ST 5/6 (PT 5/6) Rules Proposal Thread--give your input here

[esr]

same here with a 350z

plus i take -0.7 for a arms

and -0.7 for shock shaft diameter and reservoir

dont think st5 will work for my car

rafael

03 350z

 

i thought one of the big goals was to let people run less expensive longer lasting tires like nt01 and such, I dont see that anywhere??!!

 

So basically st5 rules are not good for a 350z. must not be a popular car!

 

man I got the wrong car!

any chance of an st4.5 class in the future??

I need yoga right about now!!

hhmmmm, hhmmmm!!!

 

 

 

 

 

Oh boy. Limit of 14:1 with no tire size modifier points. Based off Greg's post in the TT forum that doesn't look good for me to stay in TT5...

 

Will wait to see the complete rule set once its posted but I'm not feeling optimistic about this...

[hufflepuff]

same here with a 350z

plus i take -0.7 for a arms

and -0.7 for shock shaft diameter and reservoir

dont think st5 will work for my car

rafael

03 350z

 

i thought one of the big goals was to let people run less expensive longer lasting tires like nt01 and such, I dont see that anywhere??!!

 

So basically st5 rules are not good for a 350z. must not be a popular car!

 

man I got the wrong car!

any chance of an st4.5 class in the future??

I need yoga right about now!!

hhmmmm, hhmmmm!!!

 

 

 

 

 

Oh boy. Limit of 14:1 with no tire size modifier points. Based off Greg's post in the TT forum that doesn't look good for me to stay in TT5...

 

Will wait to see the complete rule set once its posted but I'm not feeling optimistic about this...

 

I think since the 350Z is produced with more than 265 HP from the factory, it's not eligible for st5.

[f1honda]

 

1. A 200TW Bridgestone RE-71R is faster than a 100TW Maxxis RC1, yet it receives a +0.3 modifier despite being a faster tire (that can run in rain, no less). A more realistic modifier would be "Non-R Compound with UTQG Treadwear rating 100 or greater +0.3". This would more reflect real-world performance and open the door to making long-lasting R-comps competitive. I thought this was one of the big goals...?

 

2. The +0.3 200TW tire modifier value is inadequate. Switching from a 200TW Bridgestone to a Hoosier R7 would only result in a 4HP loss or a +54 pound ballast in my car. I can only assume the Hoosier, even with the de-tune or ballast, would be 2-3 seconds quicker per lap minimum. This modifier should be something much closer to 1.0 (even THAT is probably insufficient), or we're just handing "wins" to people on Hoosiers, not earning wins with driving skill.

 

 

in TT/ST4, the mod factor from R compound to A is 1.0. I would think there is a larger performance gap from R to 200 TW, vs R to A.

[HAZE]

 

^^yes!

 

Please change the tire modifiers to give the 100+ R-comp tires a chance to be competetive. The Maxxis RC1 is a great value with a generous contingency program. I was hoping that ST5 would finally be the place where you don't HAVE to have Hoosiers to be competetive.

 

Maybe something like:

 

-0.3 - DOT Race

+0.3 - 100+ TW R-Comp

+0.5 - 200+ TW Street

 

 

-A-arm modifier is a great addition. Not sure if -0.7 is the right number, but I'm glad it's being factored in

 

-New tire section width system looks good

 

-4 door modifier needs to go

 

-More incentive for BTM Aero (or more penalty for non-BTM) would be better as well IMO.

 

[Greg G.]

Overall: I think the rules strike a great balance between fairness and simplicity. It's a solid foundation.

 

My car will be assessed either -10HP or +140 pounds because I have an SLA suspension. That's a pretty big hit, especially against say, a torquey BMW. Colin Chapman once said "any suspension will work well if you don't let it", and I believe that strut front suspension cars such as BMW, Porsche, and FRS/BRZ aren't REALLY at that much cornering disadvantage when we all have pretty dialed in setups. BMW E36M3 are hugely competitive and have a TON of lap records... they seem to be doing pretty well with struts up front. If you've got controlled roll and a good alignment, an E36 or BRZ will be utilizing it's tires similarly to an Miata or S2000. We also tend to forget that SLA cars lose contact patch and hence braking traction from front-end squat.

 

The dubiously realistic SLA assessment aside, my biggest heartburn is tire compound.

 

1. A 200TW Bridgestone RE-71R is faster than a 100TW Maxxis RC1, yet it receives a +0.3 modifier despite being a faster tire (that can run in rain, no less). A more realistic modifier would be "Non-R Compound with UTQG Treadwear rating 100 or greater +0.3". This would more reflect real-world performance and open the door to making long-lasting R-comps competitive. I thought this was one of the big goals...?

 

2. The +0.3 200TW tire modifier value is inadequate. Switching from a 200TW Bridgestone to a Hoosier R7 would only result in a 4HP loss or a +54 pound ballast in my car. I can only assume the Hoosier, even with the de-tune or ballast, would be 2-3 seconds quicker per lap minimum. This modifier should be something much closer to 1.0 (even THAT is probably insufficient), or we're just handing "wins" to people on Hoosiers, not earning wins with driving skill.

 

The ruleset is a nice piece, but I think the SLA and tire modifiers are off. I'll take the SLA hit grudgingly... but the tire modifier means that if I show up at all, it's just to show up and hand points to folks on Hoosiers. I have no interest in dropping $1200 on short-lived consumables.

 

For the most part, the BMW's would have to take the -0.5 for control arms and -0.2 for bushings to get similar performance as the A-arm suspension vehicles (so, same -0.7 total).

The tire modifier value can be adjusted in the future, with a conservative start, because some of the supposed 200 treadwear tires do perform better than R-compound tires.

[Greg G.]

I have to agree that .7 for A arm is a bit extreme. I can understand .3 or .4, but A arms are definitely not worth 10 whp or 140 lb in performance when compared to a well setup bmw or brz on strut.

 

Giving more incentive to run 100 TW tires will also increase entries, at least for TT guys.

 

I thought idea of ST formula was to simplify the rules, and just mainly focus on p/w, tires and aero.

FR-S & BRZ have rear upper A-arms.

[Greg G.]

The advantage modifier for sedans is still there too. No difference between an E36 M3 coupe and sedan. Hard to see how an STi or Evo is at a disadvantage compared to a coupe...

STi and Evo are not eligible vehicles in ST5.

 

M3's have always been problematic with this rule, but it is still valuable for many other models that need the help against the "sports" cars.

[Greg G.]

Contradiction on the bushing rules:

 

Does a LCA offset non metallic bushing for added camber result in adjustment to ptw or not? Suspension paragraph 3 and 5 specifically contradict.

Re-read 6.1.8.5. It says "Non-OEM metallic and/or spherical design replacement suspension bushing...." It doesn't say "non-metallic".

 

(Also, your signature still shows you as the NE TT Director)

[Greg G.]

I wish having a splitter didn't take extra points.....no reason to run a wing (in my case) without a splitter. And just sayin', new dyno cert seems fair but even more complicated than. Anyone that comes to my dyno, I'm NOT doing your math for you!!!!!

 

How about considering the C6 Grand Sport Fascia for the BTM like the BMW? It has no advantage over the base fascia without the splitter, and it's the only fascia I have. I'm definitely going to a low power class next year, not sure which one though.

I don't think that any Corvettes made after the 70's are eligible for ST5/TT5.

 

In regard to the Avg HP calculations, we are planning on having a nice on-line calculator produced, where drivers can enter their 250 rpm data points, and it spits out the Avg HP.

[Greg G.]

Just a guess, but wishbone generally has three connection points, two on the body, one on the hub/carrier. BMW lower arm has one and one. Not really a wishbone.

Correct, but lower A-arms are not included in this Mod Factor. I believe some of the Mustangs have A-arm lowers without A-arm uppers, and they would not take the Mod Factor in that case.

[Greg G.]

same here with a 350z

plus i take -0.7 for a arms

and -0.7 for shock shaft diameter and reservoir

dont think st5 will work for my car

rafael

03 350z

 

i thought one of the big goals was to let people run less expensive longer lasting tires like nt01 and such, I dont see that anywhere??!!

 

So basically st5 rules are not good for a 350z. must not be a popular car!

 

man I got the wrong car!

any chance of an st4.5 class in the future??

I need yoga right about now!!

hhmmmm, hhmmmm!!!

 

 

 

 

 

Oh boy. Limit of 14:1 with no tire size modifier points. Based off Greg's post in the TT forum that doesn't look good for me to stay in TT5...

 

Will wait to see the complete rule set once its posted but I'm not feeling optimistic about this...

 

I think since the 350Z is produced with more than 265 HP from the factory, it's not eligible for st5.

Correct.

[hufflepuff]

Overall: I think the rules strike a great balance between fairness and simplicity. It's a solid foundation.

 

My car will be assessed either -10HP or +140 pounds because I have an SLA suspension. That's a pretty big hit, especially against say, a torquey BMW. Colin Chapman once said "any suspension will work well if you don't let it", and I believe that strut front suspension cars such as BMW, Porsche, and FRS/BRZ aren't REALLY at that much cornering disadvantage when we all have pretty dialed in setups. BMW E36M3 are hugely competitive and have a TON of lap records... they seem to be doing pretty well with struts up front. If you've got controlled roll and a good alignment, an E36 or BRZ will be utilizing it's tires similarly to an Miata or S2000. We also tend to forget that SLA cars lose contact patch and hence braking traction from front-end squat.

 

The dubiously realistic SLA assessment aside, my biggest heartburn is tire compound.

 

1. A 200TW Bridgestone RE-71R is faster than a 100TW Maxxis RC1, yet it receives a +0.3 modifier despite being a faster tire (that can run in rain, no less). A more realistic modifier would be "Non-R Compound with UTQG Treadwear rating 100 or greater +0.3". This would more reflect real-world performance and open the door to making long-lasting R-comps competitive. I thought this was one of the big goals...?

 

2. The +0.3 200TW tire modifier value is inadequate. Switching from a 200TW Bridgestone to a Hoosier R7 would only result in a 4HP loss or a +54 pound ballast in my car. I can only assume the Hoosier, even with the de-tune or ballast, would be 2-3 seconds quicker per lap minimum. This modifier should be something much closer to 1.0 (even THAT is probably insufficient), or we're just handing "wins" to people on Hoosiers, not earning wins with driving skill.

 

The ruleset is a nice piece, but I think the SLA and tire modifiers are off. I'll take the SLA hit grudgingly... but the tire modifier means that if I show up at all, it's just to show up and hand points to folks on Hoosiers. I have no interest in dropping $1200 on short-lived consumables.

 

For the most part, the BMW's would have to take the -0.5 for control arms and -0.2 for bushings to get similar performance as the A-arm suspension vehicles (so, same -0.7 total).

The tire modifier value can be adjusted in the future, with a conservative start, because some of the supposed 200 treadwear tires do perform better than R-compound tires.

 

Greg,

 

Thank you for the clarification. It seems there are E36M3s setting lap records seemingly without the -0.5 for control arms and -0.2 for bushings, but i'd have to look up their points sheets.

 

You're correct- People say the RE-71R is up to a second faster than say a Maxxis RC1 or a Nitto NT-01. I think this would still be at least 2 seconds behind a Hoosier.

 

As the previous poster (f1honda) pointed out, in ST4 the modifier from "R" to "A" tires is +1.0, and I would think the difference between a street tire and a Hoosier R7 would be at least as large. Hoping some other folks, possible with data, chime in. But I know that I switched from Toyo R888 to bombed out, flat-spotted Hoosiers takeoffs at VIR and comfortably went 3 seconds faster with more on the table. No amount of driving can ever fix that if the rules don't equalize.

 

So without a TRULY realistic penalty on 40 TW slicks, it will still come down to who spends more money on sticky rubber get handed a trophy (EARNING it is something entirely different).

 

Instead of erring "conservatively" in favor of Hoosiers, why not err conservatively on the side of >100TW since this is supposed to be a budget class?

 

I think it will still be in Hoosier's favor if this rule was changed to "100TW and greater tires +1.0", but it may just give budget drivers in a budget class a chance to contend, and hopefully open the door to more novice drivers (something that I also thought was a goal).

[bionicbelly]

 

As the previous poster (f1honda) pointed out, in ST4 the modifier from "R" to "A" tires is +1.0, and I would think the difference between a street tire and a Hoosier R7 would be at least as large. Hoping some other folks, possible with data, chime in. But I know that I switched from Toyo R888 to bombed out, flat-spotted Hoosiers takeoffs at VIR and comfortably went 3 seconds faster with more on the table. No amount of driving can ever fix that if the rules don't equalize.

 

So without a TRULY realistic penalty on 40 TW slicks, it will still come down to who spends more money on sticky rubber get handed a trophy (EARNING it is something entirely different).

 

Instead of erring "conservatively" in favor of Hoosiers, why not err conservatively on the side of >100TW since this is supposed to be a budget class?

 

I think it will still be in Hoosier's favor if this rule was changed to "100TW and greater tires +1.0", but it may just give budget drivers in a budget class a chance to contend, and hopefully open the door to more novice drivers (something that I also thought was a goal).

I would think the difference between a street tire and a Hoosier R7 would be at least as large.Definately not RE-71's are faster than Toyo RR's and Hoosier R6.

 

We did a good bit of testing this summer, and it is a fact that R7's are the fastest non-A tire. By a good bit. The RE-71's and Hankooks are about 1.5-2 seconds behind R7's at HPT, While RR's and R6's are 2-3 seconds slower. (the RR's were almost done though, so they may be a bit faster if they had been newer)

 

But I know that I switched from Toyo R888 to bombed out, flat-spotted Hoosiers takeoffs at VIR and comfortably went 3 seconds faster with more on the table. I also tested this, and your statement is true, no doubt. But the thing is, R7's don't cycle out like the older compounds. I ran a set of ~30 heat cycle R7's back to back with fresh tires (one break in heat cycle) , and while they did feel different, lap times went down by 0.3 seconds with the new tires. Those old ones corded at the next event. And, since the R7 is about 3 seconds faster than the RR, I am sure it is about the same for 888's.

 

FYI- I own a tire machine and balancer, so I flip tires after every event, True, that helps with the life of the tire, but I did not go through two full sets of tires this year. I did some things to conserve, like run old RR takeoffs for warm ups, and friday test days, and I didn't run every session, but the new R7's are really a good tire. Not the fragile flower that I hear so many rumors about. I actually heard someone say they get 0.2 second a lap slower for every heat cycle. They relayed this information like it was gospel, and it couldn't be further from the truth. They stay fast to the cords, break away is better, and they are fun to drive on. But, yeah, they are $$$.

[hufflepuff]

 

As the previous poster (f1honda) pointed out, in ST4 the modifier from "R" to "A" tires is +1.0, and I would think the difference between a street tire and a Hoosier R7 would be at least as large. Hoping some other folks, possible with data, chime in. But I know that I switched from Toyo R888 to bombed out, flat-spotted Hoosiers takeoffs at VIR and comfortably went 3 seconds faster with more on the table. No amount of driving can ever fix that if the rules don't equalize.

 

So without a TRULY realistic penalty on 40 TW slicks, it will still come down to who spends more money on sticky rubber get handed a trophy (EARNING it is something entirely different).

 

Instead of erring "conservatively" in favor of Hoosiers, why not err conservatively on the side of >100TW since this is supposed to be a budget class?

 

I think it will still be in Hoosier's favor if this rule was changed to "100TW and greater tires +1.0", but it may just give budget drivers in a budget class a chance to contend, and hopefully open the door to more novice drivers (something that I also thought was a goal).

I would think the difference between a street tire and a Hoosier R7 would be at least as large.Definately not RE-71's are faster than Toyo RR's and Hoosier R6.

 

We did a good bit of testing this summer, and it is a fact that R7's are the fastest non-A tire. By a good bit. The RE-71's and Hankooks are about 1.5-2 seconds behind R7's at HPT, While RR's and R6's are 2-3 seconds slower. (the RR's were almost done though, so they may be a bit faster if they had been newer)

 

But I know that I switched from Toyo R888 to bombed out, flat-spotted Hoosiers takeoffs at VIR and comfortably went 3 seconds faster with more on the table. I also tested this, and your statement is true, no doubt. But the thing is, R7's don't cycle out like the older compounds. I ran a set of ~30 heat cycle R7's back to back with fresh tires (one break in heat cycle) , and while they did feel different, lap times went down by 0.3 seconds with the new tires. Those old ones corded at the next event. And, since the R7 is about 3 seconds faster than the RR, I am sure it is about the same for 888's.

 

FYI- I own a tire machine and balancer, so I flip tires after every event, True, that helps with the life of the tire, but I did not go through two full sets of tires this year. I did some things to conserve, like run old RR takeoffs for warm ups, and friday test days, and I didn't run every session, but the new R7's are really a good tire. Not the fragile flower that I hear so many rumors about. I actually heard someone say they get 0.2 second a lap slower for every heat cycle. They relayed this information like it was gospel, and it couldn't be further from the truth. They stay fast to the cords, break away is better, and they are fun to drive on. But, yeah, they are $$$.

 

Thanks very much for sharing. Most people guard their hard work and efforts, but this sort of data is key to trying to equalize rulesets.

[lutfy]

Overall: I think the rules strike a great balance between fairness and simplicity. It's a solid foundation.

 

My car will be assessed either -10HP or +140 pounds because I have an SLA suspension. That's a pretty big hit, especially against say, a torquey BMW. Colin Chapman once said "any suspension will work well if you don't let it", and I believe that strut front suspension cars such as BMW, Porsche, and FRS/BRZ aren't REALLY at that much cornering disadvantage when we all have pretty dialed in setups. BMW E36M3 are hugely competitive and have a TON of lap records... they seem to be doing pretty well with struts up front. If you've got controlled roll and a good alignment, an E36 or BRZ will be utilizing it's tires similarly to an Miata or S2000. We also tend to forget that SLA cars lose contact patch and hence braking traction from front-end squat.

 

The dubiously realistic SLA assessment aside, my biggest heartburn is tire compound.

 

1. A 200TW Bridgestone RE-71R is faster than a 100TW Maxxis RC1, yet it receives a +0.3 modifier despite being a faster tire (that can run in rain, no less). A more realistic modifier would be "Non-R Compound with UTQG Treadwear rating 100 or greater +0.3". This would more reflect real-world performance and open the door to making long-lasting R-comps competitive. I thought this was one of the big goals...?

 

2. The +0.3 200TW tire modifier value is inadequate. Switching from a 200TW Bridgestone to a Hoosier R7 would only result in a 4HP loss or a +54 pound ballast in my car. I can only assume the Hoosier, even with the de-tune or ballast, would be 2-3 seconds quicker per lap minimum. This modifier should be something much closer to 1.0 (even THAT is probably insufficient), or we're just handing "wins" to people on Hoosiers, not earning wins with driving skill.

 

The ruleset is a nice piece, but I think the SLA and tire modifiers are off. I'll take the SLA hit grudgingly... but the tire modifier means that if I show up at all, it's just to show up and hand points to folks on Hoosiers. I have no interest in dropping $1200 on short-lived consumables.

 

For the most part, the BMW's would have to take the -0.5 for control arms and -0.2 for bushings to get similar performance as the A-arm suspension vehicles (so, same -0.7 total).

The tire modifier value can be adjusted in the future, with a conservative start, because some of the supposed 200 treadwear tires do perform better than R-compound tires.

 

Greg, I'll beg to differ here. Having raced BMWs in both BMWCCA IStock and IPrepared, my experience shows that the stock rear control arm is plenty adequate to get the desired negative camber at the rear. Is it flimsly? Yes. Do you have to upgrade it? No. What if you do? Well you get a tad more than -2 at the rear "if" you choose to do so but having run 800/900lbs springs in I Stock, the rear arm upgrade was not legal and later racing in IPrepared (where it was legal), it was not the bees knees. So no a BMW can save the 0.7 hit the rest of the modern car field is taking.

 

On the other hand, having an FRS where I can not adjust the rear camber (luckily we can get to the desired camber by lowering but its never even) most folks in TTC actually upgraded their arms. This is now costing them big time. 1.3 ratio hit!!

 

Anyways long and short, the E36 comes out as a clear winner by a long shot (all things equal) for TT5. But such is racing

 

Thank you for putting this all together.

 

Cheers,

 

Lutfy

[TurboShortBus]

The advantage modifier for sedans is still there too. No difference between an E36 M3 coupe and sedan.

I have seen this comment several times before.

 

Disclaimer: I run a 2-door car.

 

IMO, I have always been a fan of getting rid of the 4-door advantage modifier. I don't buy that they have "worse aero" than their 2-door counterparts (as I have been told), especially if you can find multiple makes/models with identical silhouettes between 2- and 4-door versions (as noted above).

 

Also IMO, if advantage factors are going to be handed out for 4-door cars because of perceived "worse aero," then advantage factors should probably be handed out for top-down or non-hardtop convertibles for their less-unknown "worse aero" conditions.

 

Mark

[HAZE]

The way the modifiers are currently set, ST5 is not the cost reducing class I was hoping it would be.

 

You will need to have all the same elements as an ST1-ST4 car to have a car optimized to these rules. Hoosiers, full aero, and expensive dampers.

 

I really want to see a class that would allow a "simple" build to be competitive. One where the aero cars might have an advantage at some tracks, and the non-aero setup might work at others. Or one where a decent R-comp tire isn't hilariously outclassed by the Hoosier tire (same modifier, really?).

 

The open rules are great, and should give people flexibility & creativity in how to optimize their car. They currently read as a guide of "these are the tires & aero package you need to have to be competitive".

[bionicbelly]

The way the modifiers are currently set, ST5 is not the cost reducing class I was hoping it would be.

 

You will need to have all the same elements as an ST1-ST4 car to have a car optimized to these rules. Hoosiers, full aero, and expensive dampers.

 

I really want to see a class that would allow a "simple" build to be competitive. One where the aero cars might have an advantage at some tracks, and the non-aero setup might work at others. Or one where a decent R-comp tire isn't hilariously outclassed by the Hoosier tire (same modifier, really?).

 

The open rules are great, and should give people flexibility & creativity in how to optimize their car. They currently read as a guide of "these are the tires & aero package you need to have to be competitive".

 

Disclaimer - I don't know a thing about aero.

 

I don't see that at all. The aero looks pretty restrictive, in a way that will lower it's effectiveness, (probably) and the modifier is pretty significant. If you do a wing and splitter, it is effectively a .9 mod factor (you lose .4 for BTM aero, and gain .5 for the splitter) Does not seem worth it to me.

 

As far as tires, one of the big advantages for Hoosier was the funky ruler they used to measure width. (I run and like Hoosiers, but really, a stack of 225's next to any almost any other 255 is almost the same) That won't come into play with this. Yes, it is a better compound, and the fastest tire, but you don't have to have them to win. Also, on the Hoosier subject, have you run them? Recently? They really are a great tire, with great support, and the best contingency. Not to mention, an american company that's single purpose is to support the hobby we like. That said, I wouldn't be mad if there were a slight penalty for Hoosiers. I would still run them.

 

Also not sure about the shock limitations. I see what they were doing, and I agree. I was actually planning on getting some bigger better shocks this year, but after some time with the calculator, not sure if that will be on the table. I don't know if I want to give up that much for them. I doubt many people will either, and if they do, may very likely be at a disadvantage.

 

edit - I guess on a 3000lb car, 40mm+ shocks would remove ~10 hp. Not so much of a disadvantage, but still something to think about.

[MemphisRob]

Very good points...

 

I too am a fan of the really nice Maxxis contingency. I'd love to say money was no object and I can just run Hoosier R7's... but it is tough to always have 5 people to make class and even then only 1st place gets the contingency.

 

I think the new tire section width is a great plan to level the field to limit the cheater wide tires, but I am curious if the 245/40/17 Hoosier R7's might still be within the tolerance of TT5... if they are under the 266mm section width limit then they will really limit the competitiveness of using the RC1's..especially if the 255 RC1's aren't within the 266mm limit. The 245 RC1's are 45 series and too tall for me to run on a E36M3... so that leaves me to run 235 RC1s against 245 R7s... which is like bringing a knife to a gun fight.

 

^^yes!

 

Please change the tire modifiers to give the 100+ R-comp tires a chance to be competetive. The Maxxis RC1 is a great value with a generous contingency program. I was hoping that ST5 would finally be the place where you don't HAVE to have Hoosiers to be competetive.

 

Maybe something like:

 

-0.3 - DOT Race

+0.3 - 100+ TW R-Comp

+0.5 - 200+ TW Street

 

 

-A-arm modifier is a great addition. Not sure if -0.7 is the right number, but I'm glad it's being factored in

 

-New tire section width system looks good

 

-4 door modifier needs to go

 

-More incentive for BTM Aero (or more penalty for non-BTM) would be better as well IMO.

[ja1217]

Very good points...

 

I too am a fan of the really nice Maxxis contingency. I'd love to say money was no object and I can just run Hoosier R7's... but it is tough to always have 5 people to make class and even then only 1st place gets the contingency.

 

I think the new tire section width is a great plan to level the field to limit the cheater wide tires, but I am curious if the 245/40/17 Hoosier R7's might still be within the tolerance of TT5... if they are under the 266mm section width limit then they will really limit the competitiveness of using the RC1's..especially if the 255 RC1's aren't within the 266mm limit. The 245 RC1's are 45 series and too tall for me to run on a E36M3... so that leaves me to run 235 RC1s against 245 R7s... which is like bringing a knife to a gun fight.

 

A few people on the mid atlantic facebook TT page measured and the 255 RC-1's do fit the template, even on a 10 inch wheel. Haven't seen any measurements for the 245 Hoosier R7 though.

[bionicbelly]

I am not sure about the 245. I have always used a 225/45-17 hoosier. Still a very wide tire. This will be interesting for sure though. If the 245 is to wide, that could really level the playing field, since there is no 235 option.

[MemphisRob]

Very good points...

 

I too am a fan of the really nice Maxxis contingency. I'd love to say money was no object and I can just run Hoosier R7's... but it is tough to always have 5 people to make class and even then only 1st place gets the contingency.

 

I think the new tire section width is a great plan to level the field to limit the cheater wide tires, but I am curious if the 245/40/17 Hoosier R7's might still be within the tolerance of TT5... if they are under the 266mm section width limit then they will really limit the competitiveness of using the RC1's..especially if the 255 RC1's aren't within the 266mm limit. The 245 RC1's are 45 series and too tall for me to run on a E36M3... so that leaves me to run 235 RC1s against 245 R7s... which is like bringing a knife to a gun fight.

 

A few people on the mid atlantic facebook TT page measured and the 255 RC-1's do fit the template, even on a 10 inch wheel. Haven't seen any measurements for the 245 Hoosier R7 though.

 

That is really fantastic news... thank you for sharing this. I have never run R7's and I really don't want to know what I am missing. Maxxis has been a very generous supporter of NASA TT and I would prefer to continue to support them. Anyone have an idea how the 255 RC1 compares to the 245 R7 in lap time? For that matter, anyone run the 255 VR1 and have some feedback?

[ja1217]

That is really fantastic news... thank you for sharing this. I have never run R7's and I really don't want to know what I am missing. Maxxis has been a very generous supporter of NASA TT and I would prefer to continue to support them. Anyone have an idea how the 255 RC1 compares to the 245 R7 in lap time? For that matter, anyone run the 255 VR1 and have some feedback?

 

I don't have data for 255 Maxxis vs 245 R7, but at VIR on 225 Maxxis I was about 3 seconds slower compared to 225 R7s, at Summit point the R7s we're about 2 seconds faster.

 

I think the more interesting comparison would be 255 Maxxis vs 225 Hoosier as I am not sure the 245 R7 will fit the template. Mr best guess is that they would still be slower than the 225 R7, but it might cut the differences I was seeing in half.

[Greg G.]

 

Greg, I'll beg to differ here. Having raced BMWs in both BMWCCA IStock and IPrepared, my experience shows that the stock rear control arm is plenty adequate to get the desired negative camber at the rear. Is it flimsly? Yes. Do you have to upgrade it? No. What if you do? Well you get a tad more than -2 at the rear "if" you choose to do so but having run 800/900lbs springs in I Stock, the rear arm upgrade was not legal and later racing in IPrepared (where it was legal), it was not the bees knees. So no a BMW can save the 0.7 hit the rest of the modern car field is taking.

 

On the other hand, having an FRS where I can not adjust the rear camber (luckily we can get to the desired camber by lowering but its never even) most folks in TTC actually upgraded their arms. This is now costing them big time. 1.3 ratio hit!!

 

Anyways long and short, the E36 comes out as a clear winner by a long shot (all things equal) for TT5. But such is racing

 

Thank you for putting this all together.

 

Cheers,

 

Lutfy

 

Possible. Our Dyno re-class data shows that it is going to be close, but we elected to start the A-arm factor high, and we can move it lower if needed in the future.

[Greg G.]

The way the modifiers are currently set, ST5 is not the cost reducing class I was hoping it would be.

 

You will need to have all the same elements as an ST1-ST4 car to have a car optimized to these rules. Hoosiers, full aero, and expensive dampers.

 

I really want to see a class that would allow a "simple" build to be competitive. One where the aero cars might have an advantage at some tracks, and the non-aero setup might work at others. Or one where a decent R-comp tire isn't hilariously outclassed by the Hoosier tire (same modifier, really?).

 

The open rules are great, and should give people flexibility & creativity in how to optimize their car. They currently read as a guide of "these are the tires & aero package you need to have to be competitive".

 

Hmmm. Try a spec class? How about Spec Miata---now up to what? $35,000 for a top level car with that level of rules restriction......

Until competitors start running size 255 of brand X tire versus 225 brand H tire, it is not clear that there is still a big advantage? Tires are a moving target, and the thing we can control is actual size, and we are going to do just that. The most simple one or two way adjustable no reservoir shocks can now be very expensive--just the way the technology has progressed.