Problem Cars

[Andy Bettencourt]

The point is to classify everyone using the same guess, then let people pick their weapon.

[tnord]

The point is to classify everyone using the same guess, then let people pick their weapon.

i know that's the intent, but i think it's coming to light that it's just not doable.

it's been brought up many times before that there are certain cars that the process fails. Honda S2000, Mazda RX8, most any Porsche derivative, 1st gen RX7 as putting the cars at uncompetitive weights. it's a bit silly to think that it can't create an overdog scenario either, like this Audi example that keeps getting trotted out.

and not all cars get the same guess anyway right?
some get different power multipliers, some get weight breaks for different physical characteristics, some get weight added. i agree that "codifyng" this methodology is a good thing, as it helps consistency now and in the future, but i think you have to recognize that it won't work 100% of the time.

i think it can work MOST of the time, but not ALL of the time.

[JeffYoung]

Travis, give us an example of an overdog that has not been corrected using the process (ignore the SIR on the ITS 325, and assume it had gotten "process weight") or that could not be corrected using the process.

Are there any out there?

[tnord]

well, this Audi is a good example. it won the ARRC yet if it were to be run through the process it would lose 200lbs no? that doesn't really pass my "smell test."

[RacerBill]

i know that's the intent, but i think it's coming to light that it's just not doable.

it's been brought up many times before that there are certain cars that the process fails. Honda S2000, Mazda RX8, most any Porsche derivative, 1st gen RX7 as putting the cars at uncompetitive weights. it's a bit silly to think that it can't create an overdog scenario either, like this Audi example that keeps getting trotted out.

and not all cars get the same guess anyway right?
some get different power multipliers, some get weight breaks for different physical characteristics, some get weight added. i agree that "codifyng" this methodology is a good thing, as it helps consistency now and in the future, but i think you have to recognize that it won't work 100% of the time.

i think it can work MOST of the time, but not ALL of the time.

I would not say that "the process fails". I would say that the results are more accurate in some cases than others. That said, I am really torn between changing the 'formula(s)' for one car, or not (and that is what you are really doing when you say 'lets add 100 lbs to the Fabulous Trashwagon' or 'lets take away 200 lbs from the 1998 Boojum'.

Friendly question for the ITAC. Do you have a spreadsheet with all the cars that have been run thru the process are listed with all of the adders and subtractors? If so then if you change one or more of those parameters, for all cars, you could see what it would do for the weights by making that change. This may be a way to fine tune the process and not be making a change the benifits/hurts a particular car. Just a thought.

And I'll say it again, I really appreciate what the ITAC has been able to accomplish, and encourage them to keep it up (even if I don't get my jacking plates ,errr frame repair, and have to tape up my windshield washer bottle ).

[JeffYoung]

Actually, it didn't win the ARRC I think. The two cars just sat 1-2 on the grid.

Is one ARRC win enough for overdog status? I mean, I just don't see Audi Coupes out there dominating ITB like the 325 did in S, or the CRX in A.

[tnord]

Actually, it didn't win the ARRC I think. The two cars just sat 1-2 on the grid.

Is one ARRC win enough for overdog status? I mean, I just don't see Audi Coupes out there dominating ITB like the 325 did in S, or the CRX in A.

ok....whatever it was. taking off 200lbs still doesn't pass my "sniff test." does it pass yours?

no, one ARRC win is not enough for overdog status, and i don't think anyone will tell you that it is. i think it is enough to say that the cars aren't completely uncompetitive though (given normal conditions).

[JeffYoung]

Yes, it passes my smell test for now. The "Great Realignment" took weight off of Z cars and the 944, all of which had either won (in some cases repeatedly) the ARRC or did well at it. That seemed to work out ok.

My point with the Audi is take the weight off and see how it does. If on track results show that it makes more than the 25% we think it makes, that's the trigger to take another look at the car.

[tnord]

Yes, it passes my smell test for now. The "Great Realignment" took weight off of Z cars and the 944, all of which had either won (in some cases repeatedly) the ARRC or did well at it. That seemed to work out ok.

My point with the Audi is take the weight off and see how it does. If on track results show that it makes more than the 25% we think it makes, that's the trigger to take another look at the car.

ooftah. i just don't agree with that.

it seems like the general principle here is to wait and react to a problem, and given the limited number of Audi ITB cars out there, it's quite possible you won't be able to get the data you're hoping for. the car stays as listed.....more people spend $15k building them.....a year or two later you finally find someone willing to give it up....adjust the weight....and piss off everyone who just built the car (as well as everyone that got beat by it previously).

i don't like that.

[gran racing]

How will track results show it makes more than 25%? It will show how well the overall package does inicluding drivers, but not if the power adder is accurate or not. The Audi is an interesting one - 5 cylinders makes it unique. It sure does get moving from low speeds quickly!

I agree that this still comes down to educated guesses, but it's a hell of a lot closer than it had been previously. I also like the fact we can ask how in the world they came to a conclusion and it can be explained. That provides people an opportunity to give the ITAC proof and other facts which may be contray to initial beliefs. Previously it was the ole "not guaranteed competitiveness" repsonse and not much more than that.

[JeffYoung]

The alternative is to make subjective determinations about on-track performance and adjust weight a priori before knowing how the car does at process weight.

I like that a lot less.

[tnord]

The alternative is to make subjective determinations about on-track performance and adjust weight a priori before knowing how the car does at process weight.

I like that a lot less.

i don't think anyone is proposing that drastic of a change either.

"back in the day" cars were listed based on whatever number the CRB felt was right, based off of imperfect information, with an eye towards on-track results. now, it's done 100% based on some formula (developed by volunteers) which is supposed to be accurate for 40 years of cars across 5 different classes.

to me.....cars get run through the process to get an idea of where it should be. and i bet 90% of the time it would work to just list the output. the other 10% is where some non-standard analysis will need to be considered....which may or may not include on-track results at the ARRC/IT Fest/IT West.

[JeffYoung]

Actually, they were given a weight based on curb weight minus an allowance for items that could be removed plus the 185 lb driver and fuel. No attempt at competitive balance at all. Run what you brung.

Listen, I agree performance should be in the mix somewhere, I just see it as a trigger for reevaluation ONLY.

[lateapex911]

About the Audi;

Two sat on the front row/pole at the ARRCs. But they didn't finish or make it to the tech shed.
First- We have NO idea what engine, head, bottom end, gearbox, etc etc etc were in them. And that's not a slam against the owners either, as it's easy to mistake engines and parts and get the wrong ones in.
Second, it was a fine day, but they were well off the record pace.
Third, it's not like they are trouncing everyone regionally.

I do agree that the result is not one that fits preconceived notions, and I have no problem, no, make that, I think it's prudent, to go digging deeper and get more data before moving further.

[tnord]

Listen, I agree performance should be in the mix somewhere, I just see it as a trigger for reevaluation ONLY.

it's how that reevaluation is done that is the sticking point. with the parameters set by the formula, i think you're going to have a damn hard time finding what you're looking for.

[JeffYoung]

In all cases -- Z cars, 944s, Integras, Miatas, E36s, RX7s, RX8s -- people have been surprisingly forthcoming with dyno data. I know that can be problematic, but the point is we have gotten the data we have needed so far.

it's how that reevaluation is done that is the sticking point. with the parameters set by the formula, i think you're going to have a damn hard time finding what you're looking for.

[lateapex911]

it's been brought up many times before that there are certain cars that the process fails. Honda S2000, Mazda RX8, most any Porsche derivative, 1st gen RX7 as putting the cars at uncompetitive weights. .

Just to clarify,
S2000 -we just don't know. The class is very young, and people think that they aren['t willing to gamble on that car. But it hasn't proven to have failed that car. And lets not trot out the "nobody is building one, therefore it fails" argument. Nobody is building 75% of the cars listed! Yet.

Mazda RX-8. Tough case, when Mazda lies about the stock power. If we have hard data, we might take a closer look, can't say for sure, but there hasn't been a solid case made for the car yet.

A 968 is doing very well in ITR in the NE, and he has yet to pre the car all the way.

1st gen RX-7 is known to be a bit heavy in ITA, but there's no sense setting it 'right' in ITB, as the car is raced happily in IT-7. The solution came too late for that car. In that sense the process fails it, but it could be rectified. But the 'fix' is worse than the existing situation. (A move to B, and the attendant swap to 6" rims)

[lateapex911]

In all cases -- Z cars, 944s, Integras, Miatas, E36s, RX7s, RX8s -- people have been surprisingly forthcoming with dyno data. I know that can be problematic, but the point is we have gotten most of the data we have needed so far.

hee hee.

[tnord]

In all cases -- Z cars, 944s, Integras, Miatas, E36s, RX7s, RX8s -- people have been surprisingly forthcoming with dyno data. I know that can be problematic, but the point is we have gotten the data we have needed so far.

because these are all popular cars with lots of them around. have fun getting data for a one-off.

[JeffYoung]

Raymond/Stephen, you guys willing to put your car on the dyno?

Everyone has seen my dyno sheets......

Blake's ITB 914 the same......

We all saw Greg's on the NX.......

Like I said, for whatever reason, IT culture is fairly open with dyno data.

because these are all popular cars with lots of them around. have fun getting data for a one-off.