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View Full Version : Dry – Intermediate – and Rain Tires…when to use which?



gran racing
09-29-2004, 08:55 AM
To be more specific:

Dry – the new Hoosiers
Intermediate – unshaved Toyo RA1s
Rain – Hoosier Dirt Stockers

In what stages of rain should the various above tires be used? I realize that if the track is currently wet and it is not raining, it makes most sense to use the Dry tires because after a few laps the track will dry up. But when do you move to the Intermediate tires instead of using dry tires? If the track is wet and it is still raining lightly but not pouring? I understand this decision comes with experience and of course some luck predicting what the weather will do never hurts.

Right now I don’t have true rain tires (the Dirt Stockers) but have the Toyos just in case, but next year who knows. If a person also has Dirt Stockers, when do they typically use them versus the Intermediates? Only if it is pouring?

For IT cars, how much does the car itself impact this decision (fwd versus rwd, weight of the car, ect.)?


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Dave Gran
NER #13 ITA
'87 Honda Prelude

apr67
09-29-2004, 09:22 AM
One way to look at it is how much slower are you on the tire.

For example, if you are 2 seconds slower on the full tread toyo than the hoosier dry tire in the dry, then how wet does the track have to be before you are slower on the dry than the wet? This is not a canned answer, it depends on car, setup, driver and track.

I would use dirt stockers when a tropical depression is located over the track. They only work well on very wet tracks, and if it drys up at all you are royalled screwed.

The toyos at full tread will tend to chunk (depending on car weight and hp, less likely on itc, more likely on ITS) if the track goes fully dry.

I would probably shave the toyos to 6/32'nds if I were going to use them as intermeidates. Full tread they are good full wets. Not as good as dirt stockers, but pretty good none the less.

gran racing
09-29-2004, 11:54 AM
In my case the car's min. weight is 2,450 lbs and has 110 hp stock (at the crank).

But curious about other cars as well.

Thanks.

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Dave Gran
NER #13 ITA
'87 Honda Prelude

Greg Gauper
09-29-2004, 01:27 PM
Temperature should be another big consideration in your tire choice.

If it is quite cool out i.e. low-mid 50's or colder and damp, Hoosier Dirt Stockers WILL hold up just fine. Otherwise you really don't want to be on Dirt Stockers unless there is quite a bit of moisture or else you will overheat and chunk them.

If it's cold out, you can't get any grip.

joeg
09-29-2004, 02:46 PM
I prefer a full-depth KUMHO Victoracer as an intermediate over a TOYO.

I use an intermediate in any damp/dirty track condition ( not concerned about drying)
because they can survive a race on a dry track.

Why? You are never going to be real fast on a damp/dirty track to justify using up a heat cycle on a dry Hoosier and while slower, they race just as well and wear slowly.

I run Hoosiers dry and the Dirt Stocker in pouring rain--beleive me it has to be pouring rain.

I have only used the Dirt Stockers twice in 9 years of racing and often do not even take them with me to the track.

I always keep the KUMHOS at hand.

Cheers.

Greg Gauper
09-29-2004, 04:33 PM
Originally posted by joeg:


I run Hoosiers dry and the Dirt Stocker in pouring rain--beleive me it has to be pouring rain.



No it doesn't! I have run DS's on a damp track in cool temps with absolutely no tire wear issues! As long as there is some moisture on the track, and it is cool enough, you will be fine.
If it is warm out, that's another story...you need moisture to keep the tires cool. But if it's cold and damp, you will be fine!

I managed to get 5 years out of my old set of DS's before I had to replace them due to sidewall rot. They had over 50% tread left and were used in about 8 rain races during that time. This was on a FWD Honda.


[This message has been edited by Greg Gauper (edited September 29, 2004).]

gran racing
09-29-2004, 04:35 PM
So if it is just raining (not pouring) but yet still steady enough, still go with the intermediates?

I too am not concerned with the Toyos if it dries up.

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Dave Gran
NER #13 ITA
'87 Honda Prelude

joeg
09-29-2004, 05:06 PM
[quote]Originally posted by gran racing:
[B]So if it is just raining (not pouring) but yet still steady enough, still go with the intermediates?

I do. Part of the reason I avoid using the Dirt Stockers in anything but a deluge is that their circumference is differnt than that of the dry hoosier or the Kumho.

In a deluge, you are going to be a lot slower regardless of tires as compared to damp racing. Dirt Stockers in a deluge makes the racing fun as opposed to a terror trip.

CaptainWho
09-29-2004, 08:17 PM
Originally posted by joeg:
In a deluge, you are going to be a lot slower regardless of tires as compared to damp racing. Dirt Stockers in a deluge makes the racing fun as opposed to a terror trip.

I'll sure agree with that. And, for us, in IT7 cars, we had no problems with tire temps in wet track to medium rain conditions at Roebling in February. Ambient temp was 50s or low 60s. Little discernable wear after five or six sessions. Had a blast. Track got wetter all day, I got slower all day, but I climbed the timing charts, nonetheless. http://Forum.ImprovedTouring.com/it/smile.gif

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Doug "Lefty" Franklin
NutDriver Racing (http://www.nutdriver.org)

Weaver7
09-30-2004, 07:57 AM
Originally posted by gran racing:
So if it is just raining (not pouring) but yet still steady enough, still go with the intermediates?

I too am not concerned with the Toyos if it dries up.


I'm a little concerned as I'm driving an ITB Golf in a 3 hour enduro at WGI in two weeks. The owner of the car told me to buy the Toyo's in full tread and shaved. He said that they do just fine with full tread.

gran racing
09-30-2004, 08:33 AM
I wouldn't be too concerned with running full tread Toyos on your car. Might not be the fastest, but it should work fine.

WGI with EMRA? Or is it a SCCA event?

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Dave Gran
NER #13 ITA
'87 Honda Prelude

Greg Amy
09-30-2004, 10:01 AM
REAL men don't use rain tires...

gsbaker
09-30-2004, 10:05 AM
REAL men use slicks...

JohnRW
09-30-2004, 11:07 AM
Real men race motorcycles, and know their orthopedic surgeons by first name. Car racers are just wanna-be's.

Weaver7 - That car will do fine on full-tread Toyos. It ran a 3-hour NASA enduro at VIR last spring, finished first among a combined class of SSB, SSC, ITB, ITC and misc. other strangely-classed crap, and has run a 2 hour and several sprint race weeks since then...all on that same set of tires. It's probably NEVER had a new shaved tire on it. I know that would never be my recommendation. But...umm....(mumble mumble mumble)...never mind.

Just make sure Ed puts the big steering wheel back in, or you'll get out of the car looking like Popeye. And put a piece of duct tape over the oil pressure gauge...because you just don't wanna know...

I will be enjoying my normal SSC ride that weekend. Reggae or Talking Heads in the stereo ? Tough decision....

gsbaker
09-30-2004, 01:32 PM
John,

Easy decision. Talking Heads, hands down.

Gregg

RSTPerformance
09-30-2004, 02:51 PM
Poor men (women) race on cords http://Forum.ImprovedTouring.com/it/smile.gif

The Glenn I don't think is rough on tires, run the Hoosiers!!!

Raymond

apr67
09-30-2004, 03:00 PM
Originally posted by Weaver7:
I'm a little concerned as I'm driving an ITB Golf in a 3 hour enduro at WGI in two weeks. The owner of the car told me to buy the Toyo's in full tread and shaved. He said that they do just fine with full tread.

They should be fine. Intermeidates are just faster in a wet but not soaked track. Full treads will work. In reality, you could just run full tread tires, but then you would be lots slower in the dry!

Weaver7
09-30-2004, 03:48 PM
John I guess I never knew what your user name was on this board. Anyway thanks for letting me drive the car with Ed and Mike that weekend really appreciate it! Ed did tell me about the oil psi at the Fun One a little scary indeed.

Bill Weaver
#63 ITA RX-7



[This message has been edited by Weaver7 (edited October 01, 2004).]