997gt3north

- just took off my tires after 5 trackdays (Watkins 1, Vir 2, Mosport 2)
- tires are real 19" mpsc front, stock OE mpsc rear
- alignment -2.8 front 1/16th total toe out, -2.2 rear stock toe in
- car was also driven 500 miles round trip to WG, 1600 miles round trip to VIR and about another 1500 miles

- i switched rims today as i'm going to run the 19" toyo r888s at Watkins next week as it might rain (hope not) and i thought it would be better to have full tread tires

What did the tires look like?
- fronts were perfect worn left to right and while they don't look brand new they look very good and have many days and many miles to go
- the rears, the back left looks good (maybe very slight slightly more worn on the inside edge)
- the back right still looks good but the inside edge is clearly more worn

Watkins, VIR, Mosport
- all tracks run clockwise
- as such the left side is getting the workout and the right rear is working the inside edge a little more as you are doing more right hand turns

My next alignment
- i think for mpsc my alignment is almost perfect for those that do 10+ trackdays a year but also daily drive
- that said, i think a slight improvement may be possible for both tire wear and performance if you fit into this group
- as the fronts are perfectly worn across the entire tread (but it is still likely that they will outlive the rears) i think even more front camber is possible for even better front end grip and turn in
- with the right rear inside edge still wearing a little uneven, and yet the car still slightly pushes in the slow stuff and does not overstear in the fast stuff my next alignment will be
- front going to -3 from -2.8 still with 1/16th toe out
- rear going to -2 from -2.2 still with stock to in

- all of the above is of course for those that are running MPSCs


My new Toyo R888s
- put them side by side next to the MPSCs before I bolted them up
- i did some measurements

The fronts 235/35/19
- measure tread wise like a 245 front versus the mpsc but have a very square side wall and therefore overall are just as wide as the stock tire that has a bulging sidewall

The rears 305/30/19
- treadwise measure like a 315 versus the mpsc but also have a very square sidewall and are actually slighly narrower overall than the mpscs but have more tread surface



paul

George3

Amazing. I have the SAME tire wear problem and a similar alignment,
-2.6F camber, no toe; and -2.2R camber, .16 toe. I'm running 18" Toyo RA1's, 245/305.

After 10 track days at VIR, Pocono, Watkins Glen, Summit Point and Shenandoah.....

Condition:
The Fronts on both sides are wearing evenly with many more days left.
The Rears are wearing unevenly. The right inside is worn considerably, the left inside is unevenly worn, but are not as bad as the right tire. Only a day or two left on the right rear tire.

My next set of tires is ready to go on: Toyo R888 255/315 in the 18" size. I don't know if the problem is the alignment or the bushings or toe links.

Maybe someone with more knowledge on this can help.

997gt3north

Since I'm on my 5th set of tires I can say that my current alignment is so far the best in terms of even wear as a combo daily / track setup - I'm on my forth different alignment with 25 trackdays and 17,000 miles so I know I'm getting close.

Previous alignments
1) stock as delivered - fronts wear very unevenly across the tire
2) OE track alignment - fronts still have uneven wear + inside rear tire edges wear so much faster than the rest of the tire - outside edges almost look totally unused
3) -2.6f zero toe, -2.3r - fronts much better but still the tiniest bit of the center of the tire wearing like there is not enough camber - rears still wearing the inside edge too fast (right side rear still wearing faster on the inside edge due to clockwise tracks)
4) -2.8f 1/16th toe out, -2.2 rear (fronts perfect, left rear very good but inside edge wearing just slightly more than necessary, right rear also good but inside edge getting close but not quite to the cords

Next Alignment (goals)
- still want the car to be a little bit better in the slower turns
- don't want the car to overstear in the fast stuff
- would be best to change all four tires at once

Therefore
- front a little bit more camber (free lunch here as the fronts will never wear faster than the rears)
- not more toe-out as I do highway driving
- reduce rear camber a tiny bit (better tire wear + shouldn't harm grip)
- rotate rear tires after all track events to even out wear of inside right rear edge

Result (for good tire wear / daily driver / trackday car)
front = -2.9 to -3 staying with 1/16th toe out
rear = -2.0 to -2.1 staying at stock toe in

If the above doesn't finaly dial it in then:
- gt2 rear bar will go from middle hole of three to fully stiff
- front camber will go from -3 to -3.x

As an aside, having just got a ride in a 996gt3 back to back against my 997gt3, one of the things i think helps the 996gt3 turn-in better is the smaller rear tire (295 on an 11" rim) that most 996gt3 guys seem to run - this car was running this setup and you could absolutely feel the looser rear end help the car rotate more naturally (that is if you like to stear with your right foot) - thus I think the need for 997gt3s in the stock tire sizes to run a more aggressive front versus rear camber to help the rotation - i.e. our 997gt3 "kussmual" settings are likely -2.9f, -2.1r than the 996gt3 kussmaul -2.5f, -2.3r

now i just need more seat time to work on my lack of skill

paul

Rob in VA

Paul, which group is going to be at WG? I'll be there on Monday/Tuesday with Chin.

997gt3north

i'm there after you leave for the next two days - the porsche cups and saucers event

sasportas

I'm going to be at WGI wed/thurs with Hudson Valley. I'd like to chat with you guys in terms of alignments. Also, maybe we can fool around with the sway bars and tire pressure to get close to a very neutral set-up. I'm currently at roughly -2.8F and -2.3R and running the sport cups. Might switch to Hoosiers or R888. Can't decide. I'd like to see how the R888's wear and handle on the track. Last year I ran -2.0 R and my tire wear was very even. This year I increased the Rear Camber. We'll see if this kills the wear and performance.

997gt3north

See you there,

- Since our alignment is almost identical (except i have the rear gt2 bar on the second hole) it should be a great comparo of the tires

- i will be driving down from toronto on a brand new set of 19" r888s, tires i have never used, so after i get use to them for a few sessions it should make for a good comparison of the two cars

- the corners where i think it will be interesting to play follow the leader are the toe, #8 and #9

- last year in a similar event at the end of the season with the Hudson Valley Group, myself, another 997gt3 and a Ruf997 went out for a few follow the leader sessions - the Ruf was on Hoosiers and it was in these slower corners, especially the toe, where it was very obvious that the Hoosiers provided better grip

i'm driving a white gt3 with a RS wing and a New Jersey plate so come by and say hello and we will hook up for the two days and run together if you would like

paul

George3

- Since our alignment is almost identical (except i have the rear gt2 bar on the second hole) it should be a great comparo of the tires

Paul -
What does the GT2 rear bar do for your handling? I assume it's a 996 GT2 bar.

sasportas

I'll look for you guys. I have a white GT3 / NJ plates. It would be good to follow each other to visualize the differences in alignment and tire choices. I also lowered my car 11 mm's this year. Looks mean - but also can double as a "street sweeper" with the front splitter.

997gt3north

- the bar is actually the new 997 not 996 gt2 bar
- the new gt2 bar is 30% stiffer than the 997gt3 bar
- if the tracks you visit have tighter turns it is probably very obvious to you that even with an aggressive alignment, the 997gt3 has a pretty good amount of push in it
- it was discovered by a fellow rennlister that the new gt2 (basically an identical car yes more hp/tq) comes with a 30% stiffer rear sway bar
- as such a few people have tried using it to help dial out some of this push that really slows the car down in the slower corners
- i have used it now for 3 events (VIR 2 and Mosport 1)
- Mosport is not the track to test out the slow stuff but the bar on the middle setting does not cause overstear on the fast stuff
- at VIR, I did notice some improvement in the lower esses where last year i was just ploughing through them - that said, i was also running a more aggressive front camber and less rear camber than last time at the track (last year I was using the OE track alignment)

- i'm going to wait until i give these r888 tires a few trackdays until i touch the alignment or sways (unless these tires really change things) to see where i want to go next

- if the tires give similar feedback then i will likely be inceasing front camber a little more, decreasing the rear and maybe going to fully stiff on the gt2 bar



paul

todinlaw

I am running the stock street alignment at the moment, when my right rear was wearing out faster is was a toe issue, I am going to go with the toe links.

Rob in VA

Paul, how did the car do at WG? Sorry we ran off so quickly after dinner. We waited outside for a few minutes thinking you'd show up. Thanks for all the WG information. I can't wait to use it next time I'm come back.

997gt3north

Rob,

Nice to see you again and thanks for letting me join you guys for dinner.
The event was great for tracktime - did about 7 sessions per day.
Lots of good guys to run with and there were about 10+ gt3s alot with similar pace so we had lots of good lapping together.
If the schedule works out for you next year,the cups and saucers event is worth the trip up.
The car worked was working well and i'm gaining more confidence with my setup and the my new 19" r888 tires
I started a new thread about the r888 tires and the p50 motorsport pads i tried on day number 2.


paul