3rd & 4th Race Weekends: Post Upgrade Report
10-09-2012, 02:47 PM
#1
Drifting
Thread Starter
3rd & 4th Race Weekends: Post Upgrade Report
Hey Gang,
So, after missing the summer race & tearing the car apart to upgrade the suspension & brakes, wheels & tires (link to upgrade thread), I've got 2 more race weekends under my belt (links to 1st race & 2nd race reports).
3rd weekend Saturday: Was a bit of a re-learning experience; I started off Saturday on my new to me scrubbed 305/35/18 Toyo R888's - my first set of R-comps, and the first time out with the new setup. It was overcast & cool with 90% humidity, 66F track temperature. With the low temps and no previous setup data to go by, I set the tire pressures at 32 psi all around for the morning practice. After several laps to get everything warmed up & get the feel of the car I started to push it a bit. I got a few hot laps in and set a new personal best at 1:19.444 (previous best was 1:21.270). Unfortunately, while exploring the braking points & entrance speeds I also discovered that the R888's don't make much noise when you lock them up, and I ended up badly flat-spotting the RF tire. The new front brakes work really well, that's for sure. For what it's worth, the tire pressures were up to 38-39 psi & 90-100F after the session. Expensive data...
Fortunately, I had ordered a set of 285/30/18 Yoko A048's for my 'inters' and they had arrived, so I missed qualifying and drove the car across town (still insured) to the tire shop and had the new Yoko's mounted. 3-hours later I was back at the track and ready to give it another go, from 18th on a grid of 20. My morning practice time would have put me 10th on the grid.
The tire shop said to take it easy in the first session, which I did for as long as I could stand. I was moving my way up the track through the slower cars in the run group, and while making a pass on a Miata in the hairpin at the end of the front stretch, I spun (to much throttle too early). No contact or damage – got into the grass & back on track and kept going. 3 laps after that I set a slightly faster personal best (1:19.235). I passed some cars & then spun again – not very pretty to be sure, and ended up 12th overall.
The tires were still warm from the drive & I had set them at 34 psi for the race. Here's where they were at after (78F track temp) – a little higher than where I used to run with Nitto NT05's:
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 41 – 104/115/124 | 131/125/118 – 43 :RF
LR: 41 – 110/129/141 | 133/133/122 – 41 :RR
3rd weekend Sunday: Main objective for the day was to start working on tire pressures, and try not to flat-spot or spin & bring it home in one piece. It's good to have achievable goals. It was again overcast & cool with high humidity. I set the pressures to 30 psi dead cold at 5:30 am before heading to the track (a solid hour plus away). While I did gain some confidence in the tires & setup, my times were not as good as the day before. I could see that I wasn't getting full contact at the outer edge of the tires, which started to lose grip about half way through the sessions – and I kept dropping the pressures (-1 on all corners for qualifying, and -1L/-2R for the race). I qualified 16th out of 23 cars and finished 10th after loosing a few battles with some fast cornering smaller cars. There was another Corvette in the field for the first time, an ultra rare white '01 Z06 driven by a new owner – this car has history at the track and has a great setup (fast times in the 1:12's), and the new owner was quickly coming up to speed – he finished 6th.
Temps & pressures after the 20 min race (88F track temp):
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 38 – 108/120/125 | 136/128/127 – 38 :RF
LR: 37 – 106/120/123 | 133/133/122 – 37 :RR
So, with a couple weeks until the next race I got to work. I got the two best remaining scrubbed 305/18 R888's and my well worn 295/18 NT05's set up on the other rims (these would be designated my dry tires), got into a buddy's shop & got the rear SKF/ARP hubs installed – which facilitated hanging the rear Performance Friction brakes & hopefully generate a better overall braking balance, and got the trailer wiring done so I could now haul all the tires to the track. The FRC is quite packed once all the gear gets stuffed inside!
4th weekend Saturday: Clear & sunny, and temps from 10-20C over the day – I put the bigger 'dry' tires on and dropped the pressures down to 26 psi for the practice session. I liked the feel of the lower pressures, but it was an interesting sensation getting them up to temp/pressure. The brakes were awesome & it is such a great feeling being able to go hard on them all day with the confidence that they wont fade like the stock brakes. Still felt like the fronts were loosing grip in the last 1/3 of the session. I came within 0.059 sec of my fast time on the mixed, used tires. I dropping the front pressures by -1 for qualifying, it felt better & I was more consistent, but not faster – still pushed a bit. 7th on the grid (a few of the fast cars sat out qualifying for some reason). Dropped the pressures another -1 on the fronts for the race. I lost a couple spots on the start through the first few corners, but gained them back in the race. Finished 7th with a best time about 0.7 sec off my fastest time – the white '01 Z06 finished 6th.
Temps & pressures after the 20 min race (89F track temp):
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 32 – 109/115/121 | 126/121/116 – 33 :RF
LR: 34 – 117/121/128 | 121/121/119 – 34 :RR
4th weekend Sunday: There was a 17 year Corvette racing veteran at the track this weekend (has a '10 ZR1, a C4 autocross car, and a Camaro track car), who was very quick & a super guy. We talked a bunch on the Saturday, and he strongly suggested taking out some front camber to help with the pushing. I'd had it set up for -3deg left & right and he felt that was too much for this track, so in the morning before the first practice, I put 2mm shims on the upper studs – which according to the Pfadt instructions should take out approximately 0.4deg. I elected to change only one variable at a time this time, and left the pressures at where I'd adjusted them to the day before. That put them at 24F/25R dead cold in the morning – and I did not change them during the day. Clear & sunny again.
The car felt much more stable & predictable in practice, and my times were more consistent – but again not faster. I got tangled up in traffic & it took me a while before I could get 1 or 2 hot laps in during qualifying. I managed 10th out of 17 cars 0.4 sec off my fast time (which would not have gained me any positions). The '01 Z06 qualified 2nd (new owner is coming up to speed nicely).
Between qualifying & the race, I had a good conversation with the Z06 guy, and the fastest guy in our run group (Honda S2000, he clinched the club championship in the race). We discussed shift points & how to manage weight transfer to gain grip & carry more speed through the corners. I've been braking too hard going into the corners and after scrubbing off all that speed, releasing too early which is unsettling the car apparently, this ultimately affects the shift points as I've not got the same exit speeds as them.
So, I tried to put some of that new knowledge to use during the race. One of the cars didn't start, so I was 9th on the grid. All around me on the grid were a bunch of the fast cornering smaller cars, and this time I didn't loose any spots through the corners on the first lap (a first). There were a few incidents (requiring dodging cars re-entering the track perpendicular to it in front of me), and the pace car came out. On the restart I got around several of the Integras on the outside of the hairpin at the end of the front straight (another first), which gave me the inside line for corner 2 and I made the passes stick. That started a rather intense battle that lasted the rest of the race. I'd run away on the straights & get caught by the end of a couple compound corners – but I kept it clean & kept them behind me. I'd worked up to 3rd by the last lap with attrition & the passes, by which time the 17 year Vette racing veteran was carving up through the traffic and was gaining on me fast. While checking for him in my mirror, I missed the braking point for corner 3 and went wide (rookie mistake) – we ended up side by side going into 4 with him on the inside and I had to yield. So, I ended my first season with my best finish in 4th with a race time only 0.5 sec off my fastest lap time. The '01 Z06 finished 2nd after leading before the restart.
Temps & pressures after the 20 min race (91F track temp):
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 32 – 108/117/118 | 124/119/119 – 33 :RF
LR: 33 – 119/127/134 | 131/125/116 – 34 :RR
These look much better to me, and the car felt quite consistent for the duration of the race after the camber change. Some Hoosier's would help (that's what almost everyone runs), but I've got a bunch to learn out of what I have now before I spend any more tire money. The Z has 3 seconds a lap on me as it is, hopefully I can trim that down next season!
So, after missing the summer race & tearing the car apart to upgrade the suspension & brakes, wheels & tires (link to upgrade thread), I've got 2 more race weekends under my belt (links to 1st race & 2nd race reports).
3rd weekend Saturday: Was a bit of a re-learning experience; I started off Saturday on my new to me scrubbed 305/35/18 Toyo R888's - my first set of R-comps, and the first time out with the new setup. It was overcast & cool with 90% humidity, 66F track temperature. With the low temps and no previous setup data to go by, I set the tire pressures at 32 psi all around for the morning practice. After several laps to get everything warmed up & get the feel of the car I started to push it a bit. I got a few hot laps in and set a new personal best at 1:19.444 (previous best was 1:21.270). Unfortunately, while exploring the braking points & entrance speeds I also discovered that the R888's don't make much noise when you lock them up, and I ended up badly flat-spotting the RF tire. The new front brakes work really well, that's for sure. For what it's worth, the tire pressures were up to 38-39 psi & 90-100F after the session. Expensive data...
Fortunately, I had ordered a set of 285/30/18 Yoko A048's for my 'inters' and they had arrived, so I missed qualifying and drove the car across town (still insured) to the tire shop and had the new Yoko's mounted. 3-hours later I was back at the track and ready to give it another go, from 18th on a grid of 20. My morning practice time would have put me 10th on the grid.
The tire shop said to take it easy in the first session, which I did for as long as I could stand. I was moving my way up the track through the slower cars in the run group, and while making a pass on a Miata in the hairpin at the end of the front stretch, I spun (to much throttle too early). No contact or damage – got into the grass & back on track and kept going. 3 laps after that I set a slightly faster personal best (1:19.235). I passed some cars & then spun again – not very pretty to be sure, and ended up 12th overall.
The tires were still warm from the drive & I had set them at 34 psi for the race. Here's where they were at after (78F track temp) – a little higher than where I used to run with Nitto NT05's:
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 41 – 104/115/124 | 131/125/118 – 43 :RF
LR: 41 – 110/129/141 | 133/133/122 – 41 :RR
3rd weekend Sunday: Main objective for the day was to start working on tire pressures, and try not to flat-spot or spin & bring it home in one piece. It's good to have achievable goals. It was again overcast & cool with high humidity. I set the pressures to 30 psi dead cold at 5:30 am before heading to the track (a solid hour plus away). While I did gain some confidence in the tires & setup, my times were not as good as the day before. I could see that I wasn't getting full contact at the outer edge of the tires, which started to lose grip about half way through the sessions – and I kept dropping the pressures (-1 on all corners for qualifying, and -1L/-2R for the race). I qualified 16th out of 23 cars and finished 10th after loosing a few battles with some fast cornering smaller cars. There was another Corvette in the field for the first time, an ultra rare white '01 Z06 driven by a new owner – this car has history at the track and has a great setup (fast times in the 1:12's), and the new owner was quickly coming up to speed – he finished 6th.
Temps & pressures after the 20 min race (88F track temp):
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 38 – 108/120/125 | 136/128/127 – 38 :RF
LR: 37 – 106/120/123 | 133/133/122 – 37 :RR
So, with a couple weeks until the next race I got to work. I got the two best remaining scrubbed 305/18 R888's and my well worn 295/18 NT05's set up on the other rims (these would be designated my dry tires), got into a buddy's shop & got the rear SKF/ARP hubs installed – which facilitated hanging the rear Performance Friction brakes & hopefully generate a better overall braking balance, and got the trailer wiring done so I could now haul all the tires to the track. The FRC is quite packed once all the gear gets stuffed inside!
4th weekend Saturday: Clear & sunny, and temps from 10-20C over the day – I put the bigger 'dry' tires on and dropped the pressures down to 26 psi for the practice session. I liked the feel of the lower pressures, but it was an interesting sensation getting them up to temp/pressure. The brakes were awesome & it is such a great feeling being able to go hard on them all day with the confidence that they wont fade like the stock brakes. Still felt like the fronts were loosing grip in the last 1/3 of the session. I came within 0.059 sec of my fast time on the mixed, used tires. I dropping the front pressures by -1 for qualifying, it felt better & I was more consistent, but not faster – still pushed a bit. 7th on the grid (a few of the fast cars sat out qualifying for some reason). Dropped the pressures another -1 on the fronts for the race. I lost a couple spots on the start through the first few corners, but gained them back in the race. Finished 7th with a best time about 0.7 sec off my fastest time – the white '01 Z06 finished 6th.
Temps & pressures after the 20 min race (89F track temp):
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 32 – 109/115/121 | 126/121/116 – 33 :RF
LR: 34 – 117/121/128 | 121/121/119 – 34 :RR
4th weekend Sunday: There was a 17 year Corvette racing veteran at the track this weekend (has a '10 ZR1, a C4 autocross car, and a Camaro track car), who was very quick & a super guy. We talked a bunch on the Saturday, and he strongly suggested taking out some front camber to help with the pushing. I'd had it set up for -3deg left & right and he felt that was too much for this track, so in the morning before the first practice, I put 2mm shims on the upper studs – which according to the Pfadt instructions should take out approximately 0.4deg. I elected to change only one variable at a time this time, and left the pressures at where I'd adjusted them to the day before. That put them at 24F/25R dead cold in the morning – and I did not change them during the day. Clear & sunny again.
The car felt much more stable & predictable in practice, and my times were more consistent – but again not faster. I got tangled up in traffic & it took me a while before I could get 1 or 2 hot laps in during qualifying. I managed 10th out of 17 cars 0.4 sec off my fast time (which would not have gained me any positions). The '01 Z06 qualified 2nd (new owner is coming up to speed nicely).
Between qualifying & the race, I had a good conversation with the Z06 guy, and the fastest guy in our run group (Honda S2000, he clinched the club championship in the race). We discussed shift points & how to manage weight transfer to gain grip & carry more speed through the corners. I've been braking too hard going into the corners and after scrubbing off all that speed, releasing too early which is unsettling the car apparently, this ultimately affects the shift points as I've not got the same exit speeds as them.
So, I tried to put some of that new knowledge to use during the race. One of the cars didn't start, so I was 9th on the grid. All around me on the grid were a bunch of the fast cornering smaller cars, and this time I didn't loose any spots through the corners on the first lap (a first). There were a few incidents (requiring dodging cars re-entering the track perpendicular to it in front of me), and the pace car came out. On the restart I got around several of the Integras on the outside of the hairpin at the end of the front straight (another first), which gave me the inside line for corner 2 and I made the passes stick. That started a rather intense battle that lasted the rest of the race. I'd run away on the straights & get caught by the end of a couple compound corners – but I kept it clean & kept them behind me. I'd worked up to 3rd by the last lap with attrition & the passes, by which time the 17 year Vette racing veteran was carving up through the traffic and was gaining on me fast. While checking for him in my mirror, I missed the braking point for corner 3 and went wide (rookie mistake) – we ended up side by side going into 4 with him on the inside and I had to yield. So, I ended my first season with my best finish in 4th with a race time only 0.5 sec off my fastest lap time. The '01 Z06 finished 2nd after leading before the restart.
Temps & pressures after the 20 min race (91F track temp):
PSI – To/Tm/Ti | Ti/Tm/To - PSI
LF: 32 – 108/117/118 | 124/119/119 – 33 :RF
LR: 33 – 119/127/134 | 131/125/116 – 34 :RR
These look much better to me, and the car felt quite consistent for the duration of the race after the camber change. Some Hoosier's would help (that's what almost everyone runs), but I've got a bunch to learn out of what I have now before I spend any more tire money. The Z has 3 seconds a lap on me as it is, hopefully I can trim that down next season!
