Orthojoe's track build journal
#1231
Joe, very interested to hear how you like the new alignment!
#1232
Nordschleife Master
Thread Starter
#1233
#1234
Nordschleife Master
Thread Starter
The car never felt quite as planted as it did with our first setup (-2.6F/-2.4R). Power out with corner exit, which is supposed to be a strength for the rear engine, just hasn't been there.
I don't know if it's the tires (trofeo vs cup2) or the setup, but I think running -3.0 in the rear was part of the problem. We'll see...
I don't know if it's the tires (trofeo vs cup2) or the setup, but I think running -3.0 in the rear was part of the problem. We'll see...
#1235
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Join Date: Jan 2013
Location: West Vancouver and San Francisco
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1) I had a talk with John @ BGB regarding the setup on the GT3, so I have the following setup based on his recommendations:
Front camber -2.7
Front toe out 1.5mm each side
Front caster 9.5 degrees
Front sway bar stiff
Rear camber -2.4
Rear toe in 3mm each side
Rear sway bar middle
Front camber -2.7
Front toe out 1.5mm each side
Front caster 9.5 degrees
Front sway bar stiff
Rear camber -2.4
Rear toe in 3mm each side
Rear sway bar middle
Regarding faster wear of MPSC2 at the front, and not seeing same pattern with Trofeos - I think it's the fact that MPSC2 have very little rubber in them. They have huge grooves for such a narrow tire. There is very little rubber touching the road there, so it wear out faster.
I'll be at Thunderhill with PCA as well, but on Sunday.
#1236
Rennlist Member
Why front toe out? Do you need more corner entry turn in? Are you pushing on corner entry? How is behavior mid and corner exit?
#1237
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Join Date: Jan 2013
Location: West Vancouver and San Francisco
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Joe will probably reply after he tries this set up next week. For me slight front toe out was a good choice because it seems to have made the sweet spot for trail braking bigger. With stock front toe in it was very close between pushing because of not enough trail brake or plowing straight because of too much trail braking. With toe out the sweet spot in between is bigger and easier to hit it just right. I still had issues with mid-corner oversteer, but that could be my tire set up or some other reasons.
#1238
Rennlist Member
It's an interesting setup. The toe out should make the car turn in really hard corner entry. Then the front bar is really stiff which is going to induce a push condition. It will be interesting to see tire wear with this.
Did you ever have the car set with no front toe at all, normal rear toe, and then try to stiffen the rear bar to get rotation?
My limited experience on a 911 with toe out made the car really twitchy. But every driver likes things different.
Did you ever have the car set with no front toe at all, normal rear toe, and then try to stiffen the rear bar to get rotation?
My limited experience on a 911 with toe out made the car really twitchy. But every driver likes things different.
#1239
Nordschleife Master
Thread Starter
I have the same setup, just with -2.5 in the rear, no caster fix (no rubbing with -2.7 front though) and both bars in middle setting. The car oversteers a little. Seems that stiff front bar is an attempt to fix that. I wonder if I should try that.
Regarding faster wear of MPSC2 at the front, and not seeing same pattern with Trofeos - I think it's the fact that MPSC2 have very little rubber in them. They have huge grooves for such a narrow tire. There is very little rubber touching the road there, so it wear out faster.
I'll be at Thunderhill with PCA as well, but on Sunday.
Regarding faster wear of MPSC2 at the front, and not seeing same pattern with Trofeos - I think it's the fact that MPSC2 have very little rubber in them. They have huge grooves for such a narrow tire. There is very little rubber touching the road there, so it wear out faster.
I'll be at Thunderhill with PCA as well, but on Sunday.
Joe will probably reply after he tries this set up next week. For me slight front toe out was a good choice because it seems to have made the sweet spot for trail braking bigger. With stock front toe in it was very close between pushing because of not enough trail brake or plowing straight because of too much trail braking. With toe out the sweet spot in between is bigger and easier to hit it just right. I still had issues with mid-corner oversteer, but that could be my tire set up or some other reasons.
It's an interesting setup. The toe out should make the car turn in really hard corner entry. Then the front bar is really stiff which is going to induce a push condition. It will be interesting to see tire wear with this.
Did you ever have the car set with no front toe at all, normal rear toe, and then try to stiffen the rear bar to get rotation?
My limited experience on a 911 with toe out made the car really twitchy. But every driver likes things different.
Did you ever have the car set with no front toe at all, normal rear toe, and then try to stiffen the rear bar to get rotation?
My limited experience on a 911 with toe out made the car really twitchy. But every driver likes things different.
Van Overbeek and 2 other shops I have spoken have said that the front bar is actually the key to stabilizing the car on exit and being able to apply power.
#1240
Rennlist Member
Well, I was always too lazy to read this tread because of the number of pages!
What a mistake! It took me 4 hours but I read every post.
FAwesome tread!!
THANKS for doing this Joe.
What a mistake! It took me 4 hours but I read every post.
FAwesome tread!!
THANKS for doing this Joe.
#1241
Nordschleife Master
Thread Starter
One of these days, I should try to organize everything in a website....
#1243
Nordschleife Master
Thread Starter
I believe this may be the first video of a GT4 on track in Northern California.
Chris took the GT3 out and caught the video. Peak ambient temps of 118F that day limited performance again, unfortunately.
The owner was nice enough to let him drive a few laps too!
Chris took the GT3 out and caught the video. Peak ambient temps of 118F that day limited performance again, unfortunately.
The owner was nice enough to let him drive a few laps too!
#1244
Dude, no buckets in the GT4?! So what did he think of the GT4 relative to the GT3?
#1245
Nordschleife Master
Thread Starter
Chris posted his impressions in another venue, but I'll copy and paste it here:
"Ok, here are my impressions. The car looks stunning from every angle except the front. The deeper front lip may be just that, but it does not have the presence of the GT3 nose. Side profile is especially beautiful. The wing and ducktail are great, and black uprights are a must, so much so that Porsche has nixed silver uprights. The GT4 feels lighter and more nimble than the GT3, but lacks the ultimate grip of it's big brother. It drives similar to the previous Cayman R with great stability, making the driver feel very confident and safe, almost unflappable. Granted I only drove the GT4 about 8.5/10ths as it's not my car and it had 700 miles on it. Felt very tossable and planted. Brakes are same as GT3, so up to to the task. Not as good as our GT3 setup of Ferodo's and AP rotors, but typical awesome Porsche brakes. The gearing is my biggest complaint. Way too long. You could drive T-hill with two, gears, 2-3 if you are slower and 3-4 is you are quick enough. I drove the GT3 immediately after and there is no doubt the GT3 is the faster car. The 100 hp is a huge difference. Personally, you can't go wrong with either. This is a case of you get what you pay for, I believe engineered that way by Porsche."