June 2011 Fastrack

[erlrich]

You guys are slipping, these have been out for a few days:

Minutes here (http://cms.scca.com/documents/2011%20Tech/Preliminary%20June%20Fastrack-May%20Meeting%20CRB%20Minutes.pdf)
Tech bulletin here (http://cms.scca.com/documents/2011%20Tech/Preliminary%20June%20Fastrack%20May%20meeting%20TB .pdf)


IT highlights:

Wheel diameter proposal goes to BoD.
ITB Golf gains 45 lbs.
Letter both for & against "inconsequential items" removal...hmmm.
ITAC wants you.
Lots of ST clarifications, etc.
Nobody wants their class combined with another at the Runoffs. (I'm shocked)

[Knestis]

You guys are slipping, these have been out for a few days:

Minutes here (http://cms.scca.com/documents/2011%20Tech/Preliminary%20June%20Fastrack-May%20Meeting%20CRB%20Minutes.pdf)
Tech bulletin here (http://cms.scca.com/documents/2011%20Tech/Preliminary%20June%20Fastrack%20May%20meeting%20TB .pdf)


IT highlights:

Wheel diameter proposal goes to BoD.
ITB Golf gains 45 lbs.
Letter both for & against "inconsequential items" removal...hmmm.
ITAC wants you.
Lots of ST clarifications, etc.
Nobody wants their class combined with another at the Runoffs. (I'm shocked)



Not me they don't. :happy204:

It took what, three years of me agitating to get the MkIII adjusted...? I don't even remember now when I started on the ITAC.

K

[Lael Cleland]

No offence but WAHOO!!! "ITB Golf gains 45 lbs." :happy204:!!!!! Can they add a few to ITB volvo's also? LOL... Rabbits may have a chance!

[JeffYoung]

Guys so we are all clear this is not a competition adjustment. This car got a 50 lb deduct for a beam axle it should not have when it was processed and weighted.

This is simply a correction.

[chuck baader]

And still nothing on motor/trans mounts?? Chuck

[JeffYoung]

Chuck, we are working on it. I think we've been as up front about this as we can.

[Z3_GoCar]

I appreciated that you're still working on aftermarked motor and transmission/transaxle/powerplant frame bushings. If there were any way to help the discussion let us know.

[JeffYoung]

There is. It's called patience. Don't mean to be rude, but trust me this thing has gotten a ton of discussion, has been contentious as hell, and is not easy to get "right" -- meaning a solution that most are happy with rather than just a small group.

I think you guys just think sometimes it's easy to make a change that seems so clear and logical -- to you. Trust me this one is not so clear and logical and there are a number of legitimate viewpoints on it.

[Knestis]

Remember that, even though it's important to try to avoid leaving any glaring loopholes, you can't foresee every opportunity for creep or intorturation, Jeff. And it won't ever be self-policing. You just have to accept that risk when the barn door gets opened, essentially deciding if it's worth the risk.

K

[tnord]

And still nothing on motor/trans mounts?? Chuck

chuck i'm going to say this as politely as i can;

you and everyone else need to quit you're bitching. it's a rule change that won't be in effect until 2012, so it doesn't make a lick of difference if it's in fastrack today or 3 months from now. no amount of nagging from you or anyone else is going to make it go any faster.

[gran racing]

so it doesn't make a lick of difference if it's in fastrack today or 3 months from now.

It kind of does in their eyes, whether it REALLY does or not. Hell, I've submitted a few requests and it's a bit tough seeing "not yet reviewed" even if at the end of the year the results are the same.

[chuck baader]

Travis, I will say this as nicely as I can. If something is being discussed it should be indicated in the minutes. Otherwise it does not exist in the minds of those who are following (trying to follow) the topic. Chuck

[Chip42]

Is the discussion about mounts happening at the CRB level, or ITAC only right now (I assume the latter)? do they post ITAC minutes? I think the committee members are being prety upfront about the topic. we've seen that crafting a bad rule with good intentions can have ramifications, so I for one understand the desire to craft a language that allows what many desire - firmer or more available mounts - without leading to undesired relocation or stiffening of the chassis whiel also not overly limiting the options for achieving the mount such that everyone has equal access to the benefits of the rule. if you think about the breadth of engineering in IT, this is not a small task.

I'm glad to see that there has been movement on the wheel size changes, and I like the rule as written in the minutes - good clear changes to the wording and the speclines make it a clean transition. well done ITAC:023:

[tnord]

Travis, I will say this as nicely as I can. If something is being discussed it should be indicated in the minutes. Otherwise it does not exist in the minds of those who are following (trying to follow) the topic. Chuck

really chuck? because every time you've asked about it, you've been told it's under discussion, so you can't claim ignorance. all you've accomplished by nagging is just being an annoyance. i think we've covered the topic in some regard every single call i've been on.

putting every painful detail of every call in the minutes isn't only unreasonable for the minute taker to document, it's totally pointless.

[RacerBill]

...
I'm glad to see that there has been movement on the wheel size changes, and I like the rule as written in the minutes - good clear changes to the wording and the speclines make it a clean transition. well done ITAC:023:

While this helps clear up the wheel diameter issue, is there any progress on changing the wheel width issue to allow ITB/ITC cars to take advantage of the multitude of good lightweight wheels that are on the market at reasonable prices, but we can't take advantage of because they are greater than 6"? I think that there are not as many new builds in B and C because of this restriction. Not nagging, just asking.

[tnord]

i wasn't on the AC then, but wasn't the ITB wheel width issue hashed out years ago?

[gran racing]

Bill, I haven't heard of any ITB cars not being built due to a lack of 6" wide rims. Is that really happening or just not as convient as some might like? Yeah Travis, it's been discussed and the change sure would impact a large number of folks.

[JeffYoung]

I would support this if requested and there was significant member support behind it.

BUT -- it is a can of worms. To run up front, it maybe you guys would have to spend the $$$ to get lightweight 15X7s (and run 275/35/15s! on the front tires!).




While this helps clear up the wheel diameter issue, is there any progress on changing the wheel width issue to allow ITB/ITC cars to take advantage of the multitude of good lightweight wheels that are on the market at reasonable prices, but we can't take advantage of because they are greater than 6"? I think that there are not as many new builds in B and C because of this restriction. Not nagging, just asking.

[Chip42]

is there any progress on changing the wheel width issue to allow ITB/ITC cars to take advantage of the multitude of good lightweight wheels that are on the market at reasonable prices, but we can't take advantage of because they are greater than 6"?

To run up front, it maybe you guys would have to spend the $$$ to get lightweight 15X7s (and run 275/35/15s! on the front tires!).

I bet you'd find the lighter, lower powered cars are super happy on 205s and 225s. big torquey things like Accords and volvi might like the bigger stuff.

either way - it would be great if someone would make a good, light, affordable 15x6 (like a kosie k1TS or something). allowing use of Hoosier SM R6s and much wider tire availability in general. it would preserve the investment of the existing field and make the 6.5 and 7" arguments more or less moot.

14x6" wheels are widely available in low weights and costs and 14" tires are out there, though never in numbers like the 15s, and from fewer manufacturers, and recently there have been avaialbility problems (even before Japan's troubles).

FWIW SSR makes a lightweight 15x6 if you have the scratch, 2 and 3 piece options exist too, and panasport/revolution/etc... will run them if there is sufficient interest (units and $$$), but all of these are costly compared to a $500 set of kosies at 15x7. I'm looking for a deal on 15x6s myself so I sympathise with the problem but I personally think x6" is still a resonable size and I wouldn't want to "force" all of the existing entrants to find new, wider wheels.

[shwah]

There are custom race wheel options that are far more affordable than the high $$$ 3 piece stuff out there. I don't see the need for changing the x6 spec in B or C. Of course I also have 4 or 5 sets of x6 wheels, only one of which could be converted to another width, so I have a bias.

[quadzjr]

There are small advantages to be had by running a 15" wheel with lower profile tire over a 14", if your ratio you are lookinng for is available, but more often than not the biggest advantage of 15" wheels is the number of take-offs available. However I have done pretty good with finding new or good take-offs for cheap for 14" on this site.:shrug:

If the diamter rule goes into affect I would investigate the use of 13" wheels for the MR2. swapping wheels and tires is alot cheaper than a final drive, and can be swapped per the track. 15" wheel for Daytona, 14" for robeling, 13" for CMP. but talk aobut an additional expense. having to have at minimum 3 sets of tires on different wheels for one car for a dry setup, then there are spares...

I am against the width issue, too big of a can of worms, that help some and not others.. If a rule is written IMHO it should affect all (or as close as possible to it) and not for additional performance.

[GTIspirit]

Guys so we are all clear this is not a competition adjustment. This car got a 50 lb deduct for a beam axle it should not have when it was processed and weighted.

This is simply a correction.

The Golf III doesn't have a twist beam rear axle?:017:

[Chip42]

The Golf III doesn't have a twist beam rear axle?:017:

it does. I think that he meant it recieved a weight break for it that it should not have, and that that has been fixed.

[Knestis]

The Golf III doesn't have a twist beam rear axle?:017:

The mythology was that it received a 50# break for "bad rear suspension." We clarified that's silly on a fwd car. Frankly, i think it just got a weight thrown at it when it was listed, since it was the era of the "soft" process.

K

[shwah]

The Golf III doesn't have a twist beam rear axle?:017:
Yep. Just like the Rabbit/Scirocco and Golf/Jetta 2 and others.
No one gets a weight break for it.

[GTIspirit]

Cars may not fit wheel diameters larger than those listed on their spec line. All ITS/ITA/ITB/ITC cars currently listed in the ITCS with a wheel size less than 15 inches would be changed to 15 inches.

Interesting, this rule turned out a bit different than I imagined. It actually opens the door for cars which currently can't run smaller diameter wheels to run them if they fit over the brakes. e.g. None of the Mk2 VW's listed in ITA can currently run 13" rims, under this new rule they could......

This is contrary to the letter I wrote to the CRB where I stated that larger wheels should be allowed because it follows current market trends and offer no performance advantage, to the contrary larger wheels are usually heavier and so would make a performance disadvantage. But allowing smaller wheels than are currently allowed would allow for a performance advantage if someone could say get their hands on a set of 13x7 rims that fit their car and could find appropriate tires.

[tnord]

i don't think running smaller than max allowable diameter wheels is an advantage at all.

[preparedcivic]

i don't think running smaller than max allowable diameter wheels is an advantage at all.

And shorter gearing isn't an advantage sometimes? There seems to be a cottage industry in numerically higher final drives.

[tnord]

And shorter gearing isn't an advantage sometimes?

irrelevant because of the already open allowance for FD ratio in IT.

[erlrich]

irrelevant because of the already open allowance for FD ratio in IT.

Yeah, but there are still a limited number of ratios available for most cars. Having the option to run a shorter tire might give some guys a final ratio they might not otherwise have available. I don't think this will be an advantage to any one car over another, but I do see it giving some cars options they might not otherwise have had.

[GTIspirit]

i don't think running smaller than max allowable diameter wheels is an advantage at all.

Lighter wheels aren't an advantage?

[tnord]

you can (and always could) have a ratio you wanted custom built. all it takes is a check.

lighter&smaller wheels = larger&heavier tires

:shrug:

[preparedcivic]

Yeah, but there are still a limited number of ratios available for most cars. Having the option to run a shorter tire might give some guys a final ratio they might not otherwise have available. I don't think this will be an advantage to any one car over another, but I do see it giving some cars options they might not otherwise have had.

Given the minutia being discussed on motor mount matters apparently, this comes across as a pretty big horse to let out of the barn. A 225/45-13 has in round numbers a circumference, and resulting shorter gearing 10% less than a 225/45-15. It's not the the little wheeled cars going up in size, but the big wheels going down.

[tnord]

letting the big wheeled cars go down is exactly the intent. ie....OEM 19'' being able to run more reasonable sizes.

there are plenty of cars out there that COULD run a 14'' wheel instead of a 15'' wheel if they wanted to today (miata being one, crx another). it doesn't seem to be a problem, but theorize and get lost in the weeds all you want.

initially, it sounds like a bigger deal than it is. we already have open rules regarding FD ratios. we already have minimum ride height rules. listings already exist with multiple sizes as an option.

the request for input was out there for months, i don't think we received a single letter against it.

[shwah]

i don't think running smaller than max allowable diameter wheels is an advantage at all.

Other than lowering the cg without doing bad things in the suspension geometry, effectively increasing the brake diameter, allowing use of the lightest DOT tire Hoosier makes and moving the rotating mass closer to the hub, they are not.

[tnord]

Other than lowering the cg without doing bad things in the suspension geometry, effectively increasing the brake diameter, allowing use of the lightest DOT tire Hoosier makes and moving the rotating mass closer to the hub, they are not.

and again....all theoretical advantages that exist TODAY, and have not posed a problem.

[shwah]

and again....all theoretical advantages that exist TODAY, and have not posed a problem.
I was not addressing that, just the statement that they offer no advantage. IMO they offer significant advantages beyond gearing, which could be achieved via allowed gear changes.

There is an element of warts and all to this class. I race against guys with much bigger brakes than me. This has not "posed a problem" for the class that I have heard. Does this mean I should be allowed to go put big brakes on?

Same for electronic vs. mechanical injection vs. carbs.

There is a line there somewhere. I don't think we should go moving it.

[R2 Racing]

I run 13" wheels on the ITB car. Combining the Hoosier 225/45 13" R6 with a readily available and cheap 4.9FD makes the grocery-getting, highway-geared transmission not suck, and those little sidewalls let me legally run the splitter/air-dam about two inches off the ground.

But that beind said, I've also been looking to sell all of the 13" wheels I have (because it's four completely different sets, in weight, brand, and offset), and buy three sets of identical 13" wheels. But finding 13x6" wheels at all anymore is freaking impossible, and what you do find will cost you two arms and at least one leg, or is complete crap.

[Russ Myers]

Kevin,
Diamond, bart, aero. Steel wheels from the world of mini-stock. and not real heavy. AND cheap.

Russ

[Andy Bettencourt]

But that beind said, I've also been looking to sell all of the 13" wheels I have (because it's four completely different sets, in weight, brand, and offset), and buy three sets of identical 13" wheels. But finding 13x6" wheels at all anymore is freaking impossible, and what you do find will cost you two arms and at least one leg, or is complete crap.

So I look at this in a couple ways:

1. You have wheels and no rule should be changed because you want your stuff to 'match'.

2. We need to consider barriers to entry of newbies building cars. They don't have wheels. It would be nice that they could actually get some parts to build. I don't think this is on the level of Volvo windshields or XXX fenders etc. This is a class-wide issue.

3. Diameter was opened up because of availability but it had far less of a performance impact than this width issue will. Everyone will need to upgrade to keep up.

4. Josh was way ahead of his time a couple years ago when he proposed opening up width and diameter for all classes...no limits except fitting the inside fenders.

This is a classis benefits vs. costs issue. Not sure where I stand.

[Flyinglizard]

Most small engined cars are faster on the 13 inwheels. VWs are for sure. I have bought entire cars to get 13x6 wheels. I have one good set after 20 yrs. of JY shopping.
Can you buy Basset 13x6? yes. About 60-70$ each.
Does Tire rack sell them? no.
15x7 are far easier to source, 205/50/15 are the best tires to source. (Other than the SFR tires thatI use.)
I think that both sides of this point are valid. The old cars have scarce wheels. The new builds may need to buy steel wheels or Panasports.
While the choices are slim, there are choices for 6 in wheels.
Maybe "Prod" them in, Add 50 # for 7 in wheels. No wider.
MM

[Chip42]

Most small engined cars are faster on the 13 inwheels.

the same as saying they are faster with a higher final drive ratio - "true" in terms of accelration but it does not always pan out on the track due to fixed ratios in the box. wheel diameter =/= overall diameter, though it is assumed that if you want a smaller wheel than what is currently allowed you want it for the smaller OA diameter that it makes avaialble.

I support the rule more for making folks with giant wheels on newer classifications get a wheel / tire package that is more available and affordable. FD is open, who cares about that effect? brake and inertia effects are part of "warts and all" to me.

[tom91ita]

i think this was due. there is no real reason in my mind why newer cars could not at least run their OEM wheel size.

[mossaidis]

Width aside, I don't see a problem with the proposed rule as written. It hits to the sprint of IT: easy, flexible, cheap and one less obvious thing to police.

[joeg]

Mike is correct about small engines and small tires and the analysis is not FD-related.

Everything just keeps getting bigger (and heavier) for OEM styling purposes.

Even Hoosiers are a lot heavier now--who remembers the pre-R04 days with the hologram tread.

Light tires!!

[R2 Racing]

Kevin,
Diamond, bart, aero. Steel wheels from the world of mini-stock. and not real heavy. AND cheap.

Russ
Thanks, Russ! Just checked out Diamond's website and they offer a 13" Mini Stock Series. They offer a 13x6" version, with a listed weight of 11lbs, at $76.50 a wheel. It also lists 4x100 as a standard offered bolt pattern, and backspacing available from 1-3.5" (typical Honda would be 1 & 3/8", or 35mm). Put in a phone call for more info, and awaiting a call back. If I can get a 13x6", 4x100, 35mm offset wheel that weighs 11lbs for $76.50 a piece, I'd be pretty happy. Will inform as I find out more. :023:

[Dano77]

Offset being different then Backspace,what is the offset positive or negative. the center of a 6 inch wheel will be 3 inches or 3 in backspace. that said if my caveman math is correct,you will need either a 1.5 back space to push the out side out past the fender or a 4.5 back space to push the out side of the wheel in side the fender. Im thinking 4.5 will work. 4.25 is even better if you can roll the fender out abit. Gonna need to do your own math but its not too tough. 35mm divided by 25 =1.4 25mm=1.0inch

Just info you are gonna need if Jimmy the wheel guy calls. They know different terminology than roadracers sometimes.

Dan 77 IT7

[924Guy]

Thanks, Russ! Just checked out Diamond's website and they offer a 13" Mini Stock Series. They offer a 13x6" version, with a listed weight of 11lbs, at $76.50 a wheel. It also lists 4x100 as a standard offered bolt pattern, and backspacing available from 1-3.5" (typical Honda would be 1 & 3/8", or 35mm). Put in a phone call for more info, and awaiting a call back. If I can get a 13x6", 4x100, 35mm offset wheel that weighs 11lbs for $76.50 a piece, I'd be pretty happy. Will inform as I find out more. :023:

Prolly won't be hard; this is where I got my current rims for my DSR. Nice that they have a 4x3.75" bolt pattern... ;)

Still heavy though, for a sports racer. Need to get some alloy once next...

[shwah]

the same as saying they are faster with a higher final drive ratio - "true" in terms of accelration but it does not always pan out on the track due to fixed ratios in the box. wheel diameter =/= overall diameter, though it is assumed that if you want a smaller wheel than what is currently allowed you want it for the smaller OA diameter that it makes avaialble.

I support the rule more for making folks with giant wheels on newer classifications get a wheel / tire package that is more available and affordable. FD is open, who cares about that effect? brake and inertia effects are part of "warts and all" to me.

No it is not just an issue of gearing.

When you change from a 205/55-14 or 205/50-15 to a 225/45-13 you lose nearly 2 inches in OD. This drops the car nearly 1 inch, without any of the ill effects to strut suspension geometry cars (roll center dropping below the ground), improving c.g. And frontal area, while enabling a lower air dam. They also reduce the ratio of tire OD to brake diameter, increasing the available braking force at the contact patch. I have run my car with the right gearing and tall tires, and short tires with their right gearing. I now have only short tires...

At the end of the day, this is an advantage for my car in the class. The proposed change is due to availability of wheels. The last time I priced custom built lightweight racing wheels, they were about $200 each. That is not unreasonable for race wheels. Just because Tire Rack does not sell them does not mean they don't exist.

The issue I have with this, is understanding why it is within class philosophy to equalize this variable, but not others. (mass air flow sensors, brakes, track width, head/valve configuration - yes I am exaggerating to make a point).

The same points hod true for width. The current wheels are available. Why make the change?

[JoshS]

We've always been at the whim of the tire companies for size availability. When that 225/45-13 came out it changed the game for cars that could use 13" tires, without a single rule changing, it changed the balance, didn't it? Some cars got to get all of those advantages you describe, some didn't.

I don't think the existence of that one tire size is a reason NOT to change the rule.

[shwah]

You completely missed my points.

2 wheel size changes have been proposed.
1) Allow any size under stock diameter or 15", whichever is larger.
It has been stated in support of this rule that there is no performance benefit. However there can be multiple performance benefits. In describing the performance benefits, I illustrated how such a change could impact the competitiveness of cars, and drawn a parrallel between this component, and any other component that impacts competitiveness of a given car. In IT we choose prepare and race our cars warts and all, as oft stated on this site.
- What is the reason for this change? You see the way this should work, is that we need to make the case FOR rule changes, not just make the changes if no case materializes against them.

2) Increase width in B and C to 7".
It has been stated that this is needed because you can't get 13,14,15 x 6 wheels.
The problem is that you definitely can. You can get them made to your custom offset and bolt pattern needs. You can get them for $150 to $250 per wheel. So the argument is false. Yet a false argument is somehow considered adequate reason to require current competitors to replace their wheel inventory because a theoretical newbie cannot find wheels at The Tire Rack...

I was addressing the errors in the assumptions provided to support both suggested changes.

[shwah]

Some cars got to get all of those advantages you describe, some didn't.

Change the topic to variable cam timing. How does the discussion change? What is a good reason not to let all cars have variable cam timing? I mean it is only fair....

Some cars DO get some advantages. Other cars get other advantages. If a change is suggested that impacts those performance impacting factors, there is a very real chance of unintended consequences in competitive balance.

[Chip42]

Change the topic to variable cam timing. How does the discussion change? What is a good reason not to let all cars have variable cam timing? I mean it is only fair....

Some cars DO get some advantages. Other cars get other advantages. If a change is suggested that impacts those performance impacting factors, there is a very real chance of unintended consequences in competitive balance.

no offense Chris but I think you're making it out to have more impact than it will if passed. roughly half of the cars in B and nearly all of those in C can already run 13" wheels. fewer in A and just 2 in S. but the bigger boys need wider tires and availability just isn't there, so I wouldn't expect a run on the 13x7" market.
yeah, you are right that there are a number of less obvious advantages to be had by going smaller, which in regards to my ealrier post has NOTHING to do with engine size.

There are all sorts of inequalities across IT in how a rule affects one specific car vs another and I don't see this as being all that out of place among them. additionally, a small mixup in the on-track order might occur. I'll agree with that assessment assuming a full field of to the hilt cars - so maybe top 5 at the ARRC? IT competition is balanced by power to weight, and that will not change with this rule where as a washer bottle COULD allow a few cars to make more power due to better intake routing, for example. THAT could upset the class balance under this model. The proposed wheel diameter change affects everyone in a more consistent way than probably any other rule in the book - the benefits are free to all who can fit smaller wheels.

I think the intent of this rule is to allow the big-wheeled guys like the new beetle, mazda protege MP3, or mini cooper a path to more availability (down to common 15 or 14" sizes) and is defensible as the opportunity already exists to tune gearing. everything else that has been mentioned many times already, such as CG/ride height/air dam clearance/brake torque are already unevenly allowed and will simply affect the existing classifications more evenly. yeah, it'll be nice to get a ~5% increase in brake torque. it'll be nicer still to see more cars out there running wheels they don't mind dropping off a curb. this is IT, it's supposed to be affordable racing.

[Rabbit05]

Why not change the rule to make TIRE size restricted for each class ?

For example only :
ITR/ITS can run max a 245 wide tire.
ITA-ITC can run a max 225 wide tire.

Or something like that..?

Wheel size would be open (dia/width)...BUT keep the original rule of having to stay within the fenders and the rolling thru the chalk to check tire patch deal.

That way ..if you want to run 17's..sure go ahead .... and the guys that already have wheels are not going to affected that much. Over time I think that things would sort themselves out to what is the hot set up...:shrug:....just food for thought ??

[jjjanos]

Some cars DO get some advantages. Other cars get other advantages. If a change is suggested that impacts those performance impacting factors, there is a very real chance of unintended consequences in competitive balance.

Actual, no. The formula used to set car weights has no interaction factor between car weights and tire size, therefore, the size of the tire has no impact on competitive balance by assumption. If it ain't in the model, it doesn't have an impact.

When the process includes some factor that adjusts for the the competitive balance between running a heavy versus light car on the same tire sizes, then you'll have a case. I.e. The Beetle weighs 2760 and a CRX weighs 1955 -- the performance of the fat car and the light car is assumed to be identical on the same tire width. If tire width matters, then the Beetle would have a lower weight to compensate for being under shod.

[gran racing]

Why not change the rule to make TIRE size restricted for each class ?

Then a TON of people will need (or at least feel so) to get wider rims. I'd probably run the same tire size as I do now, Hoosier 225s, but certainly would benefit from using a 7", maybe 7.5", maybe... Not saying it won't happen in the future, but right now I do not see a supply issue for ITB & ITC cars sourcing 6" wide rims.

[shwah]

no offense Chris but I think you're making it out to have more impact than it will if passed. roughly half of the cars in B and nearly all of those in C can already run 13" wheels. fewer in A and just 2 in S. but the bigger boys need wider tires and availability just isn't there, so I wouldn't expect a run on the 13x7" market.
yeah, you are right that there are a number of less obvious advantages to be had by going smaller, which in regards to my ealrier post has NOTHING to do with engine size.

There are all sorts of inequalities across IT in how a rule affects one specific car vs another and I don't see this as being all that out of place among them. additionally, a small mixup in the on-track order might occur. I'll agree with that assessment assuming a full field of to the hilt cars - so maybe top 5 at the ARRC? IT competition is balanced by power to weight, and that will not change with this rule where as a washer bottle COULD allow a few cars to make more power due to better intake routing, for example. THAT could upset the class balance under this model. The proposed wheel diameter change affects everyone in a more consistent way than probably any other rule in the book - the benefits are free to all who can fit smaller wheels.

I think the intent of this rule is to allow the big-wheeled guys like the new beetle, mazda protege MP3, or mini cooper a path to more availability (down to common 15 or 14" sizes) and is defensible as the opportunity already exists to tune gearing. everything else that has been mentioned many times already, such as CG/ride height/air dam clearance/brake torque are already unevenly allowed and will simply affect the existing classifications more evenly. yeah, it'll be nice to get a ~5% increase in brake torque. it'll be nicer still to see more cars out there running wheels they don't mind dropping off a curb. this is IT, it's supposed to be affordable racing.

I do see your point. My goal was just to make the point that this can, and to some extent will have a performance impact. We likely will not agree on the amount of performance impact is relevant to a decision like this, but I wanted to make it clear that this is not a "no-brainer because it has no performance impact".

Keep in mind that in the lower power classes, small increments of performance become more important. We can likely all agree that adding .040" bore to a small motor in and of itself has a very small impact on performance, but to build a top performing car, we all do that, as well as balance/blueprint and eke out the last .0x of compression allowed within the rules.

[shwah]

Actual, no. The formula used to set car weights has no interaction factor between car weights and tire size, therefore, the size of the tire has no impact on competitive balance by assumption. If it ain't in the model, it doesn't have an impact.

No. If it is not in the model, then we do not manage it's impact. That does not mean that it does not impact the relative performance of real cars in real race tracks.

[Chip42]

I do see your point. My goal was just to make the point that this can, and to some extent will have a performance impact. We likely will not agree on the amount of performance impact is relevant to a decision like this, but I wanted to make it clear that this is not a "no-brainer because it has no performance impact".


agreed, this can and will produce changes on track. but it's one of those things LIKE the over-bore allowance which came into being to allow hard parts to stay in service, and thus make the cost to compete (not run at the front) a bit lower. yes, it opens the envelope, but the allowance was there for everyone (except rotaries) despite having mixed perfomance gain. the same is true for all IT allowed mods - the changes are common, the effects are not. some affect power, which can upset the power/weight balance model. some effect handling, which don't.

my point is only that it helps everyone a little and helps some a lot - either on track or in the wallet. My support for the diameter rule change is based on the latter, and I believe the performance changes will be insignificant overall.

[jjjanos]

No. If it is not in the model, then we do not manage it's impact. That does not mean that it does not impact the relative performance of real cars in real race tracks.

I didn't say that there wasn't a real world impact. I said that the classification of cars already is off because tire size is assumed to have no impact. Change the available tire sizes and no weights change, so, as far as the system is concerned, there is no impact on performance.

This is a natural outcome of the deterministic process used. Don't like it? Then ask that we go back to the bad old days of "well, what do you think the weight should be?"

[ShelbyRacer]

Then a TON of people will need (or at least feel so) to get wider rims. I'd probably run the same tire size as I do now, Hoosier 225s, but certainly would benefit from using a 7", maybe 7.5", maybe... Not saying it won't happen in the future, but right now I do not see a supply issue for ITB & ITC cars sourcing 6" wide rims.

For those of us (currently) locked into 15" wheels, there may not be a "lack" of availability, but the cost is significantly higher.

My proposed rule change (over a year ago) was simple- allow those running 15" wheels in ITB to use a 6.5" wide wheel. These are available everywhere in almost any configuration for very little money. Many take issue with the idea that those who already own things having to buy new- but what about when they can buy 3 sets of wheels in the new size for less than what it would cost me for one set of the current? Also, limiting the wider width to only 15" cuts down on the number of people affected, and also negates some of the advantage of running the smaller OD tire/wheel combo. Want, or have to have, the big wheels? Here's a tiny bit of width. Decide to run the smaller ones? Stick with 6". I left out ITC since it is a "slower" class, and also only the Beetles (old and new) are stuck with 15" (or 16).

Granted, if downsizing is allowed, that negates the cost issue for me, and I will stick with 6"...

[gran racing]

So someone else states the same theory for their 16" wheels, but in their case it really needs to be 6.75". We can't be making these types of rules otherwise it'll create quite the mess.

[shwah]

For those of us (currently) locked into 15" wheels, there may not be a "lack" of availability, but the cost is significantly higher.

My proposed rule change (over a year ago) was simple- allow those running 15" wheels in ITB to use a 6.5" wide wheel. These are available everywhere in almost any configuration for very little money.

Compomotive sells 15x6 and 16x6 wheels in 4 and 5 lug patterns with a wide range of offsets, for a much lower price than the typical Keizer, BBS, etc. custom 3 piece wheels. You specify bolt pattern and offset when ordering. Their US distributor is Fifteen52 tuning.

The one group I do have some sympathy for is the New Beetle or anyone else with the stock wheel being 6.5 wide. I could see letting them run stock wheels (not stock size, stock wheels) or any wheel that meets the class rules...

[Chip42]

The one group I do have some sympathy for is the New Beetle or anyone else with the stock wheel being 6.5 wide. I could see letting them run stock wheels (not stock size, stock wheels) or any wheel that meets the class rules...

10000% agreement. even with the rule change proposed, anyone should be allowed to run stock parts (any correct stock parts) even if outside of the normal rules. I think only the wheels fall outside of that concept.

[JeffYoung]

I agree. I think we missed the boat on that.

[tderonne]

10000% agreement. Even with the rule change proposed, anyone should be allowed to run stock parts (any correct stock parts) even if outside of the normal rules. I think only the wheels fall outside of that concept.

100% agreement here (can't agree more than 100% right?).

Stock wheel OR blah x blah x whatever.

Allowance to run the stock wheel would take care of the availability argument.

You ITB Mustang guys with piles of stock 15x7 phonedials need to speak up!

[Knestis]

I agree. I think we missed the boat on that.

Ditto. I clearly remember at least one of those conversations. We should never PROHIBIT someone from using a stock part. All rules *must* be in terms of "allowances" - what folks can do - consistent with IIDSYCYC.

K

[tom91ita]

100% agreement here (can't agree more than 100% right?).

Stock wheel OR blah x blah x whatever.

Allowance to run the stock wheel would take care of the availability argument.

You ITB Mustang guys with piles of stock 15x7 phonedials need to speak up!

can we have 1000% agreement if we agreed 10 times?

i like the way you put it Stock Wheel or .....

grassroots, entry level is what IT is about and i ran my OEM for a while in the beginning. but then 13x6 was a step up from the 13x5's that were on it...

stock size should always be an option.

[dickita15]

are you sure you can define what a stock wheel is?

[Chip42]

just as well as I can define maximum valve seat pressure. either there's a clear callout in manufacturer specs or is subjective and the teritory of tribal knowledge.

not ideal but most of the cars where stock size is outside of the bounds of the classification are pretty modern and well known (now). maybe we can have part numbers added to the specline? ::ducks::

[JoshS]

stock size should always be an option.

Are you sure that stock size (really, any stock part) isn't already an option? 9.1.3.D says that the changes listed in that section are the only authorized ones. Isn't "no change" implicitly authorized?

Yes, I know this is a gray area. The wording in the book authorizes things, but then disallows some things. It's not the right way to do it.

[Eagle7]

100% agreement here (can't agree more than 100% right?).

Stock wheel OR blah x blah x whatever.

Allowance to run the stock wheel would take care of the availability argument.

You ITB Mustang guys with piles of stock 15x7 phonedials need to speak up!
So that would make stock 15x7 wheels legal for ITB? Is that what everyone's 10000000% agreeing with?

[quadzjr]

4 cyl mustangs came with 15X7 wheels? I thought 4 cyl mustangs got 14" wheels. I know V8's had 15" wheels. And everyone and their brother (including dealers) swapped over GT wheels on their lesser stnags to make them look the part.

[Knestis]

are you sure you can define what a stock wheel is?

More sure than being able to define what a stock crankshaft is, anywho.

K

[Greg Amy]

More sure than being able to define what a stock crankshaft is, anywho.
My first thought upon reading Dick's post was "as much as we can for Showroom Stock". But then I think I got the crux of Dick's post, in that we can have cars in the class that are almost a half-century old...but I guess so are the crankshafts.... :shrug:

[Gary L]

My first thought upon reading Dick's post was "as much as we can for Showroom Stock". But then I think I got the crux of Dick's post, in that we can have cars in the class that are almost a half-century old...but I guess so are the crankshafts.... :shrug:
WRT to stock wheels though, at least the basic dimensions should be in the half-century old shop manuals, right? I know they're in mine, but I don't think I wanna go there... 15 x 4.5... yippee!!!

[gran racing]

I keep thinking about Kirk's usual "unintended consequences". Marty already pointed one example out but as more ITB & ITC cars get classed, I wonder how this will impact things? Could there be 15 x 8 rims, and there's a sport option which makes them nice and light weight?

At the same time I do agree that OEM makes is a lot easier for the noob trying to build their first car.

I wonder if some type of provision should be available to address those issues if they do arise.

[CRallo]

At that point it would fall under the "warts and all" clause... def a good point tho!

[tom91ita]

Are you sure that stock size (really, any stock part) isn't already an option? 9.1.3.D says that the changes listed in that section are the only authorized ones. Isn't "no change" implicitly authorized?

Yes, I know this is a gray area. The wording in the book authorizes things, but then disallows some things. It's not the right way to do it.

Josh,

very interesting comment!

so one could take the modification section and basically argue that the wheel section is the maximum modification allowed....




B. INTENT

It is the intent of these rules to restrict modifications to those useful and
necessary to construct a safe race car.





6. Maximum allowable rim widths: ITR - 8.5 inches, classes
ITS and ITA ‑ seven (7) inches; classes ITB and ITC ‑ six
(6) inches.


so if i had an OEM wheel that was 6.5" in ITB and was protested, my appeal could be something like this:


the maximum allowable rim width is listed as the maximum allowable modification. my rims are OEM and therefore no modification was completed. i am not restricted from running my car with its stock equipment unless that equipment must be specifically removed, e.g., driver's seat upgrades.....

very new perspective that i had not considered! :023:

[Flyinglizard]

I dont see how IT can not allow the OE part. If it was legal for SS stock, it should also be legal for the IT classes. The shop manual list the wheels. Dealer installed is not listed and should not be legal. IMHO.
If it came on the car, it should be legal, IMHO. MM

[jjjanos]

Josh,

very interesting comment!

so one could take the modification section and basically argue that the wheel section is the maximum modification allowed....

One could argue that. One would most likely amuse the SOMs reading that justification. I think the problem is the failure to recognize that the rules are of two types -
A. Those establishing the maximum legal modification to a component
-and-
B. Those listing the mandatory modifications to a component.

Requirement to run a maximum wheel size is a commandment. You can run any wheel/tire you want as long as it meets the limits 7.a

Note the difference:

Any wheel/tire combination may be used within the following limitations: <size limits based on class>
versus

Stock wheel/tire or an alternate may be used subject to the following limitations: <size limits based on class>

[Knestis]

What JJJ said. It *should* be the case that a stock wheel is allowed, but the way the rules have been to this point, that's not the case if the stock wheel is wider than the mandated maximum.

K

[Bill Miller]

Ditto. I clearly remember at least one of those conversations. We should never PROHIBIT someone from using a stock part. All rules *must* be in terms of "allowances" - what folks can do - consistent with IIDSYCYC.

K

I brought this issue up when the NB was initially classed in IT, that it was not allowed to run stock parts. IIRC, the general response was "yeah, so what?".


lighter&smaller wheels = larger&heavier tires

LOL! The gospel according to Travis. :p:023:

From TireRack

Hoosier R6

225/45/13 16# 20.9" diameter
225/45/15 19# 22.9" diameter

I hate it when facts get in the way! :D

[rsportvolvo]

So SCCA sends me emails confirming the Volvo 240 letters 3282 & 3623 will be answered in the June Fastrack, but no dice. Any insight on this?

[Greg Amy]

Final is posted: http://www.scca.com/documents/Fastrack/11/11-fastrack-june.pdf

[JeffYoung]

I am pretty sure we did vote and made our recommendation on the 240, but not the 142.

I'll have to check.



So SCCA sends me emails confirming the Volvo 240 letters 3282 & 3623 will be answered in the June Fastrack, but no dice. Any insight on this?

[JoshS]

Yes, the ITAC made a recommendation to the CRB at the last meeting, but things got a little hung up at the next point. Weird that you got a notification that would be published though. I'm sure this will get straightened out at the May meeting.

[dickita15]

The CRB voted to follow the ITAC’s recommendation but after the meeting found a conflict in the technical specs that needed to be rectified before the spec line could be written. The notice was auto generated when the CRB moved the item forward as approved. Once it was pulled back to fix it the notice was already generated.

[Knestis]

It's reassuring that technical inconsistencies will get caught by the current system.

K