IT Class Philosophy

[gran racing]

Andy, this is essentially what I would use as a general guideline. (From post 52)

A point when one can build a solid cage and doesn't need to skimp on safety; when it is not necessary to push the envelope to get down to minimum weight; and when a person does not need to put the car on a rotisserie. One should be able to go into a home garage with farily basic tools and be able to accomplish this. Pretty basic stuff like taking the carpeting out, rear seat, passenger seat, take a chisel and remove the sound deadening on the interior surface, take the A/C out, remove the sunroof and plug that.[/b]

I agree that there will always be people spending significant sums of money on motors, suspensions, tuning, weight placement, yadda, yadda, yadda. Within the IT principal, I just don't feel that attain weight should be of an overly challenging (see above) process.

This is only a small part of my reasoning, but as someone relatively new to IT racing, it would have been frustrating to know that in order for me even just to get to my spec weight it would consume a significant amount money and time. In this scenario, it just makes getting into IT a bit harder and more expensive. I know, I know. Choose a different car; but how many people want to race the car they have sitting in the driveway, or the car they just think is cool.

Hey, I'm done with the weight thing as I'm all to throughly enjoying having my passenger seat in, among other balast to make weight. I am so thankful I'm on this end of the spectrum.

[Andy Bettencourt]

I know, I know. Choose a different car; but how many people want to race the car they have sitting in the driveway, or the car they just think is cool.
[/b]

And this my friend, is NOT the way to the podium as a general rule for the average racer. In every form of racing, there will always be 'a car' for the class.

[tnord]

the guy that cares so much about racing a specific car is not the guy who cares so much about winning. same theory applies to the ease of achieving weight thing.

the guy that refuses to spend the time and money on getting to weight is the same guy that refuses to spend $7k on a good motor, so even if he could get to weight easily, he still wouldn't be competitive.

[924Guy]

Amen. And that guy (formerly me) needs to be content with just getting to the top half of the field, in sight of the podium.

The only reason I'm no longer that guy is thankfully the ITAC saw fit to correct my classification... though only after I'd been racing the car for many (4-5?) years. Till that point, I was happy, but getting discouraged. I still wanted to race my car, not change. I started a different racing series with the "other guys" (NASA) where I could be competitive as-is.

But my car still had a good 3- seconds left unused in it!! Not just build; actually more driver than anything. I was always pretty slow.

[gran racing]

Don't forget that my car was in ITA not so long ago. It wasn't until it was moved to ITB when I started dumping money into the car.

[lateapex911]

Don't forget that my car was in ITA not so long ago. It wasn't until i I went off big in West Bend that I REALLY started dumping money into the car. [/b]

fixed that for ya....

[gran racing]

I had a well prepped motor before that. The other items were actually in big part due to us deciding to have a kid next year and my realizing that I better build the car the way I want it now. LOL

[Bill Miller]

Read the whole 5 pages, lots of good discussion.

The more I think about this, the more I like just setting a process weight, and class, for a car based on what is a reasonably expected min. weight. I don't think you can use a percentage of curb weight (but that might not be a bad place to start), because each car will be different. Some will come stock w/ lots of heavy stuff that can get tossed (pwr w/l, sunroofs, etc.). Once that weight/class is determined, the process weight for the next class down should be determined, and the car given the option of running in Class X a xxxx # or Class Y at yyyy #. I think if you do it for everybody, then no one can gripe that they didn't get the same opportunity as everyone else.

I had considered Greg's (and others&#39 option of setting a cutoff percentage of weight change from one class to the other, but that may make sense. Just haven't thought about it enough to form an opinion.

If a car is in the fat part of the curve - can comfortably make process weight - then it shouldn't be a candidate. If it's an outlier, it might make sense.[/b]

Kirk,

I'm really surprised at seeing a comment like this from you. "Comfortably make process weight"

[Knestis]

Having done a 10/10ths chassis build-up, I really do understand the law of diminishing returns on the IT lightening gig. Do I think that it should be possible for someone to take a car that can make its specified process weight, whittle out the last 20 pounds, and put them back in the form of additional rollcage stiffening or something else that puts weight in a more optimal place? Yes. Do I think it should be necessary to do so - that the process (or the spec'd weights of cars within the process) should be tweaked such that it is necessary to do so? No, I don't necessarily think this.

Remember that I'm already on record as saying that I'm more than comfortable with the reality that the normal variance in laptimes imposed by the average club driver's skill level are WAY greater than the potential change due to +/-50# of weight. Probably even 100#. We don't need a micrometer to build a doghouse, so it's silly to argue about 1/000ths of inches when quarters or eighths will do just fine.

The rules have to accommodate that someone WILL go crazy but I agree that they shouldn't HAVE to go crazy, but I'm talking within my 50 pounds personal threshold of pain. Don't strip the crap out of the interior? No love from me. That's a right of passage and if you aren't willing to go at least that far, don't whine.

K

[Bill Miller]

Thanks for the explanation, I was worried for a sec.

[Jake]

I like the sound of the “let the process let the car fall where it may” stuff – it “sounds” like it takes out the subjectivity.

But speaking of subjectivity – I’m trying to get a handle on the “subjective” adders and subtracters. If the MR2 process weight (sounds like something that came out of a computer) is 2550 – where is the subtracter that it only is a 1.6L motor which makes it harder make torque or hp than a 2.0L that much of the class has? And who verifies that it really needs a 100lb adder to offset its weight distribution. Is this a sound engineering number? Do 50/50 distribution BMW and Miata’s have the same weight adder?

As it has been said, I firmly believe that the RX7/MR2 moves to B will be lateral moves. Still backmarkers, but at least they can make weight. But I’m not sold that some cars are the cars to have and some will never be competitive. There are REASONS for this – real engineering ones. (Lack of TQ for RX7’s, lack of potential for MR2’s, etc.) And if those don’t warrant a variable in the process function, I’m bothered by the fact that the MR2’s weight distribution gives it another 100lbs over it’s FWD sister car the Corolla. And worse – nearly 100lbs over the GEO Prizm that has a version of the same motor that produces 130hp stock. (and before anyone asks – those parts cannot be used legally) Talk amongst yourselves...

[Andy Bettencourt]

I like the sound of the "let the process let the car fall where it may" stuff – it "sounds" like it takes out the subjectivity.

But speaking of subjectivity – I'm trying to get a handle on the "subjective" adders and subtracters. If the MR2 process weight (sounds like something that came out of a computer) is 2550 – where is the subtracter that it only is a 1.6L motor which makes it harder make torque or hp than a 2.0L that much of the class has? And who verifies that it really needs a 100lb adder to offset its weight distribution. Is this a sound engineering number? Do 50/50 distribution BMW and Miata's have the same weight adder?

As it has been said, I firmly believe that the RX7/MR2 moves to B will be lateral moves. Still backmarkers, but at least they can make weight. But I'm not sold that some cars are the cars to have and some will never be competitive. There are REASONS for this – real engineering ones. (Lack of TQ for RX7's, lack of potential for MR2's, etc.) And if those don't warrant a variable in the process function, I'm bothered by the fact that the MR2's weight distribution gives it another 100lbs over it's FWD sister car the Corolla. And worse – nearly 100lbs over the GEO Prizm that has a version of the same motor that produces 130hp stock. (and before anyone asks – those parts cannot be used legally) Talk amongst yourselves...
[/b]

Jake,

Most of your questions hav been answer a hundred times on this site. We just can't keep typing it over and over. People will hear and read what they want. Maybe a search can get you up to speed.

[Knestis]

... There are REASONS for this – real engineering ones. (Lack of TQ for RX7’s, lack of potential [emphasis Kirk's] for MR2’s, etc.) And if those don’t warrant a variable in the process function, I’m bothered by the fact that the MR2’s weight distribution gives it another 100lbs over it’s FWD sister car the Corolla. And worse – nearly 100lbs over the GEO Prizm that has a version of the same motor that produces 130hp stock. (and before anyone asks – those parts cannot be used legally) Talk amongst yourselves...
[/b]

Dumb question - has the Prizm been rescaled with the process? Maybe IT is the outlier.

Interesting point about the RWD/FWD difference. Just like the division was made larger for high-HP FWD cars in S, maybe it's appropriate to re-examine the assumptions about the difference for lower-powered cars. The split might not be so large for cars down around 110-120 hp, that just can't overuse the front tires so much.

Now, on the "lack of potential" point: If we follow the good advice elsewhere here about separating the tweener issue of a car not being able to make its minimum weight and DO put the MR2 in ITB, is the problem solved? Does it get into the predicted performance envelope for the class? (Note that this is an entirely separate issue from, "Do real examples on the track get competitive?" I'm not going there.) If it DOES, then the ITAC's work is done and it's time for racers to do their thing.

However, I'm bothered by the suggestion that it's about "lack of potential" - that the car is just not up to the task of actually achieving the predicted performance envelope. ASSUMING that we get the "can't meet minimum weight" issue resolved by the move, what is the basis for suggestions of lack of potential? If the move to B is just one step in a series of requests for relief because nobody seems able to get up front with one, I'm going to lose enthusiasm for my support for the move, pronto.

K

[Jake]

Sorry for my poorly written post. Wife yelling at me to get off the PC, kid can't get to sleep, etc. I'll try again...

The lack of potential I was referring to was the lack of the 4AGE to get predicted power gains. There are more than one 100% motor builds (less the new ECU rule) that aren't getting 110hp to wheels. THIS is why the car isn't as competitive as it looks on paper. THIS is why it doesn't have the same potential.

Why doesn't it respond to the same tweeks a 2.0L VW or Honda Motor does? We can easily get into a engineering discussion on that. First off it is a 1.6L (20% smaller) and produces the same stock hp as some ITB Hondas/VWs by reving up very high and a fairly optimal head/header design. There are engine builders that have found match porting actually hurt hp, and nobody has designed a header that had gains of more than a 2-3hp. This can be argued to death as I am not a Toyota engine development engineer.

However, as Kirk points out - the RWD "adder" has some engineering shortcomings. While an ITS FWD is certainly going to have problems getting the power down, at ITB power levels it is a totally different story. FWIW, I run an OPEN diff and still can't spin a wheel on the track.

[Andy Bettencourt]

Sorry for my poorly written post. Wife yelling at me to get off the PC, kid can't get to sleep, etc. I'll try again...[/b]

I hate when life gets in the way of bench racing!

The lack of potential I was referring to was the lack of the 4AGE to get predicted power gains. There are more than one 100% motor builds (less the new ECU rule) that aren't getting 110hp to wheels. THIS is why the car isn't as competitive as it looks on paper. THIS is why it doesn't have the same potential.[/b]

Note: Open ECU's are not new...can a MoTec fit in the stock box?

Why doesn't it respond to the same tweeks a 2.0L VW or Honda Motor does? We can easily get into a engineering discussion on that. First off it is a 1.6L (20% smaller) and produces the same stock hp as some ITB Hondas/VWs by reving up very high and a fairly optimal head/header design. [/b]

CRX 108 stock hp - 1.6L. Miata 116 stock hp - 1.6L.

There are engine builders that have found match porting actually hurt hp, and nobody has designed a header that had gains of more than a 2-3hp. This can be argued to death as I am not a Toyota engine development engineer. [/b]

Sounds EXACTLY like the 1.6l Miata (except for the port matching piece - unknown on that - Miata's have very small intake and exhaust ports) in that all the bolt ons do little to enhance power. The real power is found in the A/F tuning. Can someone post a dyno sheet with A/F ratios for one of these Toyotas?

However, as Kirk points out - the RWD "adder" has some engineering shortcomings. While an ITS FWD is certainly going to have problems getting the power down, at ITB power levels it is a totally different story. FWIW, I run an OPEN diff and still can't spin a wheel on the track.
[/b]

There is no RWD adder. Only a FWD subtractor. Mid-engine layout in ITB is VERY unique and could be considered an advantage - especially under braking.

[Jake]

I hate when life gets in the way of bench racing!
Note: Open ECU's are not new...can a MoTec fit in the stock box?
CRX 108 stock hp - 1.6L. Miata 116 stock hp - 1.6L.


Sounds EXACTLY like the 1.6l Miata (except for the port matching piece - unknown on that - Miata's have very small intake and exhaust ports) in that all the bolt ons do little to enhance power. The real power is found in the A/F tuning. Can someone post a dyno sheet with A/F ratios for one of these Toyotas?



There is no RWD adder. Only a FWD subtractor. Mid-engine layout in ITB is VERY unique and could be considered an advantage - especially under braking.
[/b]

MoTec won't fit.

Doesn't sound like the Miata. SM Miata engines put out more HP than IT MR2's. The TVIS system also hurts the engine's potenial. There have been some MR2's built that removed this system that puts a restriction on the intake - but that is against IT rules.

RWD adder/FWD subtracter = semantics. Weight dist isn't that diff from BMW/Miata. I agree it is an advantage, but I'm not convinced it is worth 100lbs. Maybe if I was allowed to use a Miata or CRX engine...

Jake

[JoshS]

Weight dist isn't that diff from BMW/Miata.[/b]

The weight distribution of a BMW might start at or near 50/50, but all of the weight one removes under the IT rules comes off the back. I can't remember the actual numbers off the top of my head, but I can tell you that my car isn't 50/50 anymore, and it's a 2-seater. I assume that 4-seater BMWs get even more askew.

On the other hand, I'd expect a mid-engined car to move more towards rear bias as legal lightening occurs.

[Bill Miller]

MoTec won't fit.

The TVIS system also hurts the engine's potenial. There have been some MR2's built that removed this system that puts a restriction on the intake - but that is against IT rules.



Jake
[/b]

Jake,

I've heard some argue that the TVIS system is part of the pollustion control system, and can be legally removed under the rules that govern that system. Don't know if it's ever been put to the protest test, but I can certainly see valid points in the arguement.

[tnord]

SM Miata engines put out more HP than IT MR2's.
[/b]

i want to see your build sheet before you can use this as a data point. and not just the engine. the computer/air metering device, the transmission, the wheel bearings, the fluids, the receipts for $34/gallon fuel, the radiator you use, everything.

most people who say they have 100% engine builds, really don't.

[Jake]

Jake,

I've heard some argue that the TVIS system is part of the pollustion control system, and can be legally removed under the rules that govern that system. Don't know if it's ever been put to the protest test, but I can certainly see valid points in the arguement.
[/b]

I don't see that argument as a valid one. The TVIS system is designed to boost torque at low RPM's - 2-3K rpm.

I don't think anyone has protested an MR2 for a very long time since none have gotten close to placing for a long time.

Hmm... maybe I should just cheat enough so I can keep up with the top ten.

I can drop in a JDM small port 4AGE nobody would ever know. (come to think of it, I've seen some MR2's running these)