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stevemhudson

 

Wheels greater than 16" are allowed, you just get a 200# weight penalty.  Is the regional competitor with a dual purpose car put off by the weight penalty?  A 5.7L car with 17" wheels has to weigh 3200#.  How many dual pupose cars can get to that weight.  The lightest min. weight I saw in the NASA CMC series is 3150# and most are well over 3200#.

 

FYI - I am a "dual purpose" car that is less than 3200#. I don't race in SCCA or NASA races because there is no where for an intake/exhaust, gutted LS1 F-body to compete. I'm built to race in a local series that has no limit on mods - just qualifying times.

 

I just fail to see how (all else being equal) a 3200lb car on 17s is any threat to a 3000lb car on 16s. As we've stated, there is NO tire available in 17" sizes that will compete with those available in 16s.

 

Also, think about it logically, in the order that a person (like me) builds a new CP car. They start out in ESP, where they add the cheapest/best wheels - which are 17x11 for my car. There is no penalty in ESP for these. Then, they move up to CP, where they can no longer run these wheels because they are too much of an advantage. This doesn't make sense - how are they an advantage in CP, but not in ESP? And, don't answer "tires", because we've all agreed there are no 17" tires that compete with 16" ones. I realize that CP rules state that they do not build upon SP rules. But, the reality is that the car DOES build upon ESP rules. Most new people in this class are NOT going to go find some junker and build a CP car from scratch. They are going to keep a 10 year old ESP car (which would only sell for $5000) and decide to CP it.

 

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2000 Trans Am
Delta Region #14 CP

This is a good debate. I will add my $.02...

The "tradition/cost" argument for keeping FP and CP in the Dark Ages of wheel diameters is itself getting long in the tooth. 1950 called and wants your bias ply tire design back. The reality is that DOT Radials are getting faster and are less expensive than "fast" soft compound slicks. Wheels are also getting less expensive for a given diameter. We see this first hand with some BMW race wheels we sell: 17x9 forged 16.6 pound wheel for $259, 18x9 forged 17.7 pound wheel is $299, 18x10 is $319, etc. Previously used 17x9.5" CCWs were 20.4 pounds and cost $550 each. So +$40 for an inch more diameter in the same size is going to break the bank? Its not always this easy to find 10-12" wide wheels this inexpensive in 17-18", of course, but that will continue to change.

Sure, 17-18" 3-piece wheels are generally more expensive/customizable ($500-600/ea and up) than that, and comparing CP-width "Real" racing wheels in 15" diameter isn't a fair comparison. What is keeping these costs down in the smaller diameter wheels is the large Stock Car / circle track crowd, who can live with generally cheaper built 15-16" wheels.

Ignore dual-purpose cars like the CP guys in their 4th gen F-bodies and they will (continue to) ignore CP and run in SMod or XP instead. Road courses are popping up all over the country (we have 4 in or being built in Dallas/Ft.Worth now?!) and occasional track events are becoming more popular and affordable to the typical Solo racer. We are building an XP Solo car that will likely get more miles of track use than Solo miles, and we have to think about things like fitting brakes bigger than 10" diameter rotors inside the wheels. Too many cars have come with 17, 18 or even 19 inch wheels and 13-14" brakes to be ignored forever.

DOT Radials have some benefits over bias ply slicks: DOTs are more consistent, have much better transient response/feel, do not require solid springs to compensate for a weaker tire carcass design, and allow better chassis tuning via shocks/springs/bars than sloppy bias ply tires. More Prepared cars are switching to Radial DOTs because more of them are getting clobbered by the comparable SMod classes. The biggest costs in SMod are not in tires, as those are a known quantity... I'd say that innovative things like TC and the unlimited engine cost potential can gobble up more of their budgets.

Now don't ask why I mess with the flakiest of all tire categories: ST tires! These are the least stable tire choice in Solo, with most models obsolete within 12 months of them becoming the Next Big Thing. In 3 years we've switched to 3 completely different ST tires. Plus you get the benefit of less grip than an HStock car in a tire that cost more than a DOT R and has to be constantly bathed in water between runs!

Fuel Injection is also becoming more mainstream than the carb'd set-ups optimized for high g cornering. MegaSquirt systems (as mentioned above) start around $350 and 21+ years of fuel injection being on every domestically sold car and truck has made for much more reasonable costs. And yes, they can make more power pretty much everywhere if tuned correctly. Just because some random internut guy can't tune his EFI set-up doesn't mean a carb is inherently better/more powerful. You think the Forumla 1 engine designers are pining for the days of carbs so they can "make more power"?  EFI doesn't rely on engine vacuum signals for fuel delivery nor does it suffer from air:fuel separation in the manifold ports (when the injector is pointing right at the back of the valve it has no time to separate); a properly designed and tuned EFI system has no downside to a "$250 Holley" other than cost. Just wait until people figure out Direct Gasoline Injection... no more need for throttle loses, but they need fuel pressures measured in 10-15 bar and semi-exotic fuel injectors. This is the next gain in power/efficiency in mainstream gasoline engines. Someday we'll have workable electro-mechanical valve actuation and then cam timing will no longer rely on a set camshaft profile (or two).

Time marches on, but it seems to have left the CP/FP rules in the 1970s. New racers will ignore these classes and go to SMod or Xprepared. If CP wants to progress there needs to be a progressive move towards more modern technology (the Car of Tomorrow!).

XP - the Un-Broken Prepared Class.

CP - The NASCAR of Solo classes.  

SMOD - Fast. Just bring truckloads of money.

I've got a million of 'em...

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Terry Fair - www.vorshlag.com - www.ast-usa.com
'93 BMW E36-LS1 (XP/TTU), '91 BMW 318is (STS), '08 EVO X (STU/TTB)
Check out the SCCAForums Vorshlag Sub-Forum

quote user="Fair"

This is a good debate. I will add my $.02...

The "tradition/cost" argument for keeping FP and CP in the Dark Ages of wheel diameters is itself getting long in the tooth. 1950 called and wants your bias ply tire design back. The reality is that DOT Radials are getting faster and are less expensive than "fast" soft compound slicks. Wheels are also getting less expensive for a given diameter. We see this first hand with some BMW race wheels we sell: 17x9 forged 16.6 pound wheel for $259, 18x9 forged 17.7 pound wheel is $299, 18x10 is $319, etc. Previously used 17x9.5" CCWs were 20.4 pounds and cost $550 each. So +$40 for an inch more diameter in the same size is going to break the bank? Its not always this easy to find 10-12" wide wheels this inexpensive in 17-18", of course, but that will continue to change.

On limited power cars, I agree dot R's are faster on a surface like HPT.  If we ran on concrete, the slicks would destroy them.  As well, there aren't any R's that can match up with slicks on high HP/heavy cars.  Stan and Stu are an unknown as Stan has said that he prefers the feel of the radials vs bias ply.  Can't say which is faster though.  Didn't see a 12in wheel in your listing?  As well, are these cheap wheels avail for every car?  As for the dark ages, GT1 still limits a 16x12.  As well, just wait until someone buys the expensive radial slick and raises the bar.  R's won't be an option to compete.  The cost is to prohibiitive for anyone to do it but Hoosier has introduced a radial.  Ver Mulm ran them at Natls last year.  I will disagree with anyone in comparing an 18in slick to an R.  No comparison, weight or grip.  You want response, try a radial slick with the proper alignment.

 Ignore dual-purpose cars like the CP guys in their 4th gen F-bodies and they will (continue to) ignore CP and run in SMod or XP instead. Road courses are popping up all over the country (we have 4 in or being built in Dallas/Ft.Worth now?!) and occasional track events are becoming more popular and affordable to the typical Solo racer. We are building an XP Solo car that will likely get more miles of track use than Solo miles, and we have to think about things like fitting brakes bigger than 10" diameter rotors inside the wheels. Too many cars have come with 17, 18 or even 19 inch wheels and 13-14" brakes to be ignored forever.

 Look at the turnover at track events. To justify changes to solo rules by using track events is not rational.  Solo doesn't depend on them nor do they depend on solo.  Reality is that no dual purpose car has presented itself and shown to be competitive at both endeavors.  As well, solo doesn't require extreme brake rotors.  Most lappers are former soloists for reasons other than tire diameters.  As well, most lappers don't mod anything past bolt ons.

DOT Radials have some benefits over bias ply slicks: DOTs are more consistent, have much better transient response/feel, do not require solid springs to compensate for a weaker tire carcass design, and allow better chassis tuning via shocks/springs/bars than sloppy bias ply tires. More Prepared cars are switching to Radial DOTs because more of them are getting clobbered by the comparable SMod classes. The biggest costs in SMod are not in tires, as those are a known quantity... I'd say that innovative things like TC and the unlimited engine cost potential can gobble up more of their budgets.

 Where do you find the consistency issue?  Both tires are grippier when they are hot.  Both take a run to warm up.  The bigger they are, the longer it takes to get heat into them.  Chassis setup is irrelevant to the justification of larger diameters.  As for SM clobbering P classes, it doesn't matter.  Haven't seen anyone switching due to SM.  As well, currently, slicks are outlasting R's when tire wear is compared and the R's are more expensive than the bias slick.  I don't see the savings.  And, you are right, the biggest cost in SM isn't tires, it is the lack of limits in the rules.  It is the F1 of autox and the number of entrants is dwindling fast. 

 

Fuel Injection is also becoming more mainstream than the carb'd set-ups optimized for high g cornering. MegaSquirt systems (as mentioned above) start around $350 and 21+ years of fuel injection being on every domestically sold car and truck has

FI is currently legal without limits.

Time marches on, but it seems to have left the CP/FP rules in the 1970s. New racers will ignore these classes and go to SMod or Xprepared. If CP wants to progress there needs to be a progressive move towards more modern technology (the Car of Tomorrow!).

First, the most attended classes are generally those with the most limits(ex. Stock).  It, generally, limits expenditures on the vehicle.  Slow? maybe but lots of entries and forces drivers to increase skill instead of spending more.  Second, if the rules have stability, people aren't as afraid to invest in building an entry for the category.  As for CP being left in the past, live axles are still the choice of many sanctioning bodies, including SCCA GT roadracing, Trans Am, etc.  In the last few years, more P entrants have zero scrub front suspensions, Jericho trans, quick change rears, lighter wheels, etc.  No matter the level of prep, it is hard to argue with a class of 50+ cars every year.  As for the other P classes, they are either cost prohibitive, lack quality competition or are sitting on their asses waiting for the rules to change so they don't have to work on their cars.  As well, I don't think it is fair to expect P cars to be built in a single year for competition, it is cost prohibitive to the avg autoxer.

XP - the Un-Broken Prepared Class.    Yeah, the only P class that has no limits other than no tubes, WTF?

CP - The NASCAR of Solo classes.   Yep, and everyone comes to watch!

SMOD - Fast. Just bring truckloads of money.  F1 of autox

FWIW, I don't have as much problem with unlimited diameters as I do with unlimited widths.  Price slicks in the sizes over 16in diameter and tell me if it is going to attract entrants or not.  And, don't tell me people aren't going to quit when someone wins on these tires.  Because if the rules allow it, there is always someone that will spend it.

In closing, I totally agree on the small P cars an R could be faster.  Not going to work on bigger, high HP cars because comparable sizes aren't available and more camber is required to make a radial work.  Yes, you can get the camber but then wear and forward bite suffer.  Solo doesn't require big brakes and everyone jumps on here touting dual purpose cars.  IMHO, most lappers aren't interested in solo because they aren't competitive, want more track time, don't enjoy it, etc.  And, I can't tell you why more people don't run FP,  probably cost prohibitive when you consider what it will take to compete with Fordahl. Do I want more P entrants, hell yes, but unlimited mods aren't going to get it and SM/SM2 are proof. 

If you want to fix participation, Autox needs to separate from SCCA as roadracing is their flagship.  Reconfigure based on participation instead of listening to those 'that would build a car if they did this' , people who want rules stability based on the 'my car is done' theory and the whiners that don't hardly participate even at their home events.

Haven't got to argue with Fair in a long time.

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turbotoddie
todd farris
CP96

Toddlet, you need to learn how to use the "quote" function. I can't tell where my text stopped and yours started!

• I still stand behind most of my statements in some aspects... DOT Rs have radically better transient response, equal or better grip on asphalt (HPT), and better selection of sizes in the larger diameters. I don't have the data to back up every instance but we will try to acquire some numbers.
• Most CP cars can't stop worth a crap, due to funky brake biases and lack of ABS, so they probably wouldn't benefit from larger rotors/better brakes. The CP cars scrub off more speed just turning the wheel than applying that funny pedal in the middle. hehe...
• The FI weight penalty is finally gone in CP? Well, that's progress then. I would still put a bet on better hp/response/high g functionality/all rpm drive-ability with the fuel injection over carb.
• Have to agree with you on flaky "track guys" not being the great feeder class for Solo. Bad argument on my part.
• Tell me your thoughts after running the BSP C4 Corvette on big Hoosiers at the Houston Divisional, and not on your big gumball Goodyear slicks? You know, we should put an AX22 or DL1 in a CP car and in Madderash's ESP car at the LaGrave Divisional and get some data. If I'm not working in your run group remind me and I'll put it in there... oh, well, I bet there's zero CP cars with a working 12V cigar lighter needed for power.
• Which car was faster at the Houston Div... ESP or CP? I'll give you three guesses and the first 2 don't count...  (CP = 121.939, ESP = 118.766, BSP (Todd!) = 118.802, SS = 117.611!)

http://www.houscca.com/SOLO/results07/houston_fin.htm

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Terry Fair - www.vorshlag.com - www.ast-usa.com
'93 BMW E36-LS1 (XP/TTU), '91 BMW 318is (STS), '08 EVO X (STU/TTB)
Check out the SCCAForums Vorshlag Sub-Forum

quote user="Fair"

 

Not the most web savy guy by far!

• I still stand behind most of my statements in some aspects... DOT Rs have radically better transient response, equal or better grip on asphalt (HPT), and better selection of sizes in the larger diameters. I don't have the data to back up every instance but we will try to acquire some numbers.
• Most CP cars can't stop worth a crap, due to funky brake biases and lack of ABS, so they probably wouldn't benefit from larger rotors/better brakes. The CP cars scrub off more speed just turning the wheel than applying that funny pedal in the middle. hehe...
• The FI weight penalty is finally gone in CP? Well, that's progress then. I would still put a bet on better hp/response/high g functionality/all rpm drive-ability with the fuel injection over carb.
• Have to agree with you on flaky "track guys" not being the great feeder class for Solo. Bad argument on my part.
• Tell me your thoughts after running the BSP C4 Corvette on big Hoosiers at the Houston Divisional, and not on your big gumball Goodyear slicks? You know, we should put an AX22 or DL1 in a CP car and in Madderash's ESP car at the LaGrave Divisional and get some data. If I'm not working in your run group remind me and I'll put it in there... oh, well, I bet there's zero CP cars with a working 12V cigar lighter needed for power.
• Which car was faster at the Houston Div... ESP or CP? I'll give you three guesses and the first 2 don't count...  (CP = 121.939, ESP = 118.766, BSP (Todd!) = 118.802, SS = 117.611!)

>First, my response was based on Prepared as a category not just CP.  From experience, that is how the SEB looks at rule changes, by category, not class.  I don't deny the capability of FI but a professionally built carb is much different than jetting and tuning a box stock carb.  $1000 for a carb or $3000 for a quality FI setup.  Which would you do on any type of budget.  

>As for the vette on the Kumho's, it was awesome.  However, a radial requires camber and a live axle car doesn't have that adjustment.  Yes, we can engineer a fixed camber setting but the downside is adverse tire wear and straight line traction limits.  Remember, we may not always be stuck at that turd pile called Heartland Park.  So, assumptions based on asphalt adhesion limits are biased.  As for the big slicks, think about the contact patch of the tall bias tire vs any radial that is as wide(the radial will be much shorter/ best comparison), the radial will suffer.  The big tall bias allows great lateral grip and acceleration.  Crutch, maybe, but the BSP Vette lacks power being the old TPI 350.  We were way down on power compared to Mark.  Anyways, in Houston, I had some of my best runs ever and still lost to Mark.  I would like to say lack of power, no seat time, whatever, anything but me!8-)  But, Kritzler's Vette is a dream!

>As for CP in Houston,  Tony's car is probably slower than Mark's car in a straight line, unfortunately.  No Janish, Stroh or me.  Bartling didn't bring the fast car either.  Not a good comparison.  And, Mark was flying all weekend.  

>As for CP and quality brakes, I can't remember too many natl courses that required more than a stab of the brakes, very little if ever any threshold braking.  So, it is hard to see the need for bigger diameter brakes.  ABS is for the weak!

 >Either ganalyst would be cool and we do have a cigarette lighter.  We should have good tires for that event.

turbo

 

 

 

 

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turbotoddie
todd farris
CP96

Howdy,

Back from the dead...

I was just browsing the '08 rules online (yeah, I'm a pretty exciting guy, alright! :-) and noticed that the CP wheel diameter penalty stayed at 200 lbs?

WTF is up with that?  I thought the latest proposal to drop that to 100 lbs was recommended to the BOD?  No?

Granted, a 100 lb penalty is still totally f*cking stupid, but at least its half as stupid as a 200 lb penalty.

Mark

(what diameter wheels were all the boys in EM & XP running this past year?)

It's a typo.  Weight adder in CP for wheel diameter is now 100#.

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Steve Hudson
DP Miata

I was just assuming it was the "Mark Andy Rim Rule"!!!!

 

turbotoddie

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turbotoddie
todd farris
CP96

marka:

Howdy,

Back from the dead...

I was just browsing the '08 rules online (yeah, I'm a pretty exciting guy, alright! :-) and noticed that the CP wheel diameter penalty stayed at 200 lbs?

WTF is up with that?  I thought the latest proposal to drop that to 100 lbs was recommended to the BOD?  No?

Granted, a 100 lb penalty is still totally f*cking stupid, but at least its half as stupid as a 200 lb penalty.

Mark

(what diameter wheels were all the boys in EM & XP running this past year?)

 

Top 4 in XP:

Tunnel: R25B's in I *think* 17" size.
Beecher: A6's, 18s
Naughton: A6's, 16s/18s
Newman: R35A's in 16" size
 

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Jesse
-2002-2006 E-stock 93 MR2 (sold)
-2007-2008 XP Spyder

R25B's were 16's.

EM actually had some 17" and 19" A6's as well as the normal 13-16" slicks. 

 

Looks like the rulebook has already been updated.

next issue... Wasn't there a John Thomas 200 lb weight penalty added to all blue Datsuns in FP?

Tom

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Tom Holt
FP199 280Z

The CP wheel rules are listed in two places in the rulebook, Appendix A and Sec. 17.

The rule is correct in Appendix A (100# for wheels over 16" in diameter) and wrong in Sec. 17.

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Steve Hudson
DP Miata

Now...where is the unlimited wheels (or up to 10") for DP Steve???   Huh??

 

BTW...Team Blenderblaster is considering a road trip to TX in May

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Tracy Ramsey
Team Blenderblaster
2000 MR2 DP Spyder

Unlimited wheels are in the same place as a VVT weight penalty

Come on down, we'll have some fun 

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Steve Hudson
DP Miata

To add to Toddles comments about dual purpose cars.

 It is almost impossible to tune the suspension for a single car so that it can win at AX and club race.  The setup is just way too different, and the heavier the car the greater the changes you have to make.  Probably the easiest one to do would be CM where everything is somewhat out in the open, but even then it would be difficult.  I'd have to spend two to three days in the shop with just the suspension on the ASedan to get it bearly AX ready and then I'd have to pick where to run it.  BSP and get killed on having to run 8" wheels or CP and get killed on having to swap out the whole suspension, plus there a quite a few things allowed in AX that I can't even get close to if I want to keep the car legal for AS or AM or CMC anything.

The same goes for my Spec Miata or the CSR.  Especially the CSR as the AX rules are completely contrary to SR and that's a class with almost no rules.

 

James R.

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James Rogerson - SowDiv; CSR #32, ASedan #2 and XP #46
Men that like golf are unhappy at home and unable to have meaningful relationships with women. - Joseph Heller