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Saturday - TT Race 1
We had 7:30 driver's meetings for TT with follow up meetings at 11:30 both days, which was nice. This "2 meetings per day" policy comes from changes implemented by NASA National office, which I agree with, as strange as that sounds.
We had 5 competitors signed up but only 3 that made it to the event. My two TT3 competitors all weekend were Bruce Mowry in a gutted E93 M3 with Hoosiers and Aero (above). He had run the Friday test day and he told me he had got down to a personal best of a 1:54 range in testing. There was also a 911 Carerra 4S driven by Joey Dumas - also gutted/prepped, on Hoosiers with aero. Joey's car lives here at the track, where he is a member, and he gets a lot of seat time here. Hmm, so scrub cars here - I might be outgunned.
Right out of the box on the TT warm up I got stuck behind a yellow Corvette, who went off in front of me at T1 in the first hot lap, and then came back on track right in front of me. Yikes!
Amy almost got the picture of this incident... I avoided collecting the yellow Corvette with a quick evasive maneuver but it ruined my lap and the session only yielded a 1:54.259 lap, putting me 2 tenths behind Mowry and 2 seconds behind Dumas.
Saturday TT session 2 put me into a 1:53.542 best, but the 911 ran a 1:51.669, so I was trailing by 1.8 seconds, but only back a tenth from 2nd. Saturday session 3 was a lot closer, with all 3 of the TT3 cars running 1:53 laps, less than 4 tenths separating us all, but I was still in 3rd.
I kept moving up the grid as I dropped time, yet still kept being held up on the first couple of laps each time. These A7 tires "switch on" very fast and get greasy by lap 2 or 3, yet other cars take longer to get up to speed. There were some quick TT1 and TT4 cars that were quicker at the end of the session, but rolling roadblocks early on. So I wasn't getting a clear track until lap 3 or 4, and by then the A7s were boiling and the oil temps spiking. Frustrating. This not being my home region it took a little time to get to know the local TT competitors and I was hoping that on Sunday I might be able to grid swap with some folks to get a clear lap 1 or 2.
I was really abusing the A7s by running them for 4 or 5 hot laps in a session, and usually by then the high oil temp issue would crop up and the car would go into limp mode, cutting off the top 2000 rpm of engine revs. Some of my best laps Saturday were while running in limp mode.
Session 4 was better - I had parked at the very BACK of the grid, planning to hold back a LOT on the out lap and try to get ONE lap clear of traffic early on in the session. I sat back there until a few guys came and asked what was up, then they moved me to like the front of the grid, and
WHAMO! I was able to get a quick first lap, dropped 1.3 seconds, and jumped into 2nd in class with a 1:52.190 best. I was back 5 tenths for the day (final Saturday TT3 results shown above), but 5 tenths is not much - maybe I can find that on Sunday, getting clear track in an early session?
Sunday - TT Race 2
Now that I was dialed in a little better to this setup and track, I planned on getting my best lap in the first session Sunday. The temperatures almost always worked out to be more favorable on the first session, and this day was no different.
I gridded better and built a bit of a gap, so I had not only a clear first lap but a clear second lap as well. Bruce as behind me but I was enough ahead that I didn't impede him, and popped off a
1:52.177 lap 1, which was only
2 hundredths quicker than my Saturday best. I kept going and slowed down to a 1:52.544 on lap 2, but still kept at it for a hot lap 3. The rear tires were sliding like mad and I knew I had overheated the rears. Oil temps had spiked and the tires were toast. I pulled off line after Start/Finish, backed off and let Bruce go by me. That sneaky M3 driver had put some A7s on without me noticing, ran his personal best of a 1:51.873, and he jumped ahead of me! Dumas put down his best in this session at a 1:51.760 staying in 1st once again.
And that's how the day ended, with no TT3 competitor going quicker in later sessions. I came in after that first session and noticed a patch of cords on peeking out of the left front tire, so I was done for the day.
The video shows a couple of laps in this first Sunday TT session, where I almost exactly matched my time from Saturday. Losing sucks, and a 3 tenth spread from 1st to 3rd made it harder. I had seen a 1:51.5 predicted time, so the car had more in it, I jut couldn't find it. My stupid mistake of gentle out laps hurt the braking performance on lap 1, which I didn't figure out until it was too late. With cords on the LF tire there was not a good way to find that time in a later session.
So the $2000 set of Hoosier A7s were done in less than 2 weekends. Fudge. It has a lot to do with the weight of this car (3900 with driver and fuel), maybe little to do with the power potential of this engine, some of it is my driving style, but mostly the fact that this 315mm tire is still
relatively narrow for the massive weight of this car. I didn't help things by taking more than my normal 1-2 hot laps on most of the 12 heat cycles I put into these A7s, which hurts their lifespan.
The weekend ran well, and NOLA region does a great job even when it is a merged event with Texas region, which triples their attendance. Sure there were a number of delays, and we ran about 1 hour behind schedule all weekend. But its the Big Easy, and you just roll with it. The suspension and spacer changes we made since COTA helped - the tires were tucked under the fenders and no longer rubbing, the suspension wasn't bottoming, and the brakes worked very well (once I put a little heat into the pads). I have since learned to not let the brakes stay ice cold for my first hot lap, so my out lap procedure now puts a
little heat into the PB13 front pads, and they work perfectly on the first lap now.
I ran that dismal 1:56.867 best lap here with Optima back in April, with the brake hydraulic mismatch issue, on 200TW street tires. Finding 5.7 seconds from that event to now was partially from the differences in tires, but the massive improvement in braking was most of it.
All of the fast cars in TT1/2/3/4 were gutted race cars with full aero, but here we were in a street car with full interior, a stock engine, and out of the box R&T coilovers. Maybe losing by 3 tenths on Sunday shouldn't sting, but it still did. It was beyond time to address this oil temp issue, and I needed to think about cutting this car (to add more tire) and putting on some real aero, or the performance is always going to suffer in TT3.
MISHIMOTO OIL COOLER
If you have been following this build thread you know we have posted many times about "high oil temps" on this 2018 model. Other 2018-19 GT track rats have seen the same thing. After 1-3 laps of HARD track driving the oil temp gauge (a digital "analog sweep" readout, but with no numbers associated to it!) spikes into the red, then the computer implements a limp mode that chops off revs to 6000 rpm max, and if you keep pushing it, it drops to 5000 rpm. By that point I just give up and come in to let everything cool down.
What's going on here? Why is this effecting 2018-19 models and not 2015-17 GTs? We have some theories. Contrary to popular belief, we don't just service Mustangs, and not all of our customers are 100$ track rats - so we have only worked on a handful of 2018+ Mustang models. Our car is what we have the most first hand track experience and this oil temp issue with, but others have mentioned similar issues on these cars online.
Question:
Don't these cars have a factory oil cooler? Answer: Yes they do - see above right. This little heat exchanger "brick" has radiator coolant that passes through it to both PRE-HEAT and hopefully "cool down" the engine oil once it has reach operating temperature. The radiator on the base model GTs are also much smaller than the PP or Shelby cars, as shown above left) and we think that the pre-heating (for engine efficiency / fuel mileage) works a little too well.
The 2018 GT also got this electronically controlled grill louver system - which can BLOCK OFF ANY AND ALL AIRFLOW to the radiator. This was originally designed for the 2015 Ecoboost cars but Ford put it on the non-PP 2018 GTs as well (see
this article). "active grille shutters (on all Mustangs not equipped with the optional Performance Pack) to reduce drag at higher speeds" That isn't helping things if it is programmed a little aggressively.
We knew that Mishimoto made a complete oil cooler kit for the 2015-17 GT but were told that it needed some changes to fit the 2018-19 cars. We aren't going to go into every detail on this oil cooler install, as I'm waiting for Mishimoto to produce the 2018-19 GT kit. Just the highlights.
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