ITB - what a bunch of crap

JeffYoung said:
And that is my personal "ME" problem. If you go to a average hp number, I've got a ton of torque below 3500 RPM or so that just isn't usable. I get killed. 325e gets killed with weight.

The average hp numbers reward high revving cars that make peak power in a narrow band.

Someone above posted something along the lines of "IT is working really well right now, why monkey with it?" That I agree with. No overdogs in S, A, or B that I can see.
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And cars that already perfrom well with little torque like the 2nd gen RX-7 will get rewarded.

Right now, things are fine IMHO. Is there a car that is hurting their repsective class because it has too much torque? The process does take it into account - just like any subjective adder - when it's anomolous to its class. The ITR pony cars are getting 100lbs for just torque.
 
JeffYoung said:
And that is my personal "ME" problem. If you go to a average hp number, I've got a ton of torque below 3500 RPM or so that just isn't usable. I get killed. 325e gets killed with weight.

The average hp numbers reward high revving cars that make peak power in a narrow band.
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Not sure you read what i wrote quite right... or if I wrote it quite right. the idea is that only the ave hp in the powerband that would actually get used(usually/often) would be considered... that however, sure doesn't make things any simpler
 
pfcs said:
Sorry Ralph but you're wrong. Torque is force and that's what accellerates a anything.
By changing gearing, you can skew that relationship but in ANY gear, the vehicle will have the greatest accelleration as it passes thru the torque peak. Period!
Because of that confusing relationship between HP & torque there is much misinformation. One fairly true rule is that you will get the best use of the package if you arrange gearing so that if you shift @max hp, the rpm falls back to max torque (torque peak). Most racer's, especially those with fairly stock engines, mistake noise for accelleration and use a higher rev range than is ideal, myself included!
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wait! who is this Ralph guy?? lol

as far as the important part goes: once again you speak some truth. And you seem to be a pretty smart (albiet stubborn) guy. However you need to review your physics...

Food for thought:
FORCE is what accelerates anything - absolutely correct!! however WORK tells us how or at what rate that FORCE is applied. - I think you said that too. WORK tells us how much energy is put into something over what distance. HORSEPOWER tells us how or at what rate that TORQUE is applied. HORSEPOWER tells us how much energy the engine puts out at what RPM

or look at it this way:
Work is putting energy into something, in this case a kinetic energy into a racecar. Horsepower is the engine's capacity for doing work. Therefore when the engine is operating at a higher horsepower it is capable of (and is) putting kinetic energy into the car at a higher rate which would result in a higher rate of acceleration.

once again the "rule" you mentioned is a good one, but not the best. The best rule would be to use the RPM band where you have "the most area under the horsepower curve" This would most likely mean revving a bit past peak hp as long as it does not drop off quickly...


My physics courses were not yesterday, I don't have all the formula's memorized but the basics of what I am telling you are true. Fact not opinion... please do some research before you try to tell me I am wrong again.
 
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Andy Bettencourt said:
And cars that already perfrom well with little torque like the 2nd gen RX-7 will get rewarded.

Right now, things are fine IMHO. Is there a car that is hurting their repsective class because it has too much torque? The process does take it into account - just like any subjective adder - when it's anomolous to its class. The ITR pony cars are getting 100lbs for just torque.
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1st part: it performs well because it has a good "area under the curve" in the RPM band that it used while at speed on the track. Torque, or lack there of, has nothing to do with it...

2nd part: and what is this based on?? are you serious?? Are those pigs not heavy enough already? 100 lbs??? ouch...
 
Understood. Then the argument becomes what is the useable power band for each car. That to me, respectfully, sounds like a nightmare.

I'd rather have the 25/50/100 subjective adder for torque.

CRallo said:
Not sure you read what i wrote quite right... or if I wrote it quite right. the idea is that only the ave hp in the powerband that would actually get used(usually/often) would be considered... that however, sure doesn't make things any simpler
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My physics courses were not yesterday, I don't have all the formula's memorized but the basics of what I am telling you are true. Fact not opinion... please do some research before you try to tell me I am wrong again.
__________________

I took physics a long time ago, but force=mass x accelleration (F=MA) still applies.
Or A= F/M. The greater the force, the greater the acceleration. In any gear, the force is maximized at the torque peak of the engine. If you shift up, the gearing multiplies the torque out of the trans, but the engine torque is lower, and the derived torque out of the transmission is less than the torque at the same output rpm (vehicle velocity). You can make it clear by thinking what happens to rear wheel torque when you shift to a lower gear-look at the torque curve and do the math: you're running a fixed ratio with a variable torque as you move along the torque curve, where will the torque at the wheels be max? At the engine torque peak. I know it's somewhat counter-intuitive, but it's the hard truth and simple physics. This does not mean we want to lug the engine, just that when you're at peak torque in any gear, the vehicle will have it's max accelleration at that velocity-if you're revving a gear past the point where the next gear would bring you to the torque peak, you're leaving accelleration on the table.
 
CRallo said:
In my eyes, the most accurate way to take "torque" into account, is to use an average horsepower number and not a peak horsepower number. This however would not be simple...

-where would the data come from??
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in order to use torque in any kind of process calculation we would need to use stock numbers like we do horsepower now. no other way would fit the premise of the process.
 
How do we determine "useable power band" for purposes of the process?

Seems impossible to me.

dickita15 said:
in order to use torque in any kind of process calculation we would need to use stock numbers like we do horsepower now. no other way would fit the premise of the process.
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JeffYoung said:
How do we determine "useable power band" for purposes of the process?

Seems impossible to me.
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Take the biggest(or average) rpm change the engine would see on a shift near redline in the first four gears based on each cars gearing. now take that number as the witdh of your powerband and take it to the horsepower graph of that car to find where it will be... however, some variables here include cars that will rev higher than stock when in IT trim and rearend gear ratio... these would have to be controlled or dealt with. It may be a can of worms not worth opening, but it's a one worth considering or building on...
 
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Andy Bettencourt said:
OK, just wanted to get your attention.

I had resisted the assertion that ITB was the 'new ITA' - but heck, this class is really redifining itself into something special. Accords, Civic's, CRX's, Volvo's, Golfs, 924's, BMW's, Audi's, Preludes, a freakin' gorgeous Alfa...

Awesome guys. Awesome. Add in Scott, The Canadians, the Blethens, Beren, Boo-hee - and oh-snap is that a showdown.

ITS seems to be the class that is static now...only 12 starters at the ARRC? Diverse yes (top 6 were all different models), but is it quality over quantity? Thoughts?
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Ironic that this post started another heated argument on IT.com about rules... just had to remind you all where we started this discussion... :blink:
 
pfcs said:
I took physics a long time ago, but force=mass x accelleration (F=MA) still applies.
Or A= F/M. The greater the force, the greater the acceleration. In any gear, the force is maximized at the torque peak of the engine...QUOTE]

You make a very, very good arguement. I've actually doubted my self a bit since we started this... However, every time I review it I come back to the same conclusion.

You are right about Force, but like you say, it's not so simple...


More food for thought:

-If torque is all that matters, than why are we so worried about hp?
-why do we measure an engine's performance (it's ability to accelerate the vehicle) in horsepower??
-ever ride a 600cc sport bike? it makes very little torque, but at 16000 RPM it makes alot of horsepower and accelerates like a bat out of hell!!!
-ask a good engine builder or dyno guy where the peak acceleration is... trust me the only reason they car about torque is because when you put some rpm into the equation you get horsepower and that is what makes the car go!




good debate, though we definitely hijacked this thread...
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CRallo said:
1st part: it performs well because it has a good "area under the curve" in the RPM band that it used while at speed on the track. Torque, or lack there of, has nothing to do with it...

2nd part: and what is this based on?? are you serious?? Are those pigs not heavy enough already? 100 lbs??? ouch...
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You don't know if they are "heavy enough" because an ITR Mustang, Camaro, or Firebird has yet to hit the track. We're not talking about adding 100# to their stock weight - we're talking about the process of listing them in ITR to include an "adder" of that amount in an attempt to take torque into consideration. Remember that the basics of the process use the stock quoted HP number as a starting point.

* * *

Dick is right on that we are constrained to the stock quoted numbers - warts and all - as the inputs to our process. We can NOT do any calculus to derive areas under curves because we don't HAVE curves to work with.

Maybe let's be a little LESS clever for a second: How can we consider QUOTED torque and/or HP to more reasonably manage the variables. My thinking was that maybe it's torque INSTEAD of HP, since the latter is derived, and since we can control what we do with that torque to some degree with final drive gearing...?

K
 
I’ve been following this discussion with great interest. I’ve posted plots in the past showing the linearity of IT classed weight with hp, and posted plots that show very little correlation between torque and IT classed weight. I’ve drawn up some models in Excel but none of them do what is needed.

As it has been pointed out, the engine only puts out a twisting force, torque, and we conveniently calculate horsepower from this so that we know how much work we can do with a particular engine. One proposed scheme would use the torque curve of the motor and simply integrate this for the area. We’d then use this area to class the car. But there are many problems here, the largest of which is we will never have the torque curves of the motors in question and anomalies such as this one (data from some very IT-like cars, probably easy to figure out which ones..):


engines.jpg




These cars would probably turn somewhat similar lap times at a similar weight. But following strict adherence to the torque curve model CarB would be classed incorrectly with respect to weight. It'd be "too fast" on track due to lack of weight in comparison with what CarA would get from the torque model.

I remember reading an article by Kevin Cameron (Cycle World writer, crew chief, engine builder, and all around guru of mechanics) where he pointed out an extremely simple but valid point. If given two motors with similar hp and torque peaks, the engine with the larger RPM difference between the hp and torque peak is the engine you want to be racing, you’ll be winning.

Maybe it would be possible to come up with a multivariate model that takes into account Peak HP, Peak Torque, and the RPM difference in these peaks. I’d certainly be willing to try it out.

Ron
 
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Whatever models you want to test, understand that you can't use dyno charts and area under the curve - because these things don't exist for 90% of the cars in the ITCS.

We all know torque is a factor but what is broken that we are trying to fix here? We are racing track cars. If you could trade your high torque-low revving tractor motor for a free-spinning, high-revving motor with less torque - at the same weight, I bet ya'll would. We aren't pulling sleds of lead for 300 feet.

I ask again, what car is out there that is hurting a class so badly that this needs to be re-invented? The hp-based model with exceptions for torque/displacement seems to be working fine. I am all for improvement - but you guys are tilting windmills, no?
 
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Andy Bettencourt said:
And cars that already perfrom well with little torque like the 2nd gen RX-7 will get rewarded.

Right now, things are fine IMHO. Is there a car that is hurting their repsective class because it has too much torque? The process does take it into account - just like any subjective adder - when it's anomolous to its class. The ITR pony cars might be getting 100lbs for just torque, if the CRB approves the inclusion of them.
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Fixored that for 'ya........:cool:
 
Andy Bettencourt said:
Whatever models you want to test, understand that you can't use dyno charts and area under the curve - because these things don't exist for 90% of the cars in the ITCS.

We all know torque is a factor but what is broken that we are trying to fix here? We are racing track cars. If you could trade your high torque-low revving tractor motor for a free-spinning, high-revving motor with less torque - at the same weight, I bet ya'll would. We aren't pulling sleds of lead for 300 feet.

I ask again, what car is out there that is hurting a class so badly that this needs to be re-invented? The hp-based model with exceptions for torque/displacement seems to be working fine. I am all for improvement - but you guys are tilting windmills, no?
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Spoil sport. It is winter and we are bored. You could at least play along for a little longer.:026:
 
Knestis said:
I PERSONALLY agree that, based on what I understand of the specification system, that the MkIII Golf is something like 50-80 pounds too light. That's compared to the process weight (as I recall, too rushed this morning to dig out the spreadsheet), not to other cars in the class that might be at different places relative to that same index.

K
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And once again I am on record as agreeing with Kirk on this one.
I like to use results as an indicator that the process needs to be double checked, but NOT as a motivation to make a change.

But I will note this (again)...
If the process says that car A is 80lbs too light and car B is 120lbs too heavy... Thats a 200lb disparity.

THAT needs to be fixed. I think most of the ITAC agrees with that and I have confidence that they are working on it.

ITB currently has the potential to be the most diverse class in club racing. Add to that the (relatively) cheap cost to play and the current economy and "getting it right" becomes very important.
I can easily see grids with ~30 cars at the big races, with as many as 10 or 11 makes and models having a legit shot at the win. But we gotta fix those little issues like 200lb "in process" weight swings first.

I get all warm and fuzzy thinking about what ITB could be in the very near future, and the amount of "secret car club" points that could be dropped in the process.
 
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