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!

[vintage914racer]

This is a really helpful thread. For the last few years I’ve run the Hankook z214 C51 compound DOT tire. They’re super cheap compared to Hoosiers and last forever. Prior to that I ran BFG R1s but availability dried up.. I switched to Hoosier R7s last fall, assuming I would burn through A7s. Apparently that’s not the case.

Are the A7s any Faster than the R7, or do they simply get up to temp quicker and therefore you’re faster earlier?

[GregAmy]

Are the A7s any Faster than the R7, or do they simply get up to temp quicker and therefore you’re faster earlier?

In my experience, the latter. But, with the A7 being a softer compound, it will in most situations be faster, though it will have a thinner margin of optimal temperature and a quicker fall off as you exceed it. Not a "bad" one, just "less and more".

But I think we racers tend to ask the wrong questions about tires. I have a very long diatribe about tire compound and size selection, with a mental flowchart of about a hundred different decision boxes. And it will bore you. But to boil it down into a few points:

- Softer is not always faster, especially if it's too soft (falls off).
- Larger is not always faster, especially if it's too large (never fully heats up).
- Driving twice as many sessions on a lesser-expensive "slower" tire will result in faster lap times than a budget-limited campaign of fewer sessions on a more-expensive "faster" tire.
- Driver feel and confidence is worth way more in lap times (and fun) than anything an alternative tire will provide.

I won't quote you "the perfect tire" because that tire will be different for each person's situation. I can tell you which one I would recommend for a unlimited-budget fully-financed team with a professionally-prepped and fully-tested car and full-time crew and pro driver who will make it their full-time job to make that car faster and always win. But something tells me that's none of us. (IMG:style_emoticons/default/wink.gif)

In my case with the historics 914, I get stuck in a group of high-dollar Triumphs and Lotus and similar under-2.5L four-bangers and I know I don't have the budget to play that game at that level, so I'm deliciously happy with the Continentals in the top-third to -quarter of the field. And if it rains, game on.

And I fully realize that even if the vintage sanctioning bodies allowed them, A7s wouldn't have me running up there with them, primarily because they'de be putting those tires on, too (and the folks that are generally behind me wouldn't really catch up on the Purple Crack either.)

For SCCA Club Racing, my team is fortunate to have limited support from Hoosier so a lot more flexibility, and we generally run the slicks. But my teammate is actually thinking of running A7s on the MR2 this year to give them a shot (I think he'll end up overheating the fronts during the summer; that car has as much a general understeer prob as the 914 does.) I'll probably start running slicks on the Civic, depending on where we end up on gear and diff ratios and what tire sizes are available, but Rs are always an option if the numbers look good (as with Brant), I'm told the MS slick is very similar in compound to the R).

But in all those cases, were I paying for tires out of my own pocket, with no serious financial incentives to win a championship, I'd run R7s at the worst, and maybe even tickle Hoosier to get me a couple sets of those upcoming 100TW "autocrosser" Contis that are rumored to be coming down...cause I'd much rather spend twice as much track time.

So..."it depends". - GA