Rules Changes for 2017-18 Season

[Loren]

Trying to stay ahead of things here. We've discussed some potential rule changes for next season here on the forum. And Steve and I have further discussed and come up with some minor changes we want to put in place. These changes will take effect at the start of the 2017-18 season in September.

You can read the full text of the proposed rules here:
http://drivefast.org/2018-stock/
http://drivefast.org/rules/2018-mod/

The major points are:
Stock Category tire width limitation - up to 20mm wider than stock (widest of front or rear may be used as basis for all four tires) (S5 can run 195)
Move AS up to S0
Move CS up to S1
Clarification to Mod Category lightening rule regarding "change in appearance"
M4 tire width limitation - changed from 225 to 205
Move AS up to M0
Move CS up to M1

That's pretty much it. Oh, we're still looking at possible changes to the points system, but that's another topic.

[Rpwolf]

curious as to the reason to limit stock class tire size to not exceed +20 mm from stock.

Just glad I saw this before buying my tires because I'd be thrown into mod class if I wanted to do 245 square (stock for me is 215/245 wide tires)

[Loren]

We're trying to be proactive and head off a problem before it becomes a problem. Under our current rules, for instance... (sorry, Miatas are always the example because we're so familiar with them) An NA Miata in S4 that comes from the factory with 195 width tires could fit 15x8 wheels and run 225's. The only significant problem with that is that it REALLY separates FAST "stock" from SCCA "street". People who are prepared to SCCA rules are running stock or nearly stock wheels... in our example, that would be 15x6. They're not likely to be running a 225 tire.

That's the kind of thing we're trying to address.

Didn't really think about huge front/rear tire size differences and squaring a setup. Perhaps we could change that to specify that whatever the widest size is, plus 20mm, can be used front or rear? That would still give an advantage over anyone who is SCCA prepped and has to run the narrower wheels in the front. But, it might be less of an advantage than being completely unlimited as we are now.

Stuff like this is why we put it out for comment.

[Carracer]

Personally I would leave the stock tire options open, I don't think FAST is going to have that problem. Sure, someone could show up with "all the tire" but could that really hurt a class all that much? You could already run an lightly built SCCA STR/STS car in stock class if you didn't put coilovers on it, and if done correctly that would SMOKE any of the typical S4 cars. Even with only running 205s on a 15X8 in the case of a Miata. A 205 RE71R is hard to beat even with more rubber. Also, M4 is a smallish class so I don't see the point in limiting it more.

Full disclaimer: I have a set of 15X8s and run S4 but I don't use them anymore.

[CaptainSquirts]

The new rules don't apply/affect me that much( I know, bad train of thought) so I don't see any issues.

Do you have an idea on how this would affect the number of vehicles running in s2 to s1 to s0? Example... 15 cars currently running in s2 and now 5 of them go to s1 while 1 car in s1 goes to s0. Thus s1 getting a higher number of people running in it while s2 loses a nice chunk.

[jmdoc66]

SCCA rules specify wheel size, not tire size limitation. I'm curious why FAST goes with tire size limitations for the stock class? I would guess its easier to measure. Just Curious.

[Loren]

Do you have an idea on how this would affect the number of vehicles running in s2 to s1 to s0? Example... 15 cars currently running in s2 and now 5 of them go to s1 while 1 car in s1 goes to s0. Thus s1 getting a higher number of people running in it while s2 loses a nice chunk.

Hard to have specific numbers because S0 and S1 are so small and variable. But, yes, it should take some cars from the typically large S2 and move them up to S1, and maybe a few other cars from S1 up to S0.

As a guideline, anytime we're trying to decide how to group classes to make FAST classes, we're looking at the PAX index and trying to keep that parity as much as we can.

S0 – SS/AS - 0.835/0.833 PAX
S1 – BS/CS - 0.826/0.819 PAX
S2 – DS - 0. 811 PAX
S3 - FS/GS - 0.814/0.806 PAX
S4 - ES/HS - 0.807/0.798 PAX

Before anyone asks why GS isn't in S4, it's got to do with class sizes AND what we normally see from each class. S4 is mostly Miatas and other lightweight sports cars or economy cars. GS is generally heavier "powerful, but not quite muscle cars". GS is not a good fit for S4. It's a better fit for S3 with heavier cars.

And it would be great for HS to be its own class, but we don't get enough HS cars to make a class. That's why S5 is what it is... a mix of S4 cars with smaller tires. That experiment seems to be paying off, S5 is a fun class, whereas a "Just HS" class would be much smaller.

[Loren]

SCCA rules specify wheel size, not tire size limitation. I'm curious why FAST goes with tire size limitations for the stock class? I would guess its easier to measure. Just Curious.

SCCA doesn't care about your budget.

Wheels are expensive. I want you to be able to run whatever wheels you might have that fit your car. Don't care if they meet "spec" or not.

Tires are expendable. We go through a set about every season. I think we DO need a limit to keep things from getting out of hand, and to keep some sort of parity for those people who want an SCCA legal car. A tire width limit seems to make more sense for us.

Philip, you're exactly one of the examples I used to justify this! You wanted to be competitive in FAST S4, so you bought 15x8's and ran wider tires. But, that setup isn't allowed in SCCA ES, so you had to run a stock wheel setup there and different tires. EXACTLY what we're trying to get away from. No, it's not a huge deal, it's not a huge problem, it doesn't happen often. But, a 20mm over stock tire width limit shouldn't affect a lot of people either. It will just keep the ultra-competitive "buy me a win" types from getting too crazy. (because we don't have a rule against fender-rolling, either... and SCCA does)

[jmdoc66]

Thank you for the explanation. Makes sense.

[JasonS]

S2 seems like it is usually a smaller class. Would moving cs up make it too small?

Don't get me wrong, I'd be all for Mr Lawson in that FR-S moving up a class....

[Loren]

Part of the motivation there is that SCCA is moving (has moved) the BRZ/FRS to DS. The NC Miata, RX-8 and 350Z are still in CS. We sometimes have a big S2 class as it is (combined CS/DS). (BRZ/FRS/WRX and Miatas are all VERY popular cars, and when they come en masse, it's huge) Splitting the two biggest models apart would make S2 less big, and add some of the bigness to S1. SCCA moving the BRZ/FRS to DS conveniently gave us a splitting point. Before that, when they were all in CS, we had no justification for a split.

DS should be sufficient to stand on its own with all the BRZ/FRS/WRX plus other cars that are eligible for that class.

At our last Open event:
S0 - 3
S1 - 8 (I think one of the Corvettes would go up to S0)
S2 - 11 (7 of them were BRZ/FRS/WRX, some of the rest would bump up)
S3 - 8
S4 - 11
S5 - 6

That's just one event, but it is representative. So, we're "fat in the middle". Just trying to spread things out some. Make S0 and S1 a little bigger. We've done what we can to expand S5 without breaking it. Not much we can do with S4 short of splitting it into two classes, which we're not eager to do anytime soon.

[twistedwankel]

Interestingly the proposed 20mm tire rule would exactly be what I ran on my 18x8" rims. Stock=225 but I ran 245mm max size for years (to react slower). No problem. Plenty of tires available. Even if I use 17x9" rims (to save $$) instead of 18's the recommended best width is 245mm. Sadly only 255/40/17 is available from all manufacturers. IMO a wider tire on a fat rim doesn't steer nearly as well (slower) as a 245 does with a stock suspension. But that's just me. I go with whatever is best bang for the buck and enhances my slowing reaction time.

I'm pretty sure most of the current drivers in S1 and S2 (not me or Gerry) are running stock rims (since I see most of them at SCCA events) a lot having to do with staggered wheels from the factory OR with AWD they just don't need a wider rim/tire with all that traction and computer controls.

It really doesn't matter what is decided since I'll simply run Class where ever my then current tires/wheels put me when the season starts I think my days of running up a class or two are over now

[ImpostorDan]

I'm definitely affected; not sure that bumping to M1 does me any favors; I figure at least Joe can go terrorize some others now & I won't have to deal with him in M2 exclusively.

Would this potentially leave M2 to the MSM's in some regard? Assuming they wouldn't bump under the CS -> M1 as they're a class bump from elsewhere already.

[twistedwankel]

No one is actively running a Porsche Boxster S in CS in FAST now but it's pretty fast at SCCA and PCA events with small front rims/tires. It was demoted this year from BS. Next year look for the BMW Z4 w/o LSD to be moved also to CS from BS. Only one guy racing that car now too locally.

This actually endorses Loren's suggestion since these two cars are very competitive in BS so no reason FAST shouldn't move them back to S1?

[Loren]

Theoretically, there's no reason that the MSM shouldn't dominate any class that it's in under FAST Mod rules. (once it's bumped up to a class beyond boost limits) Unlimited tire, unlimited boost, unlimited engine mods in a good lightweight sports car platform. It is what it is. Not sure where you're going with that. (and if you're going anywhere at all... the same could be said for the NC Miata... BETTER lightweight sports car platform, unlimited tire, unlimited engine mods, etc... such is the peril of having nearly unlimited mod rules)

But, if you look at the results (and I know you do), you'll see that the top of M2 and M1 are nearly the same time-wise, and M2 is often faster. If you're "in the hunt" in M2, you'll be "in the hunt" in M1. It's just a question of where to draw the line between them. The MSM aside, I think moving CS up will make the "other cars" in M2 more competitive. At the end of the day, with the two classes (M1 and M2) being so close to each other, we all know that it comes down to driver.

[Loren]

This actually endorses Loren's suggestion since these two cars are very competitive in BS so no reason FAST shouldn't move them back to S1?

BS PAX = 0.826
CS PAX = 0.819

On course where A Mod would run 32 seconds (typical Brooksville course), that's:
38.741 vs 39.072

3 tenths of a second difference. Not completely insignificant, but generally within the realm of "driver error" at our level of competition.

What makes more of a difference (course dependency) is whether the cars of of the same "flavor" or not. A light/nimble/underpowered car that is capable of running 39 seconds on a "typical" course vs. a heavier/bigger/powerful car that can run the same time on THAT course... put them both on a more open course and the more powerful car has an advantage. Grouping the same TYPES of cars together is what's more important, IMO. In this case, BS & CS cars are all reasonably quick nimble sports cars.

If we tried to combine FS w/ CS, for instance. Even though the PAX difference is the same. They are vastly different TYPES of cars, and the course dependency would be a disaster for that class. FS wouldn't keep up on a tight course. CS couldn't keep up on an open course. Bad combination of cars. That's why we generally don't do it.

(and that's yet another reason we want to move CS out of M2... the FS cars are in M2, and they can do a lot of mods, but they can't make up for their weight and size disadvantage)

[Z1NONLY]

I'm not looking for season points so it's easy for me to say that I'm fine with the changes.

They do make sense to me though.

[Rpwolf]

I didnt want to wait until end of season to buy tires but I just may have to, depending on when this becomes official.

since I have staggered wheels I would be ok with
"no more that +20 mm wider that the stock rear tire"

it would be more cost effective to run a square setup. these tires are crack prices.

[Native]

I'd be ok with allowing a non-square stock setup to be changed to square with the larger tire setting the limit.

[Loren]

Updated the rule to account for square setup allowance.