There has been some discussion of a spec tire in FC and while I am neutral on the subject at the moment, I did post the question to the FF guys as they have been on a spec tire for a year now. I wanted there feedback on the cost, durability and racing that exsists with the Spec tire.
While I have mentioned this on the 2017 Runoffs post, I thought I should move it to its own discussion. This is just one aspect we need to discuss to get the class healthy.
These are some of the comments from the FF guys that I thought would bring up some good discussion points on the FC side.
I will say that I think the Hoosier spec tire for FF has been a good thing. But for some cars, it has been a easy change over yet for others I has required a lot of work to get the tires to perform. For FF the big issues are the much larger diameter of the front tire and how that effects the design geometry of the front end. Next is changing from bias ply to radial tires. That has required new or modified control arms to get the new camber settings necessary for the radial tire. And finally because the spring qualities of the tires are so different, bias vs. radial, the shock settings/valving have required a lot of work to get just right.
The FC adaption to the spec Hoosier that is used in the FRP F2000 series was not without significant pain and it took some time to get the setups that we are using now.
Now when all these changes are accommodated, the performance on the spec radials is very good and tire life is vastly better.
I can not tell you how much of the effort was necessitated by the change to radial tires alone and how much was necessary because the radials came with a much harder compound. Bottom line may be how much the average club race will be able to do the development work to get his car satisfactory vs. just park the car and not race it. It darn sure is not as simple as just bolting on new tires and running.
I will say that for me and the Citations, FF the spec tire is still a work in progress. I am no where close to the setups we have for FC. Remember that before the radial tires almost any FF was competitive now you see complete dominance by one or two makes of cars.
I have run two different series with two different spec tires. I will give you the good and bad of each below but I think that the general conclusion is, get a tire that can work on a number of different cars. As Steve mentioned above, the radial works well for some FF and not for others. Bias Ply seems to work on all cars but.... it is not where SCCA went.
So here is my experience:
Spec Tire #1 - American Racer
Bias Ply tire that is relatively hard. Was designed for FF and so the sidewall is both a bias ply and designed around the weight of the car. Cost for these tires is truely remarkeable. I think the cost per set was something around $525 (without shipping, taxes, mounting, balancing). They are reasonably durable. 12 heat cycles was about what you could expect and then they fell off (depending on the track, more abrassive = less cycles). I would run two to three race weekends (that was two qualifying sessions and two races for 4 cylces per race weekend) on a set and then turn them into test tires for the friday test day with a new set for qualifying and racing. This cycle worked very well.
Spec Tire #2 - Hoosier
Radial tire that seems softer than the AR but the lap time does not show it (they are slightly faster but not much). I personally think the Hoosier tire for FF is the same design, construction, and compound as the SRF tire (I have no data to prove this but they are remarkably similar). If I am correct in this, then not only is the sidewall stiffer from being a radial, it is also designed for a car about 500lbs heavier. In my opinion, this is a bad spring that is harder to control than the AR. Cost is $760 per set (without shipping, taxes, mounting, balancing). You get about the same 12 heat cycles out of them. They are heavier prompting SCCA to raise the minimum weight to 1110 (I would really like to go back to 1100... something about F=MA blah blah blah).
So for an additional $200 I get a marginally faster tire, with a sidewall that does not mesh well with my car (Swift DB-1 due to the limited camber I can run), is stiffer than needed for the car, I get to run Hoosier's name on my car 22 times (4 per tire and 6 more stickers), and because of the "great price" they gave us, there is no contingency program (AR did not have a contingency program either but their price actually was a "great price").
This is why I say, pick a tire that actually works on the majority of cars out there. When SRF makes a tire change, it is relatively easy because they only need to make sure that it works on one chassis. Also keep in mind that Economics will play out. What I mean is that with open tires, manufacturers are more willing to offer contingencies for you to run their stuff thus reducing the cost. Without the competition, you might get a cheaper tire but there is no reason to offer contingencies. It may prove out that the all-in cost is no different between the two when this is considered. The move to a spec tire is a complex endeavor with winners and losers (i.e. those with cars that either will not work with the new tire or require expensive modifications to make work with it). You will not find a perfect solution. You will find some that are better and some that are worse.
Brian. You have probably figured out already that those that would benefit most from a spec tire are the ones that will oppose it most fiercely, and the ones most likely to quit the class. They would have to throw away their magic set-up, that sees them running 5-10 seconds per lap off the potential pace of their cars, and develop a new setup. Even if that were true, it would be a good thing, but either way, it's a hard sell.
Clearly, the ideal spec tire, in the year 2017, is a big dumb radial tire, as produced by many tires companies (Hoosier, Cooper, Pirelli, etc) and used as spec tires in many classes. While the very serious will make some significant changes to help their car perform better, most will add some camber, and go. As we saw with FF, some people with old cars, like John Benson and Derek Ketchie, just embraced the radial tire and went better than ever. Others, with the same cars, had nothing but trouble as they tried to reinvent their programs for those "nasty" new tires. IMO, attitude was more important than the technical aspects.
The really really really fast guys in FF can wear out a set of the FF spec tires in a weekend at some of the more abrasive tracks. That is rare. Most of us regular guys can run as many as 20-30 sessions without any wear issues. You do notice a difference putting on new tires after 20 session tires but it is 10ths, not seconds. Pictured is the tire I used on my Reynard FF that has the tire stampings from numerous FRP events. It was still as competitive as one would expect of an old man in an old car. I probably picked up half a second of pace when I put on new tires. I believe that my personal program was benefiting more from increased laps, rather than better tires.