April '19 ST Rules Revision Highlights

[Greg G.]

Hi Folks, we are releasing the April '19 revisions for both of the ST Rule sets today.  Here are the highlights from ST1-4 & SU (v13.3) and ST5 & ST6 (v2.4):

All ST/TT Classes

1) All Electric Vehicles (EV’s) are only eligible to compete in SU/TTU.  NASA testing and research is ongoing, with the expectation that eligibility and rules regarding EV’s for ST1-6 will occur in 2020.
2) All Hybrid internal combustion/electric vehicles must be approved by the National ST Director for ST1-6/TT1-6.
3) All non-subframe/non-suspension cross-members (other than the rear frame cross beam) may be modified
4) Strut tower bar(s) addition is specifically permitted
5) Modification of the rocker panels for jacking point reinforcement is permitted
6) Reminder that the HP number listed on the Car Classification Form can and should be higher than the measured Avg HP found in pre-competition Dyno testing.  Competitors should optimize their listed weight and Avg HP on the Car Classification Form so they end up with an Adjusted Wt/HP Ratio at the limit for the class, leaving as much room as possible for both Dyno variance and weight.
7) Only one Car Classification Form should be uploaded in the ST/TT Form database at a time for each car in each class.  Use the edit function to make changes.  Don’t re-upload a new form.
8-- Effective July 1, 2019: No changes may be made to the ST Car Classification Form or to the vehicle that would affect the Form after the first Qualifying competition session for the remainder of the event without the approval of the Race Director. Any approved changes will result in the vehicle moving to the back of its class (or back of the field if not gridded by class) on the pre-grid for the next race. It is at the discretion of the Race Director whether a grid position change penalty will apply if the changes are approved after a race, but before the next Qualifying competition session. Note, specifically, this rule will deter most tire type/size and weight changes once competition has started. (NASA is moving in the direction of technical inspection digital and barcode identification and verification, and any changes made after competition begins will hamper this effort.)
9) Reminder and clarification that failing to meet the declared Minimum Competition Weight listed on the Form will result in a DQ.
10) Reminder that failing a Dyno test by going over the number listed on the Form by any amount (regardless of the measure Adjusted Wt/HP Ratio), is a Procedural Violation with resulting penalties (not a full DQ).

ST1-3/TT1-3

1) ST3 BTM Aero—Hood Vent lips/louvers/vent insert mounting hardware must not protrude more than 3/8” from the hood surface.

ST4/TT4

1) Conversion from coil spring to coilover shock spring configuration is permitted.
2) ST4 Aero— Hood Vent lips/louvers/vent insert mounting hardware must not protrude more than 3/8” from the hood surface.
3) Front Splitter maximum thickness is 3/4”
4) Rear wing end plates maximum size changed to 144 square inches.

ST5-6/TT5-6

1) ST5-6 Aero— Hood Vent lips/louvers/vent insert mounting hardware must not protrude more than 3/8” from the hood surface.
2) Front Splitter maximum thickness is 3/4”
3) Rear wing end plates maximum size changed to 144 square inches.
4) Final drive gears in FWD and “transaxle” vehicles are unlimited.
5) Subframe connectors beneath the floor are permitted with the addition of a torque arm.

Note: Enforcement of the Hood Vent rule change will begin on July 1, 2019--See Technical Bulletin

Edited December 27, 2019 by Greg G.

[tcdesign]

Greg, What is a "rear frame crossbeam" please give an example of what you mean on a typical ST car.

 

-tony

[rherold9]

What was the reasoning on settling for 3/8" for hood vents? Just chosen out of thin air? Did you measure several hood vent companies vents? Was there any data from current ST/TT drivers and what they are running?

Seems pretty ridiculous we are changing something so simple to something so specific in the middle of the season. Some people may have to replace their whole hood from this new and sudden rule change... (I can luckily bend mine if needed, but this also changes the cooling aspect and could make vent not very effective depending on angle...)

I have a very big feeling that a lot of people will have to bend their hood vents to a low angle to pass this.

Edited April 25, 2019 by rherold9

[srproductions]

Rules are the rules, we all have to follow them but we need come clarification since this is being sprung on us mid-season.  Many S2000, M3s,Miatas, and BRZ's are running TrackSpec Motorsports hood vents. Are these legal?  It is impossible to measure them from the surface to the hood to the top of the vent accurately.  I am requesting feedback on this so we can make sure we are legal.  If not, we need to be ordering a $500 used hood to replace our cut up hood before the next event.  Our next NASA NE event is only 9 days away and we don't want to get protested over something so trivial.  Is there a method or procedure for ensuring compliance of this rule?  The hood is not straight at any point and forms a constant curve on most cars so measurements will vary.  

I concur with the intent of this rule to prevent giant flaps on the hood trying to be played off as just hood vents but it seems this particular 3/8th measurement is difficult to enforce due to the challenge of accurately measuring it.  Additionally, it leaves a huge amount of competitors changing an expensive component of the car mid season.  

 

Examples of the TrackSpec vents

 

 

 

 

 

 

[nkracing]

Hi Greg, I know it has already been brought up but I would also like to voice concern over the hood vent rule. A vast amount of FRS/BRZs use the Trackspec and Verus Engineering (small center ones, I have both) that are designed to sit flush in the hood, however the frame of the vent prevents it from being completely flush. 

 

[f1honda]

Looks like I will probably have to get a new hood also. I have those aluminum hood vents.

[Greg G.]

14 hours ago, tcdesign said:

Greg, What is a "rear frame crossbeam" please give an example of what you mean on a typical ST car.

 

-tony

Tony,

It depends on the application, but the best example is the Corvette (two long frame rails held together for the most part by the "rear frame cross beam"). 

For unibodies, it would generally mean the aspect of the frame that supports the rear bumper.

 

As an aside, this is not a new rule--been around for many years:

6.2.1 Chassis and Body Modifications to Production Vehicles
Other than the listed exceptions, every Production vehicle must retain its
unmodified:
1) OEM frame rails/rear frame cross beam...

[Greg G.]

2 hours ago, srproductions said:

Rules are the rules, we all have to follow them but we need come clarification since this is being sprung on us mid-season.  Many S2000, M3s,Miatas, and BRZ's are running TrackSpec Motorsports hood vents. Are these legal?  It is impossible to measure them from the surface to the hood to the top of the vent accurately.  I am requesting feedback on this so we can make sure we are legal.  If not, we need to be ordering a $500 used hood to replace our cut up hood before the next event.  Our next NASA NE event is only 9 days away and we don't want to get protested over something so trivial.  Is there a method or procedure for ensuring compliance of this rule?  The hood is not straight at any point and forms a constant curve on most cars so measurements will vary.  

I concur with the intent of this rule to prevent giant flaps on the hood trying to be played off as just hood vents but it seems this particular 3/8th measurement is difficult to enforce due to the challenge of accurately measuring it.  Additionally, it leaves a huge amount of competitors changing an expensive component of the car mid season.  

 

Examples of the TrackSpec vents

 

 

 

 

 

 

I wouldn't be able to tell you about those specific applications, but they look like they would be close.  I will measure by putting a straight edge over the louvers, and seeing how high they are compared to the adjacent hood.   We were in consultation with one manufacturer of hood vents, and the 3/8 inch measurement was well above the mounting hardware and louvers of their "surface" design.  We also measured them on various cars at the track--looking primarily at the mounting aspect surround.  The problem became evident when we were asked by a driver about to put $600 down on the 2" high winglet type vent if that was BTM Aero compliant, noting that drivers were starting to do it.  The vast majority of cars do not have non-compliant hood vents, and we didn't want to see a rush for all ST4-6 and TT4-6 competitors to have to purchase them to "keep up".   Since the CCR provides for some tolerance (1/2 of the last decimal point), in this case, I would say that 1/2 of 1/8" would be the tolerance, or a true max of 7/16".  For those who can't make that, then there is bending, grinding, cutting that can certainly be done for the close ones without having to purchase a new hood or vents.  For others, it may require the purchase of new vents.  For those who didn't follow the written intent of the rule (for weight reduction and venting), and chose to go with vents with louvers that can serve dual purposes, sorry, but that is how loopholes get closed.  We purposely try and avoid having to write specified rules like this, but when the wording of the rules are challenged and parsed, we have no choice.  When rules like this are written mid-season, you can thank your fellow competitors.   BTM Aero does not equal DTM Aero.

As far as the implementation of this rule goes, we meant to give some time leeway, but not enough that drivers had to go out and get "temporary" 2" vents to keep up with their competition.  So, I will be adding a Technical Bulletin that enforcement of this rule will begin in 6 weeks, on June 6, 2019.

 

Edited April 26, 2019 by Greg G.

[Savington]

13 hours ago, Greg G. said:

The vast majority of cars do not have non-compliant hood vents

 

I really doubt this is true. I have had the same Singular hood vents in my car since the inception of the ST4 class in 2017. They are one of the most popular Miata hood vents on the market, and the Miata is one of the most popular ST5/6 cars in the country. My car has been examined closely by my competitors and nobody has ever said a word about my hood vents. Now they are illegal, just barely, and I have 6 weeks worth of notice to change or modify them? That's more than a little frustrating. 

There is happy medium between allowing all current hood vents on the market which meet the spirit of the rules as they were written, and banning the new winglet-style vents which clearly do not meet the spirit of the old rules. I think 3/8" +/- 1/16" doesn't even come close to that happy medium. 

I understand the logic behind this change, but I am deeply disappointed in the implementation thus far. 

[srproductions]

What vents are popular other the Singular and TrackSpec?  From what I see in our huge turnouts in the MA and NE regions, these are on the vast majority of the cars.

[Greg G.]

I saw a post by a competitor that the Tracspec vents are compliant per the company.   I can not personally verify this though. 

 

[Greg G.]

If 6 weeks isn’t enough time to fix a hood vent(s), I wonder what happens when there is damage in a race, blown engine, trans failure, etc.  I guess us old guys are just used to changing out an entire engine or clutch or transmission overnight at the track so we could complete the next day—especially at the Champs. ?

[Savington]

6 weeks is plenty of time to swap hood vents. My point is that I don't think I should have to swap them at all, let alone in a short period of time. 

 

Edited May 11, 2019 by Greg G.

[Greg G.]

I thought you made the point above that having only six weeks to fix them was frustrating?

We need to weigh the immediate costs (or most likely just time with a vise grips or grinder) of the few, versus the true high dollar costs of the many over many years.  Sorry if you are caught in the middle but someone always is generally when we need to make changes.  Again, you can thank your fellow competitors for this one—-it was never on our radar until competitors started stepping “out of bounds”. 

Benefit from the BTM Aero Mod Factor that was meant for base trim factory Aero—-using wind tunnel designed parts with multiple functions above the written intent of lightening and venting—-no. 

[srproductions]

I am all for the intent of this rule.  3/8” is difficult to measure on a curved surface though.  Even with a straight edge over the vents(which are curved) the hood is constantly curved and no off the shelf tool can accurately measure 3/8” there.  Perhaps a more reasonable measurement like 1” would be appropriate here?

The vast majority of competitors running Singular and TrackSpec vents would not have to change anything.  It should be noted that this particular mod is not simple as just unbolting a part since there is a massive hole left in the hood. It will require a new hood to correct if the vent isn’t legal which can be very expensive. 

I spoke with TrackSpec this morning and they will post their measurements.  They believe their product to be legal and will include CAD drawings.  Even with this, I can see the product failing at impound since the small measurement is very difficult to replicate accurately.  

Since this rule has a delayed start and has a large impact on a significant amount of drivers, is there a possibility that the restriction be changed to be less then 1”?  I believe this number would follow the original intent of the venting rules, allow competitors to keep their existing vent, disallow the new “cheater vents”, and satisfy the customers.  It will also be easier to enforce because the popular vents are much less then 1” leaving the only vents open to close scrutiny being ones that are trying to gain an aero advantage. 

[rherold9]

At minimum, I can agree if this rule stands, either provide a specific way to measure or template similar to the section width tool for tires. That way no one will be dq'd because different regions or people in impound may measure differently....

I too can get behind extending measurement to a larger number. A lot of customers I think will be affected based on the loose wordage of measuring.

If more data is needed I'm sure several TT/ST5 driver's would be more than willing to measure at Hyperfest on what brand hood vents and if they pass or fail. I think there will be more failures than what is believed

Edited April 26, 2019 by rherold9

[Savington]

2 hours ago, Greg G. said:

I thought you made the point above that having only six weeks to fix them was frustrating?

We need to weigh the immediate costs (or most likely just time with a vise grips or grinder) of the few, versus the true high dollar costs of the many over many years.  Sorry if you are caught in the middle but someone always is generally when we need to make changes.  Again, you can thank your fellow competitors for this one—-it was never on our radar until competitors started stepping “out of bounds”. 

Benefit from the BTM Aero Mod Factor that was meant for base trim factory Aero—-using wind tunnel designed parts with multiple functions above the written intent of lightening and venting—-no. 

It is. About as frustrating as changing a transmission on a Saturday night instead of drinking beer. Things can be both entirely doable and frustrating at the same time.

You're missing the point. 

Nobody here is arguing that this rule is not needed or warranted. Nobody here is telling you that hood vents which clearly serve an additional aerodynamic purpose should be allowed in ST4/5/6. Nobody here is blaming you for implementing this rule. There is clearly an unintended loophole, competitors are exploiting it in a way which was not originally intended, and it should be closed. 

What we ARE telling you is this: In addition to banning those unintended aerodynamic devices, this implementation captures a large number of competitors with hood vents which DO NOT serve any additional aerodynamic purposes. I suspect that in the coming days, you will see an awful lot of comments from current competitors with hood vents which are both 1. well within the spirit of the rules as you wrote them, and 2. now forced to change their cars to meet the letter of the new rules. These competitors bought readily available, off-the-shelf hood vent solutions which do not contain sculpted aero devices or excessively tall louvers which clearly are intended to do more than vent and/or lighten the hood. Now, they are force to modify or replace these vents, even though they are not the competitors who are causing you to write this rule in the first place. 

These competitors have been racing their cars in the lower ST classes for multiple seasons, and you have almost certainly seen their hood vents, and not once did you (or anyone else) bring up an issue with them. Only recently have these new, "tall" hood vents caused issues. 

If your intent is to prevent the larger competitor group from being forced to spend time and money on their cars, I don't see how forcing a large number of competitors to change their hood vents fits in with that intent. 

Again, I agree with you that there is a clear need for clarification in this area of the rulebook to prevent competitors from gaining an unintended advantage by abusing the old hood vent rule. My issue here is entirely with the implementation of this new rule, and with all due respect, the blame for that poor (IMO) implementation lies entirely on your shoulders. 

 

[Savington]

1 hour ago, srproductions said:

The vast majority of competitors running Singular and TrackSpec vents would not have to change anything.

From the measurements I have taken and/or seen, all Singular vents are now illegal. 

[focusedintntions]

Can you show what an example of what a vent that does more than relieve underhood pressure and increase cooling?  I don't see why this kind of rule is needed.  Even with 2" tall louvers it's not going to aid in downforce.  Weight reduction aside it doesn't matter since the class is power to weight based?

[srproductions]

1 hour ago, Savington said:

From the measurements I have taken and/or seen, all Singular vents are now illegal. 

In the body of the post I suggested if the rule was changed to 1” then Singular and TrackSpec users wouldn’t have to change anything. 

[Mike1ch]

Or create exceptions to the commonly used(unmodified) hood vents that majority of us are using that are close to that 3/8 spec. With our cars that have a curved hood and a curved hood vent designed for our car, that 3/8” measurement can be measured with a different result each time depending on who at nasa measures it.

Also a straight edge going across a curved hood vent will not measure correctly.

Most of this has been said but it has to be known that most of us agree with the concept of the rule change to keep competitors from getting an extra aero benefit but let’s find a way to have the rule change not effect a majority of the class over a possible 1/8”-1/4” measurement variance since there is no accurate way to measure.

 

[Greg G.]

FYI, we had suggestions by competitors to disallow everything except for wire mesh screen over the hood vent hole--no louvers above or below the hood surface.  We obviously decided against going that extreme.  But, we essentially decided to leave vents as "surface" only.  So, the 3/8" is meant to cover any mounting surround, and if there are some louvers that are at that height, fine.  We were aware that many, if not most "surface" vents were going to be compliant with the 3/8".  We specifically did not want to go to 1". 

I'm a bit surprised that nobody has proposed an addition to the permitted ST4, ST5, ST6 Aero Mods rule-- Hood vents with a higher profile.  In other words, take it away from BTM Aero, but leave it for those not getting that Mod Factor.  We thought about it, but decided against it.

Of course you guys are welcome to e-mail in all of the hood vent measurements you want.  I don't see this as a rule that will be strictly enforced using a micrometer, which is also the reason we didn't spec. it out in mm.  Obviously, the surround's height, which was our original intent, can be pretty easily measured.  If you are able to measure the louver height in relation to the surround (frame of the vent), the two added together should make the 3/8" plus tolerance.   Nobody is talking about putting a three foot 2x4 on top of the louvers and showing that the hood curves away leaving the "height" at 3".   As a policy, we don't go out into the world and try to find the specifications for whatever aftermarket parts someone is selling and try to include all of them.  The expectation is that we decide on a rule, and the competitors figure out how to comply, and them if vendors decide to build something that is legal to the spec., more power to them.   That being said, if it was found that lets say 40% of ST4-6 competitors currently have hood vents that are not compliant by 1/8" , them we would certainly entertain proposals and requests for a revision to that specification.  But, if there are 10% out of 500 or more, then we likely would not, and the expectation would be to get the grinder out, or bend the louvers down a bit.   As someone mentioned, he is a paying customer.  But, the other 90% who don't want to go out and spend on new Louvered vents (to have the "only" one that is right up to the edge of the specification) are also paying customers.

We do have some time built in here, and we don't expect this to change, but as always, NASA, unlike many other big organizations has the ability to make changes when necessary.

If you want to submit measurement data, a photo of how you measured would be appropriate.  

[f1honda]

2 hours ago, Greg G. said:

I'm a bit surprised that nobody has proposed an addition to the permitted ST4, ST5, ST6 Aero Mods rule-- Hood vents with a higher profile.  In other words, take it away from BTM Aero, but leave it for those not getting that Mod Factor.  We thought about it, but decided against it.

 

i agree with this part. If someone is not taking BTM Aero points, then they should be able to run taller vents. 

i'm running these vents which were pretty popular for e36. changing to a new hood vent design is not doable without getting a new hood, since the hood is already cut for one particular vents. most vents have a center support that has a fixed angle to the fins, so bending them is not easy also. so the only feasible option is to cut or grind them. the vents i'm using measure exactly 3/8 from the base of the vents, but since mine are top mount (like most are), they would be illegal if measured at the hood. top mount is easier to do and looks better. 

i think increasing the limits to 1/2" would make 90% of these aluminum type vents out there legal, and don't really have a huge aero advantage. as far as the rule not being strictly enforce, lets say at national event where there's a lot at stake, and someone wanted to protest, you can lose positions because the vents are 1/8 too high. 

http://vraptorspeedworks.com/bmwuniversal-hood-louvers/?fbclid=IwAR0e2-DRKtzGFHJlIgAqYBkQjTLAyigoKv18BzIiBklu01VSskeohgtFG_U

 

 

 

 

Edited April 27, 2019 by f1honda

[flier129]

For another data point, here is my measurement of the most popular hood vent on 90-05 miatas, Singular Motorsports.

This is generation 1, which has a removable gurney flap in front of the vent. So I'm somewhat lucky there. Gen 2 has the gurney flap built into the vent itself.

[AZELISE]

It looks like an angle grinder would solve the problem for flier129. It looks like one could bend (twist) the upper part of the louvers or use an angle grinder on the car picture by f1honda and it wouldn’t be an excessive effort. 

Edited April 27, 2019 by AZELISE