rodneyr

Well, I ended putting on my new shoes a little sooner than I originally planned. I know a lot of people talk about heat cycles cut the life of the tires and I am sure they are correct. The same people say you should limit driving the R-comps on the street because they are not good in heavy rain, and I am sure they are correct.

However, in less than 2 years I have had 4 flat tires which were all independent events with the MPSC. Two of the flat tires were when I was driving to Lime Rock as a spectator for a professional race. The tires just suck up screws and nails like they are on a mission. Have other people had this many incidents with these tires or do I just have bad luck.

The good news is now I can use my PS2's on the stock rims and just keep the MPSC for the Volk's. In addition, I now have the option to put the stock rims back on.

My informal measuring was the Volk's weigh 5lbs / tire-wheel less than to stock rims with similar tires. So, I will be saving 20 lbs with the Volk's over the stock rims. I will be at Watkins Glen instructing with TrackMasters next week so I will get a chance to use the new stuff.

Here are a few pics of the new wheels.

mtksurfj

I have those on my C4... The weight savings was definitely apparent in suspension behavior, acceleration and braking. I had advan A048's on them from tire rack with their heat cycle/shaving option.

996FLT6

Ne issues with offset and they are 18's right?Mike

rodneyr

I am being realistic / conservative and I am not expecting much improvement in suspension behavior, acceleration and braking or reduced lap times. However, it would be nice to pick up a few tenths, and get close to the 60 second lap at LRP. I know I have more room on the down hill and a better entry to big bend. I am sure the car in the hands of a Pro driver is a 60 second lapper a LRP in its current configuration.

So, far no issues with the offset and they are 18's just like the stock setup.

auto-xr

What are the widths and offsets (front/rear)? Just curious if you opted for the 9" front with 46 offset.

HIGHcard

wow...that looks serious

amaist

Yes, MPSCs will pick up nails faster than normal street tires. A friend of mine picked up two nails at the same event when going off track to gas up. I now leave the car at the track and go in the tow vehicle to fill gas jugs. That might be too paranoid, though.

CWay27

^ Did you move up to a toe vehicle and trailer??

PTEC

BOING! Oh man I love those wheels! Excellant choice.

rodneyr

I did feel a little difference with the Volks in terms of improved braking at LRP on the main straight vs. the stock wheels.

Also, I noticed on a real Hot day today in CT the MPSC started cold at 27 psi and went up to 40+ psi hot. At this temp in hot weather towards the end of a session (after 23 laps) is not good news. My left rear tire lost grip going through the right hander at LRP today and I ended up pointing in the wrong direction. The good news was both feet in and I did not hit anything.

Rickard 993 Turbo

why do you check your tires cold, MPCS should be like 30psi WARM not cold

LVDell

Rodney, do you keep a log book of any kind? You will need to adjust your tire pressures for the track. For example, at VIR I have to run about 2 psi higher on right side as it doesn't come to temp like the left side does. 27 is a good starting point but you need to adjust from there. Michelin suggest starting at 25F 28R and then adjust accordingly. You need to shoot for low to mid 30's for optimal grip levels (32-36psi). A good trick I use at the track is use a starting point, go out for the session and then come in WITHOUT a cool down lap and then checkc pressures immediately. Then bleed the pressure to what you are looking to have as a HOT target. Then when you tires are cold, check what the PSI is at and try that as a starting PSI and see if you hitting your target after the next session. After a couple sessions on the track you have it down pretty good and a good feel for pressures (cold) based on the track and the temp outside.

blake

What Dell said!

The only thing that I will add is that I find 32f/34r the ideal hot temps for my MPSCs.... Once they start to get hard (as they did for me on "Day 5" last Monday), I dropped the pressure 1-1.5psi and could feel a little more softness. That worked for me as two sessions later, my two outer tires corded!

-B

rodneyr

Dell, Yes I try to constantly monitor the tires. I typically start out anywhere from 26-27 front and 27-28 rear. Also, I have well over 50 days at LRP so I am familar with the track -- most many of the days with the MPSC's between my 996 TT & 996 GT3.

However, I noticed a similar issue at Watkins Glen with the brand new TC37's and MPSC's. The tires did have had around 300 miles (the drive to the track). After my first session started with my usual 26fr & 28rear & I noticed the hot pressures much higher than usual -- around 40psi instead of 35-36psi. Maybe I got a bad tire batch because I don't think it had anything to do with the wheels.

At LRP The air temperature was around 80+ degrees and humid so that may have been a contributing factor to my spin. By the 3rd session the tires were dialed in fine because I bleed them down as you described.. For my next event I will probably start at 25, because I will have another hot & humid summer day, all around and check the pressures after the session. The other item would be to take it easy in the first session (come in early) and check the pressures as you described.

As I mentioned before it takes a couple of factors to cause a spin or something to go wrong. First thing wrong was left rear pressure was over 40psi. Second item was I entered the corner 3 mph faster than previous laps. Third item was I turned in a little tighter at the apex. Fourth item is I believe I hit the curbing. Having the data acquisition & video really told the story when I saw my line for that lap. Two spins in 2 months is not good and is two more spins than I had in the previous 5 years. I hope I got out my spins out of my system for a long while.

LVDell

&Isn't DA a great thing?