Hoosier wets vs. dirt Stockers

[gran racing]

On the 4th of July at Lime Rock Park, we had fairly light rain, and there were no puddles. (It was far from pouring rain.) The temperature was fairly mild and not what I'd consider to be cold. I thought for sure the tire of choice would be the Hoosier wet tires, but several people after the races mentioned the tire to have that day was the Dirt Stockers. I was surprised by this, and wonder if that was really true? If it is, when would the Hoosier wet tires be the tire of choice?

[924Guy]

I've heard that the Wets are better in a true rain situation with standing water, in that the proper grooving does a better job of clearing the water out of the way; by comparison, the Dirt Stockers are just a soft sticky tire with some grooving, and still will hydroplane, just not as bad as R6's.

Can't say myself; while I have run R6's and Dirt Stockers, the sponsor hasn't ponied up any tire money for rains...

[lateapex911]

I think the Dirt Stockers are faster in most wet conditions because of the soft compound.

But...if it dries mid race, you're screwed. Only actual back to back testing would really answer the question.

[JLawton]

Yes, the Dirt Stockers seemed to be the tire of choice. As Jake said, they get heated up and good and sticky....

Anyone know what the ITS BMWs were on?

[Jeremy Billiel]

Yes, the Dirt Stockers seemed to be the tire of choice. As Jake said, they get heated up and good and sticky....

Anyone know what the ITS BMWs were on?
[/b]

I am 90% sure they were on Wets as they don't make dirt stockers in their sizes.

[RSTPerformance]

We went to a "Rain" test day at Lime Rock last year and put 3-4 hours on a car simply doing car set-up. We made pit stops changed from wets to dirt stockers and back again. lap times were very similar. I don't think that you could actually get the true benefits of one tire vs. the other without a DL1 or simmilar, but here is what we decided...

From last years NARRC Runoffs posts:

"Tuesday Testing:

We came down for the test day and Stephen was able to turn 1:19’s and 1:20’s consistently on the cold open wet track, so we new that he would do well in the rain. I had a slipping clutch due to what we thought was a bad rear main seal (I tried fixing oil leaks and apparently got more). I was still able to turn consistent 1:22’s without using 4th gear at all, so we also new that with a fixed car I should be able to get into the 1:19’s along with Stephen. During testing we also tested several setups and found out some interesting stuff… New Hoosier rains were about 1 second a lap faster than Dirt Stockers with better grip under braking and acceleration, however the Dirt Stockers were more comfortable with better grip in the actual turns. Also changing camber settings really had no effect on how the car handled or felt nor did it change what we were able to get for tire temperatures/pressures. "

I know what my wish setup is and it isn't what I have... but I can say that I did kick some ass last year on the Dirt Stockers

Raymond "Sorry to kill the ego's but its all about the driver on this one" Blethen

[Andy Bettencourt]

We grabbed a few temps over the weekend and the Dirts were almost 40 deg warmer than the Wets coming off the track.

[gran racing]

Raymond "Sorry to kill the ego's but its all about the driver on this one" Blethen [/b]

Just to clarify, I never said that wasn't the case with the Jim beating me. That aside,there were still several people talking about the two different tires related to several different cars & classes. I had always thought that the dirt stockers were the tire to have in a heavy down pour, but the Hoosier wets were the tire for wet but not heavy rain conditions.

[Greg Amy]

Dirt Stockers are the choice right up until you start to overheat them (i.e., anything but a completely wet track). Then you go to...

Wets, right up to the point you start to overheat them (e.g., fully dry track), then you go to...

A6 compound, right up until you start to overheat them (e.g., anything but a cold dry track surface), then you go to...

R6 compound. Right up until you suck.

The limiting factor is temperature, plain and simple.

Problem is, that first choice soon won't be a choice; as far as I can tell, Hoosier has discontinued the Dirt Stocker. Ergo, no point in getting all worked up about that tire, because as soon as the existing tires get all hardened up from sitting in the sun on these open trailer tire racks, the D.O.T Wet will be the tire to have...

[charrbq]

I've heard the same as what Greg wrote. You can still find some Dirt Stockers in old stock situations, but it's rare. I've been told, by some Hoosier guys, that if the track is virtually flooded, the Dirt Stockers are the best, but if it's regular old rainy weather, the rains are the thing as they will stay reliable longer.

However, if you're like me, I used my Dirt Stockers once...moved me right up the grid in the middle of blaster cars. Trouble was, it was dry for the race, and I was a mobile chicane for a lap or two. The rest of the time the tires sat on my trailer until the tread was ready to crubble, and the carcass was two hard to drive a nail through them.

My new rain tires are covered and brought inside after every race weekend.

[RSTPerformance]

Dave-

I wasn't picking on you You drove one hell of a race, and you were smart As we both know Jims car is fast and handles very very well.

Andy, thanks for the data, I have a few questions not to critisize but to learn, I love the rain and want to do better... Anyway, did you get the temps from your Miata's? Why did you choose different tires? Was it the same or different drivers? What were the lap times? If it was the same driver (running in two groups) was the finish in the rain vs a sprinkle?

I am just curiouse as we get our front tires very very hot and had no real difference from one tire and the other in reguards to tire temp. That was with the same driver, same conditions, similar lap times, and in back to back sessions.

Raymond

[Z3_GoCar]

On the 4th of July at Lime Rock Park, we had fairly light rain, and there were no puddles. (It was far from pouring rain.) The temperature was fairly mild and not what I'd consider to be cold. I thought for sure the tire of choice would be the Hoosier wet tires, but several people after the races mentioned the tire to have that day was the Dirt Stockers. I was surprised by this, and wonder if that was really true? If it is, when would the Hoosier wet tires be the tire of choice?
[/b]

What is this rain you speak of? On the fourth we got up to 112F but it truly was a dry heat, with a relative humidity of 1% My friend uses his dirt-stockers to hold his sun shade canopy down. I suspose that's why no races are on our calender untill September.

[Andy Bettencourt]

This was later in the day in the wet drizzle. Two FWD cars, one with DS and one with Wets. I chose the Wets because it is supposed to be their latest and greatest...and I am sure they are better in some ways. The DS weren't available when I got these 18 months ago.

Bottom line, exploit you advantages where you can! Joe and Rick would have whipped me even if I had had Dirts. They were on.

[gran racing]

The 7/4 LRP lap times were just recently posted and I found the results to be very interesting. I took a look at the 1st place ITB car's lap times (James Macmahon) who was on dirt stockers vs. my times on Hoosier wets. After looking at it more closely while knowing the background of the race dynamics, it appears the tire choice may have been a wash like Ray stated. A couple of laps into the race, Jim caught me and I decided not to push so hard I took myself out of the race. Once he passed me (around lap 8), I was able to learn quite a bit from him and started pushing things harder but attempting not to do anything dumb.

I realize that Jim probably wasn't pushing 10/10ths, but I was surprised to see that my fastest time was over 1/2 second faster than his. This goes right back to what Ray said, "its all about the driver" (meaning Jim was the man that day!). Maybe it's time for me to move out to Seattle so I can get more rain experience. There are some 185s dirt stockers for sale at a reduced price ($100 each) that I was tempted to buy, but it looks like I should spend my money in other places.

Wet, but far from pouring rain conditions (lap times)

[Gary L]

A couple of points I haven't seen mentioned WRT to the nearly extinct Dirt Stockers vs the other "wets".

- The DS is a totally different construction (bias ply) with totally different feedback. My experience with the DS is that it gives you less overall grip than some of the newer rubber on a wet (but not flooded) track. However, the DS seems to give you about a mile and a half of warning before it lets go. It is very easy to drive at the edge of adhesion, but that edge will probably not be as fast as some other tires under the same conditions.

- If you look at the footprint of the DS vs the R6 in a given size, you'll typically find about an inch less width, and you also have to subract all that area where there is no rubber... the grooves. Bottom line is that you're probably running on at least 25-30% less rubber with the DS. Less rubber equals less grip - again, we're assuming a wet, but not flooded, track. When it really rains though, size for size, the narrower DS has an inherent anti-hydroplane advantage, tread patterns notwithstanding.

[Andy Bettencourt]

For me, its all about compound. The DS seems to heat up MUCH quicker. If you have a cool day with enough water to keep them cool but not enough to hydroplane, I think they are a superior tire. Typically the amount of grip available is not enough to notice a significant charateristic difference.

[RSTPerformance]

I think we need an autocross wet tire to be made

Raymond

[lymanator]

Perfect example was last weekend at Barber:

The Saturday race started maybe 1/2 wet, with a light sprinkle. I was on RA1's, and we did like an "intermediate" setup. I went from 6th to 2nd by the end of lap one (20th to 7th overall), and was on the leaders ass by lap two. Then it started pouring, and the RA1's went to slop. I just worked on maintaining position, and finished 2nd, like 10 seconds back. The winner had Dirt Stockers on, but I clocked fast lap on lap two. Seems that Greg is right, the stockers are for total rain conditions, then move away from that with degrees of dry track.

[charrbq]

Who started this thread, anyway?! I hadn't touched my rains in three years...this discussion starts, and all of a sudden I run into a rain race with no crew. I didn't know I could change tires so many times in one weekend and still make grid! All I needed was for someone to start a thread about brakes and those would've gone away worse than they did!

Not that I'm superstitious or anything

[gran racing]

Great idea! A "How to manage brakes when they've run out of material" thread.