lap time differences between new and used slicks?

Apologies up front for the very generalized thread title, but I'm really just hoping for a round about answer (general approximate).

The general scenario question is what would an approximate lap time difference be for an FE running brand new slicks vs very used slicks (10+ heat cycles / 1yr old), on a track between 2-2.5 miles long with 14 or more turns?

If you have anything relevant to share, even substituting variables from the above scenario (i.e. FM instead of FE), I'd appreciate it.

This really is mostly just a curiousity question, as I am only able to do track days with my FE for now and have been using used tires while I learn the car.

Thanks,
Mike

It all depends. Period.

There is no cut and dry answer.

It really depends on how much you are able to get out of a set of new stickers, using every ounce of available grip versus managing to coax life out of a very used set.

Two years ago, I could tell you that a new set versus six heat cycles could be 1 to 3 seconds depending on track, temperature, other rubber, etc.

jim

2-3 seconds.

There are tons of guys on this site that are smarter than me but I can share my two cents after a year and seven race weekends with an FE. Unless you are a front-runner and can consistently hit marks and lap times, the delta is not significant between ten h/c and stickers. For tracks close to you, I've done 1:11's at Roebling with (I'm embarrassed to say) 12 h/c on test day, then could not do more than 1/3 sec better with stickers for Q and R. For me, it is totally about how "into the moment" I am (concentration and desire to push). Plus having a rabbit to chase does a lot for me. Same at Road Atlanta...I've done 1:31's with old and new tires. Look forward to racing with you someday.

thanks guys.. i too am definitely looking forward to racing. this was going to be the year, but then work threw a wrench in the plan and precludes my availability to do any racing before July next year. i've managed some seat time at a very technical track in NY this fall (new york safety track) but my source of good used tires was the generous southeast FE guys who would give me take-offs after 4 or 5 heat cycles. Unfortunately I can't make any events even as a spectator to refresh my used tire supply, hence running these last 2 sets all the way down to the wear bars. Threshold braking occurs at only about 1.4G and max cornering seems to be limiting to around 1.7G. I'm pretty sure I'm at the limit for these old used and abused tires, as I am having to catch the car to stop the rear from coming around in several places. Not saying my line is perfect, but it is pretty good. The tires don't even pick up any pebbles really after coming off track either.
I'm pretty sure I'll be up to speed on new tires within a couple sessions, but trying to determine what my goal should be for lap times based upon what I accomplished there this fall. Perhaps aggressive, but I think I'm going to set a goal of 1:29.xx. The track is 2.1 miles, with a half mile front straight and 18 turns. I ran a best of 1:34.3 while learning the track this fall. I'm estimating I'm giving up around 2 seconds in the brake zones at least and hoping to make the rest up in corner speed. there are several very long corners.

:beer:

Mike

IMO, if you are good on used tires, and rarely buy new tires, then the gap will be smaller. New tires require being more aggressive to fully maximize their performance. Having the ability and temperment to exploit that performance means that you will wear the tires more, sooner, and perhaps struggle as they get more "used". Drivers with the ability and temperment to go well on the older used tires, probably won't adjust their driving enough on the rare occasions that they put on stickers. The good news, however, is those sticker tires will probably have a longer life.

About a second per lap.