orthojoe

Hjc. Already tightened down and fixed. Lol

oldskews4

That's some great driving, Joe.

I would love to see you track all the way out to the rumble strips after 4. Do it just once? For me?

orthojoe

Lol. Thanks. I still don't track out far enough for almost all of the exits. Easy for me to do when driving at 6/10th, not so much at 9/10ths! That will be the key to shave some substantial time off

Crazy Eddie

Great driving bud !!
I was saying to myself what a nice guy he is waving to all the flag station guys
Cant wait to get to the track ( especially LS )
Regards
Ed

orthojoe

Thanks! Hope to see you out there soon!

orthojoe

Returned to Thunderhill this past Friday. Perfect weather. Ran the 5 mile course with the west side bypass. This car continues to get more fun each time I drive it. It gives you so much confidence and begs you to take it up to the next level each time you go out. I find myself driving more at the edge with this car of the GT3, which makes it more exciting and rewarding. Put almost 200 miles on the track with the GT4. About 25 with the GT3.

orthojoe

Video of best lap running Thunderhill 5 mile with west side bypass config. Shaved 3 seconds off my prior best lap time. Almost 4, but totally biffed T14.

orthojoe

Bridgestone RE71R tires continue to impress. They are so consistent. They also seem to get faster the harder and longer you drive them. No decrease in performance even when driving for 1/2 hour straight. Usually my best lap time is lap 2 or 3. With these tires, my best lap times are near the back end of the session and are very consistent. I think the ideal hot pressures are 34-35psi front and 35-36psi rear. Even after driving hard for almost 1/2 hour, the pressures never went higher than 36psi after the pressures were dialed in.

The front tires are wearing faster than the front, and after the equivalent of 3-4 track days (415 track miles), I think they are done. If the front would wear more evenly and at the same rate as the rear, I think an extra day could be squeezed out.

Pics of the front tires:




Shot of one of the rear tires:

orthojoe

I talked to buddy who is a pro driver about the front tire wear. He said to leave my tire pressures alone overnight and see what they read the following day. If they are all about the same, then more camber is needed. If the front is much lower, than I am overdriving the tires and the car. I checked this morning and my tire pressures were even across all 4 tires. So, it looks like I'm not overdriving the tires.

So the suggestion is to run more camber. I'm currently at -2.8. I could add more, but others have said that the outer edge wear doesn't go away even with added camber. USCTrojan has found that adding stiffer front springs evens out the tire wear. This looks like a potential solution as well.

This brings me into discussion of the DSCsport unit. Some may recall my skepticism of the device. Well, the folks at DSCsport called me out and gave me the opportunity to test the device for them. The first unit I ran 2 weeks ago was defective, so I was sent a new one to run this past Friday. I ran the GT4 the first half of the day with the stock PASM system. The second half of the day I ran the DSCsport unit. My thoughts:

1) The car dives less under braking
2) The car leans less under cornering
3) Corner entry oversteer cured

I still don't believe the unit will magically make the car itself 2 seconds faster, HOWEVER:

1) Now that corner entry oversteer is cured, you can enter a corner more confidently and get more CONSISTENT laps. The first half of the day, I had to work hard to get 3:12 laps. The second half of the day I was able to easily get 3:12 laps over and over with a 3:11 best lap. Was it me or the the DSC unit? I think a bit of both, but I don't think it was all me.
2) Less dive under braking lets you enter the corner in a more stable position
3) With less dive and lean, will the front tires wear more evenly without needing more negative camber? I really want to find out. I'll be mounting a new set of RE71 and will run the DSC unit and monitor tire wear. If the DSCsport unit cures the tire wear problem as well, I think a compelling argument can be made about the device.
4) I will continue to test the device on the GT4 both with and without the unit and find more information.

ExMB

That equates to how many heat cycles? Some track days are 4 sessions, some 5 and some others are more.

DeerHunter

Aaaaaw, I miss the visor salute

orthojoe

2 of the 3 days were open track days. No sessions, drive as much as you want and I only used the re71r for half of one of those days. It's about 16 heat cycles.

Lol. Tightened down.

ExMB

OK thanx. IIRC correctly you get about 20 - 25 heatcycles out of MPSC2s. Using 20 heatcycles as an example that would mean you got about 20% less life out of the RE71Rs at a cost reduction of 35% (based on 19" MPSC2s)

orthojoe

Based on what I'm seeing lately, probably 15-20 heat cycles out of the cup2 depending on weather and track. I think wear is about the same between the 2. My front cup2 with 3 days on them don't look so hot and are similar to re71r wear. The rears look better than the re71r, though.

laranja

That towhook cam is scary fast looking!

I like watching your helmet cam view for a better
feel of what you are doing - at least trying to figure out
what I can emulate.

Could you add a 4th cam - windshield mount -
so mortals could benefit

I'm also just glad I wasn't in the way on those laps.

I'm surprised you don't have the stiffer springs already.
If you had those and the DSC...