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-   -   New Hoosier radial slicks & contigency plan (https://rennlist.com/forums/racing-and-drivers-education-forum/491677-new-hoosier-radial-slicks-and-contigency-plan.html)

bobt993 05-24-2010 07:55 PM

Hey Norm the contigency changed a little this year. 6 or less cars in class yields one tire for 1st and one for 2nd. Seven cars or more gets you 2 for first and 2nd plus 3rd each get a tire. Pretty decent rewards when you realize you can replace any tire you want for the podium.

claykos 05-24-2010 08:08 PM


Originally Posted by cstreit (Post 7597862)
I've run them two weekends now, ran the Dunlop GT's the last two seasons...

1. Most important: Lap times. The Hoosiers (R100 compound) have been about 2-3 tenths quicker than the Dunlop GT thus far. I've broken my previous best lap time at two familiar tracks on the new Hoosiers. Nothing else changed on the car since prior rears. Similar heat cycles both times. I'm not convinced at this point that they REALLY are faster or perhaps I've gotten a little faster, but after 10 years at these tracks I can confidently say they aren't slower.

2. Price: I paid $1480 for the Hoosier slicks, $1668 for the Dunlops. Almost $200 per set cheaper.

3. Heat cycles: Not sure about the number of heat cycles the Hoosiers will take before really going off. I was only getting 8 good and 4 more okay heat cycles out of the Dunlops. After the next race weekend I'll have 14 on the Hoosiers and see if they fall off badly or not.

4. Availability: No issues either way but Hoosier is right next door, a real bonus.

5. Camber: They both seem to like the same camber on my car. About 2.5 deg neg. based on temp readings.

6. Weight: Subjectively the hoosiers feel a little heavier, but I haven't actually weighed them. Will do that this week.


I have run through several sets by now. They are pretty good tires. For me, the Hoosiers fall off fairly badly after about 5 cycles. They still feel fine and are fine for practice but they are .5-1 second off the pace of stickers. If I start a race on tires with 4 or 5 cycles on them, about midway through the race they slow down a lot, whereas I can push hard for a full race on stickers without this issue.

doc#66 05-25-2010 09:39 PM


Originally Posted by analogmike (Post 6546513)
I ran the same set from Atlanta again at the Lime Rock club race and broke the track record in my first warmup session. Here's what I wrote in the Cup Car area:

I ran the new 2009 Hoosier at Lime Rock again this weekend. They had 4 heat cycles including 90 minute enduro at Atlanta on them. All my sessions on these used Hoosiers, used Michelins blues with the same amount of use, and new Michelin blues were all about the same lap times. The car was set up better for the Hoosiers, I forgot to adjust the bars and the car plowed on the Michelins due to the smaller front tires. I think the car was FASTEST on Friday when it was cool on the used Michelins but I never got a really clean lap.

I ended up racing on the new Michelins and of course they held up well.


a same price,you take Hoosier or Michelin?

Thanks

wanna911 05-26-2010 10:22 AM

I have 3 Hoosiers 2 R80 (265) and 1 R100 (320) that I'm selling for $175 each plus shipping. All of them have only a moderate amount of DE laps on them because the car they were on kept cutting one side. Two weekends of DE on them with low numbers of laps per session (5-6).

If anyone is interested I'll sell them for $175 a piece. They are too big for my car, cannot use them.

jrgordonsenior 05-26-2010 03:19 PM


Originally Posted by doc#66 (Post 7601223)
a same price,you take Hoosier or Michelin?

Thanks

But they're not the same price. The Hoosiers are about $400. less per set. Also, you can get bigger tires if you're allowed like in NASA or GTA. I run the 265 fronts and 305 rears which are almost an inch wider per wheel....

joseph mitro 05-27-2010 12:42 AM

i bought five 265/645/18 R80s from Bob Chick for less than $500 shipped, and have five more coming.

these tires are fantastic compared to the Yokohamas and Hankook slicks I used before. Set personal records by nearly 1 second in practice, qualifying, and race with heat cycled tires. and no change in setup.

Hoosier recommends tire pressures of 29-30 psi on flat tracks. in my case, the car actually handled best with front pressures of 32psi using my gauge. this is for a front-engine 2500 lb BMW

wanna911 05-27-2010 03:33 AM

Did Bob finally get some tires in? I've been after him for a while for some Hoosiers/Yokos and he didn't have much in stock.

va122 05-27-2010 02:25 PM

great tires, fall off by 8 HCs, I'll keep buying them.

ukrbmw 01-17-2011 12:23 AM

Sorry to bring this back from the dead, but curious what kind of improvement did those switching from A6s see on their lap times? Just interested to see if there is really a point in upgrading.

bobt993 01-17-2011 09:27 AM

Most of the comparisons are with R6 not the A6 which is a softer autocross tire. I know some guys run them for qualifying and on a light car for sprint races, but 911s are pretty hard on rear tires for them to last very long. I know one racer in NASA MA that runs them for qualifying and he reports they are .5secs faster than the R6 for a couple of laps. The slicks are similar if not a little faster and last much longer.

ukrbmw 01-17-2011 09:46 AM

I've read several threads on here last night, looks like nobody really runs the A6s on 911s. I'm coming from a Corvette where I could get the As to run all day.

Well, I'm going to try a comparison and see how they stack up. Trying to see if the slicks are worth the $400 or so price difference. For the record, this is for time trials, not wheel to wheel, so overall longevity is not my prime objection, although extra heat cycles you can get from the slicks are certainly nice.

Slantnose! 01-17-2011 10:41 AM

Hey , just saw this thread restarted.
I've been wondering the same thing...
...think the A6's are faster, but heard they fall off after 2-3 laps?
We're probably going to start off this season doing a TT, but should be racing too.
But, I cannot determine what the deal is with the R80's-R100's.
The Hoosier chart shows they are very firm, but are they a better choice that R6's or A6's?

ukrbmw 01-17-2011 11:21 AM

Marc,

I'm by no means an expert, furthermore have 0 experience with rear engined cars until now. With that disclaimer, here is my take on this from a Corvette and BMW standpoint (which maybe more relevant to you in a 944/951 car).

A6 is about a 1-1.5 seconds faster than R6 on a same car and day (no changes to the car in terms of setup before anybody gets on me for that). However, As are only good for about 3-4 heat cycles before the begin to drop off pretty significantly. For racing most prefer Rs due to their longevity. Some folks with deep pockets run As in the race and even in a 3100 pound Corvette can run out a whole race with good results.

I don't know how much faster slicks would be over an A6 and that is the dilemma for me. I'm only doing Time Trial so lasting 30-45 minutes is not an issue. However slicks are about $400 a set more than A6s. I've already left two messages this morning trying to get a set of slicks in 265/645/18 and 305/645/18 to compare them against A6s in 255/35/18 and 315/30/18. So, hopefully I'll get some data at the next track event. If it's anything less than a second I'd have a very hard time justifying the extra price for the slick (again for time trial, in racing the slick will outlast the A6 by a VERY wide margin). As for compounds R80 I think is the softer one and R100 is harder.

Alex

Larry Herman 01-17-2011 11:35 AM

This is pretty much based upon observation and having raced on Hoosier Rs, Pirelli & Michelin slicks, but no real back-to-back testing. The Michelins are the fastest, and I feel that they should be at least as much faster than the As as the As are over the Rs. YMMV.

claykos 01-17-2011 12:03 PM

I have run A's and The hoosier slicks before on a couple different 911s. The A's are a good bit faster than R's. The slicks, for one lap were good for about ~0.5 seconds on a short lap (~1 min lap) over the A6s.

Most of the benefit is from consistency throughout a race. I ran the tires on 2 different cars with similar chassis, but 1 with 350 rwhp, one with 250 rwhp. Both cars ~2500 lbs. On the 250 hp car the A6s were not an issue in a 40 min race. On the 350 hp car the A6s would fall off badly after a couple of hard laps. Slicks were much faster over a race distance, but as I said, not a huge amount faster on a single qualifying lap.


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