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 @http://www.914world.com/bbs2/index.php?showuser=47 ?
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!
definitely the A7
those are the fastest tires I've used...
I also have a bunch of vintage legal tires in 15 that are all slower than the A7
A7 and R7 no longer vintage legal in my neck of the woods, nor SVRA
but 2nd best is the hoosier speedster
3rd best the RA1
4th best the hoosier Bias ply
if you can run the A7 I'd recommend it.
mine held up very well (30 heat cycles +... no cords... but definitely timed out on heatcycles)
I talked with the hoosier engineers when I tried them the first time
they were build for corvette's and mustangs.. all which weigh much more
our cars are easy on tires with the balanced weight bias.
I had no problems switching from the R7 to the A7 and noticed no wear problems.. but did notice how much quicker they came up to temp and grip.
a local hot shoe who always takes the podium in SCCA nationals uses them on his corvettes even.
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
when the speedsters first came out... the hoosier engineer told me they were exactly the same compound as the R7
might be... when they were fresh they were pretty good
but they seemed to cycle out much faster than I was used to with R7
I wish I could buy more A/R7 tires...
they won't except them in SVRA
and have pretty tight regs on what they will accept
thus the reason I tried the speedster, R1, and bias ply.... all legal for SVRA
but not fast
sorry I don't have experience with the slicks...
I will add the bias ply seem to work better on heavier cars
the muscle guys love them on the track
but I don't think I was able to get the heat into them that they wanted
a much different driving style... a lot more loose... they like to slide... and probably that helps the heating too. the V8 guys hang their rear ends out on every corner and I think the tires like that...
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?
I've got fresh Toyo RR's ready for this season. I ran them on my previous 914, and while certainly not Hoosiers, they will last dang near the whole season.
Hooked on Driving offers the "Toyo Bucks" program to coaches that pays $50 per event towards a set. I racked up about 8 of them so I got a full set for a few hundred bucks in mounting, balancing, etc.
Like I said, not Hoosiers, but for practice and fun stuff absolutely acceptable.
Thank you all very much for the great info! It sounds like the A7 will work well for POC or other non-vintage. I do have 3 sets of wheels and 1 has some Michelin TB5s, which I haven't checked into as to vintage legality. Around here that would be VARA and I'll check their rules soon.
I can relate to sometimes struggling to build heat with the Hoosier R# tires and things can get interesting when stone cold. My car is around 1950lbs wet. Those Hoosier S slicks were like crack; looking forward to trying out the A7 and will report back. Depending if I may need a separate vintage-legal set soon, I might look at those Toyos as well.
This thread was great
Well just a quick mildly depressing update - I did get a set of A7s and they look sweet but missed the event I was targeting a couple weekends back, due to work as well as my alternator failing. Interesting that that A7/R7 has essentially zero tread even vs the R6, it's effectively a 'slick'. Will follow up with thoughts/results as soon as I can get the car back on the track!
Those 4 square dots are your tread depth
14 heat cycles are what they used to say for them
My current set has 35 heat cycles on them
They still run faster than my toyos. But leave a lot on the table also.
New tires are on my racing list
[quote name='brant' date='Apr 26 2023, 04:31 PM' post='3074039']
My current set has 35 heat cycles on them
They still run faster than my toyos. But leave a lot on the table also.
New tires are on my racing list
You must have better track surface than me!
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)