It was a nice day for a season opener at the ORP yesterday. Save for some mishaps and frustration early in the morning (data communication issues, GoPro charging, falling plastic trim that scared me as it could've gotten stuck between the brake pedal, rotating phone mount in the air vents. Thankfully club events are in open session format so it's not like I blew a whole session.
I had a chance to compare both tire/wheels (staggered RR setup in 18" vs SQ SC3Rs in 19" setup). Some photos from the event:
Morning Run with Apex SM-10 wheels and Toyo RR tires
and then with Apex ARC-8 wheels and SC3R tires
Those 19x11" Apex wheels with 305 SC3R tires look very beefy but Corvette fender flares do good job covering them IMO
Time to go back home
A few things to mention:
Due to small hiccups I mentioned above, I missed the opportunity of testing in the morning which is the most ideal time for an ultimate lap. It was mid 40s in the morning and by the time I had my all time PB , it was in mid 60s. Typically that kind of change in temps are accounted for about 2 seconds at the ORP. Since it was a sunny day, track temps are more noticeable compared to a cloudy day (even at the same ambient temps)
In addition to that, as I didn't drive a fast car like a Camaro, it takes me sometime to get into the previous pace after a Miata so there's that
I should say I am pretty happy with the sway bars, all that body roll issues with sticky tires were gone. Much less understeer and steering feedback too. Whereas with the previous car, I was having horrible understeer and body roll at tight corners.
I could only drive one session with RRs as I had to go back to paddock and fix some of that issues, I decided to mount the SC3Rs during the lunch hour since it was getting warmer to compare them. With the RRs, I was slightly behind my PB with the old car (1:55.2) but the optimal lap time shows 1:54.5 which is about the same with my previous PB with used slicks. Although the body roll was pretty much gone, I still noticed some corner entry understeer.
RRs were pretty consistent throughout the session though and warm up pretty quickly as expected. I had to go back and lower my tire pressures after about 6 laps. They reached 35-36 psi pretty quickly even when I started with 28psi. I dropped them to my target pressure which is 32psi and after that it looked like pressures stayed at a plateau .
And the video with RRs. As I mentioned if I had more time with them and could test them early in the morning I think I could shave another 1-1.5 seconds with them easily.
And now the SC3Rs. Holy cow, going with full 19x11" wheels all around and 305s (well we know they're wider than 315 RRs on same 11" wide wheels) made a big difference. Car immediately gave tons of confidence and it didn't only stop better but all that turn in and corner entry understeer were gone, thanks to added contact patch. It's so much easier to rotate the car with maybe a slight oversteer vs understeer (just the way I like in a sports car).
I ended up shaving 2.4 seconds in about 10 degree warmer weather.
I have to mention though, I don't think the tire compound alone is responsible for that improvement but the combination of things. I am now thinking to get 18x11" wheels for up front so that I can run 315 RRs SQ as I already have them. Then I can try 315/30/18 Hankook Z214s which should be even faster than the SC3Rs. Car feels much more neutral with SQ setup, added rubber and roll resistance to compensate all that. Ryephile was completely correct about his assessment about SQ setup and roll bar rates.
Other thing to mention, 18" setup felt faster on straights because they're 2 lbs and shorter so if I can fit a 18x11" wheel I think things will change dramatically.
That said SC3Rs may be still faster than the RRs but I doubt they can be 2 seconds faster when compared to same width tires and wheels.
Anything close to (or below 1:50) at the ORP is very competitive lap time and I believe I can still shave another second or two on a cooler day and after more seat time. I am really hoping that I can take it below 1:51 that would be amazing.
Also, I did my best lap time on 6th lap with SC3Rs, just ignore the optimal lap saying 1:47s I am pretty sure RaceChrono merged some sectors or some other error. It's also very consistent like the RRs but maybe more available grip (we'll see if that's the case when I get some wider wheels to fit 315s)
Here's my all time PB at the ORP with SC3Rs