Planet 9

diverdog · #1 04-08-2009, 07:57 PM

Finally had my first day of running on R comps at Pocono North course. Even though the temp was 40-55 degrees these things stick like glue! I loved it but the GT3 drivers in the white group hated to get passed by a lowly CS. lol

**KS-CS** · #2 04-08-2009, 08:17 PM

What kind of cold and hot pressures did you run?

diverdog · #3 04-09-2009, 04:46 AM

Started at 32F 33R C 38F/39R H --last run of the day came in at 40F 42 R. Feeling a little slick at those pressures.

245/40-18 F 275/40-18 R on 8.5" /10.5" Enkies

lisocayman · #4 04-09-2009, 11:22 AM

I ran 25 sessions on my first set of NT-01's. I've also had MPSC and R888's. I just bought my second set of NT-01's. They are a great mix of performance and value on the track. My first set was 235 up front but I'm running 245 on the second set.

Great tire for the track. PS2's on the street.

**STLPCA** · #5 04-09-2009, 01:03 PM

Originally Posted by diverdog

Started at 32F 33R C 38F/39R H --last run of the day came in at 40F 42 R. Feeling a little slick at those pressures.

Cold pressures depend on variables, e.g., ambient temp, track temp, track configuration, how hard you drive, etc. I generally start off cold at 30F 34R (for my drive to the track) and bleed off pressure as the day progresses based on my pyrometer readings (optimal 160-220F) and to keep the hot pressures from going above 40 psi where I've found the NT-01s start getting greasy.

+1 to lisocayman. I'd get better front wear if I had more neg camber, but I really like these tires. Work well in 245F/275R x 18.

DMN987S · #6 04-09-2009, 01:26 PM

I saw a post by PolarPorsche and he ran 33 hot up front. I had 38/38 hot at my last DE and the fronts were squeeling in a few turns, I thought I'd try the lower pressure up front in my next DE.

beez · #7 04-09-2009, 01:40 PM

I switched to NT-01s this season (used mpsc last two seasons) and like them a lot better, certainly the price is better, too. I start out with 29# front and 31# rear stone cold in the morning, and found the sweet spot to be about 34-35# in the front and 37-38 when they're hot. They stick like mad at those temps, and wear well, too. To and from the track, I run them about 32#/36# cold. I'm running 245/40 front and 275/40 rear, on BBS RS-GT 8.5"/9.5" wheels.

brad

**consolidated** · #8 04-09-2009, 04:13 PM

Originally Posted by DMN987S

I saw a post by PolarPorsche and he ran 33 hot up front. I had 38/38 hot at my last DE and the fronts were squeeling in a few.. turns, I thought I'd try the lower pressure up front in my next DE.

I love the NT-01 having gone thru 5 sets now. They'll just about stop squealing when it turns into a slick, it's also when I get the best lap times. They're also awesome as brand new sticker tires, then drop off and pick up grip again as they become a two groove slick. Just a great tire, and not as fussy as the R888.

On my M3 they will give some chatter as they wear towards slicks, I think that car just needs more negative camber however.

jonathan · #9 04-09-2009, 04:53 PM

Beez et al,

Any reason why you're running the 275/40's in the rear instead of the 275/35's?

beez · #10 04-09-2009, 05:07 PM

My reason may be different than others', but I run the 40 profile in the back because the tire is sized more closely to the stock diameter that the ABS system (in revolutions per mile) sensors are expecting. I know there's a 3-4% tolerance, but I was using the mpsc 265/35/18 rears last year and had the stiff braKe pedal problem at Turn 3 at Thunderhill last year, and had to drive the car off the track. In doing the math, I found it was very close to the 4%, and more than the 3% I like to keep it to. I can't help but think this had something to do with that incident.

I know that the smaller diameter tire is supposed to give you an effective "shorter" gearing, and thus more grunt out of slow corners, but now having driven the two different sizes on the same tracks, I'm not seeing a difference I can tell in either feel or in lap times. I'd rather have confidence in my brakes.

brad

DMN987S · #11 04-09-2009, 05:37 PM

I run the same as Beez, 245/40ZR18 and 275/40ZR18, the stock rear is a 40 profile.

How many track days are you getting? I trashed my first set in 3 days due to a street alignment and some abuse by me. I added PSS9s and some negative camber (I think I need more than -2.0 in the rear) so I'm getting better wear.

lisocayman · #12 04-09-2009, 05:40 PM

I run the 40 series as well. 245/40/18 and 275/40/18 on the track. I find the tire size is closer to spec (since 265/40 is spec). I ran MPSC in 265/35 and I wasn't a fan of that size.

I also agree when n they get down to slicks they have great traction. I pulled my 2:03.9 over the cyclone at T-hill with them close to slicks.

**consolidated** · #13 04-09-2009, 07:04 PM

Originally Posted by beez

My reason may be different than others', but I run the 40 profile in the back because the tire is sized more closely to the stock diameter that the ABS system (in revolutions per mile) sensors are expecting. I know there's a 3-4% tolerance, but I was using the mpsc 265/35/18 rears last year and had the stiff braKe pedal problem at Turn 3 at Thunderhill last year, and had to drive the car off the track. In doing the math, I found it was very close to the 4%, and more than the 3% I like to keep it to. I can't help but think this had something to do with that incident.
brad

My reasoning is the same. My car is also lowered and has stiffer springs than stock so the extra sidewall is appreciated. The 40 series tires also fill out the rear wheel opening nicely, the 35 on 18" wheels look skinny, which some people like I suppose.
I've run them from 36-40psi hot and frankly they turn about the same lap times and G's on my traqmate. However, there are a few threads out there of people running the R888 up to 47psi with better results, I know, counterintuitive. Not the same tire of course, but a close relative and interesting to read.

diverdog · #14 04-09-2009, 07:20 PM

I talked to lots of folks running PSC's 888's & NT01's last year while I was running my PSII's. I wanted to get a season under my belt before going to R comps. The consensus was by far NT01's for value and performance. I'm running -2.2 F & -2.0 R camber. The car is transformed with these tires. I was also concerned about potential braking issues with 35 series in the rear.

Lots of great information shared on this site helping to avoid costly mistakes. Thanks to all of you sharing your experience

**STLPCA** · #15 04-09-2009, 07:28 PM

What everyone else said re: running the 40 series rears. Closer to stock spec = less likelihood of electronic control gremlins.

DMN987S · #16 04-09-2009, 08:23 PM

Originally Posted by consolidated

My reasoning is the same. My car is also lowered and has stiffer springs than stock so the extra sidewall is appreciated. The 40 series tires also fill out the rear wheel opening nicely, the 35 on 18" wheels look skinny, which some people like I suppose.
I've run them from 36-40psi hot and frankly they turn about the same lap times and G's on my traqmate. However, there are a few threads out there of people running the R888 up to 47psi with better results, I know, counterintuitive. Not the same tire of course, but a close relative and interesting to read.

I can tell you first hand 45 is too much. I put PSS9s on my car and ran a DE with a new set of NT01s. I got out on the track and I was sliding everywhere, I checked my pressure and had 45 lbs. I lowered it to 38 and handled alot better.

jonathan · #17 04-09-2009, 09:05 PM

Wow, in the few hours since my last post I can't believe how many of you have commented on this tire size question. Thank you! I guess I will stick with 275/40's at the rear. I've never had the brake problems you've had and I certainly don't want to invite trouble!

I ran through three sets of Toyo RA-1's before I switched to NT-01's. I don't think the Nittos are any better than the Toyos. I thought the Toyos were better in the rain, but they come with deeper tread. The Nittos are less expensive, but, perhaps due to having less tread when new, they don't last as long as the Toyos. IMO, they are both great. I think I will probably get around 8 - 10 track days per set of Nittos. I might get more. And my track days tend to see lots of track miles.

I was playing with tire pressure a lot at the end of last season and I was starting to think that these Nittos may actually stick a little better in the mid 30's than they do closer to 40psi. I think others have commented on this, too.

I run -3.5F and -2.5R camber. The tires are wearing fairly evenly. My tire wear varies largely based on the track(s) I run at. Tighter tracks tend to beat the tires up much more than the high speed ones.

**consolidated** · #18 04-14-2009, 10:16 PM

FYI all, NT-01s are a few bucks less than usual on ebay for 1 more day from the usual vendor.

Fronts $218, rears $246, free shipping.

FT · #19 04-15-2009, 06:38 AM

What is the overall camber recommendation with the NT-01s? RA-1s require much more camber than the stock configuration can provide; however, R888s seems to be doing fine with the little camber I have and are wearing very well, I now have 36 sessions (not DEs, DE sessions) on them, and I think I can do at least 2 maybe 3 more DEs with them. Performance seems to be maintaining as well with only a small drop (~1 sec/lap). The only issues I have is the size issue, I am running 255/35 and 305/35 sizes and I'd like to run a little smaller size, but no avail.

So, NT-01 certainly seems to be a good option from the comments, but I used to wear the shoulders of the RA-1s much faster than I could wear the thread and I am concerned the same might happen with the NT-01s.
Thanks for any input.

**KS-CS** · #20 04-15-2009, 07:40 AM

Originally Posted by FT

What is the overall camber recommendation with the NT-01s? RA-1s require much more camber than the stock configuration can provide; however, R888s seems to be doing fine with the little camber I have and are wearing very well, I now have 36 sessions (not DEs, DE sessions) on them, and I think I can do at least 2 maybe 3 more DEs with them. Performance seems to be maintaining as well with only a small drop (~1 sec/lap). The only issues I have is the size issue, I am running 255/35 and 305/35 sizes and I'd like to run a little smaller size, but no avail.

So, NT-01 certainly seems to be a good option from the comments, but I used to wear the shoulders of the RA-1s much faster than I could wear the thread and I am concerned the same might happen with the NT-01s.
Thanks for any input.

I have camber settings of 0.8 F and 1.7 R on my stock suspension (the max I could get), and I probably have over 50-60 sessions on my NT01s. They are now essentially full slick w/ maybe 1/16" tread left.

I was starting to get some beveling of the outer shoulders and was afraid I might cord the shoulders before I wore out the tread, so I flipped them inside out about 3 DEs ago. I expect that they will last maybe another 2-3 track days. I suspect that the wear on the R888s and NT01s should be pretty similar.