FC 8x10 wheels..Why not?

[Bob Wright]

Steve- you bring up some interesting points (this should probably be a new thread, but what the hey).

One thing that has been pointed out is FC is a Formula class, not a spec class. A spec class by definition gives the closest competition, but maybe not the best. I contend that one of the reasons there is so much crashing in the junior spec classes is because the cars are so close, the drivers have to take extraordinary chances to get ahead.

A 'formula' class allows innovation within a set of rules and 'the unfair advantage' by being smart enough to build the better mousetrap. Yes, its more expensive than spec, but I think far more interesting and healthy for the class in the long run.

There have been a number of items that I can think of over the years that have improved the quality (if not the competition): AP clutches- in the dark ages we used stock clutches in FF and had to change them more often than I care to think about. Along that vein-the new Taylor clutch slave cylinder- how many times have you had to split a bellhousing to replace o rings in a VD? Brake pads, rotors, improved cv joints...

[enjoythetrack]

One thing that has been pointed out is FC is a Formula class, not a spec class.... A 'formula' class allows innovation within a set of rules and 'the unfair advantage' by being smart enough to build the better mousetrap. Yes, its more expensive than spec, but I think far more interesting and healthy for the class in the long run.

Hi, my name is Steve and i'm the newbie. The above makes A LOT of sense. Yes it also means the guys with the large bank accounts will be able to develop their cars to the Formula faster than those of us who live in our enclosed trailer. Bob makes a good point.

[Zebra]

Open up the Aero formula for real fun, Please, please please I have some people who would like to do some interesting things but hit a few roadblocks with the Formula

Charles Finelli

[Douglas Kniffin]

Charles... you drinking again?

[RussMcB]

Open up the Aero formula for real fun, Please, please please I have some people who would like to do some interesting things but hit a few roadblocks with the Formula

Charles Finelli

Is this a serious request?

[formulasuper]

As has been suggested before, if you want a formula car with unlimited aero (actually unlimited everything) there is a class already available to play in. It's called Formula S.

[Mark H]

I don't know how I missed this one. Being a foot in mouth guy too I will join in.

There is no way 8's and 10's should be allowed!!!!! They are faster dah.

First the Alum head and now this!!!!!!!!!! All that crap from the engine builders about no good cores, just none of the cores they want to use...something like 1973 casting #. We were duped into that rule change so they could sell us all new $4000 heads.

The Alum head IS faster!!

The 8 and 10's ARE faster!!

So now I will have to go buy 12 new wheels too!

If we let this one slip by too WE ALL WILL HAVE TO SPEND $5000!!!!!!!!!!!

If we vote for this whats next..... Hillary??

[Greg Mercurio]

Thomas: There are only 2 FC's on the grid for next weekend. That gives you 5 track sessions to do back to back testing of your precepts. If you can talk Steve and Rick into changing tires during the practice and qualifying sessions you could have true data comparisons.

I promise not to protest any results as long as you don't have contact.

Are you game for the Great Experiment?

[greg pizzo]

Greg

do you mean I can turn down my HP and run too ??? I dont have small wheels but the rest is FC legal ........ or could be ...... with a few key strokes ........
or does any one have a few 6" wheels ?? I have 4 ..8" ........

Ill be there any way ...........

[greg pizzo]

Thomas ??? ...... <echo>
Greg ..??? ...... <echo>.......


Im about 95% JK ...........but I couldnt resist the generous offer ..........

[Greg Mercurio]

Greg: I'd do it because I think I remember Thomas promised to spank you too. Last year, right here in this forum. But I'd use the 10 and 8's so there'd be no unfair advanage.

You guys can go head to head, add some data to TC's experiment, and have yourseves a race. I'll watch. I'll try to keep up as best I can in that old chassis with the skinny wheelz. Brenner can take pictures. We can post the results er..data..right here. Hafta warn ya tho TC, I'm changin' gears this weekend, changin' the oil too. That old POS is gonna be loaded for BEAR!

[Greg Mercurio]

In all seriousness, if you really want to run in FC, I have a set of wheel you can use. They need tires though, the ones that are on them have 4 heat cycles.

[greg pizzo]

DID Thomas REALLY say he was going to kick my ass ??? IN public ?? SILLY man !!! I thought one of his goals this year was not to embarrass himself on THIS forum.........OR on the track !! ............LOL

maybe Ill have to think on this FC thing ....... if you have wheels for me ........then its just key stokes and pedal work !!

..........hummmmm.......

6 days .....

[R. Pare]

Guys:

Sorry to have to play the spoiler again, but this "test" you are proposing will prove nothing that any halfway decent engineer or race mechanic already knows:

1 - The cars will accellerate slightly slower because of the greater MOI of the heavier wheels and tires.

2 - The cars will be a bit slower in a straight line because of the extra drag.

3 - Assuming that there is a diameter difference ( I honestly don't know - never looked at the spec comparisons), geometry may be adversly affected - camber curves may need to be VERY different.

4 - If the car was at max width with the smaller tires, with the wider tires offset inwards to match the max width, scrub radiuses will be adversly affected. Without making major changes to the upright geometry, this will necessitate caster changes that may be out of the range of available adjustment

5 - If the wider tires are used on a car that wasn't already at max width, the above doesn't apply, assuming that the center of the contact patch can be placed at the same widths, though caster changes may still be necessary for decent steering effort.

6 - If the tires have to place all their extra width inboard, suspension interferance can become an issue, especially front lock availibility. Front wing interferance might also become an issue on many cars.

7 - Differences in lateral and vertical tire spring rate will necessitate different springs and shock valving ( already necessary because of the greater unsprung weight). These differences might also necessitate changes to the RC heights.

There's a lot more, but you should get the gist of what I'm saying : Just throwing on a wider set of tires proves NOTHING one way or the other. It is ONLY when the car gets optimized (which might necessitate cutting and welding) for the wider tires that you can start to get legitimate answers.

Sorry!

[Purple Frog]

Richard,
In this case I think the situation is that folks have already been running 8s & 10s on their VDS in the Cooper zetec pro spec. So throwing on 8s & 10s is not an issue. Going back to 6s & 8s may require set up changes...

Rumor has it that Sean O'Connell is going to test his F1000 (FB) at the Road Atlanta test day with both 8s & 10s, and 6s & 8s, both on fresh rubber. Same track, same day, same car, same driver. Should be interesting... at least for Sean. I'm already training to do my Crashcar, over-the-wall rapid tire change, impersonation. The last time I did it was at HOLY Topeka for Dave. 1:50 and change...

[Stan Clayton]

1:50 and change...

Slacker! Back in the day at Le Mans the driver used to have time to hop out for a smoke, a glass of wine and a personal pit stop while the mechanics took 3 or 4 minutes to service the car.

[R. Pare]

Froggie:

This whole thread has been a debate about the vices and/or virtues of allowing 8s & 10s, and whether or not it will force cars not designed for them - ie - all current Club FCs - to switch.

So, this "experiment" is supposedly being performed to answer that exact question, when in reality it cannot do anything more than highlight the obvious - that a car designed and optimized for 6s & 8s is most likely going to underperform with the larger shoes just thrown on. It does NOT answer the question as to whether or not a 6&8 car will be faster or slower with 8s & 10s once optimized, or whether or not there will be "preferred" packages at different tracks - ie - one package at Road America vs the other at Gratten. To prove that one way or the other will take someone willing to spend the $$$ and time, and who is at the pointy end of the spectrum both engineering-wise and driving-wise.

Not to denigrate those who plan to do this test, but that isn't the scenario we have here!

If anyone really thinks this test will truely answer the question, they are only kidding themselves.

Let's say that this test goes as I expect - the cars are slower - and the rules are changed based on these results. Now, that hypothetical monied and capable car owner spends the time and $$ modifying and testing and finds that indeed the 6s & 8s are faster at RA under all conditions, and the 8s & 10 are faster at Gratten once the suspension is redesigned, shocks changed, springs changed (or worse yet - faster on hot days, but slower on cold days!).

I'll leave it up to those here to fill in the blanks about what has just been done to the class!

[Jeff Read]

The simple fact is that your car needs to conform to the rules NOT the rules conform to your car. The guys who bought the Cooper spec cars knew that their cars were not legal in FC without the proper mapping and proper wheel size. So just because the series that you bought your car for is now defunct you want the rules changed so that you are now legal in FC . Cooper spec cars are legal in FA already so no one is stopping you from running. If you want to run FC then , Thomas buy some 6" & 8" wheels.

JR

[carnut169]

I agree with Richard that this test will only tell us how the different sizes effect MY car at Road Atlanta. I run RA often so for me this is fantastic info. Not sure yet if I'll share it or let all the guys w/ new F1000s find out for themselves (I'm going to need all the help I can get for the ARRC)...


I also own equal sets of wide and narrow so no additional $$ other than testing both sets.

I do think that the test will give us some clue as to what might happen if we allowed the wider tires on an FC as my car is very close to an FC in terms of aero, weight, power, etc.


Now to confuse matters more the wider tires are actually a bit lighter than the narrow ones! As weighed today both used sets, one on 5 spoke OZ, one on Jongbloeds (I'll weigh the naked rims later when my tires arrive, but I remember the rears were the same and the OZ fronts weighed less).
OZ & Hoosier 6 & 8's: Front- 19.8, rear- 24.2lbs
Jongbloed & Hoosier 8 & 10's: Front- 19.8, rear- 23.8.

Hmmm.

Aero drag is not so clear-cut eithor.
OZ front: 21" x 8" (to sidewall buldge) and 6.5" of tread
OZ rear: 22.125"x 10.25 and 8.5" of tread

the wider tires are
front: 20.25"x9.5" with 8.5" of tread
rear: 22.375"x11.750" with 10" of tread.

So the fronts, while wider are .750 shorter- wonder how that plays into determining drag?

Rears are both taller and wider but are 4lbs less each...






I guess I don't personally care if 8 & 10s are allowed in FC or not. If the plan is to eventually combine classes then having the wider wheels make sense. If not, leave the skinny wheels in place.
FWIW The guys at Hoosier firmly believe the 6 & 8s will be better in almost every condition. They said it was the case in both FM and FA- going skinny meant going fast. Too bad the fat ones look so cool.

But we will see.....

[R. Pare]

Sean:

Good info on the size and weight differences.

I think that you will find that the wider tires will indeed be heavier when mounted on like manufacturers rims - Jongbloeds tend to be very light, and OZ's very heavy.

Aero footprint-wise, one of the biggest factors is the width of the contact patch, and therefore the width of the high pressure wedge of air that is being pushed just ahead of it. Wider = more drag (and lift). Some old SAE papers actually show that both ( drag and lift) can be decreased almost linearly with grooves in the tread, but obviously at the expense of contact patch area. Overall width played a larger role than height, but the percentage differences were small. The shape of the shoulder ( how square or round) played a major role.

The wheel design also will play a major role in aero drag - try a spin coast down test with different designs and you'll be in for a surprise.

With the current body width rules, almost nothing can be done on an FC to mitigate the aero drag from the wider tires. F1000 with it's rules, well, that's another story altogether!

The next big factor will be getting heat in the rubber - generally a bit harder to do with the bigger tires as the unit loading of the contact patch is decreased - but this can be overcome quite a lot with the right shock valving, and gets helped big time when the track temps are sky-high - when the skinny tires are more prone to over-heating unless you go to harder compounds. Fat tires will generally allow the use of much softer compounds, even in the high heat situations. Under these conditions, the fat tires will almost assuredly have a big advantage at tight, twisty tracks.

[carnut169]

I know this is a bit of a thread hijack, so sorry guys.

Its interesting to look at the sidewalls of these tires- the FC front is much more square than the wider tires or even the Fc rear.

I'm thinking that the wide tires will be fantastic at a track like Barber, in July. I ran a whole season on the set you see pictured which shows that what Richard was saying is correct- they never got hot.


I'll do that spin test on my balancer...

[Jeff Read]

I see by the results that Greg beat Thomas in both the National races this weekend at T-Hill. Here is the link to the results.

http://www.mylaps.com/results/showev...st=3&org=32147

JR

[Stan Clayton]

I see by the results that Greg beat Thomas in both the National races this weekend at T-Hill. Here is the link to the results.

http://www.mylaps.com/results/showev...st=3&org=32147

JR

That's true, but I think Thomas has earned a rematch.

In Saturday's race they were qualified right next to each other, but Thomas broke second gear in the race and that put Greg well and truly out of reach. For the Sunday race Thomas out-qualified Greg by the better part of a second, but then had intermittent electrical issues that slowed him on-track. At one point I caught and passed Thomas only to have him repass me a couple of laps later...going by me like he was doing Mach 2 with his hair on fire!

It was a blast!

Oh, and Jeff...check out all those SFR FE's!

Stan

[Greg Mercurio]

I wish Thomas had a better performing car myself. On Saturday I lost the carb shaft nut and retainer, running on less than a single barrel from about lap 7 on. Amazing how little acceleration you get without the whole 2 barrels. He would'a killed me.

Sunday I was looking forward to a great race with Thomas but his electrical gremlins returned just about the time the greeen waved.

Looking forward to a rematch!!!!!!

[Thomas Copeland]

Actually, second gear went very early on in Saturday qualifying (and like a nitwit I kept driving without it--I plead red mist!!). With a new gear from Greg (thanks Mr. M) I got it fixed barely in time for the race.

In the Saturday race I passed Greg on the first lap on the outside of the turn 2 sweeper and had about a 2 sec lead on him before the electrical problems started. Add that with his problems and Saturday was like Greg said to me afterwards "The Battle of the Crippled Cars".

Between the gear thing and the electrical thing I think I only got 3-4 clean trouble free laps in all weekend (starting to be a trend). But on what would have been my best lap of the weekend during Sun qual I got balked by Greg Pizzo twice (thanks a bunch Greggy!). That one was my 1:56 time. I was sure I was heading for the lap record on that very lap!!

Anyway, by the time I could diagose exactly what the electrical problem was the weekend was nearly over (it's got to be a short wire somewhere...probably something annoyingly minor...it always is). I also thought I had it fixed more than once.

On Sunday I knew on the warm-up lap I was a goner and when I planted my foot down at the green flag the car just went "see ya!, I'm going home". That turned into one of the hardest races I've ever driven, just keeping the car moving in a forward direction and not letting it quit on me. Surprised I finished.

Definitely have to do a rematch. I really hate getting beaten by my old car.

[Rick Kirchner]

OBTW, in the decision making process of allowing the Zetecs in on 6's and 8's vice 8's and 10's did anyone consider that this was going to create a supply problem affecting ALL the cars? Used wheel prices are up something like 65%. With virtually no true FCs being produced in the past 4 years and a quantity of drivers looking for 6s and 8s I believe this falls in the catagory of "unintended consequences". Another one of those "it seemed like a good idea at the time" things.

[Greg Mercurio]

But the good news is that 8 and 10 prices are depressed.


Hey Thomas, you might also mention the yeoman's job my crew did in getting your gearbox reassembled, (twice).

Thanks John Morgan, a very, very good guy to have around.

[Thomas Copeland]

Oops, Greg, I had originally wrote about that but the post ended up being too long so I edited it (kept that in it). Then I decide not to post it. Then later I wrote the whole post again forgetting to mention about it. Thanks for the assist you and John provided and thanks for the gears. Gotta remember to get those 18/28's to ya.

[Rick Iverson]

Fellas;

If I am not mistaken, the SME consensus is the 8 and 10" wheels provide no added value in performance. If this is the case, and there are members that desire this for the cosmetics alone, then why not?

Iverson

[Bill Steele]

Fellas;

If I am not mistaken, the SME consensus is the 8 and 10" wheels provide no added value in performance. If this is the case, and there are members that desire this for the cosmetics alone, then why not?

Iverson

I have read the same thing regarding the aero negatives and rolling resistance of the 8's & 10's, but I have to say, I am a little skeptical of these conclusions.

An example of what breeds my skepticism: I was out at Sears Point today watching a friend practice for their upcoming Pacific F2000 series race later this month. The fast guys in these cars (VD RF0X/Zetec) run 1:31's and 32's at Sears, that is 6+ seconds faster than the fastest FC cars ran on Labor Day weekend. The Pacific F2000 cars run on 8's & 10's.

[Rick Iverson]

Geez Bill, six seconds is HUGE. Can it be this is solely a function of tires?

You know Fellas, we're in this for the speed. Perhaps another compelling reason that is certainly less cost prohibited than, say and aluminum head. Thoughts?

Iverson

[Bill Steele]

Rick,

I really don't think the difference is solely wheel width difference. Some of the guys running in the Pacific F2000 series out here are really fast drivers when compared to the run of the mill club racer. In addition, the series is pretty competitive so the state of setup and tune is probably a notch above a normal club effort.

On the other hand, one of the front runners in the Pacific F2000 series is Thomas Merrill. When he was running FC last year in the region he was turning mid 1:36's at Sears, so again, the wider tires seem to be a factor in the faster times. BTW - The SCCA qualifying lap record at Sears for FC is 1:35.3, the race record is 1:35.4. One of the guys I was visiting yesterday that is a mid-packer in the Pacific F2000 series was running 1:35’s in his morning warm-up session, when he came in he discovered he had VERY incorrect tire pressure in his left rear tire!

I am not saying I believe allowing 8's and 10's is a bad idea. I am saying the basis of the argument resting solely on "no performance advantage” is probably not accurate. If the rules changed for FC to allow 8’s and 10’s, for sure, the dearth of narrow wheels would certainly be fixed once and for all.

One last factor is if 8/10’s were allowed in FC it might improve the entry numbers out here as some of the Pacific F2000 guys might run some of the local races as FC (instead of running as FA’s like they do now). Unfortunately, if the Pro's back east decided to stay with the narrow spec it might have the opposite effect, probably netting a loss in total entry numbers.

[DaveW]

I have read the same thing regarding the aero negatives and rolling resistance of the 8's & 10's, but I have to say, I am a little skeptical of these conclusions.

An example of what breeds my skepticism: I was out at Sears Point today watching a friend practice for their upcoming Pacific F2000 series race later this month. The fast guys in these cars (VD RF0X/Zetec) run 1:31's and 32's at Sears, that is 6+ seconds faster than the fastest FC cars ran on Labor Day weekend. The Pacific F2000 cars run on 8's & 10's.

This is the essence of this discussion - that no one knows for sure how the wheel/tire cominations would match up at every track. Not knowing means that if you are serious, and have the $, you would test all of the tire possibilities on both sizes of wheels, for every track.

I and other modestly-budgeted, full-time employed racers would not have the time or $ to do this. It would be another advantage (they have enough already) for those with deep pockets.

[Bob Wright]

This topic keeps rearing its head. The Cooper Series is dead. FC SCCA GCR rules state 6"/8" wheels for the class. The F2000 Championship Series will be running only 6/8 wheels in 2008. The 2006/2007 Series rules allowing 8/10s were an accomodation.

We determined early on that it was near impossible to equalize performance between the different size wheels on every track, under every condition- requiring, as Dave pointed out, all teams have the expense of carrying both size wheels (and all the other specs required).

[Thomas Copeland]

I heard the same thing, that some of the Pac2000 guys this week were doing '32's. Let me tell ya if they are it's more than just the tires giving it to them. When I ran the Cooper series in 2004 at Sears Point the fastest guys like Howard, Wilson were doing '32's and that's with an unrestricted Zetec and 8x10's. Bet if ya slapped 6x8's (with the right tire compound) on those PR1 cars they'll still be doing 32's.

I don't know if this issue is entirely dead yet, although I'm sure there are those amougst us that wish it were.

[Bill Kincaid]

I have to say I think it's a bit amusing that the arguments against 8s/10s are basically that "the SCCA rules are for 6s/8s" and "it would be too expensive for competitors to add another variable". There is nothing sacred about the existing rules- if enough people are in favor of changing them, then change them! I personally think FC would be an even better class with 8s/10s and 160 hp (easy, with either motor). As for expense? Well, SCCA rules allow an awful lot of expensive stuff as it is. If you want any semblance of cost containment you need something along the lines of the old Cooper spec or the current Pacific spec. I'm perfectly happy to spend money on tires, gas, and testing instead of the latest shock package or aero bits. I also like knowing that when I get beat it's mostly because I need to drive faster instead of spend faster (though I'm sure my wife thinks it wouldn't be possible to spend faster).

[Bill Steele]

...Bet if ya slapped 6x8's (with the right tire compound) on those PR1 cars they'll still be doing 32's..

1:31's and 32's at Sears Point is absolutely flying in these cars. I am pretty certain if you changed the slightest thing the results would be much higher times. As for "slapping" on a set of 6's and 8's and turning 31/32's, I would say that would be unlikely.

I posted my response to Rick's observation without going back through all that had been said before. Obviously, many feel the thing has been beaten to death, so I apologize for whipping the old mare just one more time.

Bill

[cparsons]

why not allow both combo's but add a penalty/rule/whatever to prevent switching back and forth? If you choose to run 8 & 10, you can ONLY use 8 & 10 and cannot switch to 6 & 8 to better suit track conditions, and vice versa? IF the 8 & 10 have an advantage the times will prove it and the change can be rescinded. If the 6 & 8 combo has competitve times then the 8&10 combo does not have an advantage and no harm/no foul.

[Bob Wright]

The issue is as I outlined it above- you can't set a penalty, equalization formula or whatever for changing track conditions: LRP and 90 deg will favor the 8/10s no matter how hard a compound you put on the car. LRP and 50 deg, the 8/10s wouldn't be competitive with a hard compound. One or the other will always have an advantage.

More importantly- the F2000 formula was developed with 6/8 wheels; there is a relationship between the tire patch, hp, wings, etc which is what makes the formula so attractive and durable. If you change the hp, change the wheels, etc- at some point it isn't a F2000 anymore.

I have been told by more than one professional driver (with great credentials who I highly respect) that the F2000 is a much more difficult car to drive than, say, either a Pro Mazda or Cooper Series car, and that is why its so good- you really have to learn to drive the car and it is a much better teacher than the others.

[Rick Iverson]

The issue is as I outlined it above- you can't set a penalty, equalization formula or whatever for changing track conditions: LRP and 90 deg will favor the 8/10s no matter how hard a compound you put on the car. LRP and 50 deg, the 8/10s wouldn't be competitive with a hard compound. One or the other will always have an advantage.

More importantly- the F2000 formula was developed with 6/8 wheels; there is a relationship between the tire patch, hp, wings, etc which is what makes the formula so attractive and durable. If you change the hp, change the wheels, etc- at some point it isn't a F2000 anymore.

I have been told by more than one professional driver (with great credentials who I highly respect) that the F2000 is a much more difficult car to drive than, say, either a Pro Mazda or Cooper Series car, and that is why its so good- you really have to learn to drive the car and it is a much better teacher than the others.

When I was contemplating the jump from CFF to FC, the madding FC crowd said "do it, and don't look back. They're funner than hell and EASY to drive". So this has whole thing has been a big fat story.