Latest recs/experience with 15" Hoosiers?, A7 vs R7 vs Radial Slicks Options

[campbellcj]

Hey All -

When I was last actively tracking my car in 2016-18 I had switched to a Hoosier Radial Slick in a soft compound which does not seem available anymore, but there are similar models in a medium compound I think will fit.

I'm aiming to get back out there a few times this year just for fun - won't be running competitively at least at first as I shake-off the cobwebs - so I'm thinking the R7 or A7 may be better in terms of longevity and pricing. (Although previously I found the slicks and R6 lasted me around the same number of heat cycles with the slicks performing better and costing more as one would assume.)

Does anyone have recent experience or info on using the A7 for short TT/TA sessions or sprint races, around 20-25min sessions? I've never used any of the A* variants but recall hearing of folks using them on lightweight cars for non-endurance events. Was that @brant ?

I'd be open to other brands as well if the correct 15" sizes are available. I run 8's/9's and my flares can fit about a 10" section width tire.

Thanks much for any insights!

[GregAmy]

I have immediate and current experience with most of the Hoosier 15" scene...we run a Honda Fit and a Toyota MR2 in H Production, 17s on an E Production Honda Civic, and I have a hisotrics 914 running 15s.

Short answer: you will not hurt the A7 on a Porsche 914. It's a light enough car and those As are tough enough to take it even on the hottest of days. However, once up to temperature, you'll find the R7s can be just as fast but last longer.

Key there is "once up to temperature". I ran A7s in back and R7s in front of the Civic to ensure I had the balance I needed at the start of the race, and just took care not to wipe out the backs once hotted up. Only time I've killed A7s was running them up front on that ~#2500 pound FWD Civic in a 100-degree afternoon. They clicked right off at the green but two laps later were panting pretty hard...didn't make the distance.

As for the radial slicks, there's surprisingly not a lot of difference to the DOTs. We back-to-back tested R7 vs the MS slicks, as close to same size as possible and on same weekend, and they drove the same and came out similar same lap times. The slicks got the tiny lap time edge and would probably get faster with more tuning.

Hoosier nixed the 15in "S" in early 2022, not enough demand. We used to run S but decided to focus setups on the MS since we knew we could get those. But if you ask around you might find some leftovers at some depots. Try calling the distributors directly, like Brian Brown at Northeast Hoosier in Manchester CT, he said he still saw some out there.

Finally...what are you doing with the car? Historics racing? I put 200TW 15" Continental "ExtremeContact Force" tires on my historics 914 for the Lime Rock 2022 Labor Day weekend and found them to be a delight to drive on! And, to much my surprise, I was about 2s per lap faster that weekend in the 914 than I was the prior June in the MR2 on radial slicks (the 914 is about 250-300# lighter). I liked them better than the Speedsters I had on prior, just drove better, more feedback. I might put the Speedsters on the street car...

Rumor has Conti will offer a 100TW version sometime this year. That should be a nice compromise tire.

Never raced on bias ply tires. That's some kinda old green car, Castrol-smelling, "scarf blowing backwards in the breeze" kinda stuff (winking @ Chris).

I'd say set your mission, set your goals - and set your budget - then pick your tire. You won't go wrong with any of these choices. - GA