Standardized VPi evaluation

[mender]

Several threads have introduced some interesting thoughts about the direction that future VPi evaluation might take. Black Magic has suggested that equal equipment would be a reasonable means of at least starting the process in a way that gets away from the present method of combining the inherited AIV values that are so highly criticized and the subjective method of assigning values based on guesses and gut reaction. 

 

I'll try to paraphrase his suggestion or at least what I think he's suggesting.

 

 Use a list of components or attributes that each have an individual value and check off the boxes that each car has, then add up the list to get a base number.

1. Power or power to weight ratio

2. Drive configuration (FWD, RWD)

3. Trans type (auto, manual, 5 speed, etc)

4. Final drive (LSD)

5. Fuel capacity or  fuel to weight ratio

6. Weight range (1800-2000 lbs, 2000-2200 lbs, etc)

7. Suspension type (struts, SLA, live axle, IRS, etc)

 

Just a preliminary but hopefully following his thoughts. There will always be arguments about how much each category should be worth; after all, this is Champ.

 

Comments? Can this or something like it get Champ onto a more objective VPi evaluation? 

 

[Ian]

What weight are we using.  Factory curb weight?  Some percentage of factory?  The current made up weights that give luxury cars a huge bonus?  Or as raced weights, decided by whom?

[mindspin311]

It needs to be done. The arbitrary stuff just sucks. How is the SC300 500pts and an E46 330 530pts. Yet, if you look at the inportant data like HP, TQ, drivetrain layout, fuel capacity, etc. they're essentially equal cars. So is the SC undervalued, or the E46 overvalued?

[mindspin311]

 

[Originalsterm]

Aero?  Some cars come with wings/spoilers to different degrees.  

[Black Magic]

Very curious what ideas you guys come up with on details. This is something several guys i know have floated around, and done well could really be good for the series. We are trying to move to big picture easily enforced tech items\limits, so as you plot this think of how it would be inspected easily without a nascar level post race teardown. 

 

We use much of this criteria now when comparing vpi values people have questioned. So it isn't a huge leap. 

 

If people would help check, verify and fill in data into an excel sheet on cars that would help a ton. A database in excel format of this stuff could really allow us to look at average value for say a 80s 90s fwd 5 speed mid sized car with 170 ish lbs per gallon and no lsd. If we see an outlier base on that criteria we would know to look harder.

 

What would people think of leaving cars on the list but not showing a vpi until asked\just for cars we race. There might be mathematically more make\model\year options on the list than drivers in the series. We spend alot of time thinking about values for cars no one drives, i would rather think about better matching the few cars we do.

 

On the negative side, many people feel like giving coolers and durability items to cars for free is bad for the series. You would either need to make them open, or put points on cars that have them vs don't. This is outside of the "physics" listing of car attributes. Another example, you might need to allow knuckle\hub swaps for some cars either as a few approved part of the car or reduce points and force that team to buy them. Spec neon comes to mind, those cars were not allowed on track without an upgrade to the acr hub or approved knuckle swap from another car. Do you care if teams make a swap to an equal geometry part to keep their wheels on, or stick to the "didn't pick your car" mantra? Any rules would need to address this in some way.

Edited October 17, 2018 by Black Magic

[wvumtnbkr]

I took a crack at this awhile ago.  I couldn't make it come out so my car had the lowest value so I gave up.

Edited October 17, 2018 by wvumtnbkr

[WilsonSteele]

Excellent idea and method to spot unicorns before they cause trouble, and bring new cars / newer models into the VPI in a reasonable manner

 

we need to add in another category, and yes its a pita...

-max fittable wheel width / tire width

Edited October 17, 2018 by WilsonSteele

[JDChristianson]

This seems like a very healthy discussion.  

 

I would add add to the FWD RWD, Mid-engine RWD 

 

I think weights should be based on as raced weights, and actual data gathered at the races, not what people say they are.

 

Things like PWR, Brakes and suspension should be based on what improvements can be made for no points.  For example if a car's camber issues can be corrected with a hogged out hole for no points that should be included in the VPI .  Some cars gain more than others from tuning an ecu, or changing injectors, that are free.  If allowed fiddling with the stock tank nets 3 or so gallons that should be included as well.  If it can run 8" wide wheels compared to stock 5" that's a big boost for no points.      In other words, how good is car xyz if it were at the track fully prepped with free mods.  

 

 

 

 

[Black Magic]

You could always just write in a max rim width and tire pump out.... And make camber adjustments open....

Edited October 17, 2018 by Black Magic

[JDChristianson]

Drew, not sure if your responding to me?   

 

What I'm after, is getting away from "car xyz is so bad stock"  Who cares what its like stock?  No body is going to show up with a Miata for example with out some minimum upgrades that don't use any points.   So  how good is a 1.6 miata with a mega squirt, and improved air intake, at least 7 inch wheels and 205 tires vs 5.5 inch 14's with 185's. Poly bushings, spring rates close to SM rates, bilstiens and 1.8 front brakes, or wilwoods that don't take points....Compared with and E30 and what ever they can do for no points.   (We've done this race, the E30 is faster.  )

 

I'm just after the best comparison, and comparing showroom brochures is not the best way in my opinion

Edited October 17, 2018 by JDChristianson

[Black Magic]

That was a directed "hey what do you think about this..." More like a rhetorical "what if". Didn't mean it to sound like an attack.

 

Meaning if all the cars could camber to what the tire needed, and had a tire width max appropriate for their size, would the rest not matter.

Edited October 17, 2018 by Black Magic

[JDChristianson]

1 minute ago, Black Magic said:

That was an open "hey what do you think about this..." Not directed to you, more like a rhetorical "what if"

 

Meaning if all the cars could camber to what the tire needed, and had a tire width max appropriate for their size, would the rest not matter.

Be careful, that sounds like more free parts to fix camber.    I personally am not for free parts.

 

[Black Magic]

16 minutes ago, JDChristianson said:

Be careful, that sounds like more free parts to fix camber.    I personally am not for free parts.

 

 

Crux of the issue...

 

For good teams you can run any camber you want for usually zero points. I can list a half dozen ways to do it on most cars. 

 

For some teams they just run less camber cause they don't know how. 

 

Big picture, i bet most laptimes will be un affected by allowing a basic camber adjustment tool, cause we have already "fixed it" on the fast cars.

 

But i get the long standing sediment against purchased stuff, even if it gives no advantage over free options. Sort of like the open spring rules within reasonable od\id, alot of the rules could potentially be more open and not change the actual outcome.

 

 

Edited October 17, 2018 by Black Magic

[JDChristianson]

13 minutes ago, Black Magic said:

long standing sediment

sorry off topic but this has to be one of the best auto corrects ever 

 

[Black Magic]

It does always settle out of these conversations every time....#nofreeanything 

[mindspin311]

Make different aspects of the car a multiplier, both positive and negative. For example...

 

500pt base starting value

 

RWD - 1.0

FWD - 0.95

AWD - 0.97

MR - 0.95

 

No ABS - 0.92

ABS - 1.0

 

Huge fuel tank (sized TBD) - 1.1

AVG fuel tank - 1.0

Tiny fuel tank - 0.9

 

Large HP (# TBD) - 1.15

Low HP - 0.85

 

 

So then you just multiply it all through... 500 x 0.95 (FWD) x 0.92 (no ABS) x 1.1 (Huge fuel tank) x 1.15 (Large HP) = 552.8 VPI

 

 

Obviously you need to fine tune everything, add more categories, etc. But it's a start. And it's easily standardized. Just plug in the values and it spits out a number.

[Ian]

19 minutes ago, mindspin311 said:

Make different aspects of the car a multiplier, both positive and negative. For example...

 

500pt base starting value

 

RWD - 1.0

FWD - 0.95

AWD - 0.97

MR - 0.95

 

No ABS - 0.92

ABS - 1.0

 

Huge fuel tank (sized TBD) - 1.1

AVG fuel tank - 1.0

Tiny fuel tank - 0.9

 

Large HP (# TBD) - 1.15

Low HP - 0.85

 

 

So then you just multiply it all through... 500 x 0.95 (FWD) x 0.92 (no ABS) x 1.1 (Huge fuel tank) x 1.15 (Large HP) = 552.8 VPI

 

 

Obviously you need to fine tune everything, add more categories, etc. But it's a start. And it's easily standardized. Just plug in the values and it spits out a number.

 

That's actually not a bad idea.

 

Similar to the WRL system, but focusing on total possible performance, instead of just PWR, which should equal out the whole field.

[hcsi99]

How about none of the cars on the VPI list exceed 500 base value and as new cars get added every year the old cars on the VPI continue to drop in value?  I'm coming into the series as a new team next year with a car that is already starting at 520 points with no modifications.  I've asked for a VPI reduction using different BMW's with lower starting VPI's as an example, but until my car races they having nothing to go off of except the number that was pulled out of someones...... hat.  Every year a new model or improved model comes out, it would be nice to have a way of letting those models in without a thesis having to be written by the team looking to run something that hasn't been run before.  As far as figuring out how much to lower the VPI year after year,  maybe a formula based on how the model performed the previous year in competition?    

Edited October 17, 2018 by hcsi99

[Black Magic]

With a rewrite of vpi's and a correct point to lap ratio taking laps wouldn't preclude you from a win. 

 

The points and laps aren't exactly built that way now. If your vpi stock is over 500 it was probably set on assumed laps it can make up, if you build to over 500 you are probably not gonna be able to make the points worth it.

[Ian]

2 hours ago, hcsi99 said:

How about none of the cars on the VPI list exceed 500 base value and as new cars get added every year the old cars on the VPI continue to drop in value?  I'm coming into the series as a new team next year with a car that is already starting at 520 points with no modifications.  I've asked for a VPI reduction using different BMW's with lower starting VPI's as an example, but until my car races they having nothing to go off of except the number that was pulled out of someones...... hat.  Every year a new model or improved model comes out, it would be nice to have a way of letting those models in without a thesis having to be written by the team looking to run something that hasn't been run before.  As far as figuring out how much to lower the VPI year after year,  maybe a formula based on how the model performed the previous year in competition?    

 

By following this logic, you cement speed creep into the rules structure.  This means all current teams are forced to either spend money improving their car, or build a new one on a yearly basis.

 

Some new cars may be getting faster, but not all are.  In the long run, a relatively stable VPI table, that attempts to keep top 5 finishers within a certain delta of unavoidable speed creep, is vastly more important to series longevity vs pandering to every new M43753XSI Grand Coupé that BMW releases.  Just because the top rung cars get faster, doesn't mean the base models do.

[ABR-Glen]

I don't think it's a bad idea, but it sure seems contrary to the idea of promoting the "variety" that some are so fond of. Without the "fudge factor" of vpi, how are you going to throw a bone to a car that doesn't perform as well in the real world as it does on paper? Compare specs of a fox body Mustang to the "golden standard" E36 and see if you can find a way to justify the current difference in vpi (which is often debated)

[Ian]

3 minutes ago, ABR-Glen said:

I don't think it's a bad idea, but it sure seems contrary to the idea of promoting the "variety" that some are so fond of. Without the "fudge factor" of vpi, how are you going to throw a bone to a car that doesn't perform as well in the real world as it does on paper? Compare specs of a fox body Mustang to the "golden standard" E36 and see if you can find a way to justify the current difference in vpi (which is often debated)

 

Suspension geometry, design, and fuel efficiency need to carry a heavy price.  The fox has a pretty terrible design and setup out of the box, and the gutless, yet almost humorously thirsty 5.0 are a pretty big handicap if you're trying to actually go fast.  Like its bow tied brother, stock 80s pony cars were really only good at turning fuel into noise.

[scottyk]

4 hours ago, mindspin311 said:

Make different aspects of the car a multiplier, both positive and negative. For example...

 

500pt base starting value

 

RWD - 1.0

FWD - 0.95

AWD - 0.97

MR - 0.95

 

No ABS - 0.92

ABS - 1.0

 

Huge fuel tank (sized TBD) - 1.1

AVG fuel tank - 1.0

Tiny fuel tank - 0.9

 

Large HP (# TBD) - 1.15

Low HP - 0.85

 

 

So then you just multiply it all through... 500 x 0.95 (FWD) x 0.92 (no ABS) x 1.1 (Huge fuel tank) x 1.15 (Large HP) = 552.8 VPI

 

 

Obviously you need to fine tune everything, add more categories, etc. But it's a start. And it's easily standardized. Just plug in the values and it spits out a number.

why do you feel FWD has a advantage?

[Racer28173]

4 hours ago, mindspin311 said:

Make different aspects of the car a multiplier, both positive and negative. For example...

 

500pt base starting value

 

RWD - 1.0

FWD - 0.95

AWD - 0.97

MR - 0.95

 

No ABS - 0.92

ABS - 1.0

 

Huge fuel tank (sized TBD) - 1.1

AVG fuel tank - 1.0

Tiny fuel tank - 0.9

 

Large HP (# TBD) - 1.15

Low HP - 0.85

 

 

So then you just multiply it all through... 500 x 0.95 (FWD) x 0.92 (no ABS) x 1.1 (Huge fuel tank) x 1.15 (Large HP) = 552.8 VPI

 

 

Obviously you need to fine tune everything, add more categories, etc. But it's a start. And it's easily standardized. Just plug in the values and it spits out a number.

MR-2   .60

any Ford   1.6

 

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