Thanks for calling by and feel free to pitch in. You'll likely find that nothing is sacred but everything is normally pretty chilled out here...

 

Yes, Graeme, it was a perfect illustation thanks. I now have that etched into my memory and have driven it a number of times mentally - I know exactly what I need to do there now. I really wish i had found this video before going out on 19th. There are some excellent clue here. For example, Craig puts his left wheels over what appears to be a service driveway after T1 that allows him to come out a bit wider and signals the turn in point to the Castrol complex. I saw that there but avoided it trying to stay within the white lines. I was having trouble marking my turn in point but this will do great for me next time Im out and its a little later than i would naturally turn but thats good for keeping the car flat for managing the Gs in the right hand elbow that follows. Coming into the tighter left hander here is interesting, I think I have this almost right but he turns in fractionally earlier and cuts a straighter line so I will play with that line too. Coming into teh hairpin hes modulating the throttle to manage traction, he comes off that right side rumble strip very early and positions to far right of the track as you had indicated, changes to second and then balances slip angles through the apex before letting it settle down a bit (throttle) and then opening it up and drifting it wide. I definitely think I can do that.

Otherwise Im pretty happy with the rest of my lines and placement, they are similar to his especially the big sweeper double apex and exit. I think I can get a bit more courage up there and end of front straight to keep it in a bit longer before laying into the brakes. I noted whilst I was driving I was holding back a bit here. After 8 months absence from driving my car on the track I was wanting to leave a bit of margin in everywhere just in case!

 

Good points Walt. PDK launch control is definitely an advantage when it comes to times launches compared to MT as Graeme says, but possibly more so a longevity/reputability thing.

Gearing is relevant. With low torque NA cars like the GT3 the extra gear for the PDK is excellent for keeping the car around the peak torque band on upshifts. This is important. Here are my gear shifts (see bottom trace) at Manfield for that same lap. You will see how well the PDK places the next gear in the rev range (peak torque 6250 in this 3.8L engine).

 

Im feeling quite positive about finding 3-4 tenths in a dry Manfield track next time having discussed these lines and analysed the Baird video, compared against my notes and videos etc. I think one key area of correction (hairpin entry, mid and exit) plus 2-3 small tweaks and improvements in lines and consistency elsewhere around the track (castrol turn in, castrol left hander entry etc), should yield these improvements in lap times once mastered allowing me to achieve my 13.8 goal with some consistency. Thanks Graeme+Walt!

 

P.S. Walt - looking at that rpm chart - I may well be on flat throttle more than 20% of the time! Ill pull the data tomorrow and tell you, but I can already quickly see that I am full throttle for cumulatively 50% of the track distance (1.5km) which I suspect equates to around 30% of the time?

 

Interesting, I never paid attention to treadwear until recently.

Looking at this review between MPSC2 (180), R888 (100) & Continentals (80) offering, treadwear as a guide goes further out the window.

http://www.tirerack.com/tires/tests/...y.jsp?ttid=184

For the GT4, Continentals look like a decent option $1,456.00 USD vs $2,049.00 USD for MPSC2 before conversion, freight & taxes, not much between the two performance wise.

 

Nice find Pel, but those do look to be the old MPSCs in that comparo? If Michelin's claims of the MPSC2 bettering the related MPSC+ (MPSC and MPSC+ both 80 AA A) by 1.8s over a circa 100s Jerez lap are credible, the same testing with the newer MPSC2s would likely see them win that same test, at least in the dry.

All the different versions of of the Pilot Sport don't simplify comparisons of course. From Tirerack:



Whether it really is Michelin's bi-compound technology (with softer grippier outer shoulders and harder wearing inners) that does it I don't know, but the MPSC2s deliver much more grip on the limit than their wear rating would otherwise suggest. There might be some exact info out there somewehere but it seems that they've basically put something like 60 compound shoulders on a tyre that's 180 across much of the rest of the tread - with cornering Gs determining which compound sees most of the action.

 

Hi Pel. Ive not come across anyone using Continental tyres on the 991 GT3 yet. Cant recall seeing this tyre used on the Gt4 board either. What Conti tyre are we talking here? I understand they have just announced a MPSC2 equivalent tyre but Ive yet to read any real world feedback on it.

The three tyres in that review are all older models and all inferior to the MPSC2/Dunlop Sport Maxx and Trofeo R the GT3/4 owners have been using on the track to date.

If you are looking for a low cost option consider the new Bridgestone RE71 aas these have just been released stateside in GT4 fitment, not Porsche approved but the hardcore track guys on the GT4 forums are finding them very good. Similar lap times and grip to MPSC2, last as long, more stable at temp but over 35% cheaper a set.

My advice would be to run the MPSC2 first, get a benchmark, maybe run two sets till you have settled into the car. On teh track you will need to max out the factory camber and possibly rotate the fronts like Leong did to get 3-4 days from these. Hes pushing on and best he can manage is 2-3 days. Now with all the DSC, sway par and aero adjustments, lowered slightly, tarret toe link, LCA mods, shims etc hes running hes is -3.5/-2.2 camber IIRC to get 4 days from the fronts and 6 from the rears. Its about the best you can get with the GT4, but it compromises road manners as he will tell you.

If I were dialing into a newly landed GT4 I think Id run up a few days on the MPSC2, using the factory aero and sway bar changes most recommended (easily achieved with a spanner and will dial out some of the inherent under-steer which the GT4 is legendary for). Then I would move to have Jeff set up te cmabers at factory maximum, rotate the front tyres if they need them and go out and do a couple more days before I looked at LCAs and shims to get the camber out further. I wouldnt even bother with the DSC personally (I dont think its needed), but after those changes I would either stop and work on getting faster organically or speak with Leong and Jeff before he leaves and benefit from some of Leongs prior experimentation (hes dont alot of stuff with his set up).

Personally I learnt the hard way with the 993 that too many changes at once is not a good idea. Also, while you are getting progressively faster in the car there is little point in making to many big changes IMO. The factory have a pretty good idea what works most of the time. Once you make big changes you always pay for it somewhere else (compromise).

For this reason I havent changed my suspension geometry since my first track day (apart with playing with the sway bars). I havent tried adjusting the rear wing yet or trying different tyres. The one thing I did do is add the DSC but in hindsight I think that was too early as it added "active" changes to the car (i.e. never does the same thing te same twice) which I find frustrating. The car is a bit quicker with the DSC but Im fighting understeer and oversteer constantly at different times and partt of the track and sometimes different from lap to lap. Ill be pulling it out when I get back and reverting to stock PASM for a while till I have hit my limits on skill and then will look to possibly trying the TrofeoR and after that maybe further development with the DSC with Matt B helping on the programming side.

 

PS. We are all buying our MPSC2 locally. They are around 20% cheaper than tireack landed and fitted!

 

[QUOTE=996tnz;13797063]Nice find Pel, but those do look to be the old MPSCs in that comparo?



Sorry guys, didn't check the date!

Was looking at alternatives, will use the MPSC2's then see what happens.

After spending so much on maintenance & upgrades over 24 months, ive had enough for a while, will live with the stock settings, see how it goes with stock camber chewing the shoulder a couple of times.

Looking forward to essentially a new car!

Saw the Feb trackday opening, is playday operating out of HD again?

 

When you repost with time selected as the base for that same graph it will be interesting to see what that suggests. Somewhere between our estimates perhaps.

 

MPSC2's for my car locally are about $2600 fitted. Much cheaper than importing.

Looked into getting RE71's locally but no one is importing. Disappointing. Would like to try a set.

 

Pel. I think that's the smart money. Just enjoy it out of the box for a few track days and go from there. That's the beauty of a new car, it needs for nothing and 70% of the changes needed to get the best out of it can be achieved in 20 minutes with a spanner using the factory supplied hardware...

Jake. I'm pretty sure Bridgestone NZ will import a set of RE71 for you if you call their HO and talk with one of the product managers. They did this for me with RE11 for 911 figments back in 2009 before they started stocking that tyre - better yet they arrived in 6 weeks are were ridiculously well priced. I think Leong would order a set or two for his GT4, mark S for his GT4 and possibly Pel too so you may have done further order leverage. Unfortunately they don't do a rear tyre for the 991 GT3 in 30" yet (305mm) but I'm hoping it's coming next year...

Walt I should have my PC back today - they can't find the fault so I'm sure it's still flakey but I'll load up that lap file and see if I can somehow work out how to figure the cumulative time at 90% and above...

 

Walt. Tell me if Im doing this wrong. Time spent at 100% throttle = 33s out of 74.24 or 44%:

 

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