Class restructure proposal

[Jake]

By using the hp/weight ratios, here are a list of vehicles that should be considered for the next lower class. The first number is spec weight, followed by hp.

ITS -> ITA

2555 / 142 AcuraIntegra(3 door)(94-95)
2780 / 154 Alfa Romeo Milano 2.5L (87-89)
2600 / 134 BMW 318i/is Twin Cam (90-91)
3100 / 145 Ford Mustang LX V-6 (94-95)
2305 / 127 Honda Civic EX Coupe VTEC (94-95)
2330 / 125 Honda Civic Si (92-94)
2305 / 127 Honda Civic Si VTEC (94-96)
2550 / 140 Honda Prelude Si (88-91)
2510 / 130 Mazda MX-3 V-6
2530 / 135 Mazda RX-7 (13 (84-85)
2625 / 140 Nissan 200-SX SE-R (95-97)
2885 / 150 Nissan 200-SX V-6 (1987)
2865 / 160 Nissan 300-ZX (84-88)
2490 / 140 Nissan NX-2000 (90-92)
2610 / 139 Nissan/Datsun 260-Z (73-74)
2770 / 150 Nissan/Datsun 280-ZX (79-83)
2820 / 150 Nissan/Datsun 280-ZX 2+2 (79-83)
2590 / 135 Toyota Celica GT Coupe & Liftback (89-93)
2545 / 130 Toyota MR-2 (91-92)
2890 / 161 Toyota Supra (82-85)
2610 / 137 Triumph TR8 (80-82)
2530 / 134 Volkswagen Jetta GLI (1991)

ITA -> ITB

2380 / 118 AcuraIntegra 1.6(86-89)
2730 / 115 AMCSpirit(79-83)
2490 / 110 AudiGT Coupe(1987)
2310 / 100 BMW2002tii(71-74)
2840 / 138 BMW318 (E36)(92-94)
2750 / 129 BMW325e/es(2 & 4 door)(84-87)
2810 / 115 BuickSkyhawk V-6(75-80)
2480 / 120 ChevroletCavalier Z-24(86-87)
2810 / 115 ChevroletMonza V-6(78-80)
3000 / 132 Dodge Stratus
2620 / 100 DodgeDaytona (1986)
2350 / 110 DodgeOmni GLH2.2
2430 / 110 DodgeShelbyCharger (83-84)
2840 / 119 FordMustang II V-6(74-78)
3000 / 119 FordMustang V-6(1979)
2550 / 120 HondaAccord Lxi12V Coupe &HB (86-88)
2140 / 102 HondaCivic Del Sol S(1993)
2330 / 102 HondaCivic DX(3 & 4 door)(92-95)
2225 / 92 HondaCivic DX(sedan & H(88-91)
2040 / 91 HondaCivic Si(86-87)
2105 / 92 HondaCRX 1.5L(standard)(88-91)
1980 / 91 HondaCRX Si(84-87)
2450 / 110 HondaPrelude Si(1987)
2855 / 90 IsuzuImpulse(83-87)
2550 / 110 Mazda RX-4(74-78)
2780 / 110 MazdaCosmo(76-78)
2300 / 102 MazdaRX-2(71-74)
2280 / 100 MazdaRX-3 / 3SP(72-78)
2380 / 101 MazdaRX-7 (12A)(79-85)
2730 / 130 Mercedes-Benz190E 2.3L 8V
2670 / 110 MercuryCapri II V-6(76-77)
2440 / 116 MercuryCapri(91-94)
2250 / 110 Nissan SentraE/XE/CXE/SL (1991)
2755 / 135 Plymouth Laser / Eagle Talon / Mitsubishi Eclipse 2.0L
2780 / 135 Pontiac Fiero GT &Formula V-6 2.8 (1988)
2230 / 91 Porsche 914-4 2.0L (73-76)
2480 / 86 Porsche912-E (1976)
2600 / 115 Porsche924 & Sebring(77-82)
2930 / 116 Toyota Celica Supra (79-81)
2445 / 112 Toyota FX-16 (1987)
2370 / 112 Toyota MR-2 1.6L(85-89)
2410 / 112 ToyotaCorolla GTS (86-89)
2005 / 96 Triumph GT-6 Mk.III (70-74)
2480 / 115 Volkswagen Jetta III (1993)

ITB-> ITC

2630 / 96 Dodge Daytona 2.2 (84-89)
2680 / 100 Dodge Shadow (89-91)
2640 / 89 Ford Mustang 2.3 (79-93)
2830 / 102 Ford Mustang II 2.3 (74-78)
2270 / 75 Honda Accord 1.7L (79-83)
2030 / 62 Honda CRX HF 1.5L (88-91)
2190 / 82 Mazda 323 1.6 (1989)
2830 / 110 Mazda MX-6 (88-91)
2705 / 102 Nissan/Datsun 200-SX / S11 (Z22) (82-83)
2230 / 75 Opel Manta 1.9 (71-75)
2280 / 75 Plymouth Horizon 1.7 (78-79)
2320 / 75 Plymouth Horizon TC3 1.7 (79-80)
2320 / 90 Plymouth TC3 / Turismo 2.2 (81-85)
2550 / 98 Pontiac Fiero 2.5 (1988)
2550 / 92 Pontiac Fiero 2.5 (84-87)
2080 / 72.5 Porsche 914-4 1.8 (74-75)
2510 / 86 Toyota Celica I 2.2 (74-77)
2310 / 75 Toyota Corolla 1.8 (80-82)
2440 (CP)2420 (Conv.) / 90 Triumph TR-7 2.0 (76-81)
2080 / 76 Volkswagen Jetta 1.7 (82-84)
2050 / 76 Volkswagen Rabbit 1.7 (81-84)
2110 / 76 Volkswagen Scirocco I 1.7 (1981)
2110 / 76 Volkswagen Scirocco II 1.7 (82-84)
2780 / 98 Volvo 242 / 244 2.0 (1975)
2780 / 105 Volvo 242 / 244 2.1 (76-81)

[Knestis]

I must say that I'm surprised at what appears to be groundswell support for the idea of formulaic classifications in IT. I'm not sure what it means but...

K

[Jake]

Kirk, I think most of us agree that hp/spec weight may be the best predictor – but other things should be considered as well and, of course, no formula is perfect. When I look at the above list, I think that most of those changes would do a LOT of good for IT. I know those pesky 12a rotaries are going to bring on an argument – perhaps the best bet for them would be to leave them in ITA and allow the 13B at a slightly higher weight.

Anyway, what do others think? Kirk, what’s your opinion?

[Jake]

BTW - if you want to know the calcs for these proposals, they’re on the "Sorted" worksheet on the “IT Class spreadsheet” on www.racerjake.com
The following criteria were used for the lists.

ITS->ITA cars with (spec wt)/(stock hp) > ITA 90-93 Acura Integra
ITA->ITB cars with (spec wt)/(stock hp) > ITA 88-91 Civic Si
ITB->ITC cars with (spec wt)/(stock hp) > ITC 84-87 CRX 1.5


[This message has been edited by Jake (edited June 22, 2004).]

[Banzai240]

Interesting method, but doesn't allow real world "knowledge"/"biases/whatever to be factored in.

It's well know that some models "gain" more than others with IT prep, and that some engine types "gain" more than others with IT prep, etc... Some cars just aren't as simple as summing up their parts...

Now, this IS a good start, but here's what IS being done currently to recommend weights for cars:

Estimated HP = Advertised HP + (Advertised HP * Est. % gained with IT prep)

Initial weight = Estimated HP * Class wt/hp factor

Final weight = Initial weight +/- (weight for brakes, tranny, suspension, etc.)

Break down the Neon weights, or the recommended weights for the Sentra, Z3, etc., and you'll see that there is a level of consistency to how this has been applied. Some cars, which have proven to be more than a sum of their parts are weighted a little cautiously, but I think you'll find that the weight of EVERY car recently recommended for classification or reclassification can be reasonably explained. I'd be happy to try to do that if you have any specific questions. Most of the attention has been applied to ITS and ITA, with some in ITB.

Only time will tell if this method will work out, and adjustments will certainly be needed. I think you will see, upon analysis, that the attempt here is to equate the mechanical/physical properties of these cars as closely as possible, using real world experience as a way of asking ourselves "does this result make sense", and adjusting accordingly if it doesn't (i.e.: weight for better brakes, tranny ratios, superious supensions, etc...)

Thank you Jake for putting this database together. When you are done updating it, I definately plan to import it to our ITAC site as a tool we can refer to.



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[Bill Miller]

Originally posted by Knestis:
I must say that I'm surprised at what appears to be groundswell support for the idea of formulaic classifications in IT. I'm not sure what it means but...

K

Funny how that's working out, isn't it? What's even more surprising is the people now embracing formulaic classification, that had previously said that a formula would never work. Things that make you go hmmm....

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Banzai240]

Originally posted by Bill Miller:
What's even more surprising is the people now embracing formulaic classification, that had previously said that a formula would never work.

Well, it depends on how you define a "formula"... What I described is NOT a formula, it's a process. The difference, as I see it, is that a formula leaves NO room for subjectivity.... It's cut and dried, plug in the numbers and take what you get. The process we are trying currently allows for real-world experience to be considered.

So, more accurately stated, those of us against a "formula" were/are against a PURE formulatic approach... We never said that Math would not be involved to some degree...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[RSTPerformance]

Originally posted by Jake:
By using the hp/weight ratios, here are a list of vehicles that should be considered for the next lower class. The first number is spec weight, followed by hp.

ITA -> ITB


2490 / 110 AudiGT Coupe(1987)

This is how things get ugly when doing reclassifying.... misinformation or poor information.

Not to pick on you Jake because I know you are doing this for a good cause.

The 1987 Audi Coupe GT listed in ITA is a 2.3 not a 2.2 it has disc brakes and more HP. probably closer to 130 than the 110 that ITB 2.2 has. I would hope that most of the other cars do not have errors and things like this that could slip through the cracks. I am already winning several ITB races and with another 15HP and 4 wheel disk brakes I hope I could win more because you can bet on it that if the 1987 moves to ITB I will be doing some mods to my car

One other thing to consider is that the update backdate rules will need to be modified because if you did move this Audi to ITB it would be very unfair to the earlier models that have the exact same shells to get out-classified.

Stephen

[Hotshoe]

I know those pesky 12a rotaries are going to bring on an argument – perhaps the best bet for them would be to leave them in ITA and allow the 13B at a slightly higher weight.

I second it...........

[Knestis]

What do I think? I think that the most valuable thing to come out of the last 24 months of wrangling with formulas, IT2, PCAs, et al. is an official recognition that weights are actively being used to manipulate competitive potential from the very outset of the car classification process. I use the term "manipulate" in the good way...

K

[Super Swift]

Jake, Kirt, Bill

Formulas flat don’t work.

1st show me all important data on these cars.
-Coefficient of Drag
-frontal area
-gearing
-suspension factors
-breaking ability
-% improvement over factory specs in all areas
-motor location
-FWD or RWD
-tire sizes able to fit under
-weight distribution (after cage and gutting)
-other

Jake your having trouble finding the correct starting HP on all the cars how are you going to find the other factors? Or how about end legal HP? illegal HP?

2nd how do you rate this data in importance. Dang, how do you get the data to relate to each other once you do rank it.

There are almost an infant number of things to research. Then once you do the research your still going to have the human factor of ranking them. That’s not gong to have any biases. The maker of the formula will make the formula to show their personal slants. Don’t believe me? Why did some cars make the grade and others not in Jake’s hp to weight move down list? Why was the line drawn where it was?

Jake I don’t want you to feel that I am calling you an idiot for trying to rate the cars. Your not. Asking to move cars just because the HP/W doesn't meet your goals for the class before you know all other important data is premature.

Formulas are a tool. I think the tool should be purely used for picking a car not classification of the car.

Bill, Kirt

I am still standing where I always have. Just because I gave data to someone I disagree with does not mean my viewpoint has changed. I helped Jake as much as I did simply because I could.

[lateapex911]

Wow...Darin.....how about adding some numbers to the variables??

Well, this is interesting, although its not new news as far as the manipulation of weight during the initial classification goes. I guess the admission of that fact is, but ....

I like this as a start, but I am conscious of the fact that the numbers are not representative of what can happen in the real world...and that is where PCS come in.

I need to look at the scope of the proposed reclassed cars...thats a BIG list!

Question, is the spec weight the current spec weight? (it looks like thats the case)Or is it your proposed new spec weight for the lower class?

If current, do you propose just moving all the cars to the new class without weight adjustments?

I am confused (I assume I am missing something) by the criteria you have listed, as two of the "bogeys" (?) are ITA cars. Can you help me here?

And I won't bother discussing the rotarys here, as this is more of a global thread, so lets not get bogged down.

And no Bill, I am no more a fan of a formula only sytem that I ever have been. As I have droned on about before, it is one tool, and an important one, but creating a formula, and relying on it soley, that could create four classes with parity from the hundreds of models we have running would be a herculean effort, and doomed to failure without a great safety net.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[Mike Guenther]

Interesting that you should suggest the BMW e30, 325e go from ITA to ITB. We have a couple in ITA that consistantly run with the top ITS cars. All of the e30 325's (c, e,i & iS) cars in should be classed together in my opinion. The differences originally from the factory seem to be easily overcome to make them equal after they are sorted out properly. I'd like my 325iS to be in ITA and I'd kick some asphalt.

Likewise the 84 & 85 first gen RX-7s with 13b motors are still competitive in ITS although they're not winning. The 13b would also kick asphalt in ITA.

Something is always going to be better than something else and it is always going to change over time. I can't afford to keep up with the car of the month. I'm happy just being close to the front and getting that adrenilene rush going door to door with my friends. But I do appreciate you guys that try to keep the classes somewhat aligned.

Thanks. Be safe and have fun.

[Knestis]

For the record, I've said everything I have to say about this option and have nothing new to add beyond the observations that I've made above. I don't think I count as an advocate for formulaic classifications anymore - because I don't believe that a wholesale effort will fly. Still.

K

[Jake]

Whao Nelly!!! First off, I agree with most of what you all are saying. I am throwing this out as a start. The data we have compiled IS incomplete and has many errors. If you know of some errors, I beg you to use the other thread so I can correct them. Even with perfect data, I fully understand the shortcomings of this method! There are many pages of threads of me arguing with Kirk about how any formula can never be perfect. I still feel that way. Most of you are preaching to the choir. This is just a compilation of cars that came out when I drew some somewhat arbitrary lines in the sand. I think these may be the vehicles that we should scrutinize and see if a class change should be in their future. I don’t think the wholesale effort should be written off so quick because A) it rewards more than just the squeaky wheels, and it’s precisely what the SCCA did a few years back in Solo II

[Geo]

Originally posted by lateapex911:
Wow...Darin.....how about adding some numbers to the variables??

Something between -1000 and +1000.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[Bill Miller]

Darin,

I'm not going to get into word games w/ you again. Call it what you want, but

Estimated HP = Advertised HP + (Advertised HP * Est. % gained with IT prep)

Initial weight = Estimated HP * Class wt/hp factor

Final weight = Initial weight +/- (weight for brakes, tranny, suspension, etc.)

is a formula.

Also, if you look back, I've never believed that a purely mathematical model would work. What I've always said, was that it would be a good approximation, and should only require minor adjusstments. What I advocate, and have all along, is that some kind of objective, standardized process be used for all cars, not the current subjective, case-by-case way things are done.



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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[Geo]

Originally posted by Bill Miller:
Also, if you look back, I've never believed that a purely mathematical model would work. What I've always said, was that it would be a good approximation, and should only require minor adjusstments. What I advocate, and have all along, is that some kind of objective, standardized process be used for all cars, not the current subjective, case-by-case way things are done.

I think Darin's point is that it's still often pretty subjective by many people's standards.

The first two items only get you in the ballpark. Now this in itself is certainly an improvement. It really helps to make sure a car doesn't end up in the wrong class. I won't say it will always work, but it will help.

The last item is pretty broad and we can and do make use of this. There is no single figure for any factor and sometimes a lot of factors are all thrown in the caldron and stirred up until we reach a consensus on what the adjustment should be.

The danger here is what we are seeing in this thread. First we will make arguments about reclassifications based upon power to weight. Then we'll see people asking what the specifics are regarding the adjustments. Then we'll have a pissing contest over the adjustments. We've had the first two already. The third is probably due in the next 12 hours or so I'd guess.

[edit for spelling]
------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[This message has been edited by Geo (edited June 17, 2004).]

[Bill Miller]

George,

I'll suggest that if you start seeing the 3rd term add/subtract more than 100 - 150 lbs, the car probably should be in a different class. BTW, it does make for an interesting excercise, if you start looking at what the weight would be if a car were in one class vs. the other.

BTW, IIRC, didn't Kirk coin the term "Miller Ratio" for the class hp/wt factor, almost three years ago?

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[jhooten]

How does actual measured perfomance on the track fit into the formula/class placement?

Although my car does break down often on the track I am still planning to put better brakes on it.