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rice_classic · 08-21-2019, 04:14 PM

If anyone was thinking about getting into racing - now is the time especially as we enter the off season where used race cars get really affordable. The T4 class in SCCA is very good and cost effective and the CT4 class in ICSCC grew quite large and competitive almost overnight.

Some updates:

Sway bars: Increasing roll stiffness was a change in the right direction. The previous attempt at softening the rear really planted the rear, however it induced lots of understeer post-apex and only half of the front tire was really getting used. By increasing roll bar stiffness front/rear, the front contact patch was much better utilized and rotation has returned. The car is now very well poised for trail braking and well setup for instant transition to WOT with some modulation when necessary.

Brakes: The ST43 rear pad was MAGICAL. I have arrived at braking nirvana. ST45 or 47 front with a 43 pad is my happy place. No more rear ABS, yet plenty of rear brake and trail braking was helped immensely. You'll see in the video how well the car worked under braking.

Tires: So far we have run: 245 (hoosier) R7s, 225 A7s, 245 (BFG)R1-S, 235 R1-S, and 225 R1-S. These are all on 17x7 wheels. The 245s weren't ideal as the feedback is very poor, more so on the R1-S due to the softer sidewall. The BFG 235 and 225 were much better in feedback but the 225 just isn't enough tire/grip for this car. Of the BFGs, the 235 is the best balance. Unfortunately, we were never able to get the BFG to be as fast as the Hoosiers. We have determined that the 225 Hoosier is the go-to tire. A7s for <80 degree days and R7s for >80 degree days.

My previous best time at PIR w/ Chicane is a 1:30.7 on sticker A7s. This past weekend I did another 1:30.7 on almost-cording A7s. This comes down the improvement in setup. I'm confident that on sticker A7s with my current setup, a 1:29 is possible. After some off-season tuning, I expect low 30s and 29s to be the new normal.

Fluids: The Penn synchromesh has been absolutely brilliant 2 (long) race weekends in a row. I'm sticking with that. The drop down from 10-40 to 5w-30 was the right choice - still plenty of oil pressure and temps stayed <250f, even when drafting. On cooler race weekends, it may be worth going back to 20wt.

On Saturday I qualified 17th on grid because I was trying to wear out some old rubber, while Totemo qualified 5th overall!! I had my work cutout for me which made for a GREAT race. He's on OLD 245 R7s and I'm on OLD 225 A7s. Enjoy.

[ame]http://youtu.be/dNyl7my-u8Q[/ame]

08-21-2019, 04:14 PM	#99
rice_classic Senior Member Join Date: Jun 2012 Drives: Nevermorange FRS Location: Seattle, WA Posts: 4,174 Thanks: 757 Thanked 4,208 Times in 1,808 Posts Mentioned: 78 Post(s) Tagged: 1 Thread(s)	Worthwhile update If anyone was thinking about getting into racing - now is the time especially as we enter the off season where used race cars get really affordable. The T4 class in SCCA is very good and cost effective and the CT4 class in ICSCC grew quite large and competitive almost overnight. Some updates: Sway bars: Increasing roll stiffness was a change in the right direction. The previous attempt at softening the rear really planted the rear, however it induced lots of understeer post-apex and only half of the front tire was really getting used. By increasing roll bar stiffness front/rear, the front contact patch was much better utilized and rotation has returned. The car is now very well poised for trail braking and well setup for instant transition to WOT with some modulation when necessary. Brakes: The ST43 rear pad was MAGICAL. I have arrived at braking nirvana. ST45 or 47 front with a 43 pad is my happy place. No more rear ABS, yet plenty of rear brake and trail braking was helped immensely. You'll see in the video how well the car worked under braking. Tires: So far we have run: 245 (hoosier) R7s, 225 A7s, 245 (BFG)R1-S, 235 R1-S, and 225 R1-S. These are all on 17x7 wheels. The 245s weren't ideal as the feedback is very poor, more so on the R1-S due to the softer sidewall. The BFG 235 and 225 were much better in feedback but the 225 just isn't enough tire/grip for this car. Of the BFGs, the 235 is the best balance. Unfortunately, we were never able to get the BFG to be as fast as the Hoosiers. We have determined that the 225 Hoosier is the go-to tire. A7s for <80 degree days and R7s for >80 degree days. My previous best time at PIR w/ Chicane is a 1:30.7 on sticker A7s. This past weekend I did another 1:30.7 on almost-cording A7s. This comes down the improvement in setup. I'm confident that on sticker A7s with my current setup, a 1:29 is possible. After some off-season tuning, I expect low 30s and 29s to be the new normal. Fluids: The Penn synchromesh has been absolutely brilliant 2 (long) race weekends in a row. I'm sticking with that. The drop down from 10-40 to 5w-30 was the right choice - still plenty of oil pressure and temps stayed <250f, even when drafting. On cooler race weekends, it may be worth going back to 20wt. On Saturday I qualified 17th on grid because I was trying to wear out some old rubber, while Totemo qualified 5th overall!! I had my work cutout for me which made for a GREAT race. He's on OLD 245 R7s and I'm on OLD 225 A7s. Enjoy. [ame]http://youtu.be/dNyl7my-u8Q[/ame] __________________ SCCA T4 - FRS