Durable tires for practice

[wulfgang]

I'm looking to get into F500/600, and I have a few questions about tires. At first, I plan to only take the car out to the track for practice, i.e. I will not enter races for a while. Thus, I need a tire that is durable and relatively forgiving while sacrificing ultimate grip. Does such a tire exist for F500? Or can I get a set of wheels that fits a passenger tire size?

My other question is about durability of Hoosiers for track days (no racing). They seem to cost $600+ per set, and people seem to get "several" heat cycles out of them in race conditions. So if I take a set of broken-in Hoosiers to a HPDE and do say 5 20-minute sessions on Saturday and 5 more sessions on Sunday, are those tires going to make it to the end of Sunday? How long do they last while providing stable (if not ultimate) grip?

[Scootin159]

Your only choices are Hoosiers, in R25B compound (what nearly everyone runs), or R35 compound which is a little harder. Beware though - less grippy tires don't just make you slower, they really screw with the balance and are less "drivable".

That said - heat cycled tires that are reasonably fresh (i.e. not 10 years old) are still very drivable right to the cords, you just won't be able to do any useful tuning with them as the balance will be off.

You should easily be able to get an HPDE's worth of driving out of a set before cording, if not a full season.

[wulfgang]

The reason I asked is that I've only been on slicks on karts, and they are no fun when they get old. If I burn through a set of tires on every HPDE weekend, then I'd probably stay home a lot!

[jim murphy]

We also hang out at www.formula500.org/forum.php

Learn everything you can from both these forums, volunteer to help a local F5/F6 driver, rent a F600 from us - www.formula600racing.com - BEFORE you spend any money - be an educated buyer.

Jim
Been messing with these cars since 1982

[lancer360]

The only legal tire is the Hoosier right now, but if you are only running HPDE you could slap just about any wheel/tire on there that would fit. Many of the F500's use a 4 on 4" bolt pattern. Clearance to the side pod would be the biggest issue as you can't go much over 19.5" tire OD and still be able to turn. That being said, most other tires, especially production car tires are going to be designed for much heavy cars. The tire is an integral part of your cars suspension and this much stronger tires could make the suspension extremely stiff. This could really screw up the handling of the car and make it extremely twitchy and likely to loose control.

Personally, I try not to run my Hoosiers over about 12 heat cycles as I feel that beyond that point the degradation exceeds my car control skills. After 12 heat cycles I feel I am more likely to cause more than $650 (cost of a set of tires) worth of damage by loosing control and hitting something.

[lancer360]

Where are you located?

[wulfgang]

I am in New Mexico. There is a local club where I can run with 2-3 other open-wheel cars, but so far as I know, there are no F5/6 cars in the state. The closest place where F5 runs regularly is in the Colorado SCCA, so HPR, Pueblo, and Pikes Peak (about 6 hours away). There may also be some guys over near Phoenix, but that's a bit further.

Our local track, Napa Speedway, is small and tight. 125cc shifter karts top out on the main straight, but not for very long. It's really just the right size for 600cc motorbikes. I've never driven F500, but I figure it's also a really good track for that size chassis.

I would LOVE to rent a car first, but that's not possible unless I travel a long way.

I am aware of and have browsed through the other 3 forums. I did not see the tire longevity discussed quantitatively anywhere, so I apologize if this is a rehash.

[lancer360]

HPDE is ok every once in a while if you need to do some test and tune, but if you have some prior kart experience I would not hesitate to jump into wheel to wheel racing. I went straight from autocrossing an Elise to road racing with no problems. Another option would be to do time trials if the regions in your area run them. Time trials are basically timed HPDE events, restricted passing zones and such but you are competing.

If you plan far ahead you could get a pretty cheap plane ticket to Atlanta and I'm sure Clint (rent's a F600) would pick you up at the airport and go racing. I would think the F600 would be the better choice for you in the Arizona heat than the snowmobile F500. I'm a bit biased though since I do race one. That being said there is a big "if". If you don't mind being the only one in your class and being the 1st one to jump in and try to attract other drivers to the class. If you really want the competition as soon as you start, then look at the results from the races you would attend this season and see what classes are popular.

If you only want to do HPDE I would probably look at a different car. Some type of sports racer would be accepted at a much wider selection of events since it has "fenders". Many track day companies do not allow formula cars because of the danger of mixing them with fendered cars.

[jlwhorf]

I have and old red devil that I use as a track day car, and use the hoosier R25B's. I got 2 seasons which turned out to be about 11 or 12 track days and still do not have much noticable wear. When they get old, they need about 5 or 6 laps on the first session of the day to get them scuffed in. They where defintely past there best after about 6 days. Old tires also can benefit from the application of tire softener.

[wulfgang]

Thanks for the responses. I'm having a hard time committing to buying a car mostly due to the tire cost. Considering that I can get about a dozen track days + 10k miles of street driving on one set of tires for my Cayman, the F500 is looking very pricey. I was looking for a cheap, fun way to get to the track in something a little bigger than a kart... maybe F500 is not the place. For the same initial investment, I can make the Cayman engine bulletproof and then spend less on tires every weekend.

F500 may be the cheapest way to go racing (I'm skeptical though, SpecMiata may be cheaper), but as I mentioned before, I'd probably only do maybe one true race weekend per year due to logistics and cost. For just getting out to the track, I think I am finding that running what you already have is the cheapest.

[Chris Elwell]

You could always get a Formula Vee and then replace the Hoosiers with a set of wheels and tires that the F1200 guys use in Canada. It's a 14" wheel with Falken street tires. One set lasts 2 seasons from what I've heard. A decent Regional Formula Vee can cost under $6000.

[wulfgang]

You could always get a Formula Vee and then replace the Hoosiers with a set of wheels and tires that the F1200 guys use in Canada. It's a 14" wheel with Falken street tires. One set lasts 2 seasons from what I've heard. A decent Regional Formula Vee can cost under $6000.

Wow, 2 seasons is a long time. Unfortunately, the FV cars just don't speak to me on any level, especially that front suspension.

[wulfgang]

How bad would it be to put a larger diameter tire on the F500? In the 4x100 bolt pattern, there are plenty of larger diameter wheels that take tires as small as 21" in diameter. I think I saw somewhere that some F500 people are running a 19" tire, so with no chassis changes, this would increase the ride height 1". Obviously that handling would change a lot, but wouldn't this make a sweet track day car with tires that last forever?

Doesn't Skip Barber do something like this for their school cars to give a more forgiving and durable tire for people to learn on?

[Scootin159]

The biggest catch with getting 21" tires to fit is bodywork clearance. On my KBS I can fit a standard space saver spare on all four corners though. While not as wide as a slick would be, they're probably pretty close to 21".

[Jnovak]

F500 tires are the lowest cost race tires there are PERIOD. Stay with your Porsche.

Jay

[Ananth K]

You have the right idea about fitting a DOT type tire on a formula car. If you simply want to pound out laps it is the right way to go. Unfortunately, on a F500, not only are there clearance issues, but the solid rear axle may not lend itself well to a low grip tire. I think F500s are very sensitive to tire grip and like someone else said, the balance is completely different when you have old tires on. You could buy an old Formula Ford and run it on DOT tires pretty easily though.....but I think the max you will get out of any DOT tire is about 1.2g regardless of whether you put it on a sedan or a formula car.

[jim murphy]

AND the F5/6's are totally set up for bias ply tires as radial tires require LOTS of negative camber to work well and the straight axle has ZERO camber.

Jim