Minimum weights - Question

Ron Earp

Ron Earp

Administrator
How many cars out there run at their minimum weight?

My Jensen is speced to weigh at 2240lbs (don't quote me, might be 2280, haven't weighed mine yet). But, the street car, in full street trim with EVERYTHING is weighing in at 2225 lbs with one I have seen. Now, I ditched the stock heavy seats and some other stuff and figured I got down to maybe 2125lbs. I'm adding in a cage and a lot of other stuff (Fire system, harnesses, accusump, etc) and I imagine that I will be quite a bit over the minimum weight with driver.

Some cars are classed near their stock curb weights, and others are not. I don't know a lot of cars in IT since I haven't owned them but as a former BMW E36 owner those came in around 3150lbs-3300lbs in street trim and sometimes more with lots of lux items. However, it races at 2800lbs (not exact, I don't have the chart), but a good 350 to 400lbs from the street trim weight, and, the car will weigh less since the race weight includes driver. So, maybe 10% less than street trim.

I'd love to race at 2000lb, or an appreciable fraction less than the street trim weight. Are weights figured from looking at what can come off the car and going that route?

Thanks,
Ron


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Ron
http://www.gt40s.com
Lotus Turbo Esprit
Ford Lightning
RF GT40 Replica
Jensen-Healey: IT prep progressing!
 
Search the archives, you see this one a lot. Not really a formula, although Darin/George/Andy can fill you in on this.

A lot of cars can't make their mins. I can, I have to run 25 lbs ballast, and I'm classed at slightly (50 lbs I think) under street curb weight. I know some 325s run ballast, and some 1st Gen RX7s. Don't know about the 240zs.
 
MOst Z's can make it as long as the driver is under 225lbs.....S14 240s are gonna struggle while I think the S13's will make it.
 
I am not the expert witness, but I did stay in a Holiday Inn Express in Atlanta, so...

I think that how much weight the car can lose is considered, but I bet it's more of a check than part of the equation.

I bet they sit down, look at teh class where they think it will most likely foit, then compare it to the "bogey acars"...in the ITS case, I would imagine those to be the Z-car and the 2nd gen RX-7.

Does the X model handle as well or brake as well or have as much power? Or is it superior in any area? Once they feel that they have a good understanding of the beast, they try to figure how it will improve in IT trim, and then set the weight accordingly. I bet they look to see if it's likely that it can meet min weight, and if it looks plausible, they let it fly. Maybe they let it fly even if it's a stretch, and let the masses decide whether they want to try and build one.

So, the goal is parity. But sometimes cars out run their expectations. I think the E36 was a case in point. Thers a car so loaded with extra "stuff" it hits min weight easily...but min weight is probably too low.

Now that we have more flexibility in adjusting weights, and the process of setting weights seems more formulaic than it's been in the past, I predict we will see more cars added to the ranks.

Thats my guess...they aim for parity, and the curb weight is merely a cross check.

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Want to expand on that no, or, is it a secret, or did Jake hit it right?

I'm just wondering how (not complaining, wondering, there is a difference) how my car got classed at its curb weight and the BMWs got classed 400lbs less than the curb weight. And I'm not picking on BMWs, it is just the only car I've owned that is in IT that I know the weight of not by hearsay but by driving it and using track scales.

If hp does, and I'm sure it does, come into the equation then the GCR has the Jensen Healey wrong. The UK motors made 140hp with Delorteo carbs and different cams, the US model with the federal cams and Strombergs made 125hp. This is documented fact, not fiction. I can't use the UK stuff since it was not on the US motors. Since nobody has raced one of these in IT I doubt it has been looked at.

Ron

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Ron
http://www.gt40s.com
Lotus Turbo Esprit
Ford Lightning
RF GT40 Replica
Jensen-Healey: IT prep progressing!
 
Remember that what the current ITAC and CRB are doing has exactly nothing to do with what has gone on in the past. Geo's "No" is probably accurate as far as it goes, but I'll wager that certain decision-makers, at certain times have indeed used curb weight as the basis for the spec.

The problem is that over the 20 years of IT history, there has never been a prescribed, documented process, so each time the staff turned over, the process changed based on their individual beliefs about "how it should be done."

At this point, you have absolutely NO idea what kind of plan got applied when the J-H was listed but take some solace in the fact that current ITAC members will admit that they start with math to get in the ballpark. That is pretty monumental.

K
 
Originally posted by Knestis:The problem is that over the 20 years of IT history, there has never been a prescribed, documented process, so each time the staff turned over, the process changed based on their individual beliefs about "how it should be done."
Click to expand...

And since there is still no prescribed, documented process, that's the way it's going to be, going forward.

And George, didn't you guys (ITAC folks) say that you didn't put the New Beetle in ITB because you didn't think you could legally take enough off of it, to make weight?

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Never a IT.com thread until Miller throws a jab...
rolleyes.gif


We can't speak for past classifications but the curb weight really has nothing to do with the classification UNTIL, as Darin said, it is used as a check to see if the car can GET TO our recommended weight.

The power and torque achievable in "full IT prep" are used along with many other factors like drivetrain layout, brake size, suspension desigh, etc, etc, ect.

Based on those factors and the current 'performance envelope' of the 4 classes, a car is placed. The curb weight is checked to see if it may be viable for the car to get to that weight. For instance, if you were to set a weight for the ITA 240SX in ITS, the target number would be way to light for the car to get there. That is just one red light that can go off if the class is totally wrong.

Take the E36 out of the equation because it is an anomoly from a power to weight right now.

Help of confuse?

AB

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Andy Bettencourt
New England Region, R188967
ITS RX-7 and ITA project SM
www.flatout-motorsports.com
 
Being a scientist, I think the numbers approach is the right way to look at things and I am glad that is being done. I imagine back when my car was classed it was done so rather haphazardly since specs in the GCR are incorrect.

That doesn't bother me right now since we'll be racing it for the first time next year, but if after a lot of work and letting some proven drivers in it, if it is still at the tail end of the pack we can write for re-classification or changes to the specification. Like I mentioned in the other post, I didn't build this thing because I thought it would sit on the pole, I built it because I liked it and I think it has a fighting chance, at least somewhat of a fighting chance. Besides, everyone likes an underdog!



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Ron
http://www.gt40s.com
Lotus Turbo Esprit
Ford Lightning
RF GT40 Replica
Jensen-Healey: IT prep progressing!
 
<font face=\"Verdana, Arial\" size=\"2\">Never a IT.com thread until Miller throws a jab... </font>
Click to expand...

What the hell are you talking about Andy? You see that as taking shots at people? If so, your skin is a tad thin. It doesn't matter how good a job you and the rest of the ITAC have done to develop a more equitable classification process, if it's not codified and documented, it will only be persistent so long as the current personnel are there.

You guys have commented countless times about not having any control/insight into how things were done before your watch. This is the crux of Kirk's comment. Why would it be any different w/ the next regime, if things aren't documented?

Not a shot at anybody, just an observation.

As far as the weight question, that's all it was, a question.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Here is my take on it Bill, The plan is still fliud because of the current trend in trying to fix some of these things. In SCCA it is hard enough to correct little things that are wrong let alone big things. I see a time when there is a process written down as a guideline repeat guideline for a process. Until now it has not even been known if the CRB was going to do any of the stuff recommended. They have now approved some of the stuff submitted, what almost a year ago?
This is a new time for IT and I for one am excited about what I see. I have customers and friends ready to jump back in if this works. That is the real question at this point is "will it work" Until this first group of things is tested we won't know and I certainly would want a process printed and made public that ultimately didn't work. You know Darin is a very good friend and I can tell you I know as much about what's going on as you do. (NOTHING) Lets just be a little reasonable until this works or fails. If it works nobody gets crap on their face for being negative about it and if it doesn't work I will lead the charge to offer a solution.
 
Joe,

I hear what you're saying, but what are your thoughts on this? I'd rather have things documented, period. If they work, great, if they don't, there's a record of what didn't work, so it doesn't get done again.


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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Originally posted by Bill Miller:
Joe,

I hear what you're saying, but what are your thoughts on this? I'd rather have things documented, period.
Click to expand...

For the record... the process IS documented, it's just not public... You aren't going to see that happen anytime soon, because it is, as Joe correctly suggested, still fluid..,

However, I have all but handed you guys the basic process of what we are attempting, so it's not really a secret. The only thing we haven't specified publicly are the target ratios for each class or the specific values for the "adders"...

Again, the "process" is:

(Estimated IT-prep HP (flywheel) * Target Ratio) + Adders for individual specs (compared to other cars in the class) = spec weight

All followed by a sanity check to decide if the numbers make sense...

I personally don't think you'll ever see a "process" or "formula" in the ITCS. We'll do our best to set the seeds and get this all back on track, but we are still only a small piece of the process.

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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
DJ_AV1.jpg


[This message has been edited by Banzai240 (edited November 21, 2004).]
 
Bill, I am gonna be honest with you. There is no other way. This club has way to many arm chair quarterbacks to just open the process up at this point. Once something is known to work I would love to see that happen. Seams I remember a fella named Kurt once had a formula that everbody shot holes through. I think that would be the ultimate.....Go to a website with your wizbang plug in your numbers and if it doesn't fit anything then it must be a floater.....If you build it anyway TFB.........don't ask for releif.....

[This message has been edited by Joe Harlan (edited November 21, 2004).]
 
Originally posted by Banzai240:

Again, the "process" is:

(Estimated IT-prep HP (flywheel) * Target Ratio) + Adders for individual specs (compared to other cars in the class) = spec weight

All followed by a sanity check to decide if the numbers make sense...
Click to expand...

Wow, this in itself is very helpful info, or at least it makes me feel comfortable that there is at least some kind of guideline. I get the feeling at times that things are more to the whim of whatever is afoot at the moment, so I'm glad to see/hear this...

To quote Mayor Quimby- *with Boston accent*
"So that is the way the winds are blowing, let no one say that I do not also blow..."
 
Originally posted by Banzai240:
For the record... the process IS documented, it's just not public... You aren't going to see that happen anytime soon, because it is, as Joe correctly suggested, still fluid..,

However, I have all but handed you guys the basic process of what we are attempting, so it's not really a secret. The only thing we haven't specified publicly are the target ratios for each class or the specific values for the "adders"...

Again, the "process" is:

(Estimated IT-prep HP (flywheel) * Target Ratio) + Adders for individual specs (compared to other cars in the class) = spec weight

All followed by a sanity check to decide if the numbers make sense...

I personally don't think you'll ever see a "process" or "formula" in the ITCS. We'll do our best to set the seeds and get this all back on track, but we are still only a small piece of the process.
Click to expand...

Darin,

Not for nothing, but the other formula was also documented. I didn't come up with it, it was relayed to me by either Kurt or Sven, I don't remember which. Maybe that's the formula Joe was referring to. But later, there were comments that it wasn't official, it was merely a guideline, etc.

I understand Joe's comment about arm-chair quarterbacks, but we do that now anyway (just look at this BB!). I guess that I believe that we shouldn't have secret ways of doing things, especially when it comes to car classification/specification.

What's wrong w/ publishing the 'process', w/ the class ratios and the "adder" values, w/ the disclaimer that it's a WIP and also only a guideline? Keeping stuff like this in the back room only perpetuates the Secret Car Club of America mindset.

And while we're somewhat on the subject, I would think that the class ratio would be somewhere in the middle of the class' performance envelope, w/ the cars in that class distributed around that 'mean'. "Adders", and any other adjustment factors, would be targeted to narrow the distribution around the mean. So, if you did a scatter plot of all the cars in the ITCS, you would see a tetra-modal distribution, w/ the cars in a respective class clustered around its ratio value. Thoughts?


/edit/ Just a comment on not puslishing things because they are 'fluid' or WIP. That becomes an easy and convenient excuse for never publishing things. They're always WIP, so they're never finalized, so they can't be published. Darin, you shot holes in using any kind of formulaic model because it would never be accurate enough. But that's what you've done, and you're content w/ (or at least accept) a +/- 75-100# margin of error. Really, the only difference between what you just laid out, and what I (and others) advocated 2+ years ago, is that your system isn't formalized and 'official'.
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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608



[This message has been edited by Bill Miller (edited November 22, 2004).]
 
Bill, again the only thing I can add is the formula is untested in the real world. My guess is we will see with this first batch of cars how it is gonna work.....Lord forbid they did a complete reshape of IT only to find out they screwed the pooch. I actually based on what Darin posted here think this can work and work well ony because I personally did a complete spreadsheet years ago based on most of this type of data and a couple of other real world items. I commend the Adhoc and the CRB for having enough sack to give it a shot. Can't be any worse than it has been with no option but to cheat if you had one of the rule bound back markers.....
 
Originally posted by rlearp:
Since nobody has raced one of these in IT I doubt it has been looked at.
Click to expand...

It's been several years, but I recall at least one Jensen in the Southeast. The Comp Board tried to de-classify it, but then did not. I can only assume that the few Jensen drivers out there spoke up.

Grafton
 
Originally posted by Joe Harlan:
Bill, again the only thing I can add is the formula is untested in the real world. My guess is we will see with this first batch of cars how it is gonna work.....Lord forbid they did a complete reshape of IT only to find out they screwed the pooch. I actually based on what Darin posted here think this can work and work well ony because I personally did a complete spreadsheet years ago based on most of this type of data and a couple of other real world items. I commend the Adhoc and the CRB for having enough sack to give it a shot. Can't be any worse than it has been with no option but to cheat if you had one of the rule bound back markers.....
Click to expand...


Joe,

I totally agree that things shouldn't get turned upside down, but if they're going to use a process to classify new cars, going forward, then I think that process should be applied to all the cars in the ITCS, to see how close the current spec weights are to what are predicted by the process. The way I see it, that's only fair to everyone.

I'm guessing that, for some of the cars that were moved down, the process was applied, and the weight in the higher class was deemed too low to be legally achieved (ala the NB in ITC rather than ITB).


This statement bothers me a bit though

<font face=\"Verdana, Arial\" size=\"2\">Can't be any worse than it has been with no option but to cheat if you had one of the rule bound back markers</font>
Click to expand...

Makes it seem as if only those that were 'rule bound' were cheating, and that if you had one of these cars, and did well w/ it, you were obviously cheating. I'm not crazy about the picture that paints.

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