RCR T70 at Charlotte Motor Speedway

Ron Earp

Admin
The SCCA was back at Charlotte Motorspeedway last week after about a six year hiatus. We figured it'd be a good time for us to test the T70 at a venue different from our usual VIR test grounds. In typical fashion a race car never disappoints when taken out for testing....

CMS is a cool track. It is much smaller than Dayonta with respect to the oval and the infield is tight and interesting. I've never driven CMS before and the Youtube video below shows my first lap ever at the track. In short, it is a lot of fun although I didn't push the car at all. We were there simply to test but on this occasion it was an actual race so this is officially the first "race" that I've entered with the car. In fact, it was a double weekend and there were two races to race, both to be completed on Saturday.

Unfortunately, due to the silly SCCA grouping policies I was stuck in the group with the big bore cars - ex-NASCARS and the like. One car that particularly stuck out was a stock car bodied as a Ford Falcon with a 876 hp engine, a really cool looking car and it was super fast. Anyhow, no racing for me as I was the only car in the ITE class. Tell you what though, this car attracts people like nothing else I've ever seen. You don't see cars like this in an SCCA paddock and people are definitely interested in it. After a couple of hours I moved my chair out of my garage space so I didn't have to answer the same questions over and over - I know that's bad but it does get tiring.

On track the car behaved very well the first session out for practice and qualifying. I'd reach terminal velocity of around 140 just entering NASCAR three and then I'd basically coast through that turn, maintain some speed in NASCAR four, then accelerate out. I was driving slow and taking it easy as I didn't want to hurt the car and it was my first time at CMS. Even at 130 mph though during the race the GT1 cars would literally blow my doors off with closure rates of what I'd estimate 40 mph. Anyhow, I qualified on the pole for ITE - yes!

Even though the day was hot water and oil pressures were great, oil temps, both transaxle and engine oil, were also much improved due to a heat shield Jeff G and I fabricated that went between the muffler and transaxle. Now we had operating transaxle temps of around 200F instead of 240F.

The race session didn't go too well though. Within about two laps the car developed a stumble that got worse as the session wore on. At first it seemed that the stumble occurred while cornering in the infield only. Then, it spread to the exit onto the banking. And eventually it occurred on the banking too even when going straight. I strongly feel it is fuel related but I was not being a good driver and didn't check my fuel pressure gauge like I should have. I was just too distracted trying to avoid getting run over by the fast cars in the group. I was happy to see the checker out and bring the car back in. What is troubling is that this problem comes on the back of two very successful VIR test weekends with nary a hint of trouble.

After that episode I withdrew from the second race since I didn't want to pay $XXX to run around and troubleshoot. There wasn't much time in the garages to do much sorting of the car and I wasn't in the mood to mess with it anyhow. However, it did net a win for the car and Team Yellow Snow.

Fortunately, I was able to get my race on at CMS as I split a nighttime ride in my buddy's ITS Miata, which of course ran flawlessly and with which we were able to take a first in class win. Nighttime under the lights at CMS is something to see and the infield is damn challenging in the dark!! Anyhow, here's a video and a picture of Robert and I putting the registration sticker on the T70 for the first race entered. All in all a successful, but a bit frustrating, weekend.

First Lap at CMS in the T70 - YouTube
 

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Jeff Young

GT40s Supporter
Track is a lot of fun. You really feel the g-forces in turn 3/4. Ron said from the data that the ITS cars were doing about the same speed as the Lola in the banking, but only because he was lifting. So, I can imagine the g-push on the Lola driver at speed would be something else.

You definitely breathed a sigh of relief when you exited turn 4.
 

Ron Earp

Admin
Great writeup Ron, thanks for posting. I'm sure the fuel problem will be easily solved.

I'm not so sure about that. What is curious is we've never seen this before and the car is definitely no stranger to the track. Ideas I have but we've not investigated:

*Carb floats
*Fuel pickups in tank
*Fuel filter is plugged (whew, this would be nice!)
*Carb boiling fuel, i.e., our heat sheild changed under cowl airflow enough such that the carb is now way too hot in running conditions

I just haven't been that motivated on the project over the last week or so due to burnout earlier in June/July when we were prepping it full bore.

The car does well though. It drives well and works as it should. That in itself is a milestone as those of you know that have worked with taking a replicar and making a race car out of it.
 

Ron Earp

Admin
EDIT - not sure where the rest of my post went....

Short version, got the car out to check it out for next week's track session. Everything about the car seems to be as it was when it ran fine at VIR. We did see that the engine "felt" hotter at CMS that it did other places, but didn't have any reason to suspect problems as the temp gauges were okay. The manifold temp gauge showed 190F and the front temp gauge showed the same. Timing good, oil good, hmmmm, water level very low.

Checking the car over today I found out that the radiator has three holes in it - not good. All of them seem to be on the underside of the radiator so they aren't from debris hitting it. In fact it has a pretty good screen in place that I put there last year that does a good job of deflecting rocks and tire buggers. Still, pressure testing the system shows the rad is in need of repair.

I suspect that this had to have happened at Charlotte as we've never had any water problems until we raced there. Not sure if maybe the transition to the banking somehow stressed the front radiator support or what, but I'm hoping the rad shop can repair it for next weekend's test day.

Other than that I think we're good for some testing at CMP. I won't be driving as I have had enough seat time to know the car is capable of what the driver is able, but three of our drivers need seat time and CMP is a great track to perform some testing. It isn't so fast that you can really damage the car horribly and it will stress the brakes something mightily, an area where I'd like to collect some hard testing data.
 

Jeff Young

GT40s Supporter
EXCELLENT test day yesterday at CMP. Car is probably 99% ready for the enduro. Ran flawlessly the whole day, six sessions or just about 2.5 hours.

Ron and Jeff G. did great work on getting this car to raceable status. Great work.
 
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