Wheel width, ITB, again

What are your thoughts in wheel widths in ITB and ITC?


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Seriously, I agree with Rodger and Greg. Open it up to what ever fits under the finder over the stock brakes, and around the suspension. I just don't see the reason to have the biggest rim under there. Of course I'm still running 16x7 stock rims that only weigh 18lbs each. The balance comes when you run more tire than the car has weight to handle or hp to spin up. Other than that pull the old "you pick your car warts and all" line.

I posted several times in the begining of this thread and I don't really have any arguements other than what I have posted as I feel that what I have already said clearly explains my view.

However I have to comment on the idea above. (Not to pick on you z3_gocar but you where the last to suggest this idea again) IS this honestly something you would really consider! Dave Gran posted some sizes of rims that would fit under the fenders for Volvos and I think Saabs. If anyone thinks that ITB is all about HP and such I think diefferently and I truelly think that MOMENTUM is huge! with 13inches of Rubber under a Volvo (or a size somewhere between 6inch to 13inch) I certainly think they will GAIN corner speed and therefor momentum and will drop lap times significantly.

would you take the challenge to race for pinks with your car... you on 4" wide tires and me on 10" wide tires?

Someone said it on some thread... Size matters :blink:

I strongly suggest that we do not consider the "if it fits run it" idea. Other ideas that have been posted are good alternatives... I still stick to the idea that you should be able to run the stock rims that came from the factory on your car. "IT catagory rules" do not guarentee competiveness and if you want the lighter rims they exist for a price.

Stephen
 
I was ok on weight untill the killer heat, want to add a cool suit but that weight has to be offset and the only place left is wheels.

QUOTE]

Roger,

Do you want lighter wheels then stock to meet minimum weight? If that is the reason I am less sympathetic. I thought your bitterness was because the "move" forced you to purchase new rims?

Stephen
 
I posted several times in the begining of this thread and I don't really have any arguements other than what I have posted as I feel that what I have already said clearly explains my view.

However I have to comment on the idea above. (Not to pick on you z3_gocar but you where the last to suggest this idea again) IS this honestly something you would really consider! Dave Gran posted some sizes of rims that would fit under the fenders for Volvos and I think Saabs. If anyone thinks that ITB is all about HP and such I think diefferently and I truelly think that MOMENTUM is huge! with 13inches of Rubber under a Volvo (or a size somewhere between 6inch to 13inch) I certainly think they will GAIN corner speed and therefor momentum and will drop lap times significantly.

would you take the challenge to race for pinks with your car... you on 4" wide tires and me on 10" wide tires?

Someone said it on some thread... Size matters :blink:

I strongly suggest that we do not consider the "if it fits run it" idea. Other ideas that have been posted are good alternatives... I still stick to the idea that you should be able to run the stock rims that came from the factory on your car. "IT catagory rules" do not guarentee competiveness and if you want the lighter rims they exist for a price.

Stephen

And you assume in the lower HP cars that a 9" rim won't slow you down in the corner.
 
And you assume in the lower HP cars that a 9" rim won't slow you down in the corner.

It quite possibly could but I don't know and that's a "chance" I don't think we should take.

And lets say your correct a low HP car would slow down... like a Suzuki. But what about a high HP car (in comparison for the class) like a volvo or Audi? Are they affected and will they be slower? If I could fit more rubber on the front of my car I do think I could go faster at some tracks. LRP is an example... I really do think I could go faster if I could get more rubber under the front of my car that weighs in at almost 1700lbs in front of the front wheels. More sustained momentum around a track like this and I would argue my lap times will drop. This is an example of how I am NOT thinking selfishly here as my car has more HP and tourque than most ITB cars and I think I would be one that could benefit.

If the only reason ITR cars need the wider tires is for the extra HP then why don't they run 6inch wide rims on the front of their rear wheel drive cars? I think it helps them with maintaining grip on entry into the corners and increasing apex speed and exit speed after the apex resulting in a greater entry speed onto the straights. Basically keeps your momentum UP increasing lap times.

JMHO it could be totally wrong but I don't have any data to support or negate it and I think the "Chance" to mess things up is high and the chance that it could upset a class that I think is pretty good with a large variaty of "cars to have" as is.

When the ITAC decides they want input on the subject I will write a letter supporting the current rules with an added allowance for stock rims from the factory be allowed. Good converstation and topic I honestly had no idea that this problem existed in my little bubble :)
 
On the NB and "allowing" them to run 15" wheels, isn't that assuming they could? Some cars can't go down 1" in diameter because it won't clear calipers and such. :shrug:

Most 'regular cars' can go down one size. A quick check on TireRack shows a 15" snow tire package with steel wheels.
 
>> So gentlemen...we are about to pull the trigger on 8 of these monsters....please make a decision so we don't buy the wrong wheels. Chuck

Sorry, Chuck but that's simply not fair to dump that decision - and the consequences - back on the ITAC. Not only is it not appropriate for us to make category-wide decisions based on individual needs, we can't control timelines to suit one racer's buying plans.

You need to do what you need to do based on the best information available at the point at which you make your decision but you DO make an illustrative case for why change - ANY change - has costs: If you can act based on reasonable confidence that things won't be different next season, you are generally better off.

K
 
A lot of people think "more tire is better"; that ain't necessarily true. I've proven to more than a few folks that unless you're getting the heat, the wider tire is slowing you down (my fav story is the PCA guy who was running ungodly-wide tires and was going slow; I talked him into trying a ~2" - yes, 2 inches - reduction in section width and he picked up 2 seconds at LRP...) So, unless you're logging tire temps, you just don't know.

That's why my having to run 205mm tires on a 1900# car really doesn't bother me TOO much (and why seeing guys stuff 225 tires on a 6" wheel and crowning the contact patch doesn't impress me too much). If 6-inch-wheel drivers - especially the lighter cars - haven't tested 205 tires on 6" wheels you may be leaving time on the table...

In the end, I just personally wish I had the opportunity to buy a lightweight 6" wheel at a decent price like the 15x7 guys do...

On that side note: Kazera T1S can't be re-drilled. Cameron told me there's "voids" 45 degrees between the existing bolt holes (he noted that's probably where a lot of the weight reduction came from), just like the Kazeras, Enkeis, and other ~13-pound SM wheels I've looked over...so, no 9-pound wheels available to Joe Suzuki... :shrug: - GA
 
A lot of people think "more tire is better"; ......

That's why my having to run 205mm tires on a 1900# car really doesn't bother me TOO much (and why seeing guys stuff 225 tires on a 6" wheel and crowning the contact patch doesn't impress me too much). If 6-inch-wheel drivers - especially the lighter cars - haven't tested 205 tires on 6" wheels you may be leaving time on the table...

Ah HA! There it is, LOL. Exactly, stuffing a larger tire on too narrow a rim is often not ideal. But Ive asked a lot of those guys, and the answer I've gotten, is "Yea, it's shady, but lap times are better with the big rubber than the smaller size". Hmmmm.
Two things could be happening. They're lying and assume it's better, or they actually know.

Here is the bottom line:
SOme cars will be fastest on smaller naroower rims...at certain tracks, and faster on wider rubber at other tracks.
OTHER cars will be faster on wider rims at all tracks.

Opening up to allowable width will result in certain cars acheiving never before possible speed and lap times. Period. Can you predict which cars, at which tracks?
Does it matter if you can? Not really.....but knowing that it will happen makes the real question:

Do we want to change the performance envelope for the class(es)? And if so, do we wish to do it in a random and unpredictable manner?
 
Do we want to change the performance envelope for the class(es)?
I suggest one must assume that a change in wheel width will result in a performance envelope change for the class.

Though, anecdotally speaking, I don't see it as significant. <---placed in a separate paragraph intentionally...
And if so, do we wish to do it in a random and unpredictable manner?
No more random and unpredictable than the current classification process (your secondary question implies the ITAC/CRB has considered all factors in wheels fitment, tire fitment, track, and performance capabilities - and their effects on equitable competition - for each car when classifying/reclassifying ITB and ITC cars. We both know this is not true.) Ergo, a change that is applied to all cars effects the class, on average, equitably (in terms of performance).

GA
 
That's why my having to run 205mm tires on a 1900# car really doesn't bother me TOO much (and why seeing guys stuff 225 tires on a 6" wheel and crowning the contact patch doesn't impress me too much). If 6-inch-wheel drivers - especially the lighter cars - haven't tested 205 tires on 6" wheels you may be leaving time on the table...

I am running the 205s on my car. As much as I try, I can't justify putting a 225 (hoosier) on a 6" wide wheel. Less rotating mass, less drag (aero and mechanical), I need all the help I can get with 1.5 liters...as do you tGA.
 
I suggest one must assume that a change in wheel width will result in a performance envelope change for the class.



GA

If one model finds the ability to run significantly more rubber, and can benefit, then the performance envelope just changed.....
...can we say that will NOT happen?
 
If one model finds the ability to run significantly more rubber, and can benefit, then the performance envelope just changed...can we say that will NOT happen?
If, under the current rules, one car can benefit by running more rubber than others, then the competition parity is ALREADY skewed...

Note, Jake, that above I agreed that the performance envelope WILL LIKELY change (though I suggest not as significant as you might think). However, I'm simply pointing out that, on average, it will affect everyone equally - certainly as "equally" as it does now (or as equally as it does in ITA). - GA
 
That's why my having to run 205mm tires on a 1900# car really doesn't bother me TOO much (and why seeing guys stuff 225 tires on a 6" wheel and crowning the contact patch doesn't impress me too much). If 6-inch-wheel drivers - especially the lighter cars - haven't tested 205 tires on 6" wheels you may be leaving time on the table...
Contact patch is not always the only variable impacted by changing to another tire size available for your car. I was not in search of grip when I went to 225s.
 
A lot of people think "more tire is better"; that ain't necessarily true.

There are many variables but it absolutely will allow some cars to benefit by allowing a larger diameter rim. Want a bigger contact patch but can't generate enough heat? Use autocross tires like some of the CRXs do. At a track momentum track like Lime Rock, I'd sure be interested in using a wider rim. Watkins Glen? Not nearly as much.
 
Contact patch is not always the only variable impacted by changing to another tire size available for your car. I was not in search of grip when I went to 225s.

Assuming tire compound equal.. in going to a 225 over a 205, the 225's are heavier, and more rolling resistance.. the only advantage on the 205 is the contact patch.. which allows more grip and allows the tire to disperse a load over a larger area for a given load relative to a 205 to keep tire temps down, and should last just a bit longer for the same reason. all of which is still related to grip. Or am I missing something?
 
I am selling my 6" wheels for the 914 and running the stock 5.5" wheels with 205/50/15 SM6 on it. If a SM can run 1:42 on them at Road A my car should be able to run 1:47 on them. So far the tire temps are good. I rolled a 225/45/15 mounded on a 6" wheel through flour and then a 205/50/15 on a 5.5" rim. There was not much difference for me to switch.

Blake Meredith
 
Now Bill, don't get all righteous on us! :)

Jake,

I'll take 'righteous' over 'inconsistent' any day.

But, the competitive reality is that you have just started a spending war with such a change. Those with the $ will raise the bar if they can, and those who had worked their way into a competitive position ...but aren't as well flushed are now looking at mandatory expense just to regain their former competitive level.

I don't recall you taking this kind of a position over the open ECU issue.

Do you really want to get into this w/ me again? Truth be told, it was your disingenuous comments and self-promotion that were the main reasons I left here to begin with. I'm beginning to think stopping by was not so good an idea.
 
Jake,

I'll take 'righteous' over 'inconsistent' any day.



I don't recall you taking this kind of a position over the open ECU issue.

Do you really want to get into this w/ me again? Truth be told, it was your disingenuous comments and self-promotion that were the main reasons I left here to begin with. I'm beginning to think stopping by was not so good an idea.

Uh ...sure Bill.
 
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