Street tires in IT??

[Flyinglizard]

The grip stays the same after the first run.
The shaved tires wil always be a little faster due to weight and roll out.

[Chip42]

Chip-

Buy a 2nd set and let me shave 'em. Test those too. Let's see how deep the "cost savings" actually are.

And before anyone says "no shaving"- send me a set of worn tires and a set of new ones. I'll send you back two sets that you won't be able to tell apart *visually*.

Matt, I'd love to but part of the attraction is the cost savings, which I'm pretty keen on myself. I can't afford set#2 right off the bat and while I certainly welcome the comparison, I wouldn't be shooting for THAT extra 10th myself, there's a lot more to be found in the loose nut.

[ShelbyRacer]

I'm pretty confident that you're going to be disappointed in the difference between shaved (or "worn") street tires and new ones, with the current crop of options. That's just one guy's pointing at the fence, tho.

K

I'm not saying that it will be a phenominal difference, but ANY difference is an advantage. I know you can appreciate that point.

Whether it's 0.1 sec/lap or 0.5 sec/lap, and no matter if the shaving or the "newness" is an advantage, it takes more financial commitment to run at the pointy end of the field. I'm simply saying that when we look at cost savings to the typical racer, you have to account for all the factors, even of those that he/she may not take advantage.

Other food for thought- the setup for street tires may vary from current race tire setups by quite a bit. The balance may shift to different cars whose suspension is better adapted. This will become another one of those "warts and all" moments, and *I'm* OK with that. If this is done at a regional level (since I am currently opposed to any inclusion in the national IT ruleset), they may find they're in for more than they thought on the management end of things...

My overall question though still is-
Are we thinking of doing this to posssibly save costs to current racers, or to bring in cars that don't currently comply, thereby expanding IT even further, or both?

[Flyinglizard]

IMHO the 180 tires would be a huge asset for the IT class by allowing more cars to race more often. The big cars would see a lot longer tire life. The smaller cars could run all season on the same tires.
Any time that you can reduce the cost per event, you can do more events.

Any time that lateral grip is reduced, the racing gets better.

Any time that that new tires are not a huge advantage ,the racing gets better.

The only setup changes we have done;
VW Golf , raise rear pressure to reduce rear grip.( iuse 195 rears , 205 fronts and will go to 225 fronts)

SM, hook up rear bar.( 195 or 205) 225 would work also .

[Chip42]

it doesn't make non compliant cars compliant - the tires are already legal and they won't undo other issues with legality. ITX or whatever is not IT, so this really has little bearing OTHER THAN shifting performance of "real" IT cars to balance better with the non-IT cars running the same tires in a catchall class, meaning more cars to run with assuming both groups show up. then again, the power to weight on a lot of those cars is different from IT, so the DOTR tires on a proper IT car might actually be a better balance to the street tired LeChumpers.

Either way, I can't imagine that voluntarily run or regionally organized IT on street tires will attract new cars in and of itself. BUT, at a lower cost to run, the overall package of cost and competitiveness gains some IF enough people run. I have no doubt the tires can do the job, I do doubt that we can get enough people to willingly shed the purple crack to make the competition element worthwhile.

in THAT sense, a rule change would make sense, forcing the competition into a group rather than picking up the stragglers and guys who simply can't (or cannot afford) to run up front to join the movement, but I don't support it on the national level, at least not yet. I might in the future. a case needs to be made and proven.

[StephenB]

Fyi, same driver, 2days with same track (NHMS) and weather conditions... ITR RX8 @2940lbs. Dunlop Direzza Z2 1:18.0. Brand new Hoosiers 1:15.8.

Food for thought.
Stephen

[Flyinglizard]

Can you post the other classes? Thanks,MM

[joeg]

Mike--Nice article on your son in this month's Sportcar.

Of course the last time I saw him, he was about two years old!

[Knestis]

Indeed! I saw that last night. Very cool.

K

[joeg]

Mike is actually from Upstate NY, K.

[Ron Earp]

i I do doubt that we can get enough people to willingly shed the purple crack to make the competition element worthwhile.

Nope, hard sell right now given the differences in lap times that the best data we've seen to date suggests.

What stinks is the damn tire sizes. In 15", the largest wheels allowed in IT other than ITR, most of these "street" tires max out at 205 or 225 sizes. That isn't a good fit for the heavier and typically higher horsepower cars one finds in ITS and to a much lesser degree ITA.

[Chip42]

Nope, hard sell right now given the differences in lap times that the best data we've seen to date suggests.

What stinks is the damn tire sizes. In 15", the largest wheels allowed in IT other than ITR, most of these "street" tires max out at 205 or 225 sizes. That isn't a good fit for the heavier and typically higher horsepower cars one finds in ITS and to a much lesser degree ITA.

BUT slower, lighter cars like mine and most of ITB and a good chunk of ITA COULD make use off them, and probably at less disadvantage. I have my ZIIs, and will be testing them soon.

[StephenB]

I was the only one on street tires this weekend. Ed was about 2 seconds slower per lap as was I. First 3-4 laps on the street tires will be your best, then they get loose and about .5 seconds slower on average. This was at NHMS, a slow corner track where you need rear grip to get you out of the corner (other than the oval).

[Xian]

Nope, hard sell right now given the differences in lap times that the best data we've seen to date suggests.

What stinks is the damn tire sizes. In 15", the largest wheels allowed in IT other than ITR, most of these "street" tires max out at 205 or 225 sizes. That isn't a good fit for the heavier and typically higher horsepower cars one finds in ITS and to a much lesser degree ITA.

Yup. For the larger/heavier cars to take advantage of street tires, they'd need to run 17's... and then you're talking about a different FD. Similar situation to the ITC cars current running 13's. They'd have to go to 15's and get a new FD. $$$

I was the only one on street tires this weekend. Ed was about 2 seconds slower per lap as was I. First 3-4 laps on the street tires will be your best, then they get loose and about .5 seconds slower on average. This was at NHMS, a slow corner track where you need rear grip to get you out of the corner (other than the oval).

Did you guys have a chance to play with setup at all for the street tires? I know that the setup I've run on race tires in the past is oversprung for street tires and I've seen big setup changes needed just moving from one street tire to another. Not faulting you guys in anyway for what you did, just wondering if there was any time left in the street tire setup maybe.

[Flyinglizard]

Thanks for the kind words Re MY Son. He is a lot nicer than I. Almost as fast.

[StephenB]

Did you guys have a chance to play with setup at all for the street tires? I know that the setup I've run on race tires in the past is oversprung for street tires and I've seen big setup changes needed just moving from one street tire to another. Not faulting you guys in anyway for what you did, just wondering if there was any time left in the street tire setup maybe.

You are 100% correct that more time can be gained! We did not change set ups since we were running back to back with only a few sessions in between. I don't think it's worth seconds but certainly some...

Stephen

[RSTPerformance]

You are 100% correct that more time can be gained! We did not change set ups since we were running back to back with only a few sessions in between. I don't think it's worth seconds but certainly some...

Stephen

Stephen didn't mention but it I worth mentioning... The car set up worked great with either tire, no need for changes. Obviously huge dollar changes/testing with a lot more time between runs could allow for some fine timing of spring rates and shocks but to be honest that also goes for the race tire... My feeling is the same time gained for the street tire is equal to what could be gained with the race tire.

Another thing is the tires had a big spin in nascar turn 1/2 at ~95mph and did not flatspot... Just another reason it's a good tire for new drivers... Hoosiers would have been toast for sure!

Raymond "still feel the Dunlop is a great tire for newbies saving money to develop car and skill" Blethen

[pfcs]

Stephen didn't mention but it I worth mentioning... The car set up worked great with either tire, no need for changes.

With such a difference in adhesion (lap times), the setups can't possibly both be ideal. At least cambers must be quite different and optimums would yield substantive changes.

[Xian]

Stephen didn't mention but it I worth mentioning... The car set up worked great with either tire, no need for changes. Obviously huge dollar changes/testing with a lot more time between runs could allow for some fine timing of spring rates and shocks but to be honest that also goes for the race tire... My feeling is the same time gained for the street tire is equal to what could be gained with the race tire.

Another thing is the tires had a big spin in nascar turn 1/2 at ~95mph and did not flatspot... Just another reason it's a good tire for new drivers... Hoosiers would have been toast for sure!

Raymond "still feel the Dunlop is a great tire for newbies saving money to develop car and skill" Blethen

Valid point that the setup may have been "good enough" for both tires but ideal for neither.

Just as another data point, I picked up a new autoX car (EF Civic) that's setup for street tires (in particular the 140TW Toyo R1R). The fast setup for this tire? How about ~5* of camber in the front and tire pressures in the 24# hot range. Bizarro.

[mossaidis]

Yeah with that much chamber, you need low pressures to increase your contact patch...