Anyone use Hooseir R3S05 (compare Mich Pilot Sport PS2)

Drive it like you stole it, and enjoy.

I bought a set of kinesis rims over the winter and am itching to put them to good track use myself. The guys at kinesis were very good to work with.

For tires, you'll run through whatever you buy fairly quickly, so this isn't a lifelong choice
I've been very happy in the past with Kumho. I used the V700s for several years. Am planning to try the newer V710s next. Don't let that sway you this time, but you might consider it for the future if their prices stay lower than Hoosier.


Lou

 

We go through 1 set of Hoosiers per car per race weekend. So be prepared to accept the fast wear rate.

You can help things by closely monitoring your tire temperature profile with needle type pyrometer to ensure car is properly setup. Obviously a smooth driving style without sliding the car or spinning the tires on power exit will help extend tire life immensely.

For non-competition test runs we also re-mount tires left to right to even out the inside shoulder wear. Usually we make the switch after about 30% wear, before the inside shoulder wear is too obvious, so as to not alter the effective camber too much.

Make sure you check your tire pressure before every run. This is especially so if you had accidentally run over the curb at apex or on exit on a previous run and you are running lower than factory recommended pressure for maximum grip. These tires can deflate. It happened to me in one race and ended up schredding brand new front left tire after just 3 laps.

I think you will like these tires in spite of the high running cost.

 

Don't have any experience with Kumho street R compound tires, but their racing slicks are much better than Michelin slicks. Last year it was the designated tire for the Formula Renault series I raced in. Almost 1 second per lap faster than Michelin slicks. Kumho slicks are also used in Euro F3 series.

I'd be very interested to hear how good the new Ecsta V710s are, which are almost slicks.

 

CWHK wrote:
"Not R3S05 experience, but I did race with R3S04 in a 360 Challenge during 2005."

Can you share the tire sizes you used for the 360 Challenge? I've had trouble finding Hoosier (and other R compound as well) sizes that keep the same diameter as OEM front and rear. Thanks.


Lou

 

As you may know OEM Pirelli slick size specified for 360C is 235/645-18 and 295/680-18. We use the closest Hooiser size 245/35-18 and 305/30-18, which incidentally are the same size tires other racers use on Porsche GT3s.

We just set the car up to the desired ride height and pitch. Smaller diameter rear significantly help lap times, as 360C 6th gear is too tall for most tracks.

 

Take a look at: http://www.europeancarweb.com/tech/0408ec_tire/

Good overview of R-compound tires.

-Peter

 

Steve:
I think I've posted this before, but just as a reminder, when I ran the Hoosiers on my 308 I had to modify the chassis "forks" that hold the a-arms in order to get 3 to 3.5 at the front and 2.25 to 2.5 at the rear. I don't recall if the studs on the front are longer or shorter than the rear, but either way, we switched the longer ones to the "shorter end" and cut out and welded in new, longer bolts to the shorter set, thereby enabling me to get the camber.

One other point, the Hoosiers (F) were 225s I think. They were about an inch wider than the A032R "wets" I was using. You'll need to roll fender lips.

Philip

 

Ran 2 years with shaved Kumho VictoRacer V700s on my 308QV then switched to the V710 for last year. They did everything I wanted them to do. However, I am not running stock suspension and can get the 265/45/16 on the rears without rubbing. Running 225/50/16s on the front. If you can get them to fit, they are worth the money.

 

Umm, I think you are talking castor here Steve, I am talking camber...

 

And Steve, don't go too big with the rubber as you'll not get it hot enough.

 

I am no expert on this stuff but here's a couple of perspectives.

I ran 225F, 245 R, Hoosiers (S04 I think). 400 F, 350 R springs. Lowered. Alignment as described before. It worked well. That said:

The race boys in UK used to tell me not to go wider than 225 as they found they couldn't heat the rubber up enough in a race if the tire size was larger if the car was sprung and ARB'd pretty much as you describe your own set up.

I think you can go for a wider/stickier tire but you will need stiffer springs (the race spec was arund 800 lb F, 500 R) and ARBs (look at the ARB on a Michelotto 308 for comparison, it's huge) and have the thing skimming the ground to get the heat into the slick/near slick to make it work optimally.

Any of this help?

 

I have raced with Yokohama 032R's and they were amazing.I used Kenesis Super cup's.I was racing on the track with the same car but with Michelin Sport cup's. It was a cold 40F and wet day.He mentioned that he could not get any traction will my car was amazing.I highly recomend them.

 

Good point. I also think he was asking whether he could use the PS2 as both a street and a rain tire. This raises the question as to what is "rain/wet" mean? For some its just the presence of moisture and for others rain means enough to create a rain line and run off. My experience with the S03 and S04 ona FWD Audi is that neither worked well once the track was wet enough to pool. As the tires get cooler (below 120) the slip gets greater and all it takes is a little pooling to aquaplane. I have also tried the Hoosier "rain tire" which was very much better than the S04 or the RA1 unshaved but heat cycled in rain and pooling conditions. Well worth the money if you can afford them. However they too are easily swamped once the track is really wet which puzzles me because I have looked at the formulations used by the Le Mans or Enduro. These guys (seemingly through magic) are able to maintain insane speeds on shiny wet tracks using tires whose concession to water evacuation seem minimal.

With all that said, the new Goodyear F1 3D seems to have won all the magazine tests of recent months for both rain and all round performance. Definitively out gunning the hallowed PS2 while the P-Zeros have turned in dismal results.. I have also heard that different sizes are getting different rubber formulations depending on their OEM application. There is for example (on Tire Rack) a different part number for Porsche PS2 tires as compared with other cars although it is not specified as to why these model numbers are suited to the Porsche.

Rob, I followed your advice with the RA1s last season and the S04s and dropped my start pressures considerably. I found it helped a lot, particularly in the first few laps and I was ending with temps solidly in the 150-160 range which Hoosier specifies and my RA1s were about 10 deg cooler. This year I am staying with Hoosier only because the RA1 is too difficult to buy heat cycled and shaved and I as a FWD car I am going with different sizes front and rear. Any port in a a storm!

 

What I said...But with that said, you do not see many Hoosiers at the front of Grand Am or Speed GT as real race cars use real race rubber whose sizes and choices make a Crayola packet look like a simple color choice !!


I was talking nonsense having forgotten that Hoosier was THE tire for the recent Rolex and has a complete range of long distnace, short, dirt, oval and if you compete they have a tire. Actually we are really lucky to have a focused manufacturer like this. They also just announced their R6 DOT race tire which will be available in March.