SHALB checking

Or, statstical SHALB analysis.
SHALB stands for Speed, Handling, Acceleration, Launch, Braking; the five categories in which every car is valued.

All of this started because I read this thread: Are racing tires overkill for a B class car, more specifically DesigningLeek47’s third post within that thread. In that post DesigningLeek47 listed good examples of how many “hit points” are satisfactory for classes within each category. I call them hit points because they’re a bit like the set of points one would distribute to assorted character attributes in a D & D type game.

The gears started cranking in my head and I recalled downloading ManteoMax’s Forza Motorsport 4 data spreadsheet awhile back. I opened it, pulled out the selection of data I needed and saved a smaller separate spreadsheet. Each piece of information I have is separated into its own column and every car is set into its own row. Before I go further I must thank ManteoMax for the hard work.

The first thing I did was separate the classes and place each on their own tab. I then ran the five ems (min, max, mean, median, and mode) for the performance index and the SHALB columns of every car. This gives us an excellent breakdown about how many hit points are “too hot” “too cold” and “just right” for each category within each class.

While looking at the individual scores I was doing some quick math in my head and noticed cars have varying amounts of total hit points relative to their performance index rating so I totaled the SHALB values for each car. The final step I did was divide each car’s total SHALB points by its performance index.

Exactly like baseball’s batting average, the quotient is a value between zero and one; it’s a representation of hit points per performance index point, though unlike a batting average the better cars have values closer to zero. To phrase it other ways: A car with a lower hit point total relative to its performance index is a car efficiently extracting performance from its ratings. A car with a higher hit point total relative to its performance index is a car inefficiently extracting performance from its ratings.

What can we do with these figures? Not too much but that which we can do is fairly important. This is a good (not excellent, fantastic, or perfect yet) method to compare built cars, especially for people who build cars to real world specifications and don’t follow the in-game performance index rating. Understand that it is possible to make a B 439 car competitive with a B 490 car. Anyway, sort these SHALB quotients in ascending order and they can rank a group of cars from best (top) to worst (bottom) performer.

I am working on a way to include the important power to weight (P:W) ratio into this rating. At this time I don’t know exactly how though I have some ideas. One method includes a P:W rating contained in the quotient, another method keeps P:W separate. Either way, it’s possible to use P:W to balance the field. Example: we have seventeen cars legal for competition. We could cut the list into six top cars, five middle cars, and six bottom cars. Meaning, give the bottom cars a bit better P:W rating, hamper the top cars’ P:W rating, and hopefully the group tightens around the middle.

How do I rate power to weight? (horsepower + torque) / weight. Use those parenthesis to maintain the order of operations. Ideally we could find the area under the power curve(s) though that would be a TON of work. It would mean breaking out the Forza Kitchen Sink spreadsheet, graphing every car’s power curves (driving each car, saving the replay, watching the replay, entering torque figures), and then mathematically finding the area under the curve. We’d need to do this for every car, stock and modified, and for every different way any given car can make power. All of that work would be worth it because we’d have one value each representing every car’s power through all RPM, not just peak numbers. It’s an awesome thing but is man-hour exhaustive.

We could enter a cluster of SHALB quotients into a graphing calculator to perform further statistical analysis. Of course, using statistics means we can observe sigma and [referring to the list of seventeen cars above] might find we have four top cars, six middle cars, and seven bottom cars. Translation: we can more accurately balance the field because we could determine the varying differences between quotients and sigma.

I am interested in seeing where else this can go. This is Forza Motorsport 4 only so far as I have not yet bought Forza Motorsport 5, though I’m sure SHALB / PI would work there too. What other ideas do people have? Also, could this formula be worked to find which cars are “leaderboard cars” without any driving … ?

Wow. Some of that went right over my head. Either way I’m looking forward to what you come up with.

the thing about PWR/weight ratio is that it factors into acceleration, handling, braking, and launch values. I ‘think’ where you’re headed eventually will be equivalent to attempting to decode the individual scores for each of the categories. As far as leaderboard cars go, I doubt that you’ll be able to discern much from this quotient that you’ve come up with. I say this because while there are cars like the Lotus Elan that are phenomenal from E to B, there are some tracks that it is rubbish on. It may show cars that are inclined to be better in a particular class though. You could test this by taking a look at the various leaderboards and figure your quotient on those cars to see if you can establish an appreciable pattern of those that have previously proven to be leaderboard cars. Not trying to be a killjoy, but as I read through how you were working on things, it’s what came to mind.

Don’t feel guilty about being a killjoy, we can have an open source type conversation and kick around ideas. You bring up a great point about power to weight already being included in the categories.

I’m not after decoding the categorical scores, though admittedly it would be intriguing to know. What I ultimately desire is the best method for balancing a field of differing cars. Performance index alone isn’t 100% accurate and maybe 100% accuracy doesn’t exist. However, if PI alone is 82% I still desire attaining 90% and it’s that extra bit of improvement I’m after.

Mine eyes have seen the glory of disc data; I’ve seen compression ratios, coefficient of drag numbers, and … I guess you can say I’ve seen Forza naked. She’s incredibly attractive beneath the cover though I suspect she shields the eyes of the uninitiated. The masses don’t easily understand or don’t much care how piston stroke and cylinder heads factor into compression ratio. It would be possible for me to use disc information to better balance a field but I’d like to come to a conclusion with what’s given to us in the game’s GUI. It’s a shame tuning doesn’t alter the categorical ratings. We can manipulate benchmark figures via tuning, just not those categories.

What else is out there? Who has more ideas?

just picking-up on this one little bit for a quick comment - Tuning does have an effect. Small, to be sure, but I have noticed on more than one of my cars that they can be moved within their class ranking in my garage without my having changed a bit of the hardware, with only tuning. Does this mean it’s “better” - not necessarily, not in my hand anyway, but “the game” does appear to rank your cars in your garage, worst to best, when you browse your garage - and I have managed to reshuffle the order (seemingly, by accident of course ;^) by having merely “tuned” the car! This is more concrete that my glowing car theory - I know these get reshuffled by “improving” their stats.

Ah ha! Thank you Leek; that sheds a bit more light on the issue.

The categories show only one decimal place but they carry out to six places. A change from 2.52:1 to 4.56:1 differential gears should alter the speed, acceleration, and launch categories by a couple tenths. Speed would decrease as launch and acceleration would increase (provided the drivetrain and tires could transfer the increase in multiplied force to the pavement).

I’m not saying that SHALB is completely bogus. But I have learned to ignore that.

Why I do say so?

There are some cars that I have… Road America car, Speed 3.0 And to my knowledge, if that track can be defined somehow, it’s speed track.

I also have handling biased cars, with handling rating on high 5’s, How ever I can outhandle those same cars with stock ElCamino. Handling rating 3.0

How ever, I do agree that SHALB might give you fairly good understanding on what the car should be able to do.

I’m with you there as I too have seen cars where the ratings aren’t exactly accurate but that’s not something us end-users can fix. Exactly as you allude, a car with a speed of 3.0 shouldn’t be very good on Road America, yet it probably is, and it is probably equal to or better than some cars rated in speed at 3.4 - 4.0.

I think those cars with low speed ratings are ones where the transmission is the limiting factor. However, differential gearing can be tuned and more speed may be extracted from the build, yet the speed rating doesn’t reflect the change (or it changes 4, 5, or 6 decimal places out where it doesn’t have an appreciable effect.)

A “Sport” or “Race” transmission can play havoc on the ratings. The S, A and L categories can all be affected, yet how much they are affected and in which direction they move all depend upon tuning. I go back to the difference between 2.52:1 and 4.56:1 differential gears. The former set is phenomenal on the Autobahn, get up to 255 KPH at low RPM and set cruise control. The latter set is great for dumping the clutch at a stop light and dragging to the next stop light.

Hey guys. Just thought I’d chime in with a bit of perspective on the whole SHALB approach. When my regular club members were still active, we did LOADS of lobby racing, particularly in either A class strictly, or in Multi-Class’ ABC’s. Though I’m pretty much with HMR for the most part, we did notice that for certain tracks there were benchmarks that sort of established the level of competitiveness the car would have in an open pack.

In A class, for example, we learned that most cars (not all–there’s ALWAYS exceptions) needed a minimum of 5.6 for handling and 6.5 top speed for high speed tracks; the higher you could get your top speed, the better off you were–so long as you had at least a 5.6 handling. Sometimes we could go as low as 5.4, but more often than not the sacrifices in the handling usually led to just enough compromise in overall speed that the gain in top end was negligible at best. Grip tracks, on the other hand (especially ones with little use for top end), would be much more competitive with a grip of at least 6.0 or more.

The point is that PI does serve some relative purpose for building a car; it presents us with a general benchmark area of expected performance. But that’s about it. I say this because (and this further supports why HMR stated what he did) there are dozens upon dozens of cars whose stats barely change when installing a race transmission, such as many of the classic muscle cars. Anybody who’s built a decent B class muscle car with a focus on drivetrain and handling more than power knows that there’s MUCH more top speed to be had with a race trans than reflected by the stats.

On the other hand…

Avanti, I think you’ve stumbled upon something incredible. Ironically, I’ve created my own calculator (though it’s never been intended to be released) and am still adding to it. Being that I’ve had to input all of the equations in myself (ensuring that the proper research was done to guarantee the math is correct), I’m going to throw something your way–it’s either a light in the tunnel for you, or a wrench in your gears.

For starters, horsepower is strictly energy generated by the engine, however, horsepower does NOT move your car. In order to move the car, it must convert this energy into a force that will move the car. That force is torque, and the conversion of energy to force is performed by your drivetrain. This is defined as such by the laws of physics, and has been for centuries.

Physics defines horsepower as the rate as which work is done; in regards to our cars, the work being done is the moving of the car and the rate at which the work is being done is the rate at which the horsepower (or energy) is converted to torque (or force). This means that power-to-weight ratio (as in horsepower) only reflects the potential of work being done by your engine. It does NOT reflect how much force is actually moving the car, or more specifically, the weight. And it’s the opposite when calculating the torque-to-weight ratio; calculating the torque-to-weight ratio only reflects how much force is actually moving the car, and not the work potential of the engine.

This is important because two cars with the same weight and completely different levels of horsepower and torque adding up to the same sum would indicate by the results that they would perform essentially to the same rate of overall potential of performance. But this isn’t the actual case. Here’s an example:

Car one has 200 horsepower and 300 ft-lbs of torque;
Car two has 300 horsepower and 200 ft-lbs and torque;
Both weigh 3000 pounds.
The sum of both would be 500, thus;
The equation is 3000 / 500, or 6:1.

Seems correct, right? The problem here is that, again, horsepower does not move the car and so adding it to the torque results in more force moving the car than is there.

In actuality, car one has 300 lbs of torque, or force, to move 3000 lbs, while car one has only 200 lbs of torque to move 3000 pounds. By computing these, we can see how much weight is actually moved per increment of force (in our case, lbs per lbs). Now car one becomes 3000/300 while car two becomes 3000/200; car one has a ratio of 10:1 while car two has a ratio of 15:1. Obviously, car one has a higher rate of acceleration because it has more force to move its weight and so each pound of torque (or force) has less weight to move. On the same token, two cars with the same weight, same torque, but different horsepower, will accelerate at the same rate so long as the gearing is essentially the same.

Since you’ve “dynoed” your cars then you should know as well as I do that your peak torque is not a constant throughout your rpm band. This means that the overall force available to move the car is contingent on your RPMs. I don’t know what your increments of measure are, but I’ve mapped mine per every 50 RPMs all the way up to redline, starting with the lowest achievable RPM possible (yes, VERY time consuming). I’m also assuming that when you dyno your cars, you also only use one gear.

It’s important to keep in mind that your drivetrain is the converter of horsepower to torque, and so when you change your gearing, you’re changing the rate of conversion (this is why my calculator also computes the horsepower and torque curve for each gear). This is critical because the force available for moving your car is different per each gear. Most importantly, and as you already noted, none of this is reflected in the SHALB stats.

All this being said, what you’ve mentioned originally is a step in the right direction. When you utilize it as I’ve described, it can be extremely rewarding for many of your cars.

The real challenge to all of this is trying to figure out the frictional losses. I can’t seem to find the math reflected in the telemetry (I assume it’s because it’s so minuscule), but there must be changes in frictional losses because overall performance is reflected by parts having the most contribution (such as lighter flywheels and driveshafts). It becomes even more challenging when considering that the losses aren’t universal among application; in other words, a sport flywheel may contribute to a one percent loss on one car while contributing to a two percent loss on another.

Either way, just food for thought. Gotta run. Cheers!

FragMent, that’s some great stuff. Your bit on power is why I would really love to have the area under the curve represent the power side of the ratio.
Yes, when I “dyno” my cars I remain in one gear and start as close to idle as I can, though I generally use 100 RPM increments.
Gearing, everybody’s favorite torque multiplier.

I had an afterthought…

After posting yesterday, I pulled up my unfinished calculator just to thumb around with it and see where I had left off. I had completely forgotten that I even incorporated a portion specific to determining how much actual torque was delivered to the driving tires. It’s a bit of a challenge to accurately determine how much of that torque can be delivered SUCCESSFULLY, however, being that the co-efficiency of friction determines how much grip you have (which is largely, though not completely, determined by how much weight is planting your tires to the ground at that time).

It would require yet another ensemble of mathematical equations to determine how much of it is ACTUALLY delivered successfully though (which is work I’m not so sure I want to commit to yet, if at all), so the original purpose was to attempt to determine where there may be excessive amounts of torque before actually driving any given car; in the plainest sense, if the weight planting the tires down, at it’s highest rate (or the most possible weight), still is not enough to provide a sufficient co-efficiency of friction for grip, then the car simply has too much torque (which may merit a change in the build).

If you’re interested in knowing how to perform these calculations, let me know and I’d be happy to share them with you. If you’d like to figure it out on your own (if you haven’t already), however, then it helps to know that your differential settings determine not the total permitted rotational difference but rather the total resistance; so a setting of 90 would equate to a 90% resistance to rotational difference, or a permitted difference of 10%. I’m curious to know what you could contribute to this too, being that you seem very detail oriented when applying such math.

Either way, I’m eager to see your reply. Cheers, Avanti!

Ok, I’m an old school mechanic and after reading all this I’m fried. lol
There is a lot of good info here but no matter how many numbers you crunch
to perfect your cars performance there is one thing that has not been mentioned
that will throw a wrench into the mix - THE HUMAN FACTOR. You tune a car to its
top or close to top performance the human factor of different people will make that
same car perform differently. Not trying to be a killjoy, just wanted to shine a little
light on an aspect that was not considered.

I hadn’t mentioned it because it’s not an intrinsic Forza equation though I do consider the human element. Whether I build a grouping of cars to a set performance index level or to real world builds I further cluster my racers by use of Forza’s online buckets.

Since there are no +% power buckets [for if there were I would +5%, 0, and -5%, for example] I leave the back of the field in a -0% bucket, the middle of the field takes a -5% bucket and the lead cars get a -10% bucket. Sometimes what I’ll do before placing (a) racer(s) into the next “down 5 %” bucket is give their car(s) a little more power. The gross change may be -5 more percent but the net change works out to about -3 more percent. I divide by a fraction to find out how much more power to give a car if I want to net a loss of power between the down fives.

I further enhance my field of drivers because I can host four buckets (0, -5, -10, -15) and via build changes it’s possible to put two racers -15%, three -13%, three -11%, one -10%, one -7%, two -5%, one -3%, and three back field racers can be aided by not having any power reduced.

I want my builds to be as equal as possible but the buckets handle the human element. Wrench nullified.

FragMent, that sort of tuning math is not my forte though it fascinates me. I have a friend on XBL who is an engineer I could put you in touch with.

One thing hit me when you said, “… still is not enough to provide a sufficient co-efficiency of friction for grip, then the car simply has too much torque (which may merit a change in the build).” Rather than a build change, how about a drivetrain tuning change? The total amount of torque may be too much for a 2.97:1 transmission gear channeled through 3.70:1 differential gears, but how about that same amount of torque through a 2.66:1 transmission gear channeled through 3.23:1 differential gears? Since gearing is a torque multiplier, easing up on the multiplier would be one way to combat that problem.

I was thinking about all this last night and most of this is like waaaaaaaaaaaaaaaaay out of my league. But I think I understand the “gist” of what you’re trying to figure out and a sliver of how you’re going about it. It’s like you’re trying to unlock the “code” of all cars and equalize the playing field. Or maybe closer than you’ve already done. I totally get that.

I have a question. In real life, if we tried to do this… it would be a different story, right? I mean, you can look at all the numbers of power to weight ratio, powerbands, torque etc and at some point isn’t there what they call that “X” factor? I mean, not every spindle in every car is shaped the same, or the tolerance between this joint and that joint varies slightly and the sum of all those difference seems like it would have an impact on the end result of a car put together. For arguments sake I’m leaving out the human factor because of course that is just another huge level of deciphering.

But in the car itself it seems like the x factor would be those little nuances and tolerance differences, weight distribution, etc etc, on and on that seems like it would make one car different from another to a degree. Heck, even among an identical car there’s gotta be some of those differences, just not to the same degree from one manufacture to another. My point would be an example, say you have a car with the same wheelbase, same width of track, same size tires and wheels, same gross vehicle weight, and engine with the same power as another. But the shape is different, put together by different hands, using a difference in certain materials here and there. Seems like the end result would be so vastly different, it’d be hard to figure out how to make it level. Or “crack the code”. Which might be the explanation of the X factor. Just something you can’t really explain but might make one car better than another. So to speak.

It may be different in the game because it’s digital and there might be way to figure out how to equalize them. I have no clue. I’m not a programmer.

If my comments are off base and sophomorish on the subject, I apologize. And maybe I’m just complicating it more than it really is. I don’t know.

“It’s like you’re trying to unlock the “code” of all cars and equalize the playing field. Or maybe closer than you’ve already done.”
That’s a great way to phrase it. I can get many builds “ballpark close” without too much effort but I want to get them down to “infield close” because “battery close” (pitcher & catcher) is neigh impossible. The closer I can get builds initially, the easier it is to keep them close later.

In real life it can be quite difficult because of the build nuances and tolerances you mention. You’re correct that each piece may differ from other seemingly identical pieces. Check this for an example: I have a friend who raced in NASA and SCCA Spec. 7 / Pro 7 and then moved on to Spec. Miata. In Spec. racing the rules dictate which parts may and may not be altered. Of the parts which may be altered is a list (a very constricted list at that) of approved replacement parts. Many pieces on a Spec. car must be factory pieces. I believe the air box is one such piece which must be factory. Some racers will go to junkyards, all junkyards within a several hour drive of their house, and buy many factory air boxes for their car. Then they take all air boxes they’ve purchased and flow test each one in search for more cubic feet of air per minute, even fractions of gain. Throttle bodies, manifolds (intake & exhaust) … anything listed “must be factory” in the rule book, some racers will go out and take advantage of manufacturer tolerances. The two best things real stewards have are air restrictors and ballast. Air restrictors are somewhat programmed in Forza but ballast isn’t.

The best series I have found in terms of building and classing cars is NASA Time Trial. There are five classes in PT, three classes in ST, and one SU class. Many cars are assessed in a multitude of ways. Each car is first placed in a class and upgrades increase the class (just like in Gran Turismo & Forza Motorsport). It gets deep, too. Fifth generation Corvettes had a floor comprised of balsa wood. NASA knows this and came up with assessments if C5 racers wanted to remove that wood flooring. When you have time, take a look at what NASA has done, here are the rule books for the different classes:
Performance Touring (41 pages) and
Super Touring (16 pages). The Super Touring book is an addendum, only specifying areas unique to the class; both categories are mostly covered in the Performance Touring book.

I used to think that myself, Avanti, until I had a sort of epiphany… It’s hard to explain without detail though, and was part of the reason I skipped mentioning it before (I’m trying to keep my posts shorter).

When I made adjustments to the gearing in such manners as you stated, not all cars would become compliant; I wanted to know why. I thought about the intrinsic nature of gears (that the larger they are the slower they spin), and applied the same concept to the tires. According to physics, torque is basically any amount of force applied to an object having a fulcrum, or point of pivot. In the case of gearing, the teeth of the gear are the objects the force is applied to, and the fulcrum is the center of the shaft that the gear is on; in regards to the tires, the fulcrum is the center of the wheel hub while the object having force applied to it is essentially the contact patch. Simple stuff, really. Here’s where it gets tricky.

When you play with the final drive, you effectively slow down or speed up the rate at which the differential is spinning (because more teeth–or a lower setting–will slow it down, and less teeth–or a higher setting–will speed it up). This has a huge effect on how each of your tires performs with what grip it has. The easiest way to understand how is with a simple visual example.

Imagine a car being pulled in neutral at 100 miles per hour. The tires are spinning (as in complete revolutions) relative to the speed the car is travelling; if it was pulled at a slower speed, the tires would be making fewer revolutions, and at higher speeds, more revolutions. Now imagine a car suspended in the air, with the engine engaged and travelling the car at 100 miles per hour (no tires touching the ground, speedometer is at 100mph). In this case, the revolutions of the tires are relative to the rpm(s) of the engine and the total gearing arrangement.

When in neutral, the drivetrain is allowed to spin at a rate relative to the car’s travelling speed. Once the engine is engaged to the drivetrain, however, the drivetrain’s revolutions will be a balance between the rotational forces induced by the engine and the rotational forces induced by the travelling speed; this means that the tires are victim to the same forces because they’re tied to the total gear arrangement–it’s what makes the tires revolve in the first place.

The idea is that ensure that the ratio of revolutions induced by gearing matches the ratio of revolutions induced by travelling speed. When the ratio becomes extremely unbalanced grip becomes unstable; each driven tire overall wants to either spin faster or slower than it needs to because that’s what the gearing is trying to do when transmitting the torque. When the gearing arrangement results in the driving tires trying to spin slower than necessary, the rear half of each tire’s contact patch succumbs to more friction and the tire “drags” itself; contrarily, when the gearing arrangement results in the driving tires trying to spin faster than necessary, the front half of each tire’s contact patch succumbs to more friction and the tire may actually lightly “hop” along the track surface. Either scenario happens in manners often too minuscule for the naked eye, but extreme cases are plainly visible or noticeable.

The importance of this has to do with the effect of reducing torque multiplication–it also affects the rate of revolutions for your tires. The effect is nearly unavoidable too; in order to effectively change the rate of torque multiplication, you must change the settings of the individual gears and/or the final drive; doing either will also affect the rate of revolutions of the adjusted components. Changing the individual gear settings alone will affect the rate of revolutions of the driven tires, but to small degrees due to the nature of the gears having a limited range of overall change due to mechanical design (simply put, gears are small). Changing the final drive will further affect the rate of revolutions, and to much larger degrees, because the ring gear is mechanically much larger.

When adjusting my gearing, I try not to deviate too much from the ideal balance for the car. It’s worth noting now that before I’ve determined whether or not a car has too much torque as I described previously, I’ve first determined how much “range” for reduction/multiplication I have to play with while still maintaining my preferred balance. I just didn’t mention all of this being that the post was long enough already. And I know it seems like a whole lot of unnecessary and tedious math for just a game, but when I have taken the time to apply the math to some of my tunes, the results can be incredibly amazing! It’s also worth noting that changing tire size will also have a similar effect in that it changes the tire’s rate of revolutions–changing a tire’s size also changes its diameter; a larger tire spins slower, and vice versa.

So in short, yes, you can technically combat the original problem by making changes in the gearing as you’ve described, but sometimes the trade-off for doing so ends up eliminating the original purpose of making the adjustments; yet again, it’s a matter of math. Have you ever had a car that you did try this on to a near extreme degree with unsatisfactory results? If so, what I’ve explained probably has a lot to do with it.

On another note, I think your method for bracket building/tuning is excellent–best I’ve seen so far. How well have the results been in testing the application of it? And I wouldn’t mind at all meeting your XBL buddy–I definitely don’t know everything and I’m always down to learn more and newer things.

Groovier, yes, yes, yes, and yes…

You are absolutely correct in that different applications of the same type of engineering concepts will have different results. I wouldn’t go so far as to say that there is almost an “X” factor though–the math can always be performed. With gearing, it’s all largely going to be the same because there’s less deviation in design from one to the next–the gearing is pretty easy to represent with the math regardless of the mechanical design. On the other hand, something like the axle arrangement (as in solid axles or independent rear axles) or the steering suspension arrangement (as in SLA, MacPherson, double wishbone, multi-link, etc.) will be a huge determinant in how much performance is affected and how much effect your settings will have.

When building a car in real life, much of it should (or will) revolve around making each one of these system components perform work as efficiently as possible; the amount of work needing to be done depends on what purpose the overall car serves. The evidence in this is all around; there are hundreds upon hundreds of racing organizations that have restrictions in place which create real-life brackets of performance very similar to what Avanti has shared with us, and the plethora of manufactured racecars produced by many different manufactures proves that the math can indeed be (and is) performed.

Think of it all as being relative in nature. If one car has a smaller wheelbase than its competitor, and both cars have an equal AMOUNT of weight removed, one will be more affected than the other. If, however, they both have an equal PERCENTAGE of weight removed, then the gains in performance can be expected to be relatively the same. By adhering to a mathematical approach more relative in nature, we can make such generalizations without concern for such “X” factors. To some extent, that’s what Avanti has essentially done. And for the record, there’s nothing “sophomorish” or complicating about your point–it was completely valid and worth mentioning.

Thanks guys. That’s crazy about the airboxes. But you made my point. Even within factory installed and made parts, there is some deviation that might affect the performance of the car. I find this to be true in all mass manufacturing. It’s the same way with firearms. You can have a CNC’d firearm with very little to no hand fitting and yet one may very slightly or significantly than the one made right after. Because there is ALWAYS some discrepancy in tolerances. If a manufacture said they could make a certain product with the “EXACT” same tolerances on each of their mass produced products, they’d be lying. There’s no way it could happen with cars and there are so many places where the tolerances are different that it blows my mind at how many different combinations of one type of car are out there.

Which is my point. You say there is always a math equation to figure it out Hackfragment, but I think I disagree. It’s possible that the tolerance difference I’m speaking of might not amount to a whole hill of beans in the end result, but mathematically it seems almost infinite in the amount of combinations. Which is what I mean by the x factor. If there are infinite amount of possibilities even under one type of car, that becomes even MORE exaggerated among different cars.

Now that’s not to say that there aren’t sanctioning bodies that do a great job of leveling the playing field. But question kind of lingers in my head: Is Tom Kristiansen really that good? (Sorry if I spelled his name wrong) Or Audi? Or is it that they somehow get some kind of leg up that because of the rules. I don’t know. Maybe a little of both? That’s just one example as I’m not real versed in who always does good in what series or race. Etc etc.

Pertaining to T.K. & Audi: Tom is a great driver, Audi made him better. Just as gearing is torque’s multiplier, Audi multiplies its drivers’ abilities. Audi prepares their race cars very well and designed a quick change rear end on their R8,

The quoted’s name is a link to the R8 race car page.

Carroll Smith wrote a series of “____ To Win” books: “Tune To Win” “Drive To Win” “Prepare To Win” “Engineer To Win” “Nuts, Bolts, Fasteners and Plumbing handbook” (which followers have lovingly code named “Screw To Win”). Audi lives this ____ to win mantra: their drivers and Audi prepare to win, Audi screw and engineer to win, and the team mechanics tune to win.
In most race bodies the teams running up front constantly are the teams best prepared. A line used in Under Siege 2 says a lot, “Chance favors the prepared mind.” The manufacturers read the rules and build a car which follows the guidelines but pushes on the borders. Teams bring spares. The members of the pit crew practice a lot for many different scenarios. Drivers and engineers (including those in charge of telemetry) are in constant contact. Teams that don’t do this have very little chance of running top-ten and even less chance of a podium spot.
I love this group and the tangents we’ve taken though I am afraid I must play a momentary bad-guy and steer this back to Forza Motorsport’s SHALB ratings. Let’s go to private messages if you have more input for our other discussion(s).

Sorry about that.

As far as the SHALB thing goes, I think it’s a good idea to further enhance the cars. I’ve been driving the U2 builds a LOT and I believe there are definitely cars that are faster than the others. And I don’t think it’s just because I drive a certain car better than another. They all are very different though. But to that end, it’s not like I’m getting 10 second differences. So… they ARE pretty close now using the current formula. But I’d be apt to steer away from some of the slower cars. Except that the slower ones always FEEL better to me because I’m not on the ragged edge with them. I guess that means their power isn’t quite there. Which does seem odd. Because if they all have the same power to weight ratio, you’d think it wouldn’t be that way. Like I think the Pinto is slow, but could take a lot more power before becoming “wonky”. Or hard to drive. And the Escort seems like it has Waaaaaaaaaaaaay more power than the chassis can handle and you have to drive more carefully with that car. But man it’s fast. With only 4 gears too.

With the pinto it’s like you can practically go full throttle all the time. Well, not really, but maybe you get my drift. Same with the Datsun. Hammer down. Even the Beemer is like that, but it’s fast because it handles soooo well. You could put a little more power in that car and I think you could keep up with your O5U7 cars. Especially on the shorter tracks. But that’s not the point, I know. I’m just saying that car feels like it’s hard to get sideways with. It’s possible, but more forgiving than the others.

Hackfragment, I was trying to disagree respectfully and just have a discussion. Please accept my apologies if it didn’t come across as respectful. I didn’t hear anything to the contrary anywhere, I just got to thinking I should say this. PLUS, I would imagine you know more about it than I do, and my 2 cents might not be worth the price of a cup of coffee. But, I was just stating my perspective and opinions on the subject for the sake of discussion.