2020 ST/TT Car Classification Rules Revisions Proposed

[Greg G.]

Hi Folks,

It's that time of the year again, and despite the mantra by some regarding "rules creep", we have gotten hundreds of requests for rules revisions and changes for 2020 by our competitors.  In general, we would love to just slap a new year and revision number on the rules and call it a day, but without addressing issues found and reasonable requests made during the year, we would not be good stewards of the goal of increasing participation numbers.  With that being said, we have whittled down hundreds of requests to those that have made the "finals".   I will present them here for comments for one week.  Some of them, like the ST3 non-DOT tire Mod Factor revision already had a long discussion thread.  Others like the coilover conversion revision were polled in each region, and others you may not have heard about until now.   As usual, please be civil and reasoned in your comments, and none of these are official rules until posted as such.  Also, for simplicity, I'm going to just post the generic change here, instead of the actual revised wording in the rules, and any reference to an ST class applies to the same TT class.   But, if there are questions that would pertain to the revised wording, feel free to ask.

1a) Leaf spring/Torsion bar to coilover spring conversion is permitted in ST4 without a Mod Factor
1b) Leaf spring/Torsion bar to coilover spring conversion is permitted in ST5 & ST6 with a -0.5 Mod Factor assessment

2) FWD Mod Factor is decreased from +1.0 down to +0.5 for factory build non-Production race cars in ST1/2/3.

3) In ST4, vehicles with a Minimum Competition Weight greater than 3000 lbs (decreased from 3100 lbs) may have a NASA Section Width tire up to 282mm.

4) In ST3, the non-DOT tire Mod Factor increases from -0.5 to -0.8.

5) In ST1/2/3, the non-DOT tire size Mod Factor of +0.3 shall apply to tires marked as large as 10.5", 270mm, or 27cm by the tire manufacturer.  (This is an increase from 10.5"/267mm).

6) The non-DOT tire exception for Continental Tire Sportscar Challenge EC-Dry and EC-Wet tires will expire on 12-31-20.  (use them up)

7) The Toyo RR will be added to the line: "Tires with a UTQG Treadwear rating 100 or greater +0.5"
So, this one would be: "Tires with a UTQG Treadwear rating 100 or greater or Toyo RR +0.5"

8.) Change to ST3 & ST4 Transmission Mod Factors:

ST3 & ST4: OEM street-legal model available paddle shift, DCT/SMG/DSG/PDK, Dog-ring/straight-cut gears, or sequential motorcycle gearbox  = -0.5

ST3 & ST4: All other sequential/semi-automatic  = -1.0

(This is an increase from -0.3 to -0.5 for the first group, except for the Dog-ring/straight-cut gears that decrease from -0.6 to -0.5.   And, the reference to automatic transmissions utilizing a torque converter is deleted)

9) ST5 & 6: In regard to transmissions, Delete reference:  "(All classes—no assessment for automatic utilizing torque converter)"  This is no longer appropriate with new technology.

10) In ST4/5/6, in regard to convertibles with hardtops, there must be a sealed rear window regardless of whether the top is compliant with BTM Aero or is aftermarket. 

11) ST1/2/3 Mod Factor for Production Car approval for Panoz GTRA and GTWC increased to -0.3 (from -0.2)

12) Add new class to Time Trial: TTEV (Time Trial Electric Vehicle)--Open class for Tesla Model 3, Tesla Model S, Porsche Taycan, and others as added, using HPDE technical inspection--with no modifications permitted to the factory motor, batteries, or EV related safety features.  For 2020, no current ST classing for electric vehicles other than SU with required approval in writing from NASA National for each individual entry.

 

 

 

 

Edited November 4, 2019 by Greg G.

[Tansar_Motorsports]

1a:   Strongly agree.

1b:  Either this modification should be free, or a multilink coilover conversion (e36 etc.) should also carry the same penalty.  As has been stated before, equivalent performance can be acheived with a torsion bar vs a coilover conversion, it is just more difficult/expensive.  

2.  Is this enough of a change to stop TCR cars from destroying ST3/TT3 again? (yes, I know they didn't win TT3 at nationals, but that is just because they got DQ'd for not having done enough TT events this year)

Everything else listed I have no strong opinion of.

 

Also, how about the elephant in the room for ST5/ST6  -->   Double A-arm mod factor?
Could you provide some clarification on the reasoning not to make any changes to this?

Based on nationals results, I would say that the rule is pretty close to being correct, but there are a few tweaks that I think would improve it.
a.  Multilink rear suspension should be treated the same as a double A-arm suspension.  It can have the same motion characteristics and the same performance potential.  To classify these two styles differently makes absolutely no sense from an engineering perspective.  If you disagree, please provide your reasoning.
b.  A car with double wishbone/multilink suspension front and rear (S2k, 350z, RX8, miata, etc) should have a performance advantage over a car that only has those style on 1 axle (e36, e46, etc).  Therefore, the single mod factor should be split into 2 separate factors:
                        1.  Driven Axle suspension style (or the rear axle of an AWD car)
                        2.  Non driven axle suspension style (or the front axle of an AWD car)
Probably the driven axle factor should be larger than the non driven axle factor.  These two factors could add up to the same total factor as currently (so no change for the current double wishbone front and rear cars).  But cars that only have it on 1 axle would get a small break.
For transparency, I have a TT5 RX8 (double wishbone front and multilink rear), so if my 2 proposals above were accepted, my total mod factor wouldn't change.  So I am not trying to gain an advantage.

[daytonars4]

The TCR that won ST3 at Nats would be taking about a 270lb penalty with these changes. It's not just the FWD change that impacts it. 

[949Racing]

Agree and support the designation of the Toyo RR on the same line/points as 100 treadwear tires. Real world, this is where that tires' performance and cost factors land. We suggested that change in designation to our contacts at Toyo a while back as well. All aimed at lowering the cost to race competitively. We understand that all tire manufacturers that support any series have a right to operate on an even playing field. This change works to that end, in our opinion.

[Al36rx7]

Makes sense for most, but Don't quite agree with the increase in the non-dot for ST3.  As stated previously on sprint style races the DOT R-Compounds take off for the first couple laps as the Non-DOT tires are coming up to temperature.  The non-DOT folks are then playing catch up and doing their very best to find a way back around people that passed them on the start even though their qualifying position is ahead of the DOT R-Compund individuals. 

How close is this to be set in stone?  Do I need to be planning to be adding weight to a non torque rotary? 

I understand there will never be an answer that pleases all, and I am being very self serving. 

Thanks.

Edited November 4, 2019 by Al36rx7

[BillsM3]

Is the increased DCT/PDK penalty aimed at the the TCR cars?  Not all street ST3 sequentials are on TCRs (mine is on an E92 M3), and a -0.5 penalty is huge for a non-racing gearbox.  The performance advantage (as opposed to the keep-the-idiot from breaking another clutch advantage) for a street gearbox is quite modest. Don't understand lumping these in with true racing boxes.

[davidfarmer]

I only work with ST1-2-3-4 cars, and what I see above looks good to me. 

My additional request would be to get rid of the 90deg airdam/splitter requirement for ST4.   I understand this is for ease of measuring splitter length, but I think a Carpenter square and a tape measure is a simple enough skill to master for measure splitter length relative to the  fascia.

I've seen lots of ST4/TT4 cars non-compliant this year, BMW's, Porsches, Corvettes, Miatas.  It is so common to use an aftermarket/OEM "lip" as the attachment for a flat splitter, the 90deg rule adds unnecessary construction complication in my opinion.

 

 

[daytonars4]

17 hours ago, BillsM3 said:

Is the increased DCT/PDK penalty aimed at the the TCR cars?  Not all street ST3 sequentials are on TCRs (mine is on an E92 M3), and a -0.5 penalty is huge for a non-racing gearbox.  The performance advantage (as opposed to the keep-the-idiot from breaking another clutch advantage) for a street gearbox is quite modest. Don't understand lumping these in with true racing boxes.

The Porsche PDK is certainly on par with the TCR DSG if not better. The Porsche GT4 Clubsport runs the same PDK as the street cars. So not sure how you could try to penalize just 1 manufacturer and ignore the others?

[esr]

45 minutes ago, daytonars4 said:

The Porsche PDK is certainly on par with the TCR DSG if not better. The Porsche GT4 Clubsport runs the same PDK as the street cars. So not sure how you could try to penalize just 1 manufacturer and ignore the others?

Thanks

m235 or m240 works fine as well

maybe the reasoning is the set gear ratios

Edited November 5, 2019 by esr

[BillsM3]

Not suggesting that one manufacturer be treated differently than another.  The question is how much faster a DCT/PDK is compared with a true manual.  -0.5 is a lot.  And not sure why ST1-2 are not encompassed by the proposed rule -- if I took out a bunch of weight, added more power and ran ST2, then the new multiplier would not apply.  Not sure that seems right.

Every E92 M3 (except mine, of course) I see has a manual -- why would that be if the DCT was any advantage, let alone a very material one?

I could be wrong, but it seems like the issue is the TCRs, and how to handicap them appropriately.  Not sure it should be done via multiple rules and end up ensnaring non-TCRs.

[Balroks]

I have to assume that the TCR cars are NOT being considered non-production cars, because well....they are a production chassis?  I also agree thats is a bit of a punch to the gut when you just spent 100k on a car that has no series here in the states.  Then again if you look at Gridlife and other series, RWD isn't the fastest kid on the block anymore.  So maybe go from +1.0 to +0.6 in general.  FWD is becoming better. 

Agree kill #4, it's balanced from what we've seen in our region.

#7 brings up a good final point.  Others have mentioned 100tw +5 isn't ENOUGH in general.  You're going up against A7's 80-90% of the time, there's no chance in hell usually, and we've seen 0 cars using them outside of RA1's in the rain.  .05 is worth a hell of a lot more in FWD then it is with 100tw tires.  So why are we calling them the same.

Edited November 5, 2019 by Balroks

[Greg G.]

4 minutes ago, Balroks said:

I have to assume that the TCR cars are NOT being considered non-production cars, because well....they are a production chassis?  I also agree thats is a bit of a punch to the gut when you just spent 100k on a car that has no series here in the states. 

 

"“Production” vehicle models are those manufactured by an automobile manufacturer (at least 500 produced per year) and approved for street use by the U.S. D.O.T., T.U.V, or Japanese government, provided it is in compliance with the modification limitations in section 6.1 and 6.2 of these rules."

They are by definition non-Production cars--They are purpose built for racing, not the street.  Also, these cars are very welcome in ST3/TT3, and have done extremely well, and presumably will continue to.  The previous FWD Mod Factor was based on someone taking a production street car with FWD, and trying to compete against ST1-3 sports cars often manufactured for track use (although sold as street cars).  This newer breed of FWD vehicles has cubic dollars of factory R&D that has never been seen in FWD vehicles at our level of competition, and that large +1.0 extra Mod Factor is not appropriate for them.  No competitor in NASA has ever shown that the +1.0 Mod Factor for FWD production based cars is not appropriate.

[Greg G.]

In regard to non-DOT's, there has been enough data to show that the "good" non-DOT's are worth more than the -0.5 Mod Factor that they currently have in ST3/TT3 (not necessarily in the higher classes where Mod Factor changes have more drastic effects because of the overall lower Wt/HP ratio).  The argument that people want to buy cheap take-offs so the Mod Factor should stay lower only would work if there was some way of having a "cheap take-off only non-DOT" Mod Factor.  If the -0.8 Mod Factor is too much, then those ST3/TT3 drivers using them will switch back to DOT's (which is what the majority of competitors use now anyway).  However, there are certainly competitors taking advantage of the most expensive, fresh non-DOT's, and they should have a more appropriate Mod Factor if they are doing so.   If you are using take-offs, and racing against someone who is using new tires, then you have already made the decision to not be as competitive as possible--which is fine, but should not be the reason that the rule should not adjusted for those with a big advantage over competitors using non-DOT's. 

[Greg G.]

The technology on transmissions has gotten to the point that they are making a big difference in performance, especially at the amateur skill level.  There is no doubt that there is measurable lap time to be gained with them.  As well, that technology continues to advance.  NASA does not want to even try to apply Mod Factors to one brand versus another for OEM transmissions.  So, they are getting consolidated as much as possible.

[esr]

4 hours ago, Balroks said:

I have to assume that the TCR cars are NOT being considered non-production cars, because well....they are a production chassis?  I also agree thats is a bit of a punch to the gut when you just spent 100k on a car that has no series here in the states.  Then again if you look at Gridlife and other series, RWD isn't the fastest kid on the block anymore.  So maybe go from +1.0 to +0.6 in general.  FWD is becoming better. 

Agree kill #4, it's balanced from what we've seen in our region.

#7 brings up a good final point.  Others have mentioned 100tw +5 isn't ENOUGH in general.  You're going up against A7's 80-90% of the time, there's no chance in hell usually, and we've seen 0 cars using them outside of RA1's in the rain.  .05 is worth a hell of a lot more in FWD then it is with 100tw tires.  So why are we calling them the same.

TCR cars are 250k plus

The Honda Civic is 300k when is all said and done.

why are they in NASA!

[daytonars4]

10 hours ago, esr said:

TCR cars are 250k plus

The Honda Civic is 300k when is all said and done.

why are they in NASA!

False. The used VW and Audi TCR’s can be purchased for 70-80k now. There are certainly non-factory race cars in ST with that much in development spent on them. New they are $120-150k. The Honda’s are extremely limited production so they have a rather disproportionate cost. 

[daytonars4]

17 hours ago, BillsM3 said:

Not suggesting that one manufacturer be treated differently than another.  The question is how much faster a DCT/PDK is compared with a true manual.  -0.5 is a lot.  And not sure why ST1-2 are not encompassed by the proposed rule -- if I took out a bunch of weight, added more power and ran ST2, then the new multiplier would not apply.  Not sure that seems right.

Every E92 M3 (except mine, of course) I see has a manual -- why would that be if the DCT was any advantage, let alone a very material one?

I could be wrong, but it seems like the issue is the TCRs, and how to handicap them appropriately.  Not sure it should be done via multiple rules and end up ensnaring non-TCRs.

The reason that most E92 M’s don’t run DCT’s is Bc it’s well known that they just frankly don’t do well in race environments. I know severely people who have spent a ton of money trying to get them to function properly and they still don’t. They can work “good enough” but not as well as people hoped. The new gen Porsche PDK’s are decisively faster than manuals. That’s the whole reason Porsche made the decision to remove manuals from the 991.1 before conceding to the enthusiasts with the 991.2. How to calculate that exact weight variance needed, it’s probably a guess until you get it right 

[BillsM3]

So I get a -0.5 factor for my DCT because PDKs are worthy of that factor?  I understand the discomfort with different factors for different makes, but this seems inequitable to me.

[rherold9]

On 11/4/2019 at 9:22 AM, Tansar_Motorsports said:

 

Also, how about the elephant in the room for ST5/ST6  -->   Double A-arm mod factor?
Could you provide some clarification on the reasoning not to make any changes to this?

Based on nationals results, I would say that the rule is pretty close to being correct, but there are a few tweaks that I think would improve it.
a.  Multilink rear suspension should be treated the same as a double A-arm suspension.  It can have the same motion characteristics and the same performance potential.  To classify these two styles differently makes absolutely no sense from an engineering perspective.  If you disagree, please provide your reasoning.
b.  A car with double wishbone/multilink suspension front and rear (S2k, 350z, RX8, miata, etc) should have a performance advantage over a car that only has those style on 1 axle (e36, e46, etc).  Therefore, the single mod factor should be split into 2 separate factors:
                        1.  Driven Axle suspension style (or the rear axle of an AWD car)
                        2.  Non driven axle suspension style (or the front axle of an AWD car)
Probably the driven axle factor should be larger than the non driven axle factor.  These two factors could add up to the same total factor as currently (so no change for the current double wishbone front and rear cars).  But cars that only have it on 1 axle would get a small break.
For transparency, I have a TT5 RX8 (double wishbone front and multilink rear), so if my 2 proposals above were accepted, my total mod factor wouldn't change.  So I am not trying to gain an advantage.

Would also like to see something like this implemented. Also a question on why the rule is exclusive just to ST5/6?

Edited November 6, 2019 by rherold9

[int2str]

If I'm understanding this correctly:

Quote

7) The Toyo RR will be added to the line: "Tires with a UTQG Treadwear rating 100 or greater +0.5"
So, this one would be: "Tires with a UTQG Treadwear rating 100 or greater or Toyo RR +0.5"

This effectively kicks Hoosier's R7's or Hancook's our of the competition.
Given that Hoosier is a strong supporter of NASA and has a great contingency program, this seams a pretty direct shot at a great supporter of the club.

I get it that Toyo is the title sponsor, but by just changing the rules in their favour, there is no incentive for improved tire competition and no incentive for Toyo to make a better tire to compete...

Am I reading this wrong?
Very, very disappointing if this is true.

[Greg G.]

1 hour ago, int2str said:

If I'm understanding this correctly:

This effectively kicks Hoosier's R7's or Hancook's our of the competition.
Given that Hoosier is a strong supporter of NASA and has a great contingency program, this seams a pretty direct shot at a great supporter of the club.

I get it that Toyo is the title sponsor, but by just changing the rules in their favour, there is no incentive for improved tire competition and no incentive for Toyo to make a better tire to compete...

Am I reading this wrong?
Very, very disappointing if this is true.

I'm going to go out on a limb and guess that you have never tested or seen test data comparing the tires you mentioned versus the weight or horsepower differences of a 0.5 Mod Factor.  I would think that would be a requirement before making the statements you made.  I personally will be sticking with my R7's with this new rule.

[srproductions]

2 hours ago, int2str said:

If I'm understanding this correctly:

This effectively kicks Hoosier's R7's or Hancook's our of the competition.
Given that Hoosier is a strong supporter of NASA and has a great contingency program, this seams a pretty direct shot at a great supporter of the club.

I get it that Toyo is the title sponsor, but by just changing the rules in their favour, there is no incentive for improved tire competition and no incentive for Toyo to make a better tire to compete...

Am I reading this wrong?
Very, very disappointing if this is true.

I completely disagree.  Are you stating this based on actual testing you conducted or is this just an assumption?  I don't plan on changing from Hoosier to Toyos because of this rule change.

I think it is great for guys who run Toyo classes and want to crossover to our class. It will help that tire be more competitive.  I'm sure the rule will be evaluated after a season and changed if needed.  

I welcome this rule change and think it will greatly benefit the class.  

 

S.Rizvi 
#732 Honda S2000

[srproductions]

On 11/4/2019 at 9:22 AM, Tansar_Motorsports said:

1a:   Strongly agree.

1b:  Either this modification should be free, or a multilink coilover conversion (e36 etc.) should also carry the same penalty.  As has been stated before, equivalent performance can be acheived with a torsion bar vs a coilover conversion, it is just more difficult/expensive.  

2.  Is this enough of a change to stop TCR cars from destroying ST3/TT3 again? (yes, I know they didn't win TT3 at nationals, but that is just because they got DQ'd for not having done enough TT events this year)

Everything else listed I have no strong opinion of.

 

Also, how about the elephant in the room for ST5/ST6  -->   Double A-arm mod factor?
Could you provide some clarification on the reasoning not to make any changes to this?

Based on nationals results, I would say that the rule is pretty close to being correct, but there are a few tweaks that I think would improve it.
a.  Multilink rear suspension should be treated the same as a double A-arm suspension.  It can have the same motion characteristics and the same performance potential.  To classify these two styles differently makes absolutely no sense from an engineering perspective.  If you disagree, please provide your reasoning.
b.  A car with double wishbone/multilink suspension front and rear (S2k, 350z, RX8, miata, etc) should have a performance advantage over a car that only has those style on 1 axle (e36, e46, etc).  Therefore, the single mod factor should be split into 2 separate factors:
                        1.  Driven Axle suspension style (or the rear axle of an AWD car)
                        2.  Non driven axle suspension style (or the front axle of an AWD car)
Probably the driven axle factor should be larger than the non driven axle factor.  These two factors could add up to the same total factor as currently (so no change for the current double wishbone front and rear cars).  But cars that only have it on 1 axle would get a small break.
For transparency, I have a TT5 RX8 (double wishbone front and multilink rear), so if my 2 proposals above were accepted, my total mod factor wouldn't change.  So I am not trying to gain an advantage.

Multilink suspensions that utilize an A arm shape already take the penalty; IE: BRZ/FRS

I think a penalty per drive axle holds merit.  This would help cars like the BRZ/FRS be more competitive.  

For transparency, I drive an S2000 and this would not impact me but would help equalize the class.  

S.Rizvi
#732 Honda S2000

[dwesterwick]

I really like a few of the proposals including:

• Reducing the mod factor for non-production FWD cars to +0.5
• Making the Toyo RR a more competitive tire option
• Recognizing that modern automatics can be superior to manuals even with a torque converter

Also, I think that -0.8 is more appropriate than -0.5 for non-DOT tires, so I reluctantly support this change too. To be honest, using non-DOT tires was going to be part of my strategy for next year and a change like this makes me reconsider, but I think -0.8 is more fair. At -0.5 with my car, the math works out to be potentially a better option (but more expensive and more of a PITA), but at -0.8 it's closer to breaking even. Back to the drawing board I guess...

Finally, just to play devil's advocate, I'm wondering about the wording for some of these new rules. These two stand out to me:

• The proposed mod factor change to +0.5 for FWD cars applies to "factory build non-Production race cars". I know this wording might not be final, but is the intent to apply this mod factor to any non-production FWD car or to apply it to non-production FWD cars that are also factory-built race cars? This might be a bit of a slippery-slope argument, but conceptually, it seems more relevant to consider how the steering and suspension might be revised (i.e. using a modified subframe) than if the car was built by a large company or in Hee-Haw's tractor shop. Of course I realize that one is more likely to be successful than the other.
• The proposed wording for the -0.5 transmission mod factor applies to "paddle shift, DCT/SMG/DSG/PDK, ..." models. Is my understanding correct that a car with a "conventional" automatic transmission that does not have paddle shifters would not take this penalty? If so, using my limited knowledge of automatic transmissions, this implies that the benefit relies on the ability to manually shift the transmission. I'll again provide what might be slippery-slope arguments: why couldn't a modern "conventional" automatic be tuned to shift like I would manually but do it faster, and would the penalty still be applied to a car originally equipped with a modern automatic utilizing paddle shifters if I physically removed the paddle shifters and let the transmission exclusively shift using the TCU? From looking at my data, there seems to be a HUGE advantage from shifting faster and less of an advantage from precise shift points (depending on your power curve shape). Also, maybe I just suck at shifting.

Neither of these rules directly affect me, but I'm curious about the specific problems with the current rules that these proposals are trying to address. Basically I'm just playing the game of "how can I exploit the wording of the rules without actually cheating?".

[Marco8]

On 11/5/2019 at 10:24 AM, davidfarmer said:

My additional request would be to get rid of the 90deg airdam/splitter requirement for ST4.   I understand this is for ease of measuring splitter length, but I think a Carpenter square and a tape measure is a simple enough skill to master for measure splitter length relative to the  fascia.

I've seen lots of ST4/TT4 cars non-compliant this year, BMW's, Porsches, Corvettes, Miatas.  It is so common to use an aftermarket/OEM "lip" as the attachment for a flat splitter, the 90deg rule adds unnecessary construction complication in my opinion.

 

 

Agree with David, or increase tolerance (5% currently) to 45% and limit height to 4”.