Radical SR3 : Dunlop vs Hoosier

[rfairwea]

I've been running Dunlops on my Radical for the last year+...mainly because I picked up 5 sets of sticker tires shortly after buying the car. Now, I need to buy tires. (Groan). My primary use will be for rack days. The Hoosiers Radical slicks are $300-500 cheaper/set.

I'd like to see what people think who've actially run both tires on a Radical.

How do the tires compare in regards to grip, feel and longevity?
Does the car setup differ significantly between the two tires?

Thanks much,

Rick

[Jamesbe]

Almost identical. If it's for lapping, go with the cheaper alternative no question!

[Ravenbk]

I've run both, and they are quite similar in overall performance. The price is much better on the Hoosiers and i have had good success with them for racing

The other thing to consider is that apparently Dunlop was to stop making tires for the radicals. Not sure if this is in effect yet.. or if its even confirmed. Maybe check with Spring Mountain (Radical Ouest) to see what they say about the subject.

[Ravenbk]

Though i would give some more feedback after the season.

Although i ran with Hoosiers competitively, it seems (very) apparent that the 2015 Dunlop compound is so much better than before AND better than the hoosiers.

Speaking with other fast Drivers that made the switch to Dunlops, they were mentioning they were getting better lap times as well as more "in the zone" heat cycles. Something like 18 heat cycles vs 13 for the Hoosiers. Also the hoosiers drop off dramatically after 6 or 7 heat cycles. The cost of a set of Dunlops is a few hundred more for all 4 corners, but i think it still comes out cheaper per heat cycle.

IF I hadn't ordered so many sets of Hoosiers this year, i would have switched to Dunlops mid season... Next year, i will for sure use Dunlops unless the Canada Radical cup imposes a different tire. (i hear that Good Year will have an option too.)


My 2cents.
Have a great winter.

[CharleyH]

Have you tried the new Michelin pilot sport GT's? Spring Mountain switched there race series to Michelins and they don't even carry Dunlops anymore. They are raving about the tire and claim it is better than the Dunlops in every way.... But they do require a new set up. I just had my car set up changed over and am giving them a try. I have only been out on them for one day and they feel good so far.

Charley

[rfairwea]

Have you tried the new Michelin pilot sport GT's? Spring Mountain switched there race series to Michelins and they don't even carry Dunlops anymore. They are raving about the tire and claim it is better than the Dunlops in every way.... But they do require a new set up. I just had my car set up changed over and am giving them a try. I have only been out on them for one day and they feel good so far.

Charley

Charley - can you give some specifics on your setup changes for the Michelin? I'm curious on how much of a change it is from the Dunlops.

Thanks much,

rick

[CharleyH]

Charley - can you give some specifics on your setup changes for the Michelin? I'm curious on how much of a change it is from the Dunlops.

Thanks much,

rick

Here is the setup information that Michelin posted on the Spring Mountain site. It uses a LOT less camber compared to the Dunlops.

Charley


About The Tire: Michelin has added a Pilot® Sport GT customer racing tire size to fit the popular United Kingdom-built Radical SR3 and SR8 sports racers. The tire helps Michelin round out its line of popular customer racing slicks. The tire is being launched just in time for the Radical gathering at Spring Mountain Motor Resort and Country Club March 26-28. “The Pilot Sport GT combines a high level of peak grip and good wear with excellent predictability and progressivity, making it well suited to broad range of driver and vehicle performance capabilities within the radical racing series,” said Ken Payne, motorsports technical director, Michelin North America.

Front Tire: 18/56-15 S9L Michelin Pilot Sport GT (MSPN 90346)
Rear Tire: 23/61-16 S9L Michelin Pilot Sport GT (MSPN 30740)

Specs:
• Recommended Vehicle Static Camber: Front camber: -3.0 to -3.5?; Rear camber: -2 to -2.5?
• Recommended hot pressure: 27.5 psi (1.9 bar) front and rear
• Physical Dimensions: Very similar to the previous tire for overall width and diameter.
Front Tire Overall Diameter 584 mm
Rear Tire Overall Diameter 616 mm
• Radial Spring Rate: Front: very slightly stiffer than the previous tire (~3%); Rear: slightly softer than previous tire (~7%).
• Operating temperatures: Optimum range is 170-210? F verified by a needle type pyrometer. The tire has a very broad window and will provide consistent grip on either side of this range. It is not a tire that will “switch on” at a particular tire temperature.

[Ravenbk]

Hi Charley,
Thanks for the info, i have yet to try the Michelins.

I would love to hear more about your experience once you had a chance to "get a grip" on the difference!

Jon

[rkjz4h]

Guys, i have had an Sr3 for nearly 5 yrs now and have used all 3 brand of tires. The hoosiers are modestly less but on a per heat cycle basis they are not cheaper and fall off after a few heat cycles. Wont buy them again. I love the dunlops but have found the michelins to last as long, if not longer and i believe with superior grip as they cycle. I am up to 18 heat cycle on my first set of michelins and they still feel great. Nevada says you can run them till the dimples are gone and that may be. I will get back with how many heat cycles i got before the car became unbalanced and noticeably uncompetitive.

I had my first sr3 for 3 yrs and then bought a 2010 sr3 about 2 yrs ago. Both have been fantastic cars. I raced fe with scca for 7 yrs and the sr3 is equally fast, safer, easier to drive , simpler to maintain and more durable. Huge fan.

[rfairwea]

Guys, i have had an Sr3 for nearly 5 yrs now and have used all 3 brand of tires. The hoosiers are modestly less but on a per heat cycle basis they are not cheaper and fall off after a few heat cycles. Wont buy them again. I love the dunlops but have found the michelins to last as long, if not longer and i believe with superior grip as they cycle. I am up to 18 heat cycle on my first set of michelins and they still feel great. Nevada says you can run them till the dimples are gone and that may be. I will get back with how many heat cycles i got before the car became unbalanced and noticeably uncompetitive.

I had my first sr3 for 3 yrs and then bought a 2010 sr3 about 2 yrs ago. Both have been fantastic cars. I raced fe with scca for 7 yrs and the sr3 is equally fast, safer, easier to drive , simpler to maintain and more durable. Huge fan.

Can you comment on the alignment parameters used for the Michelins vs the Dunlops?

Thanks much,

Rick

[rkjz4h]

Rick, per nevada they run less camber and equal tire pressures than the dunlops but i havent changed anything and the tire temps across the face are within 10-15 degrees. i adjust pressures to get close to the recommended 175 so it just depends on conditions if i monkey with those a degree or 2. i will be sticking with the michelins now that dunlops are a tad softer than before. i didnt get the life out of the most recent set of the dunlops i purchased thru canada that i had out of the harder dunlops that nevada sold prior to adopting the michelins.

Be safe.

[birvine]

Can I ask what you are generally starting with for tire pressure on the Michelin's. Just took my SR3 out for the first time last weekend and was not building much heat in the tires. Started at 22 front and 20 rear only gained about 4lbs. I know tires are a bit older but no idea how many heat cycles he had on them .

Thanks

[CharleyH]

i usually start with 23 in the front and 22 in the rear...

[AWay]

Anyone ever try JB Racing tires? Someone recommended them to me at this track this past weekend so I gave them a call. Supposedly 3/4-full tread take offs from test sessions. Maxed out a $70/tire for the full tread Dunlops. So they claim anyway. Seems like a super cheap way for 'new' rubber but that's just it, I don't know, and he didn't seem to indicate, exactly how old the tires are. My current tires have plenty of tread but are over a year old...

Anywho, just curious if anyone had experience with buying 'used' tires for track day fun in the past? No racing here unfortunately.

[Jamesbe]

I bought tires from them. It's hit and miss as full rubber and heat cycled out are not the same.

Some tires were fine and had about half the life of new, some were just cycled out or lasted a few sessions only.

In the end it seemed like buying 1 new set and running them till they were done was cheaper then buying 3-4 mediocre sets and having to get them mounted.

[AWay]

That was kind of the logic I was leaning towards. Dicking around with a couple sets of half life used tires I might as well just do a new set and know their history from the get go. Are the Dunlop’s just the going rate or is one place cheaper than another to purchase them from?

[CharleyH]

Until you get really fast the tires last a long time. Just get new tires.

Charley

[AWay]

The only place I saw that appears to sell the Dunlops online is competition Motorsport. I’ll have to see if there is anyone more local to me.

[CharleyH]

The only place I saw that appears to sell the Dunlops online is competition Motorsport. I’ll have to see if there is anyone more local to me.

I would call Wisconsin Racing at VIR. They should be able to ship them to you for a reasonable price. Shipping tires is only about $100

[AWay]

You mean WISKO? Righto, I'm quite familiar with them by now.

[CharleyH]

You mean WISKO? Righto, I'm quite familiar with them by now.

Yes... spell check “fixed” that for me. . Yes the people at your local Radical dealer become your best friends.

[crossbarphoto]

Guys, i have had an Sr3 for nearly 5 yrs now and have used all 3 brand of tires. The hoosiers are modestly less but on a per heat cycle basis they are not cheaper and fall off after a few heat cycles. Wont buy them again. I love the dunlops but have found the michelins to last as long, if not longer and i believe with superior grip as they cycle. I am up to 18 heat cycle on my first set of michelins and they still feel great. Nevada says you can run them till the dimples are gone and that may be. I will get back with how many heat cycles i got before the car became unbalanced and noticeably uncompetitive.

Hey guys...it is now late 2020. To drum up an old thread what is the latest consensus on the best tire to run on the SR3...specifically a Gen2? I just bought a set of sticker Hankooks and will be giving them a try. Was going to buy a set of other tires and was wondering what people think between the Michelins and Dunlops now.

Any current data points would be appreciated.