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-   -   orthojoe 991.2 RS at Thunderhill and track talk (https://rennlist.com/forums/991-gt3-gt3rs-gt2rs-and-911r/1131811-orthojoe-991-2-rs-at-thunderhill-and-track-talk.html)

orthojoe 03-02-2019 08:56 PM

orthojoe 991.2 RS at Thunderhill and track talk
 
I was FINALLY able to find a clear day at Thunderhill yesterday to try out the RS. I already had 2 failed attempts, which included me towing the RS all of the way up to willows only for it to rain heavily all day (ended up practicing in my spec miata instead). Conditions were pretty ideal for fast laps. Cool weather and overcast. The only issue was standing water at the apex of T14. Anytime I had traffic which negated a fast lap, I would crash through the particularly slippery water and slide through it, but it would never go away for some reason. I don't think that really costed me more than .2 at the most, though.

Prior PB at Thill in the 991.2 GT3 was 1:57.1 on the 3 mile cyclone config.

New PB at Thill in the 991.2 RS was 1:54.8 on the 3 mile cyclone config.



Do I think the RS is 2.3 seconds faster? No, I don't. My driving on the regular 3 was sloppy and the theoretical best was 1:55.9. My driving in the RS was more consistent and the theoretical was only a bit faster at 1:54.6. I think realistically that about one second separates the cars. At laguna I did a 1:34.8 in the 3 and a 1:34.1 in the RS. In comparing the 2 cars, it is interesting to note that the peak speeds are the same, but that is because I was bouncing off the rev limiter in the GT3. At high speeds, the GT3 gains speed faster than the RS. I assume that this is because of the aero and I do have the wing set at maximum attack angle. Maybe somewhere in between might be faster? Here is the overlay graph. RS in lizard green and GT3 in GT silver:

https://i.postimg.cc/y8JvD161/rsvs3.jpg

In the GT3 I was overdriving the car and couldnt get on the throttle soon enough. You can see how getting on the throttle early makes ALL of the difference in the world.


The event was with speed district and there was a TON of track time. We're talking 8 25-30 minute sessions with an open track the last hour of the day. This was day 3 on my dunlops. The first 2 events were on stock alignment, which was -1.5 camber on all 4 corners. To combat edge wear, I had the car bumped down to -2.5 degrees on all 4 corners. Zero toe up front and 2mm of toe in at the rear (4mm total). My sway bars are at stiff front and middle rear, but every really needs to adjust this based on what they personally prefer. After the 4th session, the car started to feel less precise and I look to see that my rear passenger side tire had cords showing on the outside.

https://i.postimg.cc/RZzTGjc9/IMG-3721.jpg

The outstanding thing for me was that up until the tires were corded, the car was still just as fast as fresh tires. I swapped in a new set of tires and the car felt just as good, albeit I turned a lap time that was .3 seconds faster than 'old tires', but that was all driver and not the tire. I'd like to see what happens with the wear now that I'm -2.5 degrees of camber. If I can get 4 fast days out of the tires before they cord, that would be fantastic. For now I can confidently say that with stock alignment you can get 3 fast days before the tires cord. Contrast that with the cup2 which are fast on day one and fall off with each successive day (at least for me).

Perhaps my problems with the cup2 are because I don't know how to manage them, but for me I'm going with dunlops from now on. Here a few key things to know:

Plan on your first session of the day as a throwaway warmup session. Unlike the cup2s, which are good to go right away after one lap, the dunlops need one session to get up to temp and pressure. I start out with 26psi dead cold on all 4 tires. The tires WILL slide everywhere if you try to push quickly, unlike the cup2 which grip right away. It will take several laps, but each lap will be faster and faster and faster. At the end of the first session pressures will be around 36psi in the front and 38 psi in the rear. Drop the pressures down to 33psi in front and 34 psi in the rear and then leave it alone for the rest of the day. The car will be super consistent. On cup2s I would usually get 3 laps to get a fast lap before the tires start falling off. On dunlops I would need 2-3 laps before they really started to grip, but I was getting fast laps on lap 3 and lap 12 with no dropoff after that. Tire pressures with constant hard driving for 30 minutes would never go above 35F/36R and that was fine. If anyone has dunlop tires that they don't want, sell them to me. I'll take them any day over the cup2.

So, thus far my RS has done 1:34.1 at Laguna Seca and 1:54.8 at Thill, which makes sense since there is about a 20 second spread between the 2 tracks. This means my goal for Sonoma should be at least a 1:44.x since there is a 10 second spread at that track. Zero doubt the car can be driven faster in the right hands.

In other news, the AP calipers continue to impress. The new 3.12 brake pads are VERY consistent. They feel the exact same at the start of the session as the do at the end. Very easy to manage. Very consistent. Pedal feels the same every time. Love them.

Mech33 03-02-2019 09:15 PM

Great wrote-up Joe! LOL at the GT Silver and Lizard Green plot lines. I’ll have to try out a set of the Dunlop’s next! Great driving as usual.

FourT6and2 03-02-2019 09:57 PM

Nice!

I played your vid side by side with my best recorded time on the same track in my GT3 (2:05 on video). I've managed to hit 2:00 flat, though. Through the corners we were at similar speeds. But coming out of the turns and out onto the straights you were 10 mph faster than me. And in one or two places you reached 20 mph faster by the same point on the track. Then I watched again and realized I could be downshifting into 2nd gear in many places. The problem I've run into with the manual is that when trying to shift down to 2nd I tend to pull the selector past the gate and into the reverse gate (without shifting up into reverse obviously). But I overshoot the 2nd gear gate for some reason. I think the adrenaline is coursing and I'm hulking the shifter too much lol. And then I try to shift into second, but I'm really trying to shift into a wall since there's no gate there. So I stopped doing that and focused on my line and just kept the car in 3rd. I've brought shame and dishonor to my family.

Oh, also... your videos... the car always sounds like it's sceeaaaaaming. And in my video you can barely hear it lol. And I have a center bypass. Is your audio from an external mic?

orthojoe 03-02-2019 10:34 PM


Originally Posted by FourT6and2 (Post 15676267)
Nice!

I played your vid side by side with my best recorded time on the same track in my GT3 (2:05 on video). I've managed to hit 2:00 flat, though. Through the corners we were at similar speeds. But coming out of the turns and out onto the straights you were 10 mph faster than me. And in one or two places you reached 20 mph faster by the same point on the track. Then I watched again and realized I could be downshifting into 2nd gear in many places. The problem I've run into with the manual is that when trying to shift down to 2nd I tend to pull the selector past the gate and into the reverse gate (without shifting up into reverse obviously). But I overshoot the 2nd gear gate for some reason. I think the adrenaline is coursing and I'm hulking the shifter too much lol. And then I try to shift into second, but I'm really trying to shift into a wall since there's no gate there. So I stopped doing that and focused on my line and just kept the car in 3rd. I've brought shame and dishonor to my family.

Oh, also... your videos... the car always sounds like it's sceeaaaaaming. And in my video you can barely hear it lol. And I have a center bypass. Is your audio from an external mic?

Based on what you are saying, you are either over driving the car (braking too late/entering too fast) or driving the wrong line or both. Apex speed is not as important to look at as exit speed. The apex speed comes if you get the entry and exit right. It's all about exit speed.

The only turn you should be using 2nd gear in your car at thill is T11.

My exhaust is stock, but I'm using an external mic mounted in the rear bumper right above the license plate

FourT6and2 03-02-2019 10:44 PM


Originally Posted by orthojoe (Post 15676327)
Based on what you are saying, you are either over driving the car (braking too late/entering too fast) or driving the wrong line or both. Apex speed is not as important to look at as exit speed. The apex speed comes if you get the entry and exit right. It's all about exit speed.

The only turn you should be using 2nd gear in your car at thill is T11.

My exhaust is stock, but I'm using an external mic mounted in the rear bumper right above the license plate

If that's what overdriving is, then yes... I'm doing that. Definitely entering too fast.

As far as not using 2nd gear goes, there are a bunch of turns where I'm down at like 5K or lower in 3rd gear (cyclone, T11, T14). So when I punch it coming out of the turn it takes forever to get up to speed. So how do I overcome that? Those three turns seem like 2nd gear would work. Is it different between the two cars because yours is PDK and has shorter gears?

orthojoe 03-02-2019 10:52 PM


Originally Posted by FourT6and2 (Post 15676347)
If that's what overdriving is, then yes... I'm doing that. Definitely entering too fast.

As far as not using 2nd gear goes, there are a bunch of turns where I'm down at like 5K or lower in 3rd gear. So when I punch it coming out of the turn it takes forever to get up to speed. So how do I overcome that? T11 = yes, 2nd gear makes sense. But also the cyclone, no? And is it different between the two cars because yours is PDK and has shorter gears?

No, in a miata or GT3 with manual (pdk is different because I leave it in auto but would still prefer 3) I leave it in 3 for the t5 cyclone at thunderhill and t8 corkscrew at laguna. Those turns exit downhill and spin the engine up very quickly. You are better off keeping the car stable and not destabilizing with a shift. The less you disrupt the car's balance, the more it will grip. Work on increasing your speed and the engine won't feel like it is lugging.

I frequently hear people say that t5 is boring because it is too slow. That is because they are too slow, LOL. T5 can be very fun and challenging and is a place where I gain on a lot of people during scca races

CDinSing 03-02-2019 11:27 PM

Joe,
Great write up. I agree with your experience on the Dunlops. I got 7 days of 4-25 min sessions per day at Sebring from mine and they are still amazingly sticky. I am waiting for them to cycle out. At -2 camber they are wearing pretty evenly but I am probably not pushing as hard as you.

usctrojanGT3 03-02-2019 11:38 PM

Great write up and a fast time. Glad you enjoyed the Speed District event, they run a great show and I love going out to their events. You should come down to Buttonwillow which they have events all the time, including the Friday and Saturday before Easter.

SmokinGTS 03-03-2019 12:26 AM

Joe
As usual fantastic write up. Now what do I do with those new Cup 2's inbound.

orthojoe 03-03-2019 12:33 AM


Originally Posted by SmokinGTS
Joe
As usual fantastic write up. Now what do I do with those new Cup 2's inbound.

Drive them for one fast day and then sell them to a guy who only does C&C , haha

orthojoe 03-03-2019 12:36 AM


Originally Posted by CDinSing
Joe,
Great write up. I agree with your experience on the Dunlops. I got 7 days of 4-25 min sessions per day at Sebring from mine and they are still amazingly sticky. I am waiting for them to cycle out. At -2 camber they are wearing pretty evenly but I am probably not pushing as hard as you.

The outer edge of your rears still look good? It's painful throwing away tires that are only worn at the edge and the rest looks fine


Originally Posted by usctrojanGT3
Great write up and a fast time. Glad you enjoyed the Speed District event, they run a great show and I love going out to their events. You should come down to Buttonwillow which they have events all the time, including the Friday and Saturday before Easter.

Yeah speed district is great. I will probably be at bw Black Friday again this year

Dougr743 03-03-2019 07:11 AM

What is the factory setting for rear toe? did you change rear toe on the 3? did it change the understeer on the car?thanks

CDinSing 03-03-2019 10:19 AM


Originally Posted by orthojoe (Post 15676527)
The outer edge of your rears still look good? It's painful throwing away tires that are only worn at the edge and the rest looks fine

The edges are more worn than the center and inside but not close corded. I admit the first two times out the car was as delivered and the handling was sketchy. The back end would get very light under braking and skip out going through turns 1 and 17 at Sebring. So I was not pushing it hard. The third event I had the car set up with more camber, lowered and much less rake, and more aggressive aero. It feels like a different car. It is stable and planted everywhere as long as I keep the tire pressures below 34. My 7th day was my fastest at 2:19.10 which is 4 seconds faster than the GT3 on new N1 cup2s. That is impressive for “old” tires.


https://cimg4.ibsrv.net/gimg/rennlis...c23c67b22.jpeg
Left rear
https://cimg5.ibsrv.net/gimg/rennlis...4b8cebe3d.jpeg
Left front

robmypro 03-03-2019 10:51 AM

Awesome stuff, Joe! A lot of really good info. Fascinating how Dunlop leapfrogged Michelin. Now i wonder how good the Dunlops are on the street?

Waxer 03-03-2019 11:23 AM

Great info Joe. To think I was at first disappointed my RS came with the Dunlop’s. Good info and advice 👌


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