Mech33

Joe, very interested to hear how you like the new alignment!

orthojoe

Me too. I'll let you know after next weekend. Chris ran a 1:58 over the top at thill last week with the setup and told me: "Do not change anything. It's perfect."

Mech33

What was the motivation for the change?

orthojoe

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...

MaxLTV

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.

Spyerx

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?

MaxLTV

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.

Spyerx

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.

orthojoe

I can't do Sunday, unfortunately. It will be my first GGR PCA event, so I'm looking forward to it. I'll let you know what I think of the setup afterwards.

It was recommended by a shop I spoke to. It's only 1.5mm toe out, so not a huge amount. Yes, there was push on corner entry. Mid and corner exit had a tendency to oversteer and limit power application

Yup, mid-corner and corner exit oversteer has been the issue for me. The rear toe in of 3mm and stiff front bar is supposed to help me with that. Will report back. If this doesn't work, I will consider dialing out more of the rear camber.

So far the tire wear looks pretty good with this setup. The rears are wearing a bit more on the outer side, but the fronts look good. The party line concern with front toe out is making the car twitchy. However, I haven't found that to be the case with this setup. The car feels totally fine on the street, and Chris really liked the turn in that resulted with the front toe out on track.

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.

PierreTT

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.

orthojoe

LMAO! 4 hours? Thanks for reading!

One of these days, I should try to organize everything in a website....

DeerHunter

I approve of this message.

orthojoe

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!

Mech33

Dude, no buckets in the GT4?! So what did he think of the GT4 relative to the GT3?

orthojoe

I guess the owner prefers real racing seats.

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."