all ever pull the codes on this?

nassaubluecoupe

Mine didn't show any codes. I went and checked them manually and there were only a few and they were all history (H).

ErnieN85

I have had crazy things like this happen also. I think it's the electronics overheating. The Tcm is in the trans pan, the ECM inside the right front fender. both places would be above air temps.
most electronic components are rated for up to 125C. but act funny when temps get close to that. (212F) that means more cooling.
I have opened the front fender vents (no neat plastic thingy to block flow)
and will eventually get a heat extractor hood
For the trans. the biggest cooler you can fit in

MarkDFW

I already have the biggest tranny cooler I could get in. I think when you're pushing 100 degrees outside, it just doesn't matter!

ErnieN85

Could be,I also added an aluminum finned pan to the trans, don't really know how much it helps though

68sixspeed

295 oil temp, not good if you like your motor...

MarkDFW

My Ron Davis radiator with integrated oil cooler may not be enough. I will probably look in to a dedicated oil cooler.

What concerns me is the tranny temps. I have the biggest tranny cooler I can get and they were still high. I may just have to forego the track when it is close to 100

SunnydayDILYSI

Safety mode or not, downshifting is a bad idea with oil temp at 295... Your car was crying for mercy. I'm in DFW as well with a C5Z; put in a Ron Davis radiator with integrated oil cooler. Took down my temps down from 290s to 250s (was at Cresson today and was running in mid 250s). If you don't go with a cooler, be sure to go with heavier weight oil in the summer to keep pressure up at those high temps.

MarkDFW

We both have the same Ron Davis setup. Interesting your temps are that much lower in similar weather. What kind of times are you laying down at MSR?

crimlwC6

Cams=hp, hp=heat. My guess is the other guy is running closer to stock=less hp. I've tracked a c6 and a c5 both w/o oil coolers. C5 runs cooler b/c less hp.

crease-guard

I ran this weekend out at Cresson and noticed funny things as well. During my 3rd session yesterday I noticed the fuel gauge not moving at all. Also felt like the engine was missing a cylinder firing as it ran a bit rough at idle but seemed to run fine on track. I did an HPTuners log that session and will check it out this week but I suspect heat to be the issue. Didn't pull any codes as I was hot and tired as was the car.

My coolant temps were 206-210 but I'm running a huge radiator with all the air ducted from the front through the radiator. Oil temps in the 260's and that's with a dedicated oil cooler in front of the radiator.

Captain Buddha

Mark: I was at ECR Saturday as well (at Pinnacle, getting final fitment, didn't run though)...were you beating up on the Stangs again?

I ran into the same issue with my wife's 2012 GS Auto...it's the bleeping auto...your temps were too high because you were driving it like you're supposed to...it was fricking annoying as heck...so there I am in July at ECR downshifting on the paddles to second just like you were...same exact thing...same temps...once it cools down it's all good. So what I did with her car: run a few hot laps and then run a few laps at a nice speed with the car just in 3rd the whole way and then back to driving it hard after it cools off.

MarkDFW

Yeah the car is fine now. I called 21st Century Muscle cars, as I have a very good relationship with them. They said it sounded like it went in to limp mode.

And yes, I was the fastest car that day and beat up on all the mustangs, ZL1's, and GT3 cars. I made my corvette brothers proud

I'm not a huge fan of the BFG R1 tires I ran. I was following the manual which suggested hot PSI of around 38, but was told by a very experience guy (after I was done for the day) that around 34 PSI works much better. He said he hates the R1 tires. Oh well. Live and learn...

Here's a few laps in a row all around 1:59, which is 1 or 2 seconds slower than I ran on the Kumho V710 back in April.

Captain Buddha

Mark, as always, nice driving! Mental note to self, don't show up on days Mark is out there LOL

Yeah Mark...after watching the video I know why your car was hot! I'm surprised it wasn't hotter...and that you got that many laps out of it without the tranny going into "stop it you abusive mudder fudder!" mode sooner!

I heard a built ZL1 blew a motor...same guy that I've seen running out there before from what I'm told...something about *not* having enough HP or something and getting beat by little low-HP cars...I dunno... sucks to blow a motor though. Just goes to show that the "driver mod" is the BEST mod that any of us can make!

MarkDFW

Thanks!

I was watching him drive when suddenly a big puff of white smoke came from his car. he limped close to where you pit out but had to pull over and get a tow back in. I heard he has 750 rwhp, or should I say "had" 750 rwhp. He sat at my table at lunch, and seemed to take it in stride. He would be better off getting a good coach, and saving money on the driving.