Tire Size (section width) +/- PWR Review

[kayha12]

Hey everyone, wanted to try get a conversation started to review bonus/penalties in relation to tire sizes. If we are giving bonuses for those running smaller tires, would it not make sense to balance the scale by penalizing cars running wider tires? Similar to the WTAC / GTA / GL rulebooks where for those folks they enforce a max tire size per class. While I don't think a maximum tire size cap makes any sense, because then you limit the cars, or ask cars to run smaller tire than they would from factory, I do think it helps balance the grip scale so we don't see domination from manufacturers that 1) run very wide tires from factory 2) have the clearance to make it happen without serious modification *ahem corvettes and camaros*

If we penalize these cars, it would diversify the classes that are already dominated by vettes... ie ST/TT 1 & 2, and may potentially open the door for folks that simply can't fit anything that big into the class

FWIW, This is my 3rd season in NASA MA TT3 and I'm in an e92 m3 haha

 

[daytonars4]

To me it seems like the simple solution is just extending the tire mods? Seems odd that you have a car on 285’s have the same mod as a car that can run 335’s. If you just simply extend the tire mod scale to >305mm is +.3 that seems like a logical continuation. A Camaro like you mentioned can get a .4 weight bonus for being heavy (Bc in theory it’s a handicap.) But a 3600lb car running 335’s isn’t really at that much of a handicap compared to a 3100lb car on 275-285mm tires. That’s a 20% increase in tire with a 20% increase in car weight. 

[Racerwong]

I agree with this...  there are bonuses for narrow tire, but once you get to a certain width, there should be a penalty also?  Maybe not as harsh as 305 having 0.3 but maybe a sliding scale.  Keeping in mind that wider tires also have more drag which is a penalty itself.  

295 +0.1 

305 +0.2

315 +0.3 

>335 +0.5

[RecklessactN]

I agree with this, the manufactures are turning out heavier cars that are designed to work with larger rubber. I feel at a disadvantage because if I want to go that high I need to spend a significant amount to buy parts and hack my car up to get something over 305mm. 

 

@Racerwong I like your scale idea just like you get + points for running a smaller tire, but would go inverse the higher you go (taking a -). This would help point everyone towards a TT tire standard of like 295. 

 

FWIW 1st full season in NASA NE TT2 in a 04 STI. 

[jrubin80]

I would say this only really effects TT2 and TT1. What percentage of the fields in those 2 classes are Corvettes that run 335 or 345 in the rear, guessing it is a lot. Not really possible to ever have a "standard" size. But you also have the fact that some of the very sticky tires, like an A052 is not available in large sizes. I would say treat it like aero  mod factors and not apply them to TT2 or TT1.

 

[Lewisracing]

So just for reference with the OPs class, and proposed changes.

ST3 2021 Nationals

P1 - BMW, P2- BMW, P3 - Corvette

TT3 2021 Nationals

P1 - Porsche, P2 - Nissan, P3 Corvette

Based off the results from the most recent national event, it seems in the class of ST/TT3 is very balanced.

ST/TT3 are VERY diverse as is. At nationals this year ST3 had a class with 13 racers and the cars with wider tires did not dominate, they were right there in the mix with all the other manufactures. TT3 had a relatively small class of 6, but most of the cars were right there in the mix, in fact 2nd through 4th were separated by less than half a second. Less than 1 hundredth separated a podium and not. 

To the "clearance to make it happen without serious modification" - Remember, you chose your chassis, as did the drivers who have the heavier chassis and wider tires. Instead of pushing for a tire rule change, why not detune and run something like TT4? That class already has limits on tires and such. It seems a driver may need to consider a class change to better suit them and their car, rather than pushing for a class rule change to fit them.

I think the real conversation is compounds. For example; The A7 vs R7 talk. DOT vs. non-DOT. Some drivers may need to reconsider their tire choices in order to properly combat overheating a tire, whether a 15 minute TT session or a 35 minute race. The heavier cars have this same problem even with a wider tire because they have the extra weight to combat. Maybe a driver that runs a smaller tire should consider moving to a non-DOT to obtain extra grip without significant penalty? Things some should probably consider. Moving the Super Touring classes to in theory spec tire classes will force more people out than it would bring in, it would almost shame those who would like to bring a newer chassis to the competition. 

ST/TT1 & 2 are naturally dominated by Corvettes and Porsches as you have a chassis that is very well sorted from the factory, add upgrades like suspension, brakes, and aero they will of course be even better. Throwing a limiting tire rule at them honestly won't change much, if anything it might hurt those classes, because you would limit cars that would need a wider tire in order to try and compete with arguably superior chassis.

And just my two cents for ST/TT3. This class is beautiful as it is, 10:1 in my opinion is an ideal power to weight ratio. Quick, but not horsepower dominated, rewards being lighter but also doesn't heavily penalize a heavy car to the point where it can't be competitive. It even allows AWD cars to join the fight, which I know can be difficult for some AWDs to find a home. 

I honestly don't see evidence of any kind that wide tires are dominating in recent results(TT/ST3 specifically), definitely not enough to warrant a rule change.

 

Cheers all

[daytonars4]

17 hours ago, Lewisracing said:

So just for reference with the OPs class, and proposed changes.

ST3 2021 Nationals

P1 - BMW, P2- BMW, P3 - Corvette

TT3 2021 Nationals

P1 - Porsche, P2 - Nissan, P3 Corvette

Based off the results from the most recent national event, it seems in the class of ST/TT3 is very balanced.

ST/TT3 are VERY diverse as is. At nationals this year ST3 had a class with 13 racers and the cars with wider tires did not dominate, they were right there in the mix with all the other manufactures. TT3 had a relatively small class of 6, but most of the cars were right there in the mix, in fact 2nd through 4th were separated by less than half a second. Less than 1 hundredth separated a podium and not. 

To the "clearance to make it happen without serious modification" - Remember, you chose your chassis, as did the drivers who have the heavier chassis and wider tires. Instead of pushing for a tire rule change, why not detune and run something like TT4? That class already has limits on tires and such. It seems a driver may need to consider a class change to better suit them and their car, rather than pushing for a class rule change to fit them.

I think the real conversation is compounds. For example; The A7 vs R7 talk. DOT vs. non-DOT. Some drivers may need to reconsider their tire choices in order to properly combat overheating a tire, whether a 15 minute TT session or a 35 minute race. The heavier cars have this same problem even with a wider tire because they have the extra weight to combat. Maybe a driver that runs a smaller tire should consider moving to a non-DOT to obtain extra grip without significant penalty? Things some should probably consider. Moving the Super Touring classes to in theory spec tire classes will force more people out than it would bring in, it would almost shame those who would like to bring a newer chassis to the competition. 

ST/TT1 & 2 are naturally dominated by Corvettes and Porsches as you have a chassis that is very well sorted from the factory, add upgrades like suspension, brakes, and aero they will of course be even better. Throwing a limiting tire rule at them honestly won't change much, if anything it might hurt those classes, because you would limit cars that would need a wider tire in order to try and compete with arguably superior chassis.

And just my two cents for ST/TT3. This class is beautiful as it is, 10:1 in my opinion is an ideal power to weight ratio. Quick, but not horsepower dominated, rewards being lighter but also doesn't heavily penalize a heavy car to the point where it can't be competitive. It even allows AWD cars to join the fight, which I know can be difficult for some AWDs to find a home. 

I honestly don't see evidence of any kind that wide tires are dominating in recent results(TT/ST3 specifically), definitely not enough to warrant a rule change.

 

Cheers all

The results you are pointing at, if anything, prove the increasing presence of 335's in ST3. The car that won at Nat's which you referenced is a LS powered BMW on 335's. Your Camaro that set the Daytona ST3 lap record was on 335's. I assume the P3 Corvette was on 305's or 335's? The P1 Porsche in TT3 was most likely on 305's or 335's and likely the P3 Corvette as well. Weren't the 2 Camaro's at Nationals having e-diff issues or something, which kind of skews the results? The structure of the ST/TT rule set is mods based on increasing tire size. It doesn't really seem to make much sense that a car on 285's should have the same mod as one on 335's. The newer gen cars are gaming the system right now. They re just longer and wider chassis, which make them heavier. They are taking the weight bonus mod and no additional tire mod. So we have the most modern cars in the field on the widest tire AND best power to weight ratio. I'm no genius, but that doesn't seem like a great idea.lol Someone shows up with a Merc Black Series or 992 GT3 you want to spot them the best power to weight in class on 335's also? I mean the other option is you can just ditch the weight mods since as you put it "you chose a big heavy chassis." But I'm betting you wouldn't want to do that?

[Lewisracing]

6 minutes ago, daytonars4 said:

The results you are pointing at, if anything, prove the increasing presence of 335's in ST3. The car that won at Nat's which you referenced is a LS powered BMW on 335's. Your Camaro that set the Daytona ST3 lap record was on 335's. I assume the P3 Corvette was on 305's or 335's? The P1 Porsche in TT3 was most likely on 305's or 335's and likely the P3 Corvette as well. Weren't the 2 Camaro's at Nationals having e-diff issues or something, which kind of skews the results? The structure of the ST/TT rule set is mods based on increasing tire size. It doesn't really seem to make much sense that a car on 285's should have the same mod as one on 335's. The newer gen cars are gaming the system right now. They re just longer and wider chassis, which make them heavier. They are taking the weight bonus mod and no additional tire mod. So we have the most modern cars in the field on the widest tire AND best power to weight ratio. I'm no genius, but that doesn't seem like a great idea.lol Someone shows up with a Merc Black Series or 992 GT3 you want to spot them the best power to weight in class on 335's also? I mean the other option is you can just ditch the weight mods since as you put it "you chose a big heavy chassis." But I'm betting you wouldn't want to do that?

So that BMW who won, if on 335s, proves that an older BMW chassis could make a 335 work. Seems an LS swap should be penalized then? A superior drivetrain. P2 was  not on 335s and battled with him the whole race? A lap record at a track like Daytona everyone knows is heavily dependent on the draft, which if you saw the video you would know I got entering the banking all the way to the bus stop. That would for sure skew the result. The P3 Vette wasn't on Hoosiers so unless you know for sure I know I can't speak for him. "Most likely" isn't definitive and is just making an assumption.

I can't speak for the other Camaro at nationals but I had my share of problems, the biggest of which was the driver. I agree bigger and heavier cars chose the big heavy chassis. Lets then ditch the weight mods, seems very fair, you bet wrong. But allowing drivers to modify to use a tire seems fair as well. My opinion is to ditch the weight mods or keep the rule as is allowing older chassis to make the tire leap if they so choose.

[daytonars4]

2 hours ago, Lewisracing said:

So that BMW who won, if on 335s, proves that an older BMW chassis could make a 335 work. Seems an LS swap should be penalized then? A superior drivetrain. P2 was  not on 335s and battled with him the whole race? A lap record at a track like Daytona everyone knows is heavily dependent on the draft, which if you saw the video you would know I got entering the banking all the way to the bus stop. That would for sure skew the result. The P3 Vette wasn't on Hoosiers so unless you know for sure I know I can't speak for him. "Most likely" isn't definitive and is just making an assumption.

I can't speak for the other Camaro at nationals but I had my share of problems, the biggest of which was the driver. I agree bigger and heavier cars chose the big heavy chassis. Lets then ditch the weight mods, seems very fair, you bet wrong. But allowing drivers to modify to use a tire seems fair as well. My opinion is to ditch the weight mods or keep the rule as is allowing older chassis to make the tire leap if they so choose.

   Ditching weight mods and keeping everything else the same seems pretty fair and logical to me. But my guess is that it's unlikely that Greg agrees to change that. The premise of the ST ruleset is that anything seen as an advantage gets a mod. I mean there is even a mod for a side exhaust.lol (Despite that still not making any sense) So I'm just not sure what the argument could be about why someone on 285's should be assessed the same mod as a car on 335's. It just objectively doesn't make sense regardless of anyone's personal feeling about chassis/tire choice etc. Just like how someone on 245's gets more of a mod bonus than someone on 275's, someone on 285 should get less penalty than someone on 335's. Has nothing to do with restricting anyone's ability to run a wide tire. I mean this type of modding/BOP stuff is literally the base premise of the ST/TT ruleset.

  Most Corvettes in ST1-3 run 305+ tires. There's a question mark in my statement regarding the P3 car, as in if you know certainly share. But based on his submitted compliance file he clearly wasn't on 275's. Not that it really matters though. The discussion is about tire width, irrelevant of car manufacturer. 

 

[Lewisracing]

11 minutes ago, daytonars4 said:

   Ditching weight mods and keeping everything else the same seems pretty fair and logical to me. But my guess is that it's unlikely that Greg agrees to change that. The premise of the ST ruleset is that anything seen as an advantage gets a mod. I mean there is even a mod for a side exhaust.lol (Despite that still not making any sense) So I'm just not sure what the argument could be about why someone on 285's should be assessed the same mod as a car on 335's. It just objectively doesn't make sense regardless of anyone's personal feeling about chassis/tire choice etc. Just like how someone on 245's gets more of a mod bonus than someone on 275's, someone on 285 should get less penalty than someone on 335's. Has nothing to do with restricting anyone's ability to run a wide tire. I mean this type of modding/BOP stuff is literally the base premise of the ST/TT ruleset.

  Most Corvettes in ST1-3 run 305+ tires. There's a question mark in my statement regarding the P3 car, as in if you know certainly share. But based on his submitted compliance file he clearly wasn't on 275's. Not that it really matters though. The discussion is about tire width, irrelevant of car manufacturer. 

 

So in that regard, wouldn't it make more sense to give point assistance to cars on a 305 or smaller? Adjusting the system to meet the new age of "most" cars running a larger tire? For example: 

DOT-approved: NASA Section Width 266mm or smaller +0.8

DOT-approved: NASA Section Width 267mm to 282mm +0.5

DOT-approved: NASA Section Width 283mm to 306mm +0.3

Something like this would possibly be a better adaptation for a new ruleset, giving assistance to cars with a smaller tire as the new normal creeps in. This would almost make it "futureproof", because as more and more new cars come it would become regular for cars to have wider tires and it would be hard to call it an advantage if say 9 of 12 cars have a tire that large. This would give the cars with a smaller tire competitive compensation and allow them to run more power or less weight. They would then be much better off on the straights because of lack of rolling resistance in the tire and possibly more power, or just less weight to move.

[daytonars4]

9 hours ago, Lewisracing said:

So in that regard, wouldn't it make more sense to give point assistance to cars on a 305 or smaller? Adjusting the system to meet the new age of "most" cars running a larger tire? For example: 

DOT-approved: NASA Section Width 266mm or smaller +0.8

DOT-approved: NASA Section Width 267mm to 282mm +0.5

DOT-approved: NASA Section Width 283mm to 306mm +0.3

Something like this would possibly be a better adaptation for a new ruleset, giving assistance to cars with a smaller tire as the new normal creeps in. This would almost make it "futureproof", because as more and more new cars come it would become regular for cars to have wider tires and it would be hard to call it an advantage if say 9 of 12 cars have a tire that large. This would give the cars with a smaller tire competitive compensation and allow them to run more power or less weight. They would then be much better off on the straights because of lack of rolling resistance in the tire and possibly more power, or just less weight to move.

I think we are agreeing on the same thing, just slicing the pie differently. I think the main reason your suggestion doesn't work is just due to the impact on lower class cars. An ST4 car for example likely doesn't make enough power to really benefit enough from a 266mm vs 283mm tire to warrant the .5 mod gap. It's also a complete restructure of the tire mods which will force almost all drivers to make car/tune modifications. Vs just making a slight adjustment to continue the current tire mods to the next natural step of 305mm at +whatever only causes a very small number of cars to make a change. Ultimately it is up to @Greg G. but kind of seems like we all agree on the same base premise.

[Lewisracing]

2 hours ago, daytonars4 said:

I think we are agreeing on the same thing, just slicing the pie differently. I think the main reason your suggestion doesn't work is just due to the impact on lower class cars. An ST4 car for example likely doesn't make enough power to really benefit enough from a 266mm vs 283mm tire to warrant the .5 mod gap. It's also a complete restructure of the tire mods which will force almost all drivers to make car/tune modifications. Vs just making a slight adjustment to continue the current tire mods to the next natural step of 305mm at +whatever only causes a very small number of cars to make a change. Ultimately it is up to @Greg G. but kind of seems like we all agree on the same base premise.

ST/TT4 has tire restrictions already, FYI.

We do not agree on the same thing, but I’ll just leave this topic here. BMW drivers do what BMW drivers do.