So about these Pony Cars for ITR...

[lateapex911]

Tristian, ask yourself why you're building your ITR car. (Welcome back, BTW...IIRC you had to step away for a bit and sell the car due to a family tragedy...if I'm right, glad you've gotten by that )

Are you building it because you like the number of cars you'll race against in the class? Are you building it because you like Nissans? Because you like the IT ruleset? (Not too much, not too little). Or?


Now, try to redraw your conclusions, but from another point of view....

 

[Knestis]

...1- Original specs from the manufacturers are under/overstated. Now, we already have issues dealing with that...

We don't adequately handle those situations currently (I don't personally think). That's a quandary for which a solution requires agreement on first principles. We don't have anything like consensus yet so it's an open question...

2- The basic assumption is that two factors will predict an outcome: Size and efficiency. It is assumed that motors that have high specific outputs just can't see large gains, (OK, I buy that), but the converse is assumed that low specific outputs WILL see bigger gains. ...

Those cases fall into the "we have to prove a negative" situation, whereby to use anything MORE FAVORABLE than a 25% power factor, we need "proof" that can't happen. It sounds harsh but make/model examples that fall into that trap are kind of doomed so I confess that I neglect that side of the problem. Of course, that argues for 25% being a FLOOR and the Nordwald Conspiracy proposes it as a middle... Hmmm.

K

 

[tnord]

We don't adequately handle those situations currently (I don't personally think). That's a quandary for which a solution requires agreement on first principles. We don't have anything like consensus yet so it's an open question...

i think the model handles those situations pretty well. it says, "i don't give a F what rating the factory gives it, it has 2.0L and should be able to achieve X power level."

 

[Ron Earp]

Those cases fall into the "we have to prove a negative" situation, whereby to use anything MORE FAVORABLE than a 25% power factor, we need "proof" that can't happen. It sounds harsh but make/model examples that fall into that trap are kind of doomed so I confess that I neglect that side of the problem. Of course, that argues for 25% being a FLOOR and the Nordwald Conspiracy proposes it as a middle... Hmmm.
K

This was my point many posts ago but I must be not understanding how this thing works. However, Travis said I did understand how it works.....anyhow.....

You take one model car/engine and say "This one gets a 25% gain". Now, any engine that meets this bogey's hp/L/cyl figure also gets a 25% gain.

If the engine we're "testing" has a stock figure is under the bogey's hp/L/cly figure, look out, because it'll be scaled up to assume to be close to as efficient as the bogey. That simply doesn't happen in practice. No matter what you do to a pushrod 3.8L OHV engine it won't be as efficient as a 1.8L 4 valve Integra.

For example, as test case, the V6 Camaro:

[FONT=&quot]200hp / 3.8L / 6 cyl = 8.77 hp/L/cyl[/FONT] <= Stock hp/L/cyl of the Camaro

[FONT=&quot]((8.77 – 19.44) / 19.44 / 3) * 100 = -18.29[/FONT] <=This number is negative because the test case is not as efficient as the bogey, the 19.44 hp/L/cyl Integra

[FONT=&quot]25 – (-18.29) = 43.29 % expected gain[/FONT] in IT trim <= % gain IS MORE than 25% because the stock engine was not as efficient hp/L/cyl as the Integra. If the Camaro produced 19.44 hp/L/Cyl then the gain would be 25%

The V6 Camaro is not going to see a 42.29% gain in IT trim. That'd be a 286 hp 3.8L OHV pushrod engine, 75 hp/L. While I know that is no big deal in the DOHC 4V VTEC domain, it is a huge deal for OHV pushrod engines to reach that sort of specific output.

There needs to be different types of scalars for different engine architectures.

Ron

 

[Tristan Smith]

Tristan I highly respect your opinion as a long time IT racer. But that argument is akin to saying Miatas have a place to race in Spec Miata, Prod, and SS so they should not be allow to race in IT. Can a car only have one place to race? Should a car type only be limited to one engine option? If so there are numerous examples in IT that would be made redundant since they are already available in various configurations, including my own 260Z.

There are a lot of racers (the letters on the subject were heavily in favor of the Pony cars in ITR) who would like to race a Mustang or Camaro outside the AS ruleset and IT fits the level of modifications they wish to perform.

The discussion on this thread about another classification process was a digression from the Pony Car thread. There is no need to alter the ITR classification process. If you have a look at the proposal, which is around 1.5 years old, you'll find nothing new or rule changing was proposed to fit the V8 Ponys in ITR.

Fair enough. Although the Miatas were classed in IT BEFORE Spec Miata was created. And the reason Spec Miata was classed, at least to some degree was because many felt a competitive Miata couldn't be built for IT (obviously proven wrong). Sure there were other reasons.....but I digress. If folks want the v8's in, bring them in. I was just voicing may opinion. The AS ruleset got progressively out of hand as competitors claimed that they had to do "X" and "Y" to the car, and "A" and "B" parts had to be put on the car to make them safe, reliable, ect. I think you will see a lot of that going on if the v8's are put in ITR. Now you all will say, "well we won't let that happen", and you probably won't, but.......just my opion. Take it for what it's worth.

 

[Tristan Smith]

Tristian, ask yourself why you're building your ITR car. (Welcome back, BTW...IIRC you had to step away for a bit and sell the car due to a family tragedy...if I'm right, glad you've gotten by that )

Are you building it because you like the number of cars you'll race against in the class? Are you building it because you like Nissans? Because you like the IT ruleset? (Not too much, not too little). Or?


Now, try to redraw your conclusions, but from another point of view....

Yep. Building an ITR 300zx because I am a Nissan guy. Already did the 240sx thing, and there aren't any other rear drive Nissans I want to try. And yes I like the prep level of IT. Hey like I said, I was just throwing in my 2 cents. I'll race who ever shows up. I won't be any less of mediocre driver if the v8's show up! ha.

As of this week (and these days I take it week by week) I am still gainfully employed. I was layed off my job is August and then reinstated a month later. Go figure. But I am grateful in this economy!

 

[tnord]

I think one of the things that makes Travis' formula more appealing is the use of the 'rwhp' factor (.85), which has the effect of smoothing the output. If you remove that constant the results are more noticeably off; you end up with the 300ZX making 305 HP, the BMW making 260, the V6 Camaro making 268, and my puny little ITA 240SX making 187.

uhh....they probably do make those power numbers at the flywheel. the .85 is in there to spit out a number you'd see from the dyno, and accounts for drivetrain loss. i did that so i can compare the formula to "what i know" regarding how much power certain cars make on the drums.

 

[Ron Earp]

I think one of the things that makes Travis' formula more appealing is the use of the 'rwhp' factor (.85), which has the effect of smoothing the output. If you remove that constant the results are more noticeably off; you end up with the 300ZX making 305 HP, the BMW making 260, the V6 Camaro making 268, and my puny little ITA 240SX making 187.

Earl, the rear wheel factor doesn't do anything with respect to "smoothing" the data. It is simply a scalar value and just gives you an approximation of rear wheel hp.

100 flywheel hp or 85 rear wheel hp. Assuming a 15% driveline loss this is the same thing.

A 3.8L OHV IT-trim Camaro with 286 flywheel hp is just as improbable as a 3.8L OHV IT-trim Camaro with 243 rear wheel hp. They are the same.

 

[Knestis]

Thanks for connecting the dots for me, Ron. I think you are kind of talking about the "floor vs. middle" question that Jake surfaced. MY disconnect was that I had *never* thought about the output of the process as anything like "real horsepower." Partially, it's because I don't know enough about the various make/model examples for them to make much sense but also - I suppose - it's because I view the outcome as a contributor to additional math that actually spits out a race weight. We already apply torque adders to the cars most likely affected by what you describe, in the Nord v.1.5 plan, and I had *NOT* done that with the output examples I played with. The WEIGHTS of the cases I looked at appeared to shake out close(ish) to where they are set by the current process, which suggested to me that it has potential. It's a proxy for torque, which I know complicates the conversation...

K

 

[tnord]

And, uhhh, no, I promise they don't make those numbers at the flywheel.


.

160whp (rumored number for a certain former 240sx) * (1/.85) = 188 crank hp.

 

[Ron Earp]

. The WEIGHTS of the cases I looked at appeared to shake out close(ish) to where they are set by the current process, which suggested to me that it has potential. It's a proxy for torque, which I know complicates the conversation...
K

Kirk,

I never got as far as looking at the weights it spits out. I couldn't get past the first steps and issues I saw with the resulting numbers, nerd I am. Tonight I'll play with it a bit more and run it in ITS to see what it does with weights. Naturally I'll post the results in a readable fashion.

I think it has some promise. But, I also feel like of all the things discussed on this board about balancing things on a pin, the slippery slope to prod, and so on - this is it. Way more so than motor mounts being free or kicking out washer bottles or removing your window glass and headlights. This can balloon into models for DOHC 4V, SOHC 2V, OHV, and rotary engines. Next thing you know folks will want to account for valve area. And cam lift. And compression. And then we're trying to build a engine dyno program with a committee. Might as well just use desktop Dyno2000, it has been done. Nobody much likes desktop Dyno2000 either.

Ron

 

[lateapex911]

The AS ruleset got progressively out of hand as competitors claimed that they had to do "X" and "Y" to the car, and "A" and "B" parts had to be put on the car to make them safe, reliable, ect. I think you will see a lot of that going on if the v8's are put in ITR. Now you all will say, "well we won't let that happen", and you probably won't, but.......just my opion. Take it for what it's worth.

Tristian, I hear you, and trust me, that aspect has been brought up and discussed. HARD.

If I may brag a bit...the ITAC has shown, I think, over the past few years (actually going back quite aways) a commendable resistance to line item exceptions (That's exactly what you are talking about). And, actually, we've done away with some, which is unheard of in the SCCA, LOL.

While I'd like to think that your concern won't be an issue because the ITAC won't let it, I'm not that naive. The major factor that will keep them in check is the fact that the IT category is a multi marque series, with a long history of "model blindness". AS is essentially a two car category, and that's morphed into a 1.5 model category. That means that changes can be implemented far more easily. Now, those changes stack up, and with time can create a different class ...but I'm not worried about that at all in IT.

If they become overdogs, we have the mechanism to fix it, and we've shown that we are up to that task in the past.

 

[Knestis]

I think it has some promise. But, I also feel like of all the things discussed on this board about balancing things on a pin, the slippery slope to prod, and so on - this is it. Way more so than motor mounts being free or kicking out washer bottles or removing your window glass and headlights. This can balloon into models for DOHC 4V, SOHC 2V, OHV, and rotary engines. ...

I couldn't disagree more, actually. In fact, my greatest fear right now is that we'll eek forward trying to do a "better job" ABSENT any explicitly defined model, and increasingly allow subjectively assessed "what-we-knows" to influence decisions.

It's NOT a major problem right now but there are several places in the current process where subjective decisions by the ITAC are allowed. If we're saddled with constraints like the "100 pound rule" and collectively (all us us) have low expectations for precision, there's a lot less organizational pressure to "get it right" than will likely be the case in the future, when "not on the head of a pin" means "within 5 pounds of what the process says."

So maybe this isn't it but it's a hell of a big step toward understanding how it might work. And REMEMBER - my first assumption is that a predictable, repeatable, transparent system that's "wrong" sometimes is better than any one that allows very much human interference. THAT'S what got Production where it is today.

K

 

[tnord]

i have to agree with kirk on that.

<----is totally fine with 50lbs outside of process weight being the target.

 

[Ron Earp]

I think it is a good idea to strive to create an impartial process that is devoid of hearsay, what we knows, and so forth. I do. But I suppose two things stand out to me:

1) IT really isn't broken. IT seems to work very well right now, although I'd estimate that if we had an impartial model in place new car classifications wouldn't be so damn hard - i.e. Pony cars and the like.

2) Any project always grows beyond the initial scope and boundaries envisioned by the creators.

We don't seem to be able to change some really simple IT characteristics that the membership as a whole seem to want. Things like "ditch the washer bottles" and "make motor mounts free" without others bringing up the "Unintended Consequences" and using that UC spectre to deny the request.

We don't seem to be able to do a simple thing like ditch the washer bottles because we don't think we can hold the rules development to that simple change only. How can we be sure that we can develop a new IT classification model, hold that model to the bare essentials of IT, and not suffer UC with a prod like result?

Hey, I'm with you on making IT a better place. But I'm also with you on not breaking it.

 

[Xian]

Ron, if someone tells me motor mounts are free, then my engine is getting lowered and moved back by several inches in the chassis. KISS, TANSTAAFL, and all that.

 

[Tristan Smith]

160whp (rumored number for a certain former 240sx) * (1/.85) = 188 crank hp.

Sorry I call bullshit on that one. My Sunbelt built and tuned (on a dyno) LEGAL motor made 158 hp and 162 ft/lbs at the FLYWHEEL. Anyone making the numbers you are quoting is either cheating or sniffing too much race gas.

 

[Tristan Smith]

I think it is a good idea to strive to create an impartial process that is devoid of hearsay, what we knows, and so forth. I do. But I suppose two things stand out to me:

1) IT really isn't broken. IT seems to work very well right now, although I'd estimate that if we had an impartial model in place new car classifications wouldn't be so damn hard - i.e. Pony cars and the like.

2) Any project always grows beyond the initial scope and boundaries envisioned by the creators.

We don't seem to be able to change some really simple IT characteristics that the membership as a whole seem to want. Things like "ditch the washer bottles" and "make motor mounts free" without others bringing up the "Unintended Consequences" and using that UC spectre to deny the request.

We don't seem to be able to do a simple thing like ditch the washer bottles because we don't think we can hold the rules development to that simple change only. How can we be sure that we can develop a new IT classification model, hold that model to the bare essentials of IT, and not suffer UC with a prod like result?

Hey, I'm with you on making IT a better place. But I'm also with you on not breaking it.

I'm with you on this Ron, and that was my concern posted earlier. The question for me then, is if we don't classify the V8's do we really still need to be having this discussion about a new classification process?

 

[Ron Earp]

I'm with you on this Ron, and that was my concern posted earlier. The question for me then, is if we don't classify the V8's do we really still need to be having this discussion about a new classification process?

Hey Tristan,

They are unrelated. The thread started about "hey, what about those Pony cars" because people knew the proposal was out there but there was no feedback from the ITAC and/or CRB. Once that got kicked off the thread degenerated into various things about the classification process - how does it address torque, how does it address % gains seen in some engines, and so on. The V8 Pony cars fit just fine into ITR although the weight is about 100 lbs more than the 300zx and they have a much poorer suspension. Wouldn't be my tool of choice but folks do want a place to race them in IT.

Anyhow, the thread that has started out about V8 Pony cars is now about the an alternative classification process that encompasses all of IT, not just ITR/Pony cars. The thread might should be peeled off into another topic but generally when that is done on forums both topics, the new one and the parent, go cold.

Ron

Ron, if someone tells me motor mounts are free, then my engine is getting lowered and moved back by several inches in the chassis. KISS, TANSTAAFL, and all that.

Cool. Turn it around 90 degrees and fix it so it drives the correct set of wheels too!

 

[Knestis]

Deep Throat - 160whp (rumored number for a certain former 240sx) * (1/.85) = 188 crank hp.


Mata Hari - My Sunbelt built and tuned (on a dyno) LEGAL motor made 158 hp and 162 ft/lbs at the FLYWHEEL. Anyone making the numbers you are quoting is either cheating or sniffing too much race gas.

Welcome to a microcosm of "what we know."

K