School me on Race Tires

[mymomswagon]

In the future, I may be subject to SCCA rules and will have to decide between de-tuning my suspension to be STH compliant or say yolo and go into classes that allow R comp or below 200tw. I've noticed some of the more affordable options like Toyo, Nankang ns2r, Federal FZ 201, others?

So what about race tires vs the best 200tw?

How much grip improvement?
How many runs compared to say Re71r?
Any other considerations?

thanks and stay safe

[aw614]

Most of the affordable options, I wonder if they get enough heat for autocross vs say a track like the FIRM or Sebring. Hoosier A7 would, but not sure about the others.

The one thing I recall with running r comps, is when they let go, they let go. Some 200tw tires do this too, but rcomps don't give you that feedback.

Not sure about runs, the older 200tw stuff, dunlop starspec and hankook rs3 had noticeably longer life, but with the 200tw wars, I wonder if the life is about the same (cough cough advans). I think you may still get a higher wear on your wagon though.

[mymomswagon]

thanks

We're getting 100 to 120 runs on re71r.

Found a post referencing 66 runs on a Mustang plus some track time for Hoosier A7.

Some of the cheaper options are comparable to 205 re71r in price, but fewer runs bump the cost.

also saw a thread suggesting a .975 pax adjustment for 200tw vs race, which would translate to about 1 second on a 40 second course.

[Native]

200tw vs race, which would translate to about 1 second on a 40 second course

Yeah, race tires are faster.

[Jamie]

It depends on how competitive you're trying to be. Frankly, the current crop of 200tw tires is pretty good. And the variety in R-compound tires has diminished...BFG is out of the game, Kumho and Hankook only make them in one or two sizes, so you're left with Hoosier (at $200/tire) and Toyo. Frankly, the Toyo 888s aren't that much better (if at all) than an RE71R. Don't know about the RR...that looks like a more serious tire, but I've never driven on it, and don't know anyone who has. Federal, Nanking, etc are all behind that.

Even then, is the car prepped to take advantage of them? Were it me, I'd run the car in whatever class it falls (FSP?) for several events, subtract a second or so from your time, and see how that stacks up against the competition and on the index...then decide where you want to spend your money.

[Loren]

Along the lines of what Jamie is saying... you may find that you're competitive just by fitting WIDER "street" tires and driving mo' betta than your competition. The DOT race rubber isn't all that much faster. And all out slicks, while potentially quicker, as was mentioned above... they take some heat to work well.

You might check with Carl and see what he can tell you about race car take-offs. If you can get those in a size that will fit your car, they're relatively cheap and could be a good way to go.

[mymomswagon]

Even then, is the car prepped to take advantage of them? Were it me, I'd run the car in whatever class it falls (FSP?) for several events, subtract a second or so from your time, and see how that stacks up against the competition and on the index...then decide where you want to spend your money.

I think car would be street modified, so definitely not prepped at the moment to fully take advantage. Much more could be done power-wise, tire width and more suspension improvement.

Here, I'm trying to get a sense of the tire side (cost, improvement) and your comments are great, thank you. Showing up, running and deciding later makes a lot of sense.

Along the lines of what Jamie is saying... you may find that you're competitive just by fitting WIDER "street" tires and driving mo' betta.

It will be fun trying

[Jamie]

I think car would be street modified....

SCCA recently created a set of rules that's essentially SM on street tires: https://www.scca.com/articles/2013398-n ... ompetition. Makes it even easier to keep tires as is, and see where you want to go from there.

[mymomswagon]

I think car would be street modified....

SCCA recently created a set of rules that's essentially SM on street tires: https://www.scca.com/articles/2013398-n ... ompetition. Makes it even easier to keep tires as is, and see where you want to go from there.

thanks, I'll check it out

[blacksheep-1]

IMHO the SCCA could really help out competitors in the race tire class by allowing traction enhancing chemicals. The reason is , in any tire, but particularly race tires, the first 3 laps you run on them will be the fastest those tires will ever go, after that they will fall off, this is why you see cars parked on pit road the last half of most qualifying sessions, they don't want to abuse the tires that they must start the race on. Most teams are boosting tire pressures so that they won't waste laps on "warming up" the tire, you basically run a warmup lap and are on the button at the end of the first lap, for 2 laps then bring it in, if you've done it right, you've made a clean lap, and you're done. If you are the type of driver that has to "work in" to a quick lap then you've already wasted the best part of that tire, you can see guys struggling to run a good lap and the tires are just degrading right in front of you. this will also throw of tire pressures since you boost pressures to run for 3 laps, after about 4 the pressure is out of the viable range, so between tire degradation, and too much pressure you're really climbing up a steep hill if you can't run a lap right off.
So...how does this apply to us? well some of the same dynamics apply, we basically abuse the tires right off, which means the tire will not last as long as one that is "broken in", with a break in tire, you are basically exchanging performance for longevity, so the tire will perform well over a period of time, but will never be as fast as one that has the 3 lap magic done to it. the 3 lap tire will drop of, sometimes precipitously far quicker than a tire that is broken in. The Hoosier/ Conti tires are very consistent over time, the Pirellis, are faster than the purple tires, but drop off of a cliff after a particular amount of laps (depending on track and temp) the Michelins seem to be somewhere in the middle, although they had a multitude of issues in the GS class at Daytona this year, but banking is a whole other can of worms to deal with.
So the same general rules apply to autocrossers, tires that are broken in will last longer, you will need to run close to the optimum pressure to start with, since they won't pick up 8 psi like at most road courses. lastly, if you run a "street" tire, to be competitive, you will need to cut the tread to get rid of squirm, and this is why I like traction enhancers, once you run a tire, it still has ample tread on it, but usually not "useable tread" from a performance standpoint, so you throw the tire away, using chemicals will allow the tire to be used longer, because you can make the tire stickier, longer. thereby saving the competitor money over the long haul, whether you are using a slick or treaded tire, you can make them live a bit longer. The team I worked for at Daytona this year used the maximum 8 sets of permitted tires at $3300 per set, that was..$26.400 for the weekend, those tires were still useable, but not competitive since they have used up the "filet" of the tire. That is an FIA race, so tires are very regulated to the point of having an IR signature in the tire itself that is interrogated every time the tire goes on or off the track and at the ends of pit lane. Still, as those tires trickle down they could be made competitive at a local level by using chemicals.
So.. boost the pressure to within about 1 psi of your optimum tire pressure to begin with, you really can't "break in" autocross tires, but on the other hand you're not abusing them as much as the road course guys either, so pounding on them from the start shouldn't really kill them as fast, cutting tread off is just something that I hate, but in fact does help treaded tires (I wonder if you did a cut, treaded tire vs slick, over time, in an identical car, which you'd have to replace first) There is a series out there running the BFG tire as a "spec" tire and they are getting great mileage out of them, in fact, running them for an entire 24 hour race is some cases, BUT..again you are forced to run that tire so everyone has to deal with the same dynamics. A "spec" tire for a local autocross club, isn't going to work, so they use the treadwear code, which works OK, but if you want to use new tires every weekend, you will always be faster, there's no way around it, but it seems a bit over the top for a bunch of guys just having fun with cars. What you might do, id have a dedicated set of autocross tires like a lot of guys do, and run a harder tire for everyday use, that would seem to be a reasonable alternative.

[blacksheep-1]

I meant to reference the A7 vs R7 above, we use almost nothing but Hoosier A7s on all of Phoenix performance race cars, the only time we use R7s is for practice so they last awhile for a couple of race weekends, but A7s are by far the weapons of choice, even at Daytona or Homestead, which is brutal on tires. Part of that is doing a thorough prep on the tires, including vacuuming the tires, running nitrogen and a bunch of other stuff to make sure they live for the entire race. I don't even know why they call these DOT tires, they throw some dents in it and call it "tread" , we do..rarely, but once in awhile actually scuff some of these tires in, but it's rare.
here's the tech sheet for those tires.
https://www.tirerack.com/images/pdf/warranty/HO0914.pdf

[Jamie]

IMHO the SCCA could really help out competitors in the race tire class by allowing traction enhancing chemicals.

They don't allow traction enhancing chems, but there are rule-legal chems to preserve or restore used rubber. I don't remember the name of the chemical that was widely used in Stock and SP back in the day -- it was pink, and you wouldn't want to bathe anything but tires in it -- but it advertised that it negated some of molecular changes due to heat cycling...you'd get some grip back over the life of the tire, but never more (and probably not equal to) when it was new. When I ran R-compounds, I usually treated my tires every half-dozen events or so -- applied it with a paint roller -- and seemed to help towards the end of the season, when they were heat-cycling out.

...if you want to use new tires every weekend, you will always be faster, there's no way around it, but it seems a bit over the top for a bunch of guys just having fun with cars.

There were -- are -- guys who do that for national events! Oddly enough, some of the current crop of street tires do need some breaking in unless shaved or well heat-cycled. BFG Rivals, in particular are known to need a few events -- 15 -20 runs? -- to hit their peak. Bridgestones seem to come in faster. I don't know if that's due to the tire construction, the tire chemistry, or the factory simply slathers so much mold release on that it takes some time to wear off. There's rampant speculation, little data, and it doesn't get mentioned in tire tests, perhaps because they usually start with heat-cycled tires to begin with.

[mymomswagon]

I do appreciate the insights here. Yeah, I fall into the "have fun on weekends" category, so the care and feeding of race tires is probably too much for me, for the $.

I'm slowly thinking through what I might want to change for STH to stay on street tires. Jamie's Extreme Street rec sounds like more fun though

[blacksheep-1]

...if you want to use new tires every weekend, you will always be faster, there's no way around it, but it seems a bit over the top for a bunch of guys just having fun with cars.

There were -- are -- guys who do that for national events! Oddly enough, some of the current crop of street tires do need some breaking in unless shaved or well heat-cycled. BFG Rivals, in particular are known to need a few events -- 15 -20 runs? -- to hit their peak. Bridgestones seem to come in faster. I don't know if that's due to the tire construction, the tire chemistry, or the factory simply slathers so much mold release on that it takes some time to wear off. There's rampant speculation, little data, and it doesn't get mentioned in tire tests, perhaps because they usually start with heat-cycled tires to begin with.

I'd really like to do some data with autocross tires, I think it would be beneficial for those who are in the extreme mod eon this. I've been accumulating tire data for 10 year son the road race stuff, I can hit my marks pretty well these days.

[twistedwankel]

In the future, I may be subject to SCCA rules and will have to decide between de-tuning my suspension to be STH compliant or say yolo and go into classes that allow R comp or below 200tw. I've noticed some of the more affordable options like Toyo, Nankang ns2r, Federal FZ 201, others?

So what about race tires vs the best 200tw?

How much grip improvement?
How many runs compared to say Re71r?
Any other considerations?

SCCA rules for your Wagon? I doubt you will ever be competitive in that car in any class! However they do have a Novice class for the first few races when you show up. "N".

I looked back at the many tires I tried out running with SCCA and FAST both over the last 14 years on several cars. I always had a really good driver take the car out a couple times to see how good it really was. Usually 3-4 seconds no matter the tires. Remember a borrowed car is always a lot faster. You don't have to fix it.

I had really well set up cars to stock standards. So the only real difference was tires or a wider wheel/tire. I always put the widest tire I could properly fit on any wheel. Always cornered better/neutral. Due to a vette having bastard wheels I couldn't rotate stock wheels. In that case at 50% wear had Carl flip tires on wheels and put on the other side. Got 128 mostly concrete airport runs which was the most over on RE71's. Over two years. They were still good and on the wear bars not heat cycled out but I sold the car and threw the tires out.

Got 10.5"x 18" wheels from Carl for square setup. Put some 295/35 Toyo Proxies 100q so I could drive safely to events. Could have run used R 305/660's @ 40q if car trailered.
Car was impressive times at Corvette T&T against Hoosier clad Z06 Vettes. So good was asked how they were on the hwy as they were getting tired of changing tires at event twice. They were very good on the hwy other than standing water like all wide tires. Got 87 runs is all. They heat cycled out at wear bars airport runs.

Put Federal R595/30's on which were a real bitch to mount on cool day 140q. They are fast the first 3 runs but would taper off when hot. Only did 20 runs and sold car. They were a great road tire and wore well. Cost me $450/set of 4 which is why I bought them. Came with 6.6mm tread needed no heat cycling. Usually $1000 for a set of C5 200 tires.

Unless you are thinking of getting a dedicated race car? Like I have always had for weekends mostly. You are not going to be competitive. Have fun and run SM in SCCA if required as the car sits. Maybe Soraya will sell you her SCCA legal Fit some day. That's racing on a penny that lady!!

Sad that a bug temporarily brought racing to it's knees this year.
I feel for you guys.
Doug

[mymomswagon]

In the future, I may be subject to SCCA rules and will have to decide between de-tuning my suspension to be STH compliant or say yolo and go into classes that allow R comp or below 200tw. I've noticed some of the more affordable options like Toyo, Nankang ns2r, Federal FZ 201, others?

So what about race tires vs the best 200tw?

How much grip improvement?
How many runs compared to say Re71r?
Any other considerations?

SCCA rules for your Wagon? I doubt you will ever be competitive in that car in any class! However they do have a Novice class for the first few races when you show up. "N".

Thanks Doug, and no argument on your point. The wagon is already out-muscled in G street. Any change I make can be mimicked by at least one G street car.

Given that, I like playing with car set-up and I'll want to chose a path and class. Tire question here was to get some sense of that angle.

[aw614]

with Falken coming out with a 245/40/15 and you having those 15x8s, I'd give STH a shot since it doesn't seem like you should have to make that many changes to the wagon. I think STH is mostly wide open, most people don't seem to stick long enough to run their turbo hot hatch for a long time due to various circimstances...

[mymomswagon]

with Falken coming out with a 245/40/15 and you having those 15x8s, I'd give STH a shot since it doesn't seem like you should have to make that many changes to the wagon. I think STH is mostly wide open, most people don't seem to stick long enough to run their turbo hot hatch for a long time due to various circimstances...

yeah that may be the way. on my current setup:
1. i'd have to ditch either the camber plates or the tts arms as they don't allow both.
2. they don't like my jb4 but are ok with a flash. dunno why but wouldn't be a big deal and would likely add power, but $$
3. I don't think I can run bump springs (my favorite mod), so I'd have to improvise something with springs and or bar
4. they will allow an intercooler change with some restrictions (fast m4 does not, with #2).
standing pat puts me in some class like extreme street, or street modified.

[Loren]

You might start by testing the waters. Maybe the local competition is such that you can be competitive with what you have in a class that it fits?

You know it's all a driver's game.

[mymomswagon]

You know it's all a driver's game.

reminds me of the last time you drove it!