M758

Yep.. start full thread. you can shave your next set if want, but for DE is it not worth it.

Hubert

dar951: thanks again for your input. the car weighs ~ 3000lbs. in track trim (w/ driver, gas, etc.). Based on that weight, what would you say aboutshaving them?

i do have a couple sets of wheels, and it would be most convinent if I could drive to the track, but i don't really want to put a lot of wasteful miles on the tires. (it's about 150 miles to buttonwillow from my house).

DAR951

dar951: thanks again for your input. the car weighs ~ 3000lbs. in track trim (w/ driver, gas, etc.). Based on that weight, what would you say aboutshaving them?[/QUOTE]

That's right about the weight of my 951 that I run full depth RA-1's on, and it's what I'd recommend, as does M758. Remember, we're talking about DE, that last fraction of a second you may get from less/no tread doesn't count... your "competition" is you. (The only reason to shave them for your application is to keep them from chunking and last longer, not make them quicker.)

Here's what you might want to try/think about... Start out with this set at full depth. If you start to see chunking, quit using them in the dry, save them for a wet set (and/or the set you drive to the track on) and buy a second shaved, dry set.

Bottom line is: If you shave them, you're pretty much necessitating a second set for the wet (or you can behave like most of the Porsche DE drivers around here and sit out/don't come to any sessions where there's rain in the forecast, even if you are running on full tread... sorry, I like the rain... just look at what else I drive).

Good luck, you're on your way to the next phase of the addiction... multiple tire/wheel sets... the trailer, tow vehicle, etc. is just around the corner...

jakermc

Results of my first time on track rubber (RA1) - went from a 1:42 lap to a 1:34!

Street tires were 6x7x16 Toyo Proxes FZ4 while RA1 was 7x9x16, so I also got wider in addition to stickier. Other major difference between the two runs I am comparing, the 1:42 was during a PCA DE event and the 1:34 was on a 'member day' at the track I belong to. I'm sure I push harder when the scrutiny of the PCA is not weighing in my mind.

Using a DL-90 data logger, I found that my times improved everywhere on the course, not just the areas where I was beginning to reach the limits of my street tires. Maybe this was the confidence thing I mentioned earlier. On the downside, I found it much more difficult to catch the rear getting loose with R-compound. Probably a combination of the extra speed and the lack of an audible warning before the rear breaks away. I'll have to work on this my next time out.

Hubert

Slight snag... the RA1's are on backorder locally, and I can't get them (or the v700's) shipped out in time to make the track day... how's the A032R as a replacement? One additional change has been the weather, it's slated to rain on Friday... how should that affect my tire choice?

JackOlsen

Yokos are about the worst R-compound tire, which is to say they will last the longest, make the best 'next step' for you from street tires, and also (probably) do the best in the rain. You will be faster than you were with street tires, too. So 'worst' is of course a relative term.

I'm going to be running a set at Willow this weekend, and I've lost count of how many events I've gotten out of them. They are a great value.

What event are you running? If you decide to get them, post here about tire pressures, and also post the approximate weight of your car. Most guys run A032R's with way too much pressure.

ninefiveone

Anyone with RA-1's and a 951 care to share their alignment settings and hot tire pressures?

Hubert

My car weighs about 3000lbs.; any idea on starting tire pressures? Also, how does the the yoko's grip (in the dry) compare to the v700's ; ra1's; hooisers etc.? Do they give up 2 sec/lap, 5 sec/ lap, 10 sec/lap? Lastly, I've been using the falken azenis street tire as my principle track tire, any comparison b/w the azenis and the A032R? Sorry for all the questions, but I'm trying not to "waste" 600 bucks on a set of sub par tires...

JackOlsen

I haven't driven on Azenis, but I hear they're a great street tire. My estimate would be that A032R's would get you about 2 seconds/lap at a typical track over street tires, with Hoosiers at the far extreme getting you maybe 5 seconds a lap at the same place. Kumhos, Toyos and MPSCs would all be in between that 2-5 second range.

I start A032Rs at 23/25 and bleed them off when they get above 25/29 hot. With Hoosiers, or a lot of street tires, you'd generally look for 38-41 hot. With A032R's, you've got to aim for much lower. They start to go away badly at 30 psi.

At least, that's my experience. I have a lighter car (2400 pounds) running fairly large tire sizes 255/315, so YMMV.

It might make sense for you to just keep running Azenis.

DAR951

Seconded...

You just tortured yourself deciding on RA-1's, waiting an event or two to get on them probably isn't worth a "$600 mistake". Also, if it is indeed going to rain, probably doesn't matter so much what you're on, so long as it has some tread... go out and have fun.

ninefiveone: still playing around with the setup but for my "home" track (Summit Point - short (2 miles) hard on left fronts) I run the RA-1's at about 32-33 cold all around (gives me about 43 hot on a 70 degree day w/sun). Because of the track, I run more negative camber on the LF (about 3 degrees) than the right (about 2.5) and around 1 degree in the rear. Front toe at positive 1/32 - 1/16, rear at zero. The car is sprung fairly softly (for a track car) with stock diameter, 250 lbs. springs (so no ride height adjustment) and 30 mm torsion bars. Also, as it sits, the car has a bit of "wedge" (cross weight% at just under 52) which helps a little with all the hard rights.

Hope that helps.

Bill L Seifert

Nobody has mentioned the Michelen (Spelled wrong) Pilot Sport Cups. They are great. We entered the 10 Heures Du Man at Gingerman. We took two sets, and ran the 10 hours. We used them unshaved, and wore the two sets down less than half. That means we could have run one set for the whole 10 hours. Try that with any of the others, and your last two hours you will be "limping down the road on the rim" to quote Charlie Daniels.

Our lap times were comparable with the old B F Goods, and Toyos I have run at that track before, and only a few Tenths off of my best time with Hoosiers. If you are new to using R compound tires, I think the Pilot Sports are the best, and they last forever.

Bill Seifert

1987 944 Race Car

M758

On my 2450 lbs 944-spec car with RA-1's I run 38 hot pressure. Seems to work pretty well. I tend to start at 31 PSI cold to do this. This works quite well for me. I used to run 32 to 33 hot on my Kumho's on the same car.

I run 225/50 R15 all 4 corners with 131 rwhp.

dmilzoff

I am now running a 2003 996TT, 3400 lbs., and love doing DEs. I have stock 18" S03As and would like to upgrade for next season (I have 5 DE days on the S03As with great tread left). My lap times are 3 seconds slower than I ran with a 944 on Yokos, yuk, partially because of the 10 year lap since tracking a car.
I have a second set of wheels and was going to go to Hoosiers but based on discussions above, it seems that the MPSC would be better. (The DEs are just for my personal enjoyment). I don't wnat to have tires for only 4 track events. I'm willing to build a tire trailer. Are the MPSCs OK for street? Are these the best choice?

Anir

Hubert,

I've had great luck with the older style Pirelli P-Zero C's over the past two years. Used them everyday during the summer, with great results even in damp conditions. Drove them to various tracks, including Road America which is about 11 hours away. Ran them all weekend and drove back.

I did NOT shave them, and was able to use them for about 3-4 track weekends (plus all the street driving). They are very easy to interpret on the track, and quite fast, although I'm sure they don't perform on the level of the Hoosiers. I particularly like the way they "talk" to you in a corner - nice, gradual breakaway characteristics.

All in all, a very nice tire with good handling and excellent wear characteristics. Purchased from Bob Woodman, who is a quality outfit. Good luck with your decision and track days.

DJF1

The MPSC's are steel belted like a street tire, so if you run them at street tire pressures they will be great on dry and you have to be very carefull in rain. When they are new they are better in rain but still they do not like water paddles etc... As a second track dedicated set they are great for DE's for sure they last many many events so you might keep your streets for rainy DE's or mount the MPSC's for damp/dry conditions. My last set gave up the ghost after 2 club racing weekends and many DE's... They are trully great in this department.