2023 Proposed ST Rules Revisions--Comment Period through 11-20-22

[Greg G.]

On 11/17/2022 at 10:43 AM, Bryan Heitman said:

What is the basis for the spec racer ford being approved in-class with SADEV while the mx5 is penalized? There is non-SADEV and SADEV versions of the SRF3.

 

I'm not sure what you are talking about, but this is off topic anyway since there were no changes to either of these classings.  However, the SRF takes a -1.0 Mod Factor just to run in ST4, then if it has a sequential, it takes another -1.0 Mod Factor. 

In regard to your other post about losing 700 lbs.  How about lose the sequential, sell it and put in a standard manual, take the extra $10,000 and put it into your ST5 racing budget?  You bought a car that is not permitted as-in in ST5, but it can be made compliant with ST5.  There is also no limit to the power mods you can do in ST4, including forced induction.

[Greg G.]

On 11/17/2022 at 9:17 AM, flier129 said:

What's the main rationale of the ST/TT5 base ratio change? 

For the a-arm modifiers would it not make sense to have separate modifiers for each axle. Say +0.250 per axle?

It will allow the lower HP cars to have an easier time with trying out different tires, or allow them more tuning options.

No, the A-arm mod factor is based on the suspension design and engineering that comes with those vehicles that come with A-arms.  Past results and even recent results indicate that it should be at -0.5 of -0.7.  With the change in the cable throttle body Mod Factor, and the fact that most Champs seem to be at horsepower tracks, we went with the -0.5 decrease.  We have people arguing on both sides of these....

[Greg G.]

On 11/17/2022 at 1:16 PM, Tansar_Motorsports said:

ST4 aero rules look great IMO.  should make crossover from other series and organizations much easier.

Super happy to see mod factors for solid rear axle in st4 and below, should increase the number of competitive chassis options.

Super super super happy to see ST5 target ratio increase slightly.  Should make it easier for the various 4 cylinder NA cars to be able to use toyos and still make the target ratio.

 

One clarifying question:  The way the A-arm penalty is worded, it could be misinterpreted as being -0.5 for front double A-arms, and -0.5 for rear double A-arms (for a total of -1.0).  Instead of saying "front or rear", I would say "front and/or rear".

 

Overall, looking at NC miata, RX8, S2K, BRZ/FRS in ST5:  0.2 change for A-arm adjustment, and 0.5 change for overall target ratio.  --> overall change of 0.3.  So for a 2800lb car with only a rear wing, on Toyos, your target ratio would go from 12.9 to 13.2,  so an average power target of 212HP vs 217HP.

It helps.

Agreed on the "front and/or rear" -- It's been written the other way for years, but this is better.  Thx.

[Greg G.]

On 11/17/2022 at 1:25 PM, daytonars4 said:

The reason the modern cars are effective on a 335/345 is bc some of them have 3k rpm of peak hp which is their avg. With how the calculator works, the old BMW's with S54's only have 1500 rpm of peak hp. So switching to a 335 tire to match them makes the mph and straight line delta so massive it's like being in a different class. The whole point of BOP is so someone is supposed to choose. You are either faster on the straights or in the corners, in theory. But with how the weight mod and ST calculator works, some modern cars get both the straight line advantage and massive tire advantage. I still don't understand why the weight mod needs to be in place bc that mod is what is undermining the BOP theory behind some of the other ST rules.  

It has been in place because of the older heavy vehicles that were running on the same size tire as the "newer" lighter vehicles, and there is a bit of an issue with TT versus fully prepped race cars as well.  But, as Scott has pointed out, with the now newer heavier, high HP, high tech vehicles, we are developing new BOP issues. 

[Greg G.]

On 11/17/2022 at 1:57 PM, hispanicpanic said:

Serious question for greg and others who complain to him to make more rules.  Is nasa in the business of Balance of Performance?  Is it NASA's intent to create an even field where no platform, new or old, have an inherent advantage over another?  There seems to be a case of rule/series intent amnesia.  Is st/tt designed to be an open class? Or should we just rename st4 as TTB all over again?

I know how competitors can get when they loose and blame it on something they think to be unfair within the rules.  In my opinion, its not NASA's job to balance platforms, and should never engage in anything remotely similar to a balance of performance.  New cars are going to be better in every way, technology advancement is a part of how this world works. Is it NASA's fault that you feel handicapped because you're on a cable actuated throttle body or have an ABS  system from the 90's?  No

My personal view is, the more rules that are created in TT/ST, the less it benefits the series. 

Yes, we have been in the "business" of balance of performance ever since NASA started and adopted Spec Classes and other more builder oriented classes that had very specific allowances, and then of course PT.  Those that asked for "open classes" soon found that it's not so much fun to lose every month to a car built with cubic dollars at times driven by someone who was less than great.  This is especially true in the lower level classes where we attempt to let folks have a competition without requiring a $75,000 investment in a used car.  We have seen regional classes die due to a lack of restrictions, and every year, we get more and  more requests for more restrictions much more frequently than less restrictions.  And yes, we would rather have a 90's car still be able to compete with a modern car at some level than to have all of the cars older than 5 years leave.

As well, it has been pointed out numerous times in the past the number of things that can be easily done with a drive-by-wire car versus an "old" cable throttle body car.  And, while some of those can be overcome with cubic dollars, some cannot.  If we do not attempt to be inclusive, then we will not have too many people competing with us--only those that want to buy a new car every 2-5 years.

[Greg G.]

On 11/17/2022 at 4:15 PM, davidfarmer said:

is the data logging an "tune pulling" rule that was in the August Bulletin going into the rules?  None of my local officials know anything about it, but it was posted .

 

Also, I don't see anything about tunes "looking OEM".  You banned my 3 year old tune for not "looking OEM".   Make sure you get that in writing, I still have the email if you need it.

 

I agree with someone about that mechanical-throttle cars shouldn't get a break....the entire point of the averaging system is to balance all tunes regardless of how you make them.  

 

Mixing printed tire size and "template" sizing is ridiculous, consistency should be maintained one way or the other.   

 

 

 

 

The Technical Bulletin that was posted on these forums and used at the Champs will be added, and is already in the rules via the TB.  From a regional standpoint, the rules are there to allow for more in depth technical inspection when desired if they are capable.  The Tech inspectors are going to be getting more in-service on these, and we also have the ability to pull and analyze tunes and logs via Internet and Facetime type apps using National staff.  

The rules regarding Dyno graphs are in the TB from 3-11-22 including this line, "Any Dyno curve resulting in aberrant data points that would otherwise be included in the Avg HP calculation that are not consistent with the usable power band or flat tune power band can be rejected by the Race Director/TT Director at their discretion, and the Maximum HP will be used to classify the vehicle."

The Average HP calculation is significantly limited by the various transmission and gearing options, creating the opportunity for competitors to use a very narrow or very wide usable RPM range, while we must limit the calculations to a fairly narrow band to avoid gaming of the system.  Well over 99% of those taking advantage of the wide usable RPM range are using electronic throttle tuning to do so, as well as for superior motorsports traction control and other advantages.

The current plan is that we are going to take our time once we decide on the size limits this week (315 DOT and 310 non-DOT as of now, but I've seen some arguments for as high as 325/320) to come up with a NSW tool.  For the most part, the tire manufacturers play games with the smaller size tire labeling much more than the larger tires--so works for now.

 

[Greg G.]

On 11/17/2022 at 6:50 PM, Kelse92 said:

In regards to ST4 aero, would hood vents above 1/8” as the current rule sits also be able to take the -0.3 or could those be considered to be added?

The current rule is 3/8".  There is no plan to change that at this time.

[Greg G.]

On 11/17/2022 at 7:24 PM, dwesterwick said:

Aside from the novel I wrote about the 305+ mod factor above, I do like how there is now a solid-axle bonus. However, I'm disappointed it's not included in ST3+. Is there a reason it shouldn't be other than the general idea of reducing rule complexity in ST1-3? I'd think the disadvantages of a solid axle will be at least as noticeable in faster classes where cars tend to be more traction-limited.

What was the reasoning for adding this change to ST4-6? What makes that group unique from ST1-3?

As I said above, I admit that I'm biased, but I'd certainly like to see that bonus extended to faster classes, even at a reduced bonus for ST1-3.

Reason:  1) It wasn't requested, 2) The higher (more expensive) classes have various options for compensating moreso than the lower classes. 

I'll bring it up for discussion with our rules committee.

[Bgoldburg]

Greg, Hankook is the only tire mfg with a non DOT NASA contingency.  This was very exciting news!!  They make a 300 or a 320.  For NON-DOT please allow 320mm Hankook tire without a penalty in ST2.

[Greg G.]

On 11/18/2022 at 12:32 AM, Eric Jensen said:

Full disclosure: My home is now in GLTC but ST4 was where I started.  Many NASA racers have moved for various reasons.  My reasons: big fields, vibes (unbelievable vibes), 1 class, high quality competition.

I still race in my TX region when scheduling allows and want all amateur racing to grow....NASA, GLTC, SCCA, etc. My issue with NASA is too many classes.  We averaged 35 cars an event this year in GLTC.  IMO, NASA should remove HC and GTS at a minimum.  ST classes should be reduced too.  Reduce the classes, build the entrant numbers.  Everyone doesn't need a trophy.  The absolute biggest difference in the current classing is Bosch ABS.  Allowed in ST/TTU-3, not allowed in ST/TT4-6.  So, combine 1-3 into 2 classes and 4-6 into 2 as well.  5 classes in ST.  

 

Eric, this has seriously been under consideration.  The question is if we sacrifice the high HP ST1 guys who don't want to detune and the lower HP ST6 guys who don't want to spend for more power/less weight, will the overall numbers grow or shrink.  I've been in agreement with your GTS comment since ST was started, and would limit HC to H4 myself.  These types of changes would be bold and piss off a lot of people, a lot!   In fact, every time we turn around, someone is pitching another new class, and someone wants to nibble on the bait.

[Greg G.]

19 hours ago, mrgsquared said:

"Nobody writing class rules seems to understand this, and it is BAFFLING"...

I'm pretty sure Greg is more aware of this than you think. Also remember that these rules need to fit BOTH ST and TT  

No, Terry knows we are just retards and got lucky building TT and ST from zero to thousands of drivers. ?    Terry, we are trying to help balance an almost impossible situation in order to be inclusive--the older heavy cars from the early 2000's are not the same as the beasts that are coming out the past few years.  But, as Griffin stated, even the beasts, when not fully prepped as race cars (for TT), need some help.  But, we definitely appear to be running closer to the wall with the newer, high tech, heavy, high HP vehicles, that when prepped do not "deserve" the weight Mod Factor.  In the "olden days", when it was Vettes and Vipers, it was definitely needed.  Yes, this tire Mod Factor will take a bit away from the "beasts" that they were given in the form of the weight Mod Factor.  If we don't continue to adapt, all of these classes will eventually require a competitor to purchase a new car every 2-5 years and junk the old ones.

[Greg G.]

18 hours ago, Kelse92 said:

Thank you for the response to all of the feedback! I wanted to chime in though and make sure the Non-DOT category is not overlooked. Those tires are similarly much more available in a 305 variety vs a 300mm and should be considered to get a similar adjustment up as well.

Yep, we will work on that, as well as make a final determination on 315 (or 325).  It looks to me like there are also 310 non-DOT's, and maybe even a 320 that is not too far from the mark.

[Tykrane30]

4 hours ago, Greg G. said:

Yes, it does make more sense.

Awesome! Thanks Greg!

[dwesterwick]

2 hours ago, Greg G. said:

Reason:  1) It wasn't requested, 2) The higher (more expensive) classes have various options for compensating moreso than the lower classes. 

I'll bring it up for discussion with our rules committee.

Thanks! Please consider this a last-minute request.

I can't think of anything that can (somewhat) overcome the limitations of a solid axle that is legal in ST3 but not in ST4 (assuming you don't take the ST1-3 non-production-vehicle penalty). Watts links are legal in both, and I don't think there are any limitations to differentials as long as there are no changes to mounting points. I can't even think of a reason you couldn't use a cambered axle in ST4, and that's a very expensive "solution" to having a live axle. Maybe there's something more clever that eludes me.

[Nick Smither]

41 minutes ago, dwesterwick said:

Thanks! Please consider this a last-minute request.

I can't think of anything that can (somewhat) overcome the limitations of a solid axle that is legal in ST3 but not in ST4 (assuming you don't take the ST1-3 non-production-vehicle penalty). Watts links are legal in both, and I don't think there are any limitations to differentials as long as there are no changes to mounting points. I can't even think of a reason you couldn't use a cambered axle in ST4, and that's a very expensive "solution" to having a live axle. Maybe there's something more clever that eludes me.

Solid cambered rear axles In Mustangs that class as ST2 have been shown to be very effective.  Well dialed in S197’s (solid axle) even without camber are still competitive with S550 IRS cars, maybe in part due to the inherently lighter design.

[dwesterwick]

1 hour ago, Nick Smither said:

Solid cambered rear axles In Mustangs that class as ST2 have been shown to be very effective.  Well dialed in S197’s (solid axle) even without camber are still competitive with S550 IRS cars, maybe in part due to the inherently lighter design.

I looked at ST2 results in our region over the last few years, and it does look like solid-axle Mustangs have been competitive at certain events. However, the outlier times at or near the track records were all set by IRS cars. Maybe this is different in other regions?

In fact, if you look at all of the ST/TT records in our region, I think I'm the only one on the list with a solid-axle car for the tracks we frequent. Even still, I'm 1+ seconds away from several records set by a fast IRS car. In fairness, there are a lot more IRS cars than solid-axle cars that compete in our region, but the records still suggest there might be a performance disparity.

Maybe the exact bonus given to solid-axle cars could be changed from +0.3, but it's no secret that (from a physics standpoint) IRS is superior on a road course. Solid axles have some advantage in terms of simplicity, ease of setup, and better anti-squat geometry. The (total) weight difference is moot in a power/weight class. Otherwise, IRS cars have the potential to have much better control over the tire contact patch. Cambered axles at least allow you to manipulate camber and toe, but they still lack suspension independence and have a lot more unsprung weight. I could see the argument that cambered axles should have a lower bonus or simply be excluded from getting the bonus, but otherwise I don't understand how a performance disparity exists in ST4 but not ST3 (or ST2).

[hispanicpanic]

7 hours ago, Greg G. said:

No, Terry knows we are just retards and got lucky building TT and ST from zero to thousands of drivers. ?    Terry, we are trying to help balance an almost impossible situation in order to be inclusive--the older heavy cars from the early 2000's are not the same as the beasts that are coming out the past few years.  But, as Griffin stated, even the beasts, when not fully prepped as race cars (for TT), need some help.  But, we definitely appear to be running closer to the wall with the newer, high tech, heavy, high HP vehicles, that when prepped do not "deserve" the weight Mod Factor.  In the "olden days", when it was Vettes and Vipers, it was definitely needed.  Yes, this tire Mod Factor will take a bit away from the "beasts" that they were given in the form of the weight Mod Factor.  If we don't continue to adapt, all of these classes will eventually require a competitor to purchase a new car every 2-5 years and junk the old ones.

To play devil's advocate, certain mods are available to everyone, but not everyone recognizes that its within their realm of possibility to do it.  Anyone can retrofit their car with modern power steering, turbos, abs, and roll center kits are available off the shelf for almost all platforms. An old car CAN be upgraded and be made "modern" to compete with newer stuff. The cost of which, to your prior point, is outside the spirit of what st5/6 was created for, so it makes sense to apply more rules there. My point is, i feel its a fool's errand to force the rules to adapt instead of the drivers/platforms. As long as all cars can have the same tech/make the same mods, it is within everyone's possibility to achieve the same laptime potential, limited only by their skill behind the wheel and their skill in the garage.  There was a rational adopted regarding some new tech coming on some new cars.... "Let everyone have it, or let no one have it". Balancing between the new haves and the old have-nots, again, is a fools errand. 

I've given tons of examples on how you don't need DBW to achieve some of the so called 'cheatery' activity some new DBW systems allow. Asking specifically, exactly which behaviors from dbw is it that you're trying to penalize? You can always just prohibit the use of things like 'anti lag' and such, instead of hurting everyone. I've said this on the fb groups, but the last time i was going over data of a r8 LMS gt3 at daytona, the more the bosch TC stepped in, the more laptime was sacrificed. It was a balance of getting the driver comfortable with the level of TC that was tuned into the car, and the driver trying his best not to lean on it, because again, the more the TC stepped in, the more laptime was sacrificed. It bought consistency, not speed. We made a dial that showed how much the TC was stepping in so that as the tires wore, he could manage his right foot better to compensate for tire degradation. If the TC intervened on the exit of turn 6, we'd lose .05-.08 down the straight. Depending on car placement, you'd have to roll on the throttle differently due to the track surface.  I'd share the data, but i don't own it. 

[daytonars4]

@hispanicpanic having to modify an “old” car to be wider, heavier, and higher displacement engine in order to add 300-400lbs to properly exploit the weight mod isn’t all that practical. Sure, “everyone can do it.” But the reality is people would rather just leave and race elsewhere. Almost ever other race series is based on trying to make your car light. ST is the reverse now. It’s a choice to turn a modern heavy car into a race car. Rewarding the “newest tech” with extra power is just a rather strange BOP system. Maybe when a 992 GT3RS (with DRS disabled) at 3600lbs shows up and starts wrecking shop things will be reassessed. 

Edited November 20, 2022 by daytonars4

[Boozshey]

 

Change rules, fine, rules change.  I drive a car with bigger than 315’s and this rule change stings, both my setup and my pocketbook,  guess the kids won’t have a good Christmas since dad needs new wheels, but I’ll overcome it.

I’m speaking specifically of the tire size mod…

However, if a tire mod size is going to be the new nerf, then the weight mod really needs to be removed.  

Let me create a real life scenario, and while exploring the compliance database it doesn’t pan out as planned with the weight mod still helping the new heavy big tire cars.  

If you take a modern 4000lb car (yes they exist and appear to dominate), they seem to be in the 530hp declared range.  However they are allowed 541hp with no other mods except the +weight mod.  With the new tire mod of -.3 they are now only allowed, 519hp.  While the intent is for them to lose 22hp, they are effectively only losing 11hp, so they are really only being penalized 50% of mod factor.

Now the lighter cars are taking slightly less of a hit but because of no weight mod factor they will be taking 100% of the mod.  And effectively they both lose near the same power, and in turn will be equally as slow and the lighter car doesn’t get any closer to the heavy car with lots of ponies.

While I won’t argue the tire size change, as I know it’s coming, I do ask that the weight mod be looked at again.  Let’s face it, the bigger heavier cars that can stuff the big tires are normally big cubed, possible power adders and don’t need a weight mod helping them.

it does seem the norm now to be heavy with power vs light with less power.

[daytonars4]

@Greg G. I believe the justification for not adding the new 315 mod in ST2 is consistent within the current ruleset. ST2 is expected to be pretty much a no limit high spend class. Just look at the seq mod. It’s only .2 in ST2 which is consistent with the BOP found in various pro series. Yet in ST3 the mod is 1.0.
 

   The seq mod is so high that it’s obvious that a seq is essentially not allowed in ST3. Which by the way is also what prevents high revving engines like S54/65 from being able to have a modification option to stay within their peak powerband. A modern DCT is about on par with a seq now for half the mod. Just look at some of the American engines. I just watched a Vette shift 2-3 times for an entire lap at Summit Point while running an extremely fast laptime. An S54 car is shifting at least 7 times a lap. It seems that the seq mod serves more as a way to further slow the non-production cars like the tube chassis/factory with a seq, but at the expense of limiting “old” low displacement cars from being able to help balance out acceleration with modern cars. 

Edited November 20, 2022 by daytonars4

[GoBlue]

I’ve held off for a few days to absorb the discord on the subject before weighing in.  I’ve been an avid competitor in TT2/ST2 since 2018 and have been building my car to the fairly consistent rules platform since I bought it in 2014.

It is not clear to me what problem statement we are attempting to solve by creating the -0.3 tire modifier in both ST2 and ST3.   NASA has access to the data of how many competitors in each class are using what size tire - there are entry fields on the classification form, however this data is not published in the classification compliance database nor on the forms themselves.   It might be worthwhile to share with the competitors the distribution of tire sizes in the 267-282mm section width (or less), 282mm to 315 printed, and >315 printed.   In my quick review of the 2022 NASA Champs database for ST2/TT2 - I only saw two cars taking advantage of the +0.3/+0.6 modifiers (TCR car and the RUSH).   I have a video I took of the ST2 grid before they rolled out, Corvette, BMWs, Porsche, - most cars had widebody fenders on them to maximize the tire they can run.   In general, the majority of NASA competitors have build their platforms maximize performance in the given rule set.   Watch the video of the grid walk and see what you think the results of the proposed rule change will be?  2022 ST2 Grid Walk

Doing some unofficial surveys of east coast competitors and review of available data for competitors at the 2022 nationals -  I saw closely matched competition with heavy Mustangs / Camaros and more middle weight BMWs and Corvettes, and even with low HP lightweight corvettes.   In my personal regional competition - I go head to head with a 4100 lbs ZL1 Camaro with my 3100 lbs Corvette.   Some days I am faster than him, some days he is faster than me, the rest of the field is 3 seconds back - In my opinion it comes down to consistent preparation of both the car and driver skillset and execution - not an imbalance in the rule set.  @Olitho drove from last to 3rd not because he had 335 rear tires, but because he was a better driver.   @JakeL dominated with only ~310hp because he was the most skilled driver and had a very well developed car with a lot of aero - he got passed multiple times on the straights.   @Emag dominates the east coast because he is the best driver and puts in the work to have his car ready.  In ST3, some late model heavier cars with large displacement motors apear to outperform lighter older platform cars.  Is it driver performance, or is there a BOP adjustment needed?  If we are trying to solve that BOP - then just tweak the power to weight modifier for the heavier cars to give them a little less HP on the straights.   3800-4100lbs cars don’t come on 315 or smaller tires for a reason.  Overtakes are generally made by getting a better corner exit than the car in front and the overtaking driver achieving position prior to the turn in point of the succeeding corner.   Applying the -0.3 tire modifier isn’t necessary to achieve that - but a tweak to the weight modifier could (heavier car will have less HP down a long straight).

In conclusion, my opinion and request to NASA is to leave ST2 alone (feels like a majority opinion from this thread), no changes are needed for tire width modifiers (very few cars will be optimized for narrow tires in this power to weight category) - the rule set has been stable and the BOP has been good.   ST2 has had some ups and downs in participation - but is on an upward trend since the end of 2021, let’s not drive people away from this class.  I don’t think any of us want to “slow down” ST2 and make the gap narrower to ST3.

If we need to fix a BOP in ST3 - consider adjusting the heavy car points modifiers slightly and leave the tires alone.

[Ale Sensoli]

20 minutes ago, GoBlue said:

I’ve held off for a few days to absorb the discord on the subject before weighing in.  I’ve been an avid competitor in TT2/ST2 since 2018 and have been building my car to the fairly consistent rules platform since I bought it in 2014.

It is not clear to me what problem statement we are attempting to solve by creating the -0.3 tire modifier in both ST2 and ST3.   NASA has access to the data of how many competitors in each class are using what size tire - there are entry fields on the classification form, however this data is not published in the classification compliance database nor on the forms themselves.   It might be worthwhile to share with the competitors the distribution of tire sizes in the 267-282mm section width (or less), 282mm to 315 printed, and >315 printed.   In my quick review of the 2022 NASA Champs database for ST2/TT2 - I only saw two cars taking advantage of the +0.3/+0.6 modifiers (TCR car and the RUSH).   I have a video I took of the ST2 grid before they rolled out, Corvette, BMWs, Porsche, - most cars had widebody fenders on them to maximize the tire they can run.   In general, the majority of NASA competitors have build their platforms maximize performance in the given rule set.   Watch the video of the grid walk and see what you think the results of the proposed rule change will be?  2022 ST2 Grid Walk

Doing some unofficial surveys of east coast competitors and review of available data for competitors at the 2022 nationals -  I saw closely matched competition with heavy Mustangs / Camaros and more middle weight BMWs and Corvettes, and even with low HP lightweight corvettes.   In my personal regional competition - I go head to head with a 4100 lbs ZL1 Camaro with my 3100 lbs Corvette.   Some days I am faster than him, some days he is faster than me, the rest of the field is 3 seconds back - In my opinion it comes down to consistent preparation of both the car and driver skillset and execution - not an imbalance in the rule set.  @Olitho drove from last to 3rd not because he had 335 rear tires, but because he was a better driver.   @JakeL dominated with only ~310hp because he was the most skilled driver and had a very well developed car with a lot of aero - he got passed multiple times on the straights.   @Emag dominates the east coast because he is the best driver and puts in the work to have his car ready.  In ST3, some late model heavier cars with large displacement motors apear to outperform lighter older platform cars.  Is it driver performance, or is there a BOP adjustment needed?  If we are trying to solve that BOP - then just tweak the power to weight modifier for the heavier cars to give them a little less HP on the straights.   3800-4100lbs cars don’t come on 315 or smaller tires for a reason.  Overtakes are generally made by getting a better corner exit than the car in front and the overtaking driver achieving position prior to the turn in point of the succeeding corner.   Applying the -0.3 tire modifier isn’t necessary to achieve that - but a tweak to the weight modifier could (heavier car will have less HP down a long straight).

In conclusion, my opinion and request to NASA is to leave ST2 alone (feels like a majority opinion from this thread), no changes are needed for tire width modifiers (very few cars will be optimized for narrow tires in this power to weight category) - the rule set has been stable and the BOP has been good.   ST2 has had some ups and downs in participation - but is on an upward trend since the end of 2021, let’s not drive people away from this class.  I don’t think any of us want to “slow down” ST2 and make the gap narrower to ST3.

If we need to fix a BOP in ST3 - consider adjusting the heavy car points modifiers slightly and leave the tires alone.

The more I think about it the more I agree with you Ben about the weight modifier vs tire rule change. 

 

[dwesterwick]

I've thought a lot of about the effect of the proposed -0.3 mod factor since it was introduced a few days ago, and I've concluded that my suspicion about which I posted earlier (that >3600 lb cars will be disproportionately affected) isn't true. I actually think this is a good change assuming the mod factors vs. weight are kept the same. As I said before, I'm biased because I have a 3800-lb Mustang on 335's, so no matter what the new rules are going to hurt me. It's advantageous for me to argue for the least penalties for my car, but I'm finding that hard to do with the proposed rule change.

In the interest in having an honest discussion about the proposed rule changes, I've attached a quick analysis I performed making the case in favor of implementing the new >315mm mod factor for all ST1-3 classes and not changing the mod factors for weight. I don't think the argument that ST1/2 cars are naturally faster and therefore need more tire width works because it ignores how that would disproportionately hurt light cars (i.e. V8 Miatas). To be consistent and fair for all car builds, ALL tire mod factors would need to be adjusted in ST1/2 to lessen the penalty of larger tires (relative to car weight) across the board.

If you can think of any reason that my analysis is invalid (outside of edge cases), feel free to share. It's definitely an oversimplification of the actual differences between car builds, but I think it addresses the high-level physical differences that could exist between them. As imperfect as the rules might be, I think the 2023 proposal generally does a better job than the 2022 rules at achieving parity between various car builds, and I can't think of an any simple changes that would make it better.

NASAModFactorAnalysisNOV22.pdf

[daytonars4]

@dwesterwickpart of the reason I say no for ST1/2 is Bc the cars that are light weight there don’t even need/want a 345. With just a 315 alone many of them are already maxed out in grip level. For example, a Ginetta, Radical, LS Miata. This goes back to the weight/tire factor discussion. I believe the newer LMP’s may be on 335’s but that’s another extreme example. Most of the examples can’t even utilize a 315 yet alone a 335. And being tube non-production cars for many of my examples, they just don’t need any help to be competitive. It also serves as another decision making point for racers. If you want to constrain costs some drop to ST3. If you want to play with the big boys in ST1/2 go in knowing the gloves are off. 
 

(Also disclosure this is for selfish reasons) I race in ST3 and this change would not slow down 90% of the ST3 field. Which means that the on track challenges we have with the slower ST2 cars will become even worse if they are relatively even slower now with the new mod. Leaving ST2 out will help to create a larger gap between ST2 back markers and ST3 front runners. 

Edited November 20, 2022 by daytonars4

[ZC6126]

On 11/18/2022 at 5:26 PM, JStutler said:

Like I said, I agree with you that the A-Arm penalty should be per axle. My point of contention was the number you chose. 
I do find it hard to see though where the GRS/BRZ needs a ton of help when you have drivers like Nick Dugdale and Jordan Hill blasting track records all over the place. For example Nick ran a very fast 2:18.0 at NCM in March, on cycled Hoosiers no less. This is a big track with long straights. Jordan ran something a 1:33.4 at Autobahn in October which is a very serious time.  Its not like the platform is languishing because others have different options. 

 

I am in utter congruence with splitting the a-arm penalty to per axle (-0.3 per F/R axle does sound fair) as many other's in TT5/ST5 have also previously lobbied for this change via facebook posts. That would be bring much more equality to class. @Greg G.

And to elaborate on this topic further. The TT5/ST5 (-0.5) suspension penalty stating; "replace or modify rear control arms / camber arms..." needs to be excluded from the massive (-0.5) penalty. Reason: Our primary competition in the Honda S2000 has the factory ability to adjust, optimize and dial in over -3.0 degrees of rear camber all while avoiding that massive penalty in class. The E36 and BRZ/86 are miles off from that rear figure, even with the implementation of eccentrics, which is a big detriment not only to lateral grip performance and ease of adjustment at the track but also the associated seasonal costs related to wildly uneven tire wear. Is the (-0.5) penalty really justified for only adjusting our rear camber less than -1.0 degree for optimized contact patch? 

@JStutler I would say the 14.5:1 is a good step in the right direction if we were on solid ground, but this change further penalizes the Hoosier R7 spec BRZ/86/MX5 chassis in unison to our competition. For example my current TT5 R7 season setup incurs a -0.3 total penalty for 2023 class ratio change, thus increasing my MCW by over 55 lbs to ~2,705.). As I can't max out on power, I depend on loosing weight to shrink the gap and make up for some acceleration. You also need to also reference tracks like (WGI, Summit Main, VIR and Road Atlanta, NJMP, AMP...) the gap is evident on the BRZ/86 if your strictly trying to form an valid argument using only "track records."

A: Mid range acceleration is single largest factor languishing the BRZ/86 chassis in TT5. The AIM data's acceleration delta vs the competition said it all for 2022 and there is no feasible way to cap on that power delta without spending over $10k for a complete swap. (Talk about class cost containment.) 

Here is a sample setup considering these class revisions remain permanent. --- If I was to run a (+1.6) 255/40/17 Maxxis RC1 my MCW would be (2,540 pounds) running a 4'' splitter penalty and rear wing, while taking the penalties for the a-arm with no bonuses. Tell me how I extract an additional 130 lbs. in order to max out an RC1 setup? I'm already risking my life in a fully gutted, AC deleted, cage-less tin can. XD It is fun though, id rather not loose my doors on the BRZ.