The Greek

This is due to the 997 uptick in values. People are being more careful and not tracking them, which is unfortunate. 991's are brand new with warranty....

orthojoe

Agree!!
Funny how a car goes up in value because it's fun, but then nobody wants to have fun with the car because it went up in value.

mooty

u didn't get the notice?
they are taking heel and toe classes

and do not pull turn signal and cruise control stalks as trey won't shift the gear box

Spyerx

Meh I bought it to drive it. Who cares. In the scheme of things the increase is immaterial.

That said it is very rare to see a 997.1rs on track. I'm usually the only one. Down south we have quite a few .2rs.

montoya

Mine timed out like the CL's on the car....

Time for the new one.

orthojoe

Lots of info to update:

1) Ferodo DS1.11 brake pads: 5 track days so far (2 at laguna). Plenty of life left and no change in performance. They are loud on the street.

2) My shop highly recommended upgrading to monoball end bushings for the lower control arms. After he installed the solid adjustable thrust arm bushings, a lot of pre-load was transferred to the lca end, which isn't ideal. So, monoball LCA bushings are next on the list.... Sheesh.. this is a GT3, why do I need to buy all this extra stuff to make the car track worthy?

3) Handling: The car feels less stable now. It wants to oversteer when you power down on corner exit. I don't know if it's the tires, the alignment, or what. I've lost confidence with the car as a result. I'd like the rear end to be more planted. The problem is, I don't know where to start. Alignment is -2.9 on all 4 corners, zero front toe, 4mm total toe in rear. Caster is back to OEM spec of 8.3 degrees up front with the thrust arm bushing. Sway bar settings are all in middle position.

4) Trofeo R tires: Interestingly, the tires don't feel any more grippy than the N spec MPSC2 and the data confirmed it. The tires get to 1.3G before they start to break away. The break away is a bit quicker than the MPSC2 and they make less noise at the limit. The grip level is contrary to what everyone else is saying, so there may be an issue with my setup. I thought maybe my pressures were too low. The car was running 30F/32R psi hot. The following day I noticed that the outer edges of the rear tires were rolling over and scrubbing the sidewalls, so it seemed like I need more pressure. However, outer edge tire temps were lower than inner AND increasing hot rear pressure to 34/35/36 psi didn't help keep the rear end planted or give me more grip. Maybe -2.9 camber isn't enough to maximize grip with these tires?
The good news is, 3 track days and they look like they have plenty of tread left. It looks like they will last at least as long if not longer than the N spec MPSC2 that the car came with originally.

New:


308 track miles later:

orthojoe

First day at Laguna Seca (finally). I've dragged my feet going there because I didn't have a solid sound solution until Mech33's idea came to fruition:

Passed 90dB sound with flying colors. Mech33's GPS switch worked flawlessly. They were checking sound that day for sure because 2 other 991 GT3s were flagged, and a Cayman GTS with turn away pipes was flagged for 93dB. Not ONE single black flag all day for the 2 of us driving the car that day. All it took in addition to the switch was this simple turnaway setup:



I was able to run 1:39 consistently, a few 1:38s, and almost had a solid 1:37 before I got too excited and screwed up turn 9 (predictive lap timer can be your enemy sometimes). You can hear the change in exhaust tone as I exit T5. The valves open up again about 1/2 way between T6 and T7.

One of my 1:38 laps:


Ben's 1:37 lap (should be a 1:37.55 per solo, but dashware has been acting weird lately)


Oh, the track app worked just fine this time. My 1:38.6 showed up as a 1:38.3 on the track app. I'm starting to like it more. I tried to export using X-mirage, but there is lag and the video ends up stuttering when I export....

I did Sonoma the following day, but couldn't put it together. I ended up being 2 seconds slower despite better weather conditions than my last outing. Will post video of that once I get it together.

Macca

Joe/Ivan,

Thanks for the intel. Big thanks Jo for the tip on tightening the valve stems. I've just had a new set of tyres fitted and the car is now in storage till I return to NZ with 45psi in the tyres. I will monitor the pressures when I return and see if we have a problem with this. Definitely a great tip for the unwary!

I see the triangle berm in the video you speak of. It doesnt seem high enough to cause an issue although i see you moving in the seat when you hit it so it must be a bit more than a ripple strip. Its weird that its there Ive never seen one like it before - Im not even sure its purpose. How high from the ground would you estimate it is raised?

Its the same down under now. You wont see a 997.1 or 997.2 RS at a track any longer. They are all garage queens now (most of them were after the first owner in any case). Now even 7.1+2 GT3 are becoming C&C cars. After having the sh*t slung at 991 GT3 owners for almost 2 years we find its on the other foot. Our group is 55 members and 35 regulars at the track and 4 of them in 991 GT3, three have GT4 on order and we have a bunch of older 996 GT3 (I think 4 or 5). You drive past them now going home from the track and they are all polished up outside cafes drinking latte and telling polite jokes ;-)

Ivan - I hate it when they put those curbs where they should not. I was specuating if the new GT3 wheels were soft or easily damaged. Right now Ive heard nothing about this and there are many owners and Kms now. That said Ive been loosing PSI from front driver and rear passenger wheels whilst car is in storage a few times since Xmas and figured a leaky tire (original since new in Nov 2013!). I just replaced the tires and will be keeping an eye on this. I checked them off against the NASCAR digital guage I have which is supposed to be atomic clock accurate and its not the TMPS, there is definitely a pressure difference/leak occurring. I thought perhaps bending a wheel could do this (plenty of Pot Holes in NZ!) but it now seems to me it could be the valve nuts are bleeding. Ill see if it happens with the new tyres and then try tightening those....

Joe. I did this with my 993 track car. I reckon you have changed too many parameters all at once. Tyres, pads (probably no relation), Caster, adjustable LCA insert with washer etc. I found when I went complete top mount mono-ball with lower control hiem jointed dog bones, I also did new geo and different tyres and low and behold it was way less trust worthy than before. i had to undo most of it and start from beginning to learn. One thing i will say is dont get rid of all the factory suspension compliance as this starts to compromise the car and brings forward traits otherwise hidden by rubber bushes LOL! It would seem by the pictures you need more camber for those tyres - which is ridiculous for a car driven on the road. I bet if you revert back to previous castor all will be back to normal. I know this still means a rubbing issue but at least you can then start to address that modification as a system of parts all at once like those LCA monoballs. Im wondering is the CUP insert isnt a better part. Its hard when we dont have the factory CAD to model up engineering and dynamic changes through things like milling a washer etc. Just a few 2c thoughts :-)

orthojoe

I guess it's actually not really a berm because it's totally flat. The 'bump' is there because there is a ditch right at the edge of the track because dirt has either eroded/washed away or was never packed into that area. I believe that is what the problem is/was




Ugh. You are totally right. I've gone down a path that I really don't want to deal with. I should have just lived with uneven tire wear, but it's the one thing that really stands out in terms of running costs on this car. Thanks for the advice!

Mech33

Glad to hear it worked out, Joe!

Ugh. I'm still on stock alignment and was set to get the caster alignment pucks installed and more aggressive camber set up next week. This makes me hesitate since the pucks remove some compliance in the A-arm assembly.

Perhaps it's only worth adding as much camber as you can through the strut top mount adjustment?

orthojoe

Got x-mirage to work a bit better. Less stutter. Same lap. One is track app. The other is orthojoe video/data setup:

track app:


Solo DL/gopro/dashware:

Macca

Joe. I think thats the thing. Something has to give when you are going this fast with no other real compromises. For your the MPSC2 were giving four hard track days before the fronts were wearing through. For most others its been 6-8. But then Ive seen you drive and you are not watching the grass grow! I think you dialled in camber first to handle tyre wear, then changed tyre compound and now tire brand. But along the way you increased castor, then now back again using LCA inserts and washer.

I think perhaps its better to run -2.5 F+R camber/0.9.?? castor and live with the consequences. These IMO are simply 5 track days to a set of MPSC2 tyres. Also a new inner front guard liner and/or push the existing inside bracket back a bit so it doesn't rub through. This way you get your fast lap times, compliance, confidence and predictability. Lets face it the brakes and pads seem to last very well on this car and quite frankly I for one never thought Id get any more than 5 track days from a set of these Cup tyres - the fact they last so long has been a revelation to us all and we all went in budgeting on them lasting less time! Soon there will be Nitto and other brands supplying 20" alternatives for Dot Rated and we will have cheaper tyres to burn on the track that may be stickier and last as long or longer. If you are to experience with you set up perhaps look at removable rear Crawford aero with custom front lip (I already have an old spare you could have if I want so far away - Im sure it wouldnt be hard to graft some extension on this). Maybe some wider front and rear rubber.

Just some ideas.

Macca

Mech33. This is where Im at. We took it as far as we could (results below). The castor moved out as you would expect but so far it hasnt caused any significant wear on the liner after 5000 miles on these settings.

Overall the wear on the first set if tires over 7000+ miles indicates the inside is wearing 20% faster than the outside shoulder of the tire. This is on a usage ratio of 15% track use vs 85% road use (i.e. 1000 miles track vs 6000 miles road).

My view is that the factory settings of -1.5 F+R would have caused at least 25% faster inside wear than outside. The track work I have done probably wears the shoulders more than the inside and brings this back into check.

Infact for the new set of tyres I have fitted I have predicted I will be increasing my track ratio to 20% vs 80% road and would expect to see the wear differential drop to around 18%.

The sweet spot for wear would be if I were to increase my track work to 50% of usage where I would expect overall life of tyres to drop, but the inside/outside wear at my current settings to effectively be even across the tyre by the end! Of course this does come at the price perhaps of optimal contact patch at the track on teh right day, in the right conditions, when its dry and the temps of the tyre are just right and the traffic is just right and the drivers head is just right.....but man those conditions have so many random variables I wonder if the few tenths Im missing on a 1.15 track are worth the compromise of massive other changes for this driver LOL!

All good debate tho...

Mech33

Macca have you not used any additional shims thickness in your alignment?

Macca

Mech33. No. I have purchased all the necessary shimms form Porsche Motorsports parts list that I need to take the camber out to -3.0 F and similar R but I have not installed these. What you see above is the maximum my guy could move my settings using the factory top mounts before running out of movement.

Given my usage with this car is likely never going to exceed 30% track vs 70% touring/fast road work, its quite likely I will never use the shims!