sperkins

At the NASA Nationals this year, the air temp was a bit cooler than normal the entire week and the first 2 days were pretty much a wash out.
That being said, I was never able to get enough heat in my HWETS to actually "use" them. I figured it was because they were a couple of years old, but a buddy running basically the same car was on sticker wets and he said the same thing.
So my question is, is there a break-even point for track temp/air temp where using a fresh street tire would actually be better than a DOT full wet?

travisnd

Paul Schmidt

I think it's all on our minds. I kid you not I was shopping for some Hoosier wets and then went came back here to see this thread. We have 8 scheduled test and tune days up here in Seattle. I plan on taking advantage of all 8, so I know there is going to be rain. It could rain all 8 days, who knows. I know people say leave it on the trailer or stay home. That isn't an option for me. So that's why I'm all ears from you racers who have been there done that. Thanks for making this thread.

Gman57

..... I'm here

RX-Ben

I would think that nothing would grip better than soft tires in any condition and the Hoosiers are the softest.
Harder street rubber is still harder in the cold.
If you had 8 working cylinders.....

rasrboy

I have raced/tested both Hoosier wets and Kumho wets and I gotta say the Kumho wets hook up a little better and have a softer compound than HWETS. Not saying this cause I do contract work for Kumho, the
W710 is basically the 710 compound with with grooves. Yes the track needs to be fully wet with standing water, otherwise if damp your better off on your A's or 710's.

Biggest thing is, who's ever tire you decide to use make sure you
scrub the mold release off first before hitting the track. Mold release and a smooth unscuffed rain tire dont mix well in the wet.

Age doesn't matter under 5-6 years as long as they were stored properly and there is no cracking. I set the pressures at 26 PSI square on my old T1 car and they work great.

That's my .02.

Aaron

PushinTheLimit

Speaking of Hoosier wets... I have a set of four 315/35-17's for sale if anyone wants them. I'll make a thread for them this weekend, but since I'm going to PTA this year... I won't be needing them.

I can't speak from experience on using them because I mounted them up and took them with me to every race this year and it never rained That was my hope that I never would need them (although thought I was going to at Roebling back in September) but I at least I had them. They are in great shape and bought them from CP Thunder on here.

Brent Dalton

Does anyone know if the hoosier compound changed in the last year? Like Aaron mentioned above, I've always heard that the W710 is faster than the Hoosier wets(mostly from the Nationally competitive AutoXers). However, I was thinking that the buzz at AutoX Nationals this year was about a new Hoosier Wet? Could be competely wrong on that.

drivinhard

There is a new Hoosier, the H20. It came out earlier this year. I still think you can get the old HWET to.

RacePro Engineering

Gentlemen,

I am certain part of the confusion, or widely varying results here, is due to the fact that we are writing about at least 2 different Hoosier "wets". This happens frequently on this Forum, and I am as guilty as anyone.

When we think of "Hoosier wets", we are referring to their full-out, racing tire - NOT their compromised DOT rain tire,

My quote from the other, currently active "rain tire thread":

At least I did say "full wets", which I just assumed others would understand as "the maximum rain tire", and not the DOT.

We have not tested against ANY Kumhos in many years, so, Aaron, I would be very interested to hear which "HWET" tire, as you call it, was involved in your test.

Ed

RacePro Engineering

Hi Scott,

I am with Ben on this topic. I can not think of a single scenario where any street tire would out-perform a purpose-built rain tire. Obviously, in the rain, one is going to slip-and-slide dramatically, no matter what. It is just a matter of degrees. And remember, all too often, a car that is setup VERY WELL for dry conditions, will work against the driver in the wet. As Dante is fond of saying, "Everything changes in the wet . . ."

One of the critical criteria of the Hoosier rain's grip are the knife-like edges of all the grooves. Once the edges of those grooves become rounded off, the tires loose their -- well, EDGE.

Ed

sperkins

Thanks Ed. I guess my thought was that a street tire doesn't have to get up to temp whereas a 40 treadwear Hoosier (non wet) must before it offers any grip - hence the reason we scrub in tires on the out lap to generate heat. Nothing says crash like a brick hard cold DOT or race tire.
Are you saying that the rolling resistance alone is enough to generate heat in a Full wet/HWET no matter the track conditions - say 34* in cold rain?

RX-Ben

Aaron - thanks for that - I should have stated more generally a DOT-R compound, not specifically the Hoosiers.

There was a NASA enduro at NJMP this year in October. 35deg and rain, with hints of sleet. Everyone I saw was on Hoosier wets (don't know about the WET vs H20) and they looked to be working well, but who knows how something like a Conti ExtremeContact DW would have done in comparison.

I thought the Wets were only good with a soaked track/downpour and then H20 for damp track or shaved for use as an intermediate.

RacePro Engineering

I think the closest we have come to those conditions was a do-or-die, single day test in October a few years ago, with the Cobra. 42 degrees, rain and wind! I am not certain Dante got ANY heat into those Hoosiers - I certainly was not going to do any pyrometer checks wearing my boots and pancho - but he was flying, compared to the 15-or-so other racers who were slogging around out there. The only suspension changes we had time to make were damper (YES - pun intended!) settings.

So, here's my reasoning, leading to a GUESS:
Even street tires generate more grip after they have been scrubbed and heated. Will the purpose-built rain tire "come in" faster than a street tire? I BELIEVE it will.
If there is no heat to be found, the sipes, the water-scavenging tread pattern, those knife-edges on the grooves, and a soft rubber compound should still afford better grip on a wet pavement, than a tire that lacks any or all of those things.

In the end, it is still a GUESS.
Ed

fatbillybob

From a practical view I'm looking at this issue a little differently. In So cal we get almost no rain. When we do get rain it is never a huge downpour. I have run Hwets but then the few times I have used them we had to pull in and take them off once the rain stopped falling. Oh and before we ran we had the car on jacks waiting until minutes before the green flag to see how much rain was falling before finally putting on tires. All that a huge pain for non-professional club racers. My new idea is to use a DOT dry race tire and hand cut grooves and maybe sipe them. This way as the track drys I'm left with a dry tire albeit with less performance but I won't have to come into the pitts because I'm going to destroy an Hwet on a drying track. That hand cut tire tread should work fine in the dry with some traction loss due to the hand cuts. Who knows maybe I'm wasting my time or maybe my day will be less painful. Any conments on that idea?

autoxer6

I use the Conti Extreme Contact DW as my racing rain tire for SCCA SS AutoX. I have compared them to the DOT Hoosier Wet (the old ones, not the H2O) at a tour. It was even steady rain. My local competitor was there with fresh (but scrubbed in) Hoosier wets. I won the event beating 7 people on Hoosiers. We both use DL1 data set up with the same parameters and we saw no difference in longitudinal or latitudinal G forces. The only differences we saw were when he broke traction and had to wait to get back on the throttle.

The newer Hoosier H2O and Kumho Hwets are faster, but I still think the street tires can be competitive for those on a budget. I'll be bringing them to nationals again this year

Chris Shay

brkntrxn

That is good information, Chris. I may need to look into those as a cost selective solution for a set of tires I know I am going to carry around for "in case" situations.

RacePro Engineering

Bob,

I think that is an absolutely ingenius idea! In a race, how long does it take to change 4 wheels (20 lug nuts)? ANSWER: An eternity!

I will be very interested to hear how this works, once you have an opportunity to try it.

By the way, here in the Northeast, that incredibly distasteful scene of "car-on-the-jacks, wheels-off, a set of slicks AND a set of wets sitting at all four corners, everyone looking at the sky as if to predict which way things will go, and as the clock ticks down, the mad scramble", is all-too-common. Unfortuately, as much as we do it, I don't think we are getting any better . . . . .

Ed

96CollectorSport

This is especially true with NASA Nationals being at Mid-Ohio again this year When we went to Nats in 08 it rained on Saturday and was nice on Sunday - pretty much the same thing happened last year. So maybe having a dry, intermediate and wet set-up would be a good idea.
I had Alex's car up on jack-stands before the NASA Mid-Ohio August race on Sunday and we decided to put the drys on. The rain stayed away and we got out to a big lead 45 + seconds over 2nd place overall - then I remembered we didn't top off the tank. Told him to baby it for the second 1/2 of the race and he ended up winning overal! We also ran out of gas on the cool down lap and had to be towed in.

I thought they had an article in Grassroots Motorsports a while back where they compared the Conti DW's to the Hoosier H2O wets and while the H2O's won the DW's did well for a street tire. We may just have to put together some scrubs and cut them to make up a set of intermediates just in case we can't decide come September.