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PostPosted: Fri Dec 01, 2017 8:48 am 
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docwyte wrote:
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

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PostPosted: Fri Dec 01, 2017 9:20 am 
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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".


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PostPosted: Fri Dec 01, 2017 10:43 am 
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HAZE wrote:
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.


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PostPosted: Fri Dec 01, 2017 11:47 am 
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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.

HAZE wrote:
^^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.


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PostPosted: Fri Dec 01, 2017 12:06 pm 
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MemphisRob wrote:
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.


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PostPosted: Fri Dec 01, 2017 12:30 pm 
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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.


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PostPosted: Fri Dec 01, 2017 2:44 pm 
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ja1217 wrote:
MemphisRob wrote:
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?


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PostPosted: Fri Dec 01, 2017 4:19 pm 
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MemphisRob wrote:
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.


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PostPosted: Fri Dec 01, 2017 9:58 pm 
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lutfy wrote:

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.

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PostPosted: Fri Dec 01, 2017 10:15 pm 
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HAZE wrote:
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.

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National TT, PT, & ST Director
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