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TT3 question

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RUQWIKR

I have a 17 Camaro SS 1LE.  Thinking TT3 with probably 4000# raceweight and 420hp dyno.  I will weigh and dyno to confirm.  Would run on 200TW.  For the Base Trim Model aero modifier:

1) If I put on OEM ZL1 1LE front and rear aero, would that still be okay to claim the positive modifier since it’s OEM from another same Gen Camaro?  This would be front fascia, hood, dive planes, and splitter up front with the trunk wing.

2) What if I did the front aero per above but stuck with the SS 1LE rear small lip trunk spoiler with factory option (dealer install) small add on wickerbill?

Thanks for your help with clarity on this.  Dave

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427R

I'd recommend going to the Car Classification/Calculator Form for some answers. Can be found under Driver Groups, Time Trial Rules, scroll to bottom where Time Trials is.  After that, take a look at the ST Rules for 2019 (they apply to TT as well) for better in depth explanations on modifications and how that affects your classification.

 

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RUQWIKR

I did but just needed clarifying if you can add OEM stuff from another version of the same car.  Basically, what does Base Trim Model really mean.

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427R

BTM refers to the car model and options as it would come from the manufacture.  Example, the different BTM's of a mustang,  offered a spoiler as a Standard item or as an Optional item.  If you pull up the different Trim Levels of your car and look at the Body Exterior Features, that should tell you what came on the car as Standard or Optional.

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dwesterwick

Basically, if it wasn't a factory-installed option available for the trim of your car, you can't claim OEM aero. Unless I'm missing an exception to the rule (or just don't understand Camaros), the ZL1 aero bits were not available on the SS, so you would have to take the penalty if you installed them.

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427R
Posted (edited)

Agree Dan.  There was also some arguments as to whether parts added by some aftermarket industries (Roush, Shelby) were considered OEM.  Never got a straight answer on that one, since the cars would go straight from the maker to the "maker authorized" aftermarket industries and then to the dealers for sale.  Nonetheless, we mustang owners :classic_cool: were lucky that most of their model cars had aero, as an example, as OEM or was optional for that model.

Edited by 427R

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Greg G.

Guys,

Please be careful giving out info if you are not 100% certain.  The best answer is to just re-post the rule itself---not sure why there is any confusion on this:

"Under this specific rule, an aerodynamic aide is considered non-BTM if it did not come configured on the base trim model (BTM) of the vehicle from the manufacturing factory. Except for those vehicle-specific higher level trim models (non-BTM) listed in Appendix B, there is no updating or backdating across trim models or the addition of dealer installed options permitted."

The base trim model is the most basic trim package of a given model that is available.  So, ZL1 parts would not qualify for BTM Aero ever.  As well, there is this rule:

"do not have non-BTM aerodynamic aides or modifications, and do not have a rear wing or rear spoiler or rear diffuser"

So, any vehicle that is potentially eligible for BTM Aero must first have any rear wing or spoiler removed (even if it came on the BTM version of the vehicle).

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427R

You're right Greg, forgot the wording and rule got changed from OEM Aero to BTM Aero.  I don't have the TT Rules from 2017,  but know it was discussed heavily regarding if a car was made with a rear spoiler, did it fall under the allowed OEM Aero rule.  2018 & 2019 Rules have cleared that all up.

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dwesterwick
22 hours ago, Greg G. said:

Guys,

Please be careful giving out info if you are not 100% certain.  The best answer is to just re-post the rule itself---not sure why there is any confusion on this:

"Under this specific rule, an aerodynamic aide is considered non-BTM if it did not come configured on the base trim model (BTM) of the vehicle from the manufacturing factory. Except for those vehicle-specific higher level trim models (non-BTM) listed in Appendix B, there is no updating or backdating across trim models or the addition of dealer installed options permitted."

The base trim model is the most basic trim package of a given model that is available.  So, ZL1 parts would not qualify for BTM Aero ever.  As well, there is this rule:

"do not have non-BTM aerodynamic aides or modifications, and do not have a rear wing or rear spoiler or rear diffuser"

So, any vehicle that is potentially eligible for BTM Aero must first have any rear wing or spoiler removed (even if it came on the BTM version of the vehicle).

I thought I understood it, but after reading this quote a few times, I'm actually not so sure anymore. My confusion mostly comes from the term "Base Trim Model". At first it sounds easy enough to understand, but after searching through the rules and the CCR, I see no actual definition for "Base Trim Model".

For example, my (previous) interpretation of this rule would have the Focus ST judged separately from the standard Focus because it's sometimes listed as a separate car (i.e. cars.com) In contrast, the standard Focus is available with the base SE trim and an optional (higher) Titanium trim, and I've never seen them listed separated while browsing models. In this interpretation, the Focus ST could quality for BTM if the spoiler is removed and no other body parts are changed. Of course, applying Focus ST components to a Focus SE would make the SE unable to claim BTM aero - unless the Focus ST is listed in Appendix B of the rules. I assumed this because if an unmodified Focus ST did not qualify for BTM Aero, even with the removal of the spoiler, at a minimum the front and rear bumpers would have to be replaced with ones from a Focus SE (which would be considered BTM). However, "there is no updating and backdating across trim models", so wouldn't that preclude the ST from EVER being allowed to use the BTM Aero factor? Is that really the intent? If so, it seems a little silly that a C5 Z06 - a car with fantastic aerodynamic performance - can claim BTM aero with no changes, but a Focus ST - a car with mediocre aerodynamic performance at best - is unable to claim BTM aero in any configuration.

Am I missing something? Possibly the term "aerodynamic aide" is adding to my confusion because it's not defined anywhere either. Would "aerodynamic aides" only be splitters, canards, etc.? I would consider entire bumper covers and side skirts to be aerodynamic aides since they can have a measurable effect on downforce and drag.

In case you're wondering, I don't compete with any kind of Focus, and my TT car is without a doubt unable to claim BTM aero. I'm just trying to understand what's actually permitted by the rules. I'm not trying to propose any changes except possibly rewriting/appending them for more clarity.

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Greg G.

The Focus ST is just a higher level trim model of the Focus.  So, it would not qualify for the BTM Aero Mod Factor unless it was approved for Appendix B (and the competitor removed the rear spoiler).   FYI, when I go to Cars.com, it just asks me for year, make, and model to search, and the model in this case is "Focus".

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dwesterwick

Maybe we're looking in different sections, but I see "Focus", "Focus Electric", "Focus ST", and "Focus RS" listed as separate models. Similarly, it lists the "Mustang", Shelby GT350", and "Shelby GT500" separately. Whatever the case, I think you answered my question. The point of the example was mostly to understand what "Base Trim Model" actually means. Also, because the rule specifically applies to "aerodynamic aides" per the wording, what components are considered "aerodynamic aides"? Should I just assume that anything on the exterior of the car is an "aerodynamic aide" unless addressed in the exception list in section 6.3?

I suppose what's still a little confusing to me is the purpose of the BTM aero factor. If I have a car like a Focus ST, then I'm pretty much forced to spend a lot of money on aftermarket aero mods because my level of aero prep is judged the same with the car stock (even without the spoiler) and with an aggressive splitter/wing/canards/diffuser on it (for TT3/ST3). Even in TT4/ST4, the OEM car (with or without the spoiler) would be judged the same as one with a splitter and a wing. Is the idea to exclude all higher trims by default just to minimize loopholes? I can understand that, but how involved is the approval process to get a higher-trim model approved for BTM aero and listed in Appendix B? I know the competitor just needs to email you, but I'm not sure about what all goes into your decision, how frequently you receive requests (and if you're backlogged), and how long it typically takes to get a response.

Again, I'm not trying to give you a hard time. It just seems that the BTM aero factor is penalizing cars that aren't actually BTM or fortunate enough to make it in Appendix B. If the approval process for Appendix B is fairly straightforward and the list is small because few people have emailed you, maybe it's not really an issue. Sorry if this all has been address elsewhere.

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Clavette
5 minutes ago, dwesterwick said:

Maybe we're looking in different sections, but I see "Focus", "Focus Electric", "Focus ST", and "Focus RS" listed as separate models. Similarly, it lists the "Mustang", Shelby GT350", and "Shelby GT500" separately. Whatever the case, I think you answered my question. The point of the example was mostly to understand what "Base Trim Model" actually means. Also, because the rule specifically applies to "aerodynamic aides" per the wording, what components are considered "aerodynamic aides"? Should I just assume that anything on the exterior of the car is an "aerodynamic aide" unless addressed in the exception list in section 6.3?

I suppose what's still a little confusing to me is the purpose of the BTM aero factor. If I have a car like a Focus ST, then I'm pretty much forced to spend a lot of money on aftermarket aero mods because my level of aero prep is judged the same with the car stock (even without the spoiler) and with an aggressive splitter/wing/canards/diffuser on it (for TT3/ST3). Even in TT4/ST4, the OEM car (with or without the spoiler) would be judged the same as one with a splitter and a wing. Is the idea to exclude all higher trims by default just to minimize loopholes? I can understand that, but how involved is the approval process to get a higher-trim model approved for BTM aero and listed in Appendix B? I know the competitor just needs to email you, but I'm not sure about what all goes into your decision, how frequently you receive requests (and if you're backlogged), and how long it typically takes to get a response.

Again, I'm not trying to give you a hard time. It just seems that the BTM aero factor is penalizing cars that aren't actually BTM or fortunate enough to make it in Appendix B. If the approval process for Appendix B is fairly straightforward and the list is small because few people have emailed you, maybe it's not really an issue. Sorry if this all has been address elsewhere.

I think it's moot point honestly.  I can't think of a single TT3 car that is competitive without aftermarket aero and Hoosiers (or true slicks).

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dwesterwick

In terms of overall competitiveness, I definitely agree with you. I was thinking more about the "barrier" of getting more people into TT3/TT4 but especially for TT3 since the TT4 aero rules are a lot more restrictive. I'm not sure what your region is like, but TT1->TT3 is pretty dead in mine. Also, I'm genuinely curious about what this rule was intended to address and how it was designed to "adapt" via Appendix B to better achieve parity between models.

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Clavette
20 hours ago, dwesterwick said:

In terms of overall competitiveness, I definitely agree with you. I was thinking more about the "barrier" of getting more people into TT3/TT4 but especially for TT3 since the TT4 aero rules are a lot more restrictive. I'm not sure what your region is like, but TT1->TT3 is pretty dead in mine. Also, I'm genuinely curious about what this rule was intended to address and how it was designed to "adapt" via Appendix B to better achieve parity between models.

That's fair.  TT3 in my region (TX) was really strong from 2014-2017.  Last year, a few of us moved out and this year the numbers are really down.

They are experimenting with a 200tw subclass to try to promote more participation.  

 

 

Edited by Clavette

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Greg G.
On 1/8/2019 at 7:03 PM, dwesterwick said:

Maybe we're looking in different sections, but I see "Focus", "Focus Electric", "Focus ST", and "Focus RS" listed as separate models. Similarly, it lists the "Mustang", Shelby GT350", and "Shelby GT500" separately. Whatever the case, I think you answered my question. The point of the example was mostly to understand what "Base Trim Model" actually means. Also, because the rule specifically applies to "aerodynamic aides" per the wording, what components are considered "aerodynamic aides"? Should I just assume that anything on the exterior of the car is an "aerodynamic aide" unless addressed in the exception list in section 6.3?

I suppose what's still a little confusing to me is the purpose of the BTM aero factor. If I have a car like a Focus ST, then I'm pretty much forced to spend a lot of money on aftermarket aero mods because my level of aero prep is judged the same with the car stock (even without the spoiler) and with an aggressive splitter/wing/canards/diffuser on it (for TT3/ST3). Even in TT4/ST4, the OEM car (with or without the spoiler) would be judged the same as one with a splitter and a wing. Is the idea to exclude all higher trims by default just to minimize loopholes? I can understand that, but how involved is the approval process to get a higher-trim model approved for BTM aero and listed in Appendix B? I know the competitor just needs to email you, but I'm not sure about what all goes into your decision, how frequently you receive requests (and if you're backlogged), and how long it typically takes to get a response.

Again, I'm not trying to give you a hard time. It just seems that the BTM aero factor is penalizing cars that aren't actually BTM or fortunate enough to make it in Appendix B. If the approval process for Appendix B is fairly straightforward and the list is small because few people have emailed you, maybe it's not really an issue. Sorry if this all has been address elsewhere.

No problem.  You are correct that the list is small because it is rarely used.  You are also right that we have the rules written as is to avoid loopholes.  The approval process requires an email and photos of the BTM model and the requested higher trim model.  I think we have only denied one so far.  

Also, the competitor with the higher level trim model can always downgrade to the base trim fascia, etc., if not approved for Appendix B, instead of spending lots on added aero.   In most cases, higher trim model fascias are easily sold to the street car world  as well.  

Might surprise folks, but the rule is a remnant of the PTA/TTA class, and was actually written to help transition the C5 Z06’s to the ST classes when PTA/TTA was deleted many years ago   Despite what is said here, a stock Z has no Aero features other than a descent coefficient of drag.   The rule has been kept because it is helpful both for TT cars and to transition TT cars to ST, and it does give competitors the option of how to prep the car.  A bunch of ya ran no Aero in ST5/TT5, and did well at the HP tracks.  

 

 

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dwesterwick
17 hours ago, Greg G. said:

the competitor with the higher level trim model can always downgrade to the base trim fascia, etc., if not approved for Appendix B

Ah ok, I interpreted "there is no updating and backdating across trim models" as you're not allowed to install a lower-trim fascia on a higher-trim car at all. This just means you're not allowed to mix parts between different generations of the model and claim BTM aero. That definitely opens up your options if you don't have aftermarket aero compared to what I originally thought.

Thanks for the explanation; that clears things up a lot for me.

Regarding the Z06, I think its coefficient of drag is a significant advantage for a power/weight class. It also has a relatively low frontal area to complement the low coefficient of drag. If you put information like this into a basic comparison using software like OptimumLap, you can see how much of an advantage is it against cars of similar levels of prep. It's far from a perfect analysis, but it's hard to argue with the physics behind it. Of course, this would be true if it has BTM aero or aftermarket aero, so it doesn't really pertain to the topic we're discussing.

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