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

[Grant Ellis]

Well being as I am going to get a -.3 in TT3 for Hoosier's and their contingency sucks I am just gonna go Pirellis next year!   

[rsotak]

For the mechanical throttle body bonus being removed for FI cars.  I assume it was removed because the thought is that turbos can control boost pressure to simulate the DBW throttle body.  For supercharged cars this isn't true since it is coupled to engine RPM.

I would proposed that the bonus not be taken away for SC cars as the disadvantages of a mechanical throttle body still exist like in a NA car.

[pastoli]

What are the chances of TT5 being allowed to run fender vents as well? Fender vents help to get hot air build up out of the front end. This will help with brake pad life, wheel bearing life, etc. The biggest argument has been to keep TT5/TT6 at a lower cost entry to race, but these can definitely help the long term cost for racers. TT4/TT5 cars can blend into other series like Gridlife where they allow fender vents. I was stoked to see the addition of TT4 getting fender vents. 

[joejenie]

Was looking at timing last weekend at Ozarks and the MX-5 Cup driven by a pro racer at that track (with slicks) was 10 seconds a lap slower than the top 2 ST4 cars.  The MX-5 Cup car is around 145 whp average and should be in ST5 with any DOT tire (Slicks it should be able to still run in ST4 but no to that as well).  Frustrating because we want to run a couple WERC races later this summer, but no reason to do it if we are 10 seconds off the pace.  

Would like to see a modification to ST5 that we can run a MX-5 Cup with the sequential but understand there will be a penalty like in other ST groups.  2nd one would be that you could run MX-5 Cup in ST-4 with the BFG slicks that it is homologated with, but again, with a penalty mod on the horsepower.  In both cases, the car has way less horsepower than if you used the mods already used and would fit fine.  Thanks for your thoughts and let me know if I can be any help in using my car for testing if needed.  

Edited April 17, 2023 by joejenie

[Greg G.]

On 4/17/2023 at 10:49 AM, joejenie said:

Was looking at timing last weekend at Ozarks and the MX-5 Cup driven by a pro racer at that track (with slicks) was 10 seconds a lap slower than the top 2 ST4 cars.  The MX-5 Cup car is around 145 whp average and should be in ST5 with any DOT tire (Slicks it should be able to still run in ST4 but no to that as well).  Frustrating because we want to run a couple WERC races later this summer, but no reason to do it if we are 10 seconds off the pace.  

Would like to see a modification to ST5 that we can run a MX-5 Cup with the sequential but understand there will be a penalty like in other ST groups.  2nd one would be that you could run MX-5 Cup in ST-4 with the BFG slicks that it is homologated with, but again, with a penalty mod on the horsepower.  In both cases, the car has way less horsepower than if you used the mods already used and would fit fine.  Thanks for your thoughts and let me know if I can be any help in using my car for testing if needed.  

Joe,

As noted in the rules, sequentials are specifically disallowed in ST5 & ST6.  Opening the door to any model, would just lead to requests for it opening up to all.  ST5 & 6 are getting expensive enough.

We are working on testing the BFG slicks used in MX-5 Cup, though.  We may end up approving those specific tires for the lower classes.

[Jon G Racer]

So a year has past and this tire rule basically DESTROYED ST2 on east coast. Completely destroyed it in the Northeast region with ZERO cars competing in ST2 in 2023. Nasa NE had one of the largest, most consistent ST2 fields in the country. Now...dead!!! If you dont believe me, check the results! You would of thought that with so many cars in ST2 in the northeast you would have had a better turnout at Nats but that was paltry as well. Sad really!

The tire rule helped no one who needed it! With the tire rule the difference in power between a Corvette ST1 and 2 car is OVER 110 whp! That's too much of a gap! Most ST2 cars needed to detune to get to ST2 power before and the rule required us to detune even further which proved too difficult for my tuner.  All prior ST2 cars tried to run in ST1 but it turned into a catchall with an ungodly amount of attrition.  

Change this rule back! Please!

[MarkIsOnFire]

100% with Jon on changing the tire rule back. The move to ST1 caused way more cars to break and motors to blow. The guys who didn't have an extra 100whp to add just faded away. XX3 cars who were on the bubble due to the 315+ rule faded away because there was no one in XX2 even if they wanted to tire up. In the end all it did was keep people from competing who otherwise would have, thereby hurting the region and nationals' pocketbooks. The people who pushed for the rule ended up jumping ship from ST3 and going to GTS anyway. So less cars, less money, less competition, less contingency = good for who exactly? Stepping away from the microcosm of our own race group in our own region, I don't think changing the tire rule improved the car counts as a whole in XX3 through XX1 so what's the point? 

Edited December 21, 2023 by MarkIsOnFire

[NorcalTT]

12 hours ago, MarkIsOnFire said:

100% with Jon on changing the tire rule back. The move to ST1 caused way more cars to break and motors to blow. The guys who didn't have an extra 100whp to add just faded away. XX3 cars who were on the bubble due to the 315+ rule faded away because there was no one in XX2 even if they wanted to tire up. In the end all it did was keep people from competing who otherwise would have, thereby hurting the region and nationals' pocketbooks. The people who pushed for the rule ended up jumping ship from ST3 and going to GTS anyway. So less cars, less money, less competition, less contingency = good for who exactly? Stepping away from the microcosm of our own race group in our own region, I don't think changing the tire rule improved the car counts as a whole in XX3 through XX1 so what's the point? 

When you say "guys who didn't have an extra 100whp to add" do you mean people that were previously not running Hoosiers and were fine with the tire rules the way they were prior?  Was the performance/horsepower too great with the 1.6 modifier even if running a Hoosier or similar?  Or, was it more to do with the 315 .3?  Just trying to understand further and not disagreeing. 

[dwesterwick]

The ST2/TT2 champion at nationals was on >315mm tires, and he seemed to be doing just fine. It's also not like he just won because the classes were small; his winning TT2 time rivaled most TT1 times seen both at nationals as well as all of the other Great Lakes regional events there.

If you don't like the rule change for >315mm tires, how else do you propose NASA should address the performance disparity? The rule exists for a reason, and if you review the discussion from the end of 2022 in this thread, there's plenty of evidence that NASA had to make some kind of change.

In terms of the rule change "destroying" the class, I honestly don't see what's so difficult about detuning, adding ballast, or changing tires (or some combination of these). Yes, it's an extra expense, it's inconvenient, and nobody enjoys making changes that worsen performance. However, it's pretty cheap and easy to add a couple lead bricks (assuming you're not at the ballast limit), so if people left it seems like it was more from spite than from cost or competitiveness. Maybe I'm missing something?

[Jon G Racer]

On 12/21/2023 at 9:55 PM, dwesterwick said:

The ST2/TT2 champion at nationals was on >315mm tires, and he seemed to be doing just fine. It's also not like he just won because the classes were small; his winning TT2 time rivaled most TT1 times seen both at nationals as well as all of the other Great Lakes regional events there.

If you don't like the rule change for >315mm tires, how else do you propose NASA should address the performance disparity? The rule exists for a reason, and if you review the discussion from the end of 2022 in this thread, there's plenty of evidence that NASA had to make some kind of change.

In terms of the rule change "destroying" the class, I honestly don't see what's so difficult about detuning, adding ballast, or changing tires (or some combination of these). Yes, it's an extra expense, it's inconvenient, and nobody enjoys making changes that worsen performance. However, it's pretty cheap and easy to add a couple lead bricks (assuming you're not at the ballast limit), so if people left it seems like it was more from spite than from cost or competitiveness. Maybe I'm missing something?

There were 3 cars in ST2 at Nationals, if that's not destroying a class I don't know what is.  You note that there wasn't much difference between ST 1 and 2 times but that's not the benchmark that we in the Northeast believe should be used. If Eric Magnussen would have ran in ST2 there is an excellent chance he likely would have won. We, in the NE use him as our benchmark.  Granted driving is a factor but we have many drivers that aren't slow by any means. While Eric ran ST2 up hear we've gotten close to him but weren't able to beat him. He runs 315's square.  Penalizing corvette guys for running a larger rear tire further distances us from him. I am of the position that the wrong benchmarks were used when trying to balance performance.  

[Emag]

Since this thread is mostly people complaining about small penalties that affect their cars, I’ll add mine.  
 

Side pipe 0.2… I understand that it’s a rule to help cars with slightly modified floor panel / rockers avoid the non production modifier, but it’s really not a performance advantage in a power / weight class.  
 

Full disclosure I cut about 1” off the bottom of my right rear rocker to fit a side pipe for packaging reasons, didn’t want to route my exhaust around a new trunk mounted 22 gallon fuel cell.  The car actually lost torque with single 3.5” exhaust compared to 3” dual.  But that 1” of rocker panel that’s trimmed is worth 0.2 in ST2/3/4.
 

 

[dwesterwick]

1 hour ago, Jon G Racer said:

There were 3 cars in ST2 at Nationals, if that's not destroying a class I don't know what is.  You note that there wasn't much difference between ST 1 and 2 times but that's not the benchmark that we in the Northeast believe should be used. If Eric Magnussen would have ran in ST2 there is an excellent chance he likely would have won. We, in the NE use him as our benchmark.  Granted driving is a factor but we have many drivers that aren't slow by any means. While Eric ran ST2 up hear we've gotten close to him but weren't able to beat him. He runs 315's square.  Penalizing corvette guys for running a larger rear tire further distances us from him. I am of the position that the wrong benchmarks were used when trying to balance performance.  

How else do you propose NASA addresses the performance disparity that the >315mm rule tried to fix?

[Jon G Racer]

1 hour ago, dwesterwick said:

How else do you propose NASA addresses the performance disparity that the >315mm rule tried to fix?

We dont see it as a dispartiy.  Certain platforms benefit from a smaller tire while some need a larger tire (particulalry rear tire).  If the cars running a 315 want to run a 345 then by all means, but they dont for a reason. 

 

 

[Jon G Racer]

1 hour ago, Emag said:

Since this thread is mostly people complaining about small penalties that affect their cars, I’ll add mine.  
 

Side pipe 0.2… I understand that it’s a rule to help cars with slightly modified floor panel / rockers avoid the non production modifier, but it’s really not a performance advantage in a power / weight class.  
 

Full disclosure I cut about 1” off the bottom of my right rear rocker to fit a side pipe for packaging reasons, didn’t want to route my exhaust around a new trunk mounted 22 gallon fuel cell.  The car actually lost torque with single 3.5” exhaust compared to 3” dual.  But that 1” of rocker panel that’s trimmed is worth 0.2 in ST2/3/4.
 

 

LOL!!  Granted we are complaining but the proof is in the pudding.   Northeast regian historlically had a large-ish field, you would think that Nats being in the NE would yeild a healthy turnout but nope...3 cars!  Not worth getting out of bed for....just sayin'

 

 

[dwesterwick]

7 minutes ago, Jon G Racer said:

We dont see it as a dispartiy.  Certain platforms benefit from a smaller tire while some need a larger tire (particulalry rear tire).  If the cars running a 315 want to run a 345 then by all means, but they dont for a reason. 

 

 

I think it's reasonable to debate the specific penalties applied to various tire sizes and the thresholds above which penalties are applied. However, if you're saying that a 295mm tire performs the same as a 345mm tires, I think you're sticking your head in the sand. I know many people (including myself) have found a noticeable difference going from a 315mm tire to a 335mm tire and to a 345mm tire. Sure, some people have light cars and don't benefit from very large tires, but that doesn't mean there isn't a disparity for other platforms.

[Jon G Racer]

25 minutes ago, dwesterwick said:

I think it's reasonable to debate the specific penalties applied to various tire sizes and the thresholds above which penalties are applied. However, if you're saying that a 295mm tire performs the same as a 345mm tires, I think you're sticking your head in the sand. I know many people (including myself) have found a noticeable difference going from a 315mm tire to a 335mm tire and to a 345mm tire. Sure, some people have light cars and don't benefit from very large tires, but that doesn't mean there isn't a disparity for other platforms.

If there is a benefit (which I'm not disputing) then they should run it.  I don't see what the problem is. 

[dwesterwick]

28 minutes ago, Jon G Racer said:

If there is a benefit (which I'm not disputing) then they should run it.  I don't see what the problem is. 

The problem is that some platforms can get more grip with larger tires (that are not penalized) than other platforms.

I posted a table in this thread in late 2022 comparing the P/W penalty vs. tire/weight ratios for all common tires sizes. There were some pretty large discrepancies for the platforms that people complained about, and those complaints resulted in that rule change. It's not an exact science, but those trends follow people's actual experiences before 2023.

[Tansar_Motorsports]

Devil's advocate.

 

instead of having weight based mod factors, and then also tire width mod factors, we could just have a target (tire width)/(car weight) ratio.

for example, target max ratio could be 275mm/3000lb = 0.092
then, if you wanted to run a bigger tire:  315/3000 = 0.105, you would take a penalty (0.1, 0.2, 0.3, etc) based on how much you exceeded the target ratio.
a bigger car would be allowed a bigger tire:  315/3500 = 0.09 --> no penalty
                                                                           345/3800 = 0.091 --> no penalty
etc