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2016 Proposed ST Rules Revisions


Greg G.

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  • National Staff

Folks, below are most of the significant proposed ST Rules revisions for 2016.

 

For those in ST1 and ST2--pretty simple--non-DOT tires now have a Mod Factor of -0.5 instead of -0.7, and you can't have aero parts protruding more than 6" from the sides of the vehicle. Also, the Dyno procedures section has been tightened up for all vehicles, but without significant changes other than Dyno tests done after 12-1-15 need to include the numeric table of RPM and HP, and vehicles that have redline over 7250 rpm need to hit the rev-limiter on at least one pull.

 

As you can see, we are making changes to ST3 that may carry over to all ST classes in the future if they prove to be successful this season. The official publish date for the rules is Dec 1st. I'm posting these now because I believe they have a very high likelihood of becoming official changes, and I wanted the ST3 competitors to be able to start looking at their situations now, especially the guys who start competing in January. Comments regarding potential unforeseen problems are welcome. All of the ST, TT, and PT Directors are reviewing the actual draft of the rules currently for their comments. However, I will delete any posts from this thread that are not helpful to this process. Due to formatting issues here, the following are not exact copies of the draft rules.

 

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Super Touring 1 (ST1) = “Adjusted Wt/HP Ratio” equal to, or greater than, 5.50:1

Super Touring 2 (ST2) = “Adjusted Wt/HP Ratio” equal to, or greater than, 8.00:1

Super Touring 3 (ST3) = “Adjusted Wt/HP Ratio” equal to, or greater than, 10.00:1

 

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11-9-15--Note: This formula is the new draft proposed formula in the comment period

8.2 ST3/TT3 Average Horsepower Calculation

 

New for 2016: The number used for calculating the Adjusted Wt/HP Ratio for the ST3 (and TT3) classes will no longer be the maximum horsepower of the three Dyno runs. It will be a calculated average giving a better approximation of the maximum horsepower available over a range of usable RPM. The Dyno test with the highest maximum horsepower will be used to calculate this average (not an average of the three Dyno runs) as follows:

 

Ave HP = Average HP calculated and used in in the Adjusted Wt/HP Ratio

Max HP = Maximum horsepower

 

The following ten (10) data points will be obtained from the Dyno’s numeric RPM/HP table printout:

Horsepower at: 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm greater than Max HP rpm

Horsepower at: 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm less than Max HP rpm

(If any of the above data points at higher RPM than Max HP RPM do not exist due to redline, then those potential data points will not be used in the calculation of Ave HP.)

 

The highest three (3) data points of the above ten (10) will be used in the calculation below:

 

Ave HP = Max HP +(sum of the highest three data points) Divided by 4

 

 

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D) ST3 Only Production Vehicle Aerodynamics (does not apply to ST1 or ST2 vehicles)

 

Production vehicles that maintain their unmodified OEM body lines and do not have non-OEM aerodynamic aides or modifications may assess the Modification Factor for “OEM Aero” in calculating the “Adjusted Wt/HP Ratio” (7.4).

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7.4.2 Modification Factors

 

The “Modification Factor” listed after each item below is added or subtracted from the actual measured Wt/HP ratio to calculate the “Adjusted Wt./HP Ratio” which determines vehicle legality in each ST class.

 

Non-Production Vehicle: = -0.4

 

 

Production Vehicle Body Type: 4-door Sedan or 5-door Wagon = +0.2

(none of these apply to Modification of the OEM roof line/shape = -0.3

Non-Production vehicles) Modification of the floor pan for exhaust clearance only

and/or the rocker panel for side exit exhaust only = -0.2

ST3 ONLY: OEM Aero (see 7.3.2.D) = +0.4

 

Engine: Rotary with a maximum of two rotors and one turbocharger turbine = +0.3

Naturally aspirated (non-rotary) engine with displacement 1.9L or less = +0.3

Rear Engine Location ('99+ year only) w/Comp. Wt. less than 2700 lbs = -0.2

Rear Engine Location ('99+ year only) w/Comp. Wt. 2700-2900 lbs = -0.1

(Rear Engine = Behind rear axle only—See Appendix A)

 

 

 

Transmission: ST1 & ST2: Dog-ring/straight-cut gears (non-synchromesh),

and/or sequential/paddle shift/semi-automatic = -0.2

ST3 ONLY: OEM street-legal model available paddle shift/DCT/SMG

or sequential motorcycle gearbox = -0.2

ST3 ONLY: Dog-ring/straight-cut gears (non-synchromesh),

and/or all other sequential/semi-automatic = -0.6

(no assessment for automatic utilizing a torque converter)

 

Drivetrain: AWD = -0.3

FWD = +1.0

 

Tires: Non-DOT approved tires = -0.5 (CTSC EC-Dry Continentals see App. A)

Size 10.5” (267mm) to 9.6” (244mm) non-DOT approved = +0.3

Size 9.5” (241mm) or smaller non-DOT approved = +0.7

Size 275 to 250 (DOT approved) = +0.3

Size 245 or smaller (DOT approved) = +0.7

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11-9-15--Disregard this rule. It is being deleted from the draft, and will be saved for possible use in the future in the potential

lower ST classes.

A) Other than the listed exceptions, every Production vehicle must retain its unmodified:

1) OEM frame rails/rear frame cross beam, and/or Unibody, and Sub-frames/

suspension cross-members (in their OEM locations)

2) Strut/shock towers

3) Inner/inboard side of the fender wells (any non-horizontal aspect)

4) Rocker panels

5) Transmission tunnel

6) Floor pan

7) Windshield frame location

8) Rear quarter panels

 

The following are permitted exceptions to 7.3.2.A above:

8a) Flaring/rolling/cutting of the outside aspect of the rear fenders and/or adding

additional material as fender flares for the purpose of tire clearance or venting for

aerodynamic and/or cooling purposes is permitted.

8b) Repair of body damage with body filler putty or fiberglass is permitted, but at

least 80% of the original body panel material must remain.

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7.3.1 Restrictions and Limitations for All Vehicles (Non-Production and Production)

 

All vehicles must adhere to the following modification restrictions and limitations:

 

1) Active aerodynamic devices and/or modifications (including, but not limited to,

computerized, cockpit adjustable, self-adjusting, and OEM) are not permitted.

Aerodynamic devices and/or modifications may not protrude more than six (6”)

inches from the vertical plane from the ground to the widest part of the right and left sides of the vehicle’s body.

 

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HP RL-2k clarification in the wording...Is this hp at 2000 rpm minus redline (I think) or minus hp at 2000 rpm? Or is it literally hp (ex, 300) at redline - 2000?

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Greg:

 

I am not clear on the modification factor for non-OEM aero for ST3/TT3.

 

It appears that modification factor is 0.0.

 

The difference between non-OEM and OEM aero is still 0.4 with the +0.4 mod for OEM aero.

 

Am I understanding this correctly.

 

Denis

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Greg:

 

I am not clear on the modification factor for non-OEM aero for ST3/TT3.

 

It appears that modification factor is 0.0.

 

The difference between non-OEM and OEM aero is still 0.4 with the +0.4 mod for OEM aero.

 

Am I understanding this correctly.

 

Denis

Production vehicles that maintain their unmodified OEM body lines and do not have non-OEM aerodynamic aides or modifications may assess the Modification Factor for “OEM Aero” in calculating the “Adjusted Wt/HP Ratio” (7.4).

 

As I read it: ST3 is 10.0:1 for a given vehicle...unless you do not add/remove/modify/replace OEM aero then it would be 10.4:1 for that vehicle.

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-------------------------------------------------------------------------------------------------------------------------

 

A) Other than the listed exceptions, every Production vehicle must retain its unmodified:

1) OEM frame rails/rear frame cross beam, and/or Unibody, and Sub-frames/

suspension cross-members (in their OEM locations)

2) Strut/shock towers

3) Inner/inboard side of the fender wells (any non-horizontal aspect)

4) Rocker panels

5) Transmission tunnel

6) Floor pan

7) Windshield frame location

Rear quarter panels

 

The following are permitted exceptions to 7.3.2.A above:

8a) Flaring/rolling/cutting of the outside aspect of the rear fenders and/or adding

additional material as fender flares for the purpose of tire clearance or venting for

aerodynamic and/or cooling purposes is permitted.

8b) Repair of body damage with body filler putty or fiberglass is permitted, but at

least 80% of the original body panel material must remain.

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Greg,

 

Can you further clarify the ruling on the addition of the rear fender ruling? So, by this wording, I cannot purchase aftermarket "wide body fenders" for my car? But I can flare the OEM Vette fenders to accomplish the same tire clearance?

 

Where is the line drawn on what I can do in the name of aero, evacuating fender wheel pressure, and feeding a diffuser?

 

As an fyi, I have yet to do any of this to my car, but depending on the rules interpretation here, there are several EXISTING cars that will have to re-engineer the rear of their cars to meet the rules.

 

 

-Kevin

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Please explain the reasoning for not allowing an aftermarket flared rear fender/quarterpanel but instead allowing the functional equivalent in the form of a DIY flare or purchased "over fender flare" or simply cut fender.

Are you guys going for a LeMons look in the ST class?

What is wrong with flared fenders anyway? They are platform neutral and typically relatively low dollar, in the grand scheme of things.

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Greg:

 

I am not clear on the modification factor for non-OEM aero for ST3/TT3.

 

It appears that modification factor is 0.0.

 

The difference between non-OEM and OEM aero is still 0.4 with the +0.4 mod for OEM aero.

 

Am I understanding this correctly.

 

Denis

Production vehicles that maintain their unmodified OEM body lines and do not have non-OEM aerodynamic aides or modifications may assess the Modification Factor for “OEM Aero” in calculating the “Adjusted Wt/HP Ratio” (7.4).

 

As I read it: ST3 is 10.0:1 for a given vehicle...unless you do not add/remove/modify/replace OEM aero then it would be 10.4:1 for that vehicle.

 

 

I think a OEM aero car would run at 9.6:1.

 

Non OEM at 10:1

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I think a OEM aero car would run at 9.6:1.

 

Non OEM at 10:1

 

This is how I read it. Aftermarket aero is no longer a penalty to the base ratio, but OEM aero gets you a .4 ratio give back. Which makes sense given the intent for ST/TT3 to split the difference in speed between ST/TT2 and PT/TTB more equally.

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Greg,

 

Do the weight tables go away? Or do they stay in?

 

 

 

Erik Davis

 

I assumed that they stayed in. Good to clarify.

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Please explain the reasoning for not allowing an aftermarket flared rear fender/quarterpanel but instead allowing the functional equivalent in the form of a DIY flare or purchased "over fender flare" or simply cut fender.

Are you guys going for a LeMons look in the ST class?

What is wrong with flared fenders anyway? They are platform neutral and typically relatively low dollar, in the grand scheme of things.

 

I assume a flared front fender is open (aftermarket allowed?)

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looks like redline, minus 2000 to me.... ie a 6900rpm redline would use 4900rpm as this number.

Yes

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Greg,

 

Do the weight tables go away? Or do they stay in?

 

 

 

Erik Davis

 

I assumed that they stayed in. Good to clarify.

Yes, same weight tables.

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The rule about rear quarter panels came from the NASA Exec's,

and is meant to prevent replacement with composite/carbon (unless

taking the non-production Mod Factor. It is not about flared fenders,

or rear fender well aero, which is why exceptions are allowed

for those. Please e-mail examples of vehicles with problems with

this rule that do not have composite/carbon replacement panels.

This would be a rule that I wouldn't mind revising and resubmitting if the intended

results are not being accomplished

 

Thanks.

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The rule about rear quarter panels came from the NASA Exec's,

and is meant to prevent replacement with composite/carbon (unless

taking the non-production Mod Factor. It is not about flared fenders,

or rear fender well aero, which is why exceptions are allowed

for those. Please e-mail examples of vehicles with problems with

this rule that do not have composite/carbon replacement panels.

This would be a rule that I wouldn't mind revising and resubmitting if the intended

results are not being accomplished

 

Thanks.

 

 

Thank you. There is probably a better way to word the rule if that is the intent. We'll put together something and send.

 

 

-Kevin

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Hmm, so ok, but has anyone come up with the reverse formula to determine your ...Max...Avg...HP at a given weight? Since most of us are detuning we'll need an ....easy...way to do that. Also curious about the .6 for seq in st3, this would all but eliminate the Mazda GT folks we used to play with (but we're out east so I'm unsure if they still participate.)

 

 

Also I think you pasted this:

 

(none of these apply to Modification of the OEM roof line/shape = -0.3

Non-Production vehicles) Modification of the floor pan for exhaust clearance only

and/or the rocker panel for side exit exhaust only = -0.2

 

But meant this:

 

(none of these apply to Non-Production vehicles)

Modification of the OEM roof line/shape = -0.3

Modification of the floor pan for exhaust clearance only

and/or the rocker panel for side exit exhaust only = -0.2

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Re: 7.4.2 A1). Assuming these rules come down to PT .....

 

20-year old Miata frame rails are typically pretty beat up. I need jacking points. With original frame rails untouched, would I have to take points for longitudinal (not lateral) frame rail reinforcement ?

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I think the method for determining average horsepower is fundamentally flawed. I don't know what the intent of the average power calculation is but I suspect it is to try and slow the field down a bit. The problem with averaging is that the peak will always be the peak, so higher than this parts around it. Meaning a 300hp average WILL have a peak HP higher than that. If you look at the equation, all power numbers are treated with equal weight, meaning they all have the same significance in determining the average. You may be thinking so what. If you consider your HP@5250 and your HP@peak equal (as could be the case with a turbo car and a digital wastegate control) than that horsepower number can grow by one for every two horsepower the HP@peak+500 falls. So a 100 hp fall from peak to peak+500 equates to an extra 50hp between 5250 and peak rpm. Another criticism that may come to mind is "how the hell is horsepower going to fall 100 in 500 rpm", easy. If my motor makes 150 horsepower at peak+500 in naturally aspirated form, I can put a turbo on that same engine to make say 322.5hp at peak and set my boost controller to go limp and peak+20. So at peak+500 I'm making n/a power. See the picture in the below link for a scratch book approach. I don't think this is the result intended by this rule change.

 

So think about this another way, what if your HP@5250 were to equal your horsepower @peak+500. Than for every one horsepower that number falls, your peak goes up by two.

 

Now you might say well your example is really great for a turbo car......so I ask you to consider a throttle by wire car, like say every ls powered lump in the St grid ....... one could tune the throttle target as a function of rpm and gradually close the throttle, electronically, from peak to peak+500, and voila you now have a brand new ZR1 eligible for st3.

 

So then make all the cars manual throttle....... how much power would your engine make if you were to ramp the timing, electronically, from whatever it may be at peak, to 0 or -5 or -10 deg at peak+500.

 

My point is this, the averaging method won't work to slow down the field, it will only work to make some crazy fast cars. Keep the rule related to peak hp, whether that be the average peak of three runs or the highest of three, keep it simple.

 

 

https://drive.google.com/file/d/0B5sTypBDDKXuemtDY0JSWTU1djA/view?usp=docslist_api

 

 

Ryan

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8.2 ST3/TT3 Average Horsepower Calculation

 

New for 2016: The number used for calculating the Adjusted Wt/HP Ratio for the ST3 (and TT3) classes will no longer be the maximum horsepower of the three Dyno runs. It will be a calculated average giving a better approximation of the maximum horsepower available over a range of usable RPM. The Dyno test with the highest maximum horsepower will be used to calculate this average (not an average of the three Dyno runs) as follows:

 

Ave HP = Average HP calculated and used in in the Adjusted Wt/HP Ratio

Max HP = Maximum horsepower

HP 500 = Horsepower at 500 rpm greater than Max HP rpm (or redline HP if does not exist)

HP 5250 = Horsepower at 5250 rpm

HP RL-2k = Horsepower at redline minus 2000 rpm—This HP number will be used instead of

HP5250 if it is greater than HP 5250 (generally, this will tend to apply to high

revving engines)

 

 

Ave HP = Max HP + HP 500 + HP 5250 (or HP RL-2K if greater than HP 5250) divided by 3

 

-----------------------------------------------------------------------------------------

D) ST3 Only Production Vehicle Aerodynamics (does not apply to ST1 or ST2 vehicles)

 

Production vehicles that maintain their unmodified OEM body lines and do not have non-OEM aerodynamic aides or modifications may assess the Modification Factor for “OEM Aero” in calculating the “Adjusted Wt/HP Ratio” (7.4).

-----------------------------------------------------------------------------------------

7.4.2 Modification Factors

 

ST3 ONLY: OEM Aero (see 7.3.2.D) = +0.4

-------------------------------------------------------------------------------------------------------------------------

7.3.1 Restrictions and Limitations for All Vehicles (Non-Production and Production)

 

All vehicles must adhere to the following modification restrictions and limitations:

 

1) Active aerodynamic devices and/or modifications (including, but not limited to,

computerized, cockpit adjustable, self-adjusting, and OEM) are not permitted.

Aerodynamic devices and/or modifications may not protrude more than six (6”)

inches from the vertical plane from the ground to the widest part of the right and left sides of the vehicle’s body.

-------------------------------------------------------------------------------------------------

The big issue I see with the "HP 500 = Horsepower at 500 rpm greater than Max HP rpm (or redline HP if does not exist)" is that I can make my engine drop 100 HP for the final 600 RPM, this basically gives me 33 free HP with minimal hit in acceleration, a ~330 lb advantage(in TT3). I think I could realistically drop even more power for the top 500 RPM. In my car's case, it revs to 8400 RPM but I shift at 8000 rpm most of the time for longevity, so I'm not using that part of the rev range most of the time anyways. I think there should be some limit of the "HP 500" number, i suggest it can't be lower than 95% of the peak HP number to avoid people doing mega de-tunes up top.

 

I like the simplicity and introducing more of an average HP formula, but I think this might be too easy to game with too few data points.

___________________________________________________________________________________

I'm not clear on the ST/TT3 OEM aero formula, so a stock car runs at 9.6, but an aero car runs at 10.4? I don't think that's the intention, but how can a car receive both an OEM aero advantage bonus and a non-OEM aero penalty? It's one or the other. Am I missing something?

___________________________________________________________________________________

Are mirrors included in the vehicles body width?

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I'm only speaking for myself, but on my car, there is a limit to how minute the adjustments are, especially at the higher rpm. While yes, I can make the power fall quickly above the peak, and cannot make it fall 100hp in 500rpm (from peak). There probably are cars that can, but I don't know that I can.

 

Rule is a good start...maybe not perfect..... Just for curiosity, I'd love to the know the story behind averaging 3 hp points instead of using torque in some way?

 

Good thing my dyno goes in next week

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I like the idea of not allowing the HP500 number to be more than a certain percentage off. Do our best to not allow people to game the system to much.

 

The aero thing is really simple. ST3 is now a 10:1 class. If you run OEM aero you get a bonus of .4, and can run 9.6:1. However since I have never seen a single ST3 car NOT running aero, it seems more simple to write the rule this way, rather than listing it as a penalty. I imagine only the rare TT3 car that is still being built will not have at least a wing on it, which is non OEM.

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I like the idea of not allowing the HP500 number to be more than a certain percentage off. Do our best to not allow people to game the system to much.

 

I have a stock cam LS1 that absolutely falls off a clip at high rpm. Well below the proposed 95%. There is no "manipulation" there, that's just the way it is, and there are lots of stock cam engines that fall off a cliff.

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I like the idea of not allowing the HP500 number to be more than a certain percentage off. Do our best to not allow people to game the system to much.

 

I have a stock cam LS1 that absolutely falls off a clip at high rpm. Well below the proposed 95%. There is no "manipulation" there, that's just the way it is, and there are lots of stock cam engines that fall off a cliff.

 

Simple answer to that, set your rev limiter so you don't use that point.

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