Class restructure proposal
- Thread starter Jake
- Start date
Banzai240
New member
I find it interesting that you guys seem to focus on that last "term" so much, when there is a TON of subjectivity in the initial estimation of IT-Prepped HP to start things off... Does it gain 20%??? 25%??? 30%??? 15%??? That's one of a couple of areas where real-world experience is put into play to help answer the question 'Is this car REALLY capable of producing this much HP??' (don't laugh... It's one of the VERY first questions that I ask when we are discussing these matters on our ITAC conference calls...)
Hey Bill... How about we compromise and call it a "Formulary Process"...
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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
I prefer "The Caldron."
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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
Well, that is something we would take a look at. Some cars are kind of in between and the class becomes a subject for debate as well.
Again, this is subjective. It can't help but be. I don't know about any hard and fast numbers, but you're right, if the adjustment is overly large, chances are good the car is going into the wrong class.
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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
Originally posted by Geo:
I prefer "The Cauldron."
Uhhh... OK! Sounds more impressive than "The Dartboard"!!!
...nyuk nyuk
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Vaughan Scott
Detroit Region #280052
'79 924 #77 ITA/GTS1
www.vaughanscott.com
Bill Miller
New member
Hey Jake, I meant to ask you, w/ all the cars that you propose to 'move down', do you have weight adjustments for the cars that aren't moving?
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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
I think that is worth stating again.
Many have pointed out in the past the many other variables that need to be considered in 'calculating' the performance potential of a given vehicle. However, these 3rd, 4th and 5th, etc. approximations don't sway the numbers as much as the original guesstimate as to the power potential.
Assume a car with 150 stock Hp and a target WT/HP range near 20:1. The difference between a 15% increase and a 30% increase is 22.5 HP or 450#. That's right 450 POUNDS, so isn't it much more critical that the HP number be closer to real world than worrying about drag, frontal area, unsprung mass, etc.? Even at that the HP numbers are peak, an RPM that we probably spend less than 10% of the time at or near. The area under the curve is much more important and what kind of rpm drops are those stock trans ratios going to dictate?
I applaud the efforts, believe that formulas can work, we just don't have the resources to get it exact. So they do the best they can and when they miss, they just may have the tools to fix it.
I just may wait until the dust settles and go from there.
Banzai240
New member
I'm telling you... if there were just a few simple values available across the board for all cars classified, mainly the actual camshaft specs, I believe I could use my Desktop Dyno II software and get within 5% of the actual values. The problem is that the full cam specs are just NOT that easy to get ahold of...
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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
Bill,
1. First, I apologize for the name of this thread. I didn’t mean for everyone to get the impression that these are the changes I am proposing. If you read my posts you’ll see a smattering of “we should look at” and “most of these seem” etc.
2. Again, the lists of vehicles are some of the ones that, using a certain metric, we might want to scrutinize and see if they would make more sense in the next lower class. If some of them seem to make sense (I personally believe many of them should drop a class) then we should start talking about if they should add a few pounds or what not.
3. The reason I am doing this is to try to look at IT as whole and not just pick and choose cars. I believe it was you who was whining about this 1.7L VW moving, but some other 1.7L VW not moving, or something like that. That’s actually what I would like to address. Big picture – lets look at the whole group, not just the ones that are owned by people who write the best letters.
1. First, I apologize for the name of this thread. I didn’t mean for everyone to get the impression that these are the changes I am proposing. If you read my posts you’ll see a smattering of “we should look at” and “most of these seem” etc.
2. Again, the lists of vehicles are some of the ones that, using a certain metric, we might want to scrutinize and see if they would make more sense in the next lower class. If some of them seem to make sense (I personally believe many of them should drop a class) then we should start talking about if they should add a few pounds or what not.
3. The reason I am doing this is to try to look at IT as whole and not just pick and choose cars. I believe it was you who was whining about this 1.7L VW moving, but some other 1.7L VW not moving, or something like that. That’s actually what I would like to address. Big picture – lets look at the whole group, not just the ones that are owned by people who write the best letters.
Bill Miller
New member
Darin, if that's the case, how do you determine if someone is running an illegal cam? I can't believe the data aren't out there. They should be available from the factory service manual, or from the dealer.
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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
lateapex911
Super Moderator
Bill, that's the number one reason IT as it is now will never go National....there just isn't the required documentation on certain cars.
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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
Sorry. I lied above when I said I was done because this confuses me. A lot.
Is this to suggest that there is more documentation avaiable on the Healey 3000 MkI, Jag XK120, Elva Courier, Lotus MkVII, Volvo P1800, Turner 1500, and Sunbeam Alpine than is available for even the rarest IT car?
Why do I think this is a red herring?
K
[This message has been edited by Knestis (edited June 17, 2004).]
Is this to suggest that there is more documentation avaiable on the Healey 3000 MkI, Jag XK120, Elva Courier, Lotus MkVII, Volvo P1800, Turner 1500, and Sunbeam Alpine than is available for even the rarest IT car?
Why do I think this is a red herring?
K
[This message has been edited by Knestis (edited June 17, 2004).]
lateapex911
Super Moderator
I should add some further info, I guess. I was suggesting that as it stands, IT, with all it's models, couldn't be considered for a National class, and inclusion in the Runoffs, due to the incomplete documentaion on many models.
Thats not to say those models couldn't be excluded.
Now, am I right in understanding that the models you refer to are in the Production category? I am not as complete in my knowledge of the Prod category, but it was my understanding that the rules allowed significant deviation from stock, and therefor the rendering of many specs as unecessary.
Of course, the beginings of Prod were a long time ago, and I'm sure there was a bit of "look the other way" (and so on...) at the time when certain documentaion items were needed.
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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
Thats not to say those models couldn't be excluded.
Now, am I right in understanding that the models you refer to are in the Production category? I am not as complete in my knowledge of the Prod category, but it was my understanding that the rules allowed significant deviation from stock, and therefor the rendering of many specs as unecessary.
Of course, the beginings of Prod were a long time ago, and I'm sure there was a bit of "look the other way" (and so on...) at the time when certain documentaion items were needed.
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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
Darin,
I agree that the more information you have the closer you can get.
I am not familiar with the software you have, (I am aware of it, just not familiar). Do you enter the cam lift, duration and overlap or do you have to enter profiles, like the lift every degree of rotation?
Further, does the software give you a max hp and torque along with the rpm that they would occur at, based on the theoretical best BMEP possible with a given set of physical attributes? Or does it plot a torque curve?
What can the software do with VTEC or VANOS- type abilities, or rotaries for that matter?
Please don't take these as critisims of the softwares' abilities. Even with its' limitations I'm pretty sure it will do a better job than our somewhere between 15-30% guesses.
Why don't we just go back to the dartboard routine? If a big mistake is made one way or the other it just makes our choices that much easier!
I agree that the more information you have the closer you can get.
I am not familiar with the software you have, (I am aware of it, just not familiar). Do you enter the cam lift, duration and overlap or do you have to enter profiles, like the lift every degree of rotation?
Further, does the software give you a max hp and torque along with the rpm that they would occur at, based on the theoretical best BMEP possible with a given set of physical attributes? Or does it plot a torque curve?
What can the software do with VTEC or VANOS- type abilities, or rotaries for that matter?
Please don't take these as critisims of the softwares' abilities. Even with its' limitations I'm pretty sure it will do a better job than our somewhere between 15-30% guesses.
Why don't we just go back to the dartboard routine? If a big mistake is made one way or the other it just makes our choices that much easier!
The problem Bill is lift and duration do not a cam make. None of the 5 different FSMs I own give the full spec of the cam profile.
Now, truth be told, I think we are headed for trouble with cams. Since the full profile is rearely (if ever) available, how do we determine a legal cam? Yes, where factory cams are still available, a cam doctor can compare a new factory cam with a used cam in a competitor's car. What is the tolerance that will be allowed? I have no idea. It's certainly not in the rule book that I've seen.
So, indeed, the question you ask of how do you tell if a cam is legal or not, well, that is a very good question.
We've determeined the PL510 SSS cam is illegal for IT. But if the factory cam is NLA from the factory, just what do we do? And don't look at me. I don't have an answer right now.
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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
The more I read about different ideas for car classification the more I like competition adjustments. Sure a "procedure" can be used for the starting point. But until you can compare developed examples of each model car (the fastest "legal" ones) you are just speculating. there are just too many factors that can make a car fast around a racetrack and even then some tracks will favor some cars. The IT classifications are not that far off and if a system for realistic competition adjustments can be made I would be all for it.
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Peter Linssen
ITE Volvo 740 Turbo
ITB Opel Manta
Oregon Region
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Peter Linssen
ITE Volvo 740 Turbo
ITB Opel Manta
Oregon Region
CaptainWho
New member
And you are assuming that we can determine the "legal" cars. At the moment, I don't believe we are making much of an attempt at that. That's a whole different argument, though. But the "legality issue" must be resolved before we can even address competition adjustments, because, until we can assure legality, we won't know what we're comparing to what.
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Doug "Lefty" Franklin
NutDriver Racing
Banzai240
New member
Just as an example... Both of my FSMs (1995 and 1998 240SX) list IVO, IVC, EVO, EVC, and there is enough information in there to also determine the lift (obviously, the above also gives One the duration and overlap...) One would think that is enough... HOWEVER... NOWHERE in either manual does it specify at what LIFT these specs are measured... Is it .050", 1mm? 2mm? 0mm??? The software I have requires that you enter specs for either .050" or for .000" lift (0-lash)... and switching between the two, all else being equal, makes a significant change to the curves...
The bottom line is that there aren't that many FSMs out there that list the cam specs in enough detail to accuratly use this software. If everyone had a "cam-card" for their cars... like the ones that come with a new aftermarket cam from Crane or ???, then it would be a piece of cake to predict the potential of these engines, in MANY different forms of prep... It's just NOT that readily available.
Additionally... You guys see how many mistakes and misinformation ends up being put in the specs now... can you IMAGINE the problems with trying to keep track of cam specs for all these different cars as well? Until we go to a World Challenge style "Vehicle Specification sheet" instead of the current "spec lines", I'm afraid we are just going to be a little bit limited. But then Hey... there IS no guarantees of competitiveness... and we ARE giving you a place to race. (albiet, some of us are trying to give you all a little more competitive place to race...
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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
dave parker
New member
Jake
In your plan what happens to the currently classed ITC cars? Where do they end up? ITD?
dave parker
wdcr #97 ITC
[This message has been edited by dave parker (edited June 18, 2004).]
In your plan what happens to the currently classed ITC cars? Where do they end up? ITD?
dave parker
wdcr #97 ITC
[This message has been edited by dave parker (edited June 18, 2004).]
Will some of you please drop the “all or nothing” approach!
First off, I do NOT believe that any formula is going to be perfect. And (stock hp)/(spec wt) has ALL of the shortcomings listed. I also understand the MANY reasons why you can’t look at finishing positions. But just because data has shortcomings doesn’t mean you should ignore it!! Some find flaws with a certain metrics and you say we should ignore it just use a dart board? Or we need to use a formula and follow it blindly no matter what so our evil biases don’t come through. Come on!!! Let’s use the formulas to provide a starting point, then refine from there.
I’m just trying to look at the whole picture. To illustrate my point, look at these three, SOHC FWD ITA cars:
Wt / hp / car
2855 / 90 / Isuzu Impulse (83-87)
2480 / 115 / VW Jetta III (93)
2350 / 115 / Golf III (93-97)
The SCCA moved the Golf III to ITB and left the others in ITA. I’m simply saying that a broader look is needed with reclassifications.
First off, I do NOT believe that any formula is going to be perfect. And (stock hp)/(spec wt) has ALL of the shortcomings listed. I also understand the MANY reasons why you can’t look at finishing positions. But just because data has shortcomings doesn’t mean you should ignore it!! Some find flaws with a certain metrics and you say we should ignore it just use a dart board? Or we need to use a formula and follow it blindly no matter what so our evil biases don’t come through. Come on!!! Let’s use the formulas to provide a starting point, then refine from there.
I’m just trying to look at the whole picture. To illustrate my point, look at these three, SOHC FWD ITA cars:
Wt / hp / car
2855 / 90 / Isuzu Impulse (83-87)
2480 / 115 / VW Jetta III (93)
2350 / 115 / Golf III (93-97)
The SCCA moved the Golf III to ITB and left the others in ITA. I’m simply saying that a broader look is needed with reclassifications.