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2 q's on the 2007 rules


roadracetransam

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Question #1

I must have missed it, because I did not find the weight/HP ratios for base classification of TTA-TTF. What is the weight/HP ratio for TTB and TTC if we want to base class our car according to that?

Question #2

I am not too hot about the tire sizes listed for each base class. There might be a problem. For an example:

1998-2002 Pontiac Firebird WS6 is base class TTC, the stock, OEM tire size (not an option) was 275/40r17. You listed TTC tire size as 245mm. That is +7 for tires that came originally, bone stock on the car. So, all the WS6's are acctualy assesed as TTC*. Even if someone wanted to run the 245 tires, I don't think 245's fit the OEM, stock 9.5"X17" wheels these cars came with.

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1) Weight/HP ratios are only for TTS and TTU. You classify yourself in TTA-TTF according to base class and modification points. The only restriction is that if you are somehow still in TTA-TTF yet have an 8.7 or better WT/HP ratio, then you automatically get bumped to TTS/TTU.

 

2) I definitely see what you mean here. On the flipside, my Evo's base class is TTB where the width is 255, but our stock tires are 235. We can bump up 20mm per corner without penalty. I personally will be in TTS, so it's irrelevant, but I did notice that.

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yeah the stipulated tire size is pretty screwy, esp when you car may come with tires wider than that which should be taken care of in base classing

 

what gives?

 

and just to make sure I'm reading the weight right, im listed at 2657 curb, and that means I can weigh in as light as 2653 with driver, saftey gear, etc without taking the 1 point for being 5 lbs lower (vs 4)

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Question #1

I must have missed it, because I did not find the weight/HP ratios for base classification of TTA-TTF. What is the weight/HP ratio for TTB and TTC if we want to base class our car according to that?

 

I am with you on that. I was looking for that info too. I have a supercharged car but it still falls short of being on TT(SUR). Where do I stand then?

 

EDIT: Nevermind...I think Greg will evaluate my case on an individual basis.

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But if you run a SRT4 with the stock tire at 205 and you are in TTC you normally run a 225 tire (hoosier) you get to SUBTRACT 4 points from your tire penalty of 10 points for running hoosiers so you get to have the sticky R comps at less points than RA1's...What I thought was funny was that the SCCA T-2 runoffs have the SRT and the EVO and the STI ALL IN THE SAME CLASS with 300lbs weight penalty on the AWD cars that and the fact that Dodge

"Although the SRT-4 is rated at 230 hp (2004+), it was revealed that Dodge underrated the car's power production. Dodge tested the SRT-4 prototypes on the dyno with a fairly hot intercooler, which negatively affected overall efficiency. Most production SRT-4s in fact rate right around 230 hp at the wheels, therefore crank horsepower is estimated at 265-275 hp. This makes them fairly formidable versus much more expensive production sports cars in real world, "roll-on" situations from 30 mph and up. "

http://wikicars.org/en/Dodge_SRT-4

So I ask the question... if SCCA runs the cars in the same class and Both SRT4's out qualified the evos..(but not the factory Subi's) why does it have a THREE CLASS ADVANTAGE IN NASA TT? (TTE* VS TTC** for the lowest class evo)..actually 4 class since most of the evos and STi are TTB..... and still retains it's weight advantage???? (SRT=2970 EVO/STI =3255/3260)

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SCCA runs the cars in the same class and Both SRT4's out qualified the evos..(but not the factory Subi's) why does it have a THREE CLASS ADVANTAGE IN NASA TT? (TTE* VS TTC** for the lowest class evo)..actually 4 class since most of the evos and STi are TTB..... and still retains it's weight advantage???? (SRT=2970 EVO/STI =3255/3260)

 

SCCA Classes a Rabbit GTI as ITB, and a first Gen RX7 as ITA, yet here the rabbit is classed higher than the RX7. The Rabbit is a lighter, but the Mazda has better suspensin, better weight distribution, better aero, more power, etc.

 

There is an ITA RX7 that turns ~2:03s at Thunderhill regularly, the best time for a Rabbit is ~2:12, and under the new revised base, we would be the same class.

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also though I'd mention that most domestic engines (5.0 Ford, LT1, LS1) use .030" as the first overbore size

 

ex. in a 302/5.0 you end up with 306 using a .030" piston. hardly points worthy is .020" is the largest allowable overbore

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Yes, I was disappointed in the new car classifications, base car classifications seem a bit off. One of the difficult things to predict is how cars will respond to modifications, not sure if their competition potential is predicted in the PT/TT model. We can look at established classes like Tom and Robispec bring up.

 

Looking at current IT classing as a predictor of performance.

From fastest to slowest

ITS

ITA

ITB

ITC

 

ITB BMW 2002 TTG** - comp. rwd irs car in ITB

ITC Datsun 510 TTF* - comp. rwd irs car in ITC

ITB Ford Escort TTG* - mid pack fwd car in ITB

ITA Mazda RX7 TTG** - mid pack rwd car in ITA

ITS Porsche 944 TTF** - comp. rwd irs car in ITS

ITB VW Golf GTI TTG** - front running ITB car

ITB VW Rabbit GTI TTF - mid pack ITB car

 

not IT classed but VW GTI Turbo (150hp) TTF at 2762lbs.

How much more power can we get out of the Turbo GTI with just some simple waste gate mods which I think are only +3 points?

 

From the above, Datsun 510 and VW Rabbit GTI appear to be misclassed. There are many more examples which are only a problem if people already own those cars.

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I guess what bugs me is that while most of the chassies I work on get points added and the specific mods I do get points too.("success blessings"). Certain cars win their division 3 years in a row and now have won at the national level without movement in class grade(and setting not only a ttc national record but also faster than ttb record ). Good I guess if you own the car and write the rules bad for anything trying to compete against the unfairly classed car.

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I'm not so sure the RX-7 example is the best one...you are talking a bouta badass driver that is probably that much better than his competition.....my 2 cents.

 

 

 

 

 

 

SCCA runs the cars in the same class and Both SRT4's out qualified the evos..(but not the factory Subi's) why does it have a THREE CLASS ADVANTAGE IN NASA TT? (TTE* VS TTC** for the lowest class evo)..actually 4 class since most of the evos and STi are TTB..... and still retains it's weight advantage???? (SRT=2970 EVO/STI =3255/3260)

 

SCCA Classes a Rabbit GTI as ITB, and a first Gen RX7 as ITA, yet here the rabbit is classed higher than the RX7. The Rabbit is a lighter, but the Mazda has better suspensin, better weight distribution, better aero, more power, etc.

 

There is an ITA RX7 that turns ~2:03s at Thunderhill regularly, the best time for a Rabbit is ~2:12, and under the new revised base, we would be the same class.

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Yes, but various ITA RX7s with different drivers are well under the 2:10 lap times at TH. I've raced wheel to wheel with ITA RX7s in a similar weight racecar with over 130 whp and our acceleration performance is similar.

 

It will take a lot of money and TT points to enable a VW GTI to get as fast as an ITA RX7 which will push the already higher classed GTI into an even faster/higher class.

 

I'm not so sure the RX-7 example is the best one...you are talking a bouta badass driver that is probably that much better than his competition.....my 2 cents.

 

 

 

 

 

 

 

 

SCCA runs the cars in the same class and Both SRT4's out qualified the evos..(but not the factory Subi's) why does it have a THREE CLASS ADVANTAGE IN NASA TT? (TTE* VS TTC** for the lowest class evo)..actually 4 class since most of the evos and STi are TTB..... and still retains it's weight advantage???? (SRT=2970 EVO/STI =3255/3260)

 

SCCA Classes a Rabbit GTI as ITB, and a first Gen RX7 as ITA, yet here the rabbit is classed higher than the RX7. The Rabbit is a lighter, but the Mazda has better suspensin, better weight distribution, better aero, more power, etc.

 

There is an ITA RX7 that turns ~2:03s at Thunderhill regularly, the best time for a Rabbit is ~2:12, and under the new revised base, we would be the same class.

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but David B in his evo can run 2:03 and in his GTI run's 2:14's...and the RX7 guy isnt 12 sec's faster than Dave B in = cars

 

Good point...so what's up with the RX-7?

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but David B in his evo can run 2:03 and in his GTI run's 2:14's...and the RX7 guy isnt 12 sec's faster than Dave B in = cars

 

Good point...so what's up with the RX-7?

 

 

Well, near as I can tell, its a Mazda. Seems to me a Mazda is the car to have. Simple, eh?

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I am very happy with the proposed rules changes. It all seems very fair to me, especially since my car remains in TTB. At least, I think it does.

 

The rule on Page 19, Engine/Drivetrain, No. 3, has me stumped. Because I have an upgraded turbo, it appears that I have to get a dyno sheet and submit it to the National TT Director for his assessment. But there are no guidelines. Like:

 

1. How much horsepower am I allowed to have and remain in TTB? Does the 8.70:1 ratio apply here? (at 3270 lb, that ratio allows me 375 hp. )

 

2. Does the director's dyno sheet points assessment REPLACE all the points I meticulously counted up in this category, or does the assessment ADD to the points? In other words, if I have 25 points in the Engine/Drivetrain category, and the engine dynos at, say, 300 hp, do I add the assessment to the 25 points or does the director assign, say, 30 points total to the entire category?

 

3. What are the guidelines for figuring out what his assessment might be? Is it a subjective decision based on gut feel, or an analytical decision based on actual numbers?

 

I based my car classification on the points in the rules dated Dec 8, because the downloadable TT car classification form is still based on 2006 rules. Will the new form still have the points added for asterisks? In other words, the Base Classification Table has my car listed as TTE*. Does the asterisk mean I have to add 7 points?

 

Rich

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above that ratio, you go from wherever you are to TTS at least (where you'd have to calculate your adjusted power-weight ratio instead of points)

 

the TTE* means you start in E with 7 points at no modifications

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Or 1.8 "lightweight" VWs like the Scirocco and GTI are definitely not the car to have.

 

The VW 1.6 and 1.7 cars have more competition potential than the 1.8s. Start with the lower based car and increase displacement and add the points to bring it back and you end up with a faster car at a lower class than starting with a 1.8.

 

IMO, the TTG* Pinto 2.3L is actually preferable to even the RX7. 200+ HP potential, fairly light at 2250 lbs, this car has some real potential.

 

The Ford Mustang Turbo based at TTG* also looks good. I owned a 79 and after increasing the boost, that car was a rocket and kept up with my friends slightly modified V8 GT.

 

but David B in his evo can run 2:03 and in his GTI run's 2:14's...and the RX7 guy isnt 12 sec's faster than Dave B in = cars

 

Good point...so what's up with the RX-7?

 

 

Well, near as I can tell, its a Mazda. Seems to me a Mazda is the car to have. Simple, eh?

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I'm not so sure the RX-7 example is the best one...you are talking a bouta badass driver that is probably that much better than his competition.....my 2 cents.

The RX7 comparison is what I brought up, as that is what races in my region. The only cars in the lower PT ranks are RX7s and rabbit GTIs. Looking at last years rules, The former Pro-7 cars class out in PTE, the former GTI Cup cars in PTF. The GTI Cup guys have beed doing development all year, getting their cars as fast as possible while still fitting in PTF, and we got within a couple seconds of the Pro-7 guys ~2:14 vs ~2:12 at T-hill, ~2:05 vs ~2:03 at Sears point (with the ALMS T7). The Pro-7 guys haven't done anything to develop for next year, so they will certainly get a little faster under PT rules. Ffor comparison an ITA spec Rx7 (different driver than the Thill example) got down to 1:59 at Sears our last event.

 

The only possible way to make the cars even remotely competitive would be to take advantage of the overly low (and incorrect in my opinion) class weight. My car is fully prepped race car, and is probably the lightest of the GTI cup cars, at ~1900 lbs empty. With the rules weight of 1865, I can legally get the car down to ~1700 with no penalty using the alternate method. This may be possible by going full Carbon Fiber/Lexan, and cutting out some of the cage, but CF is beyond my budget, and I am not willing to comprome my cage to try and get my car competitive.

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but David B in his evo can run 2:03 and in his GTI run's 2:14's...and the RX7 guy isnt 12 sec's faster than Dave B in = cars

Good point...so what's up with the RX-7?

 

Maybe GG's junking the Neon and moving to a different class and needs a ride with as much "class cushion" as his SRT. Just think you can get a 03-05 SRT and you get to ADD FIFTY ONE POINTS to run in TTC while the same TTC class EVO can't even run R-compounds and stay in class...these are the same T-2 class cars remember that were VERY competitive at nationals head to head.....

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above that ratio, you go from wherever you are to TTS at least (where you'd have to calculate your adjusted power-weight ratio instead of points)

 

the TTE* means you start in E with 7 points at no modifications

 

Thanks for the asterisk explanation.

 

But you didn't answer the dyno question. What do they do with dyno results BELOW the allowed ratio?

 

Like, if the ratio allows me 375 hp at 3200 lb what happens if I dyno at 374? (I WISH!!) How many points do I get? Do they add onto the 20 points I already have for an intercooler and other stuff? Or is there some overall number assessed for engine and drivetrain mods?

 

Not knowing all this makes it difficult to figure points toward a classification.

 

Rich

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I only answer what I know... heh sorry

 

cars like mine are simple to class... tires, shocks, brake pads, camber and a whole lot of effort from the driver

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Gentlemen-

 

I'd just like to post a quick note to remind you all that personal attacks against Greg or anyone else participating in these forums will not be tolerated. Greg worked very hard on these rules with my direct supervision and there is no plot afoot to make the RX-7 or the SRT-4 into the ubercars as some of the previous posts imply. There were reasonable metrics applied to arrive at the base classes and this involved many hours of hard work and careful research. To suggest that we made changes otherwise questions our integrity directly without merit and I would hope that those of you who have done so might perhaps consider how disrespectful and unneccesary this tactic is before firing off such incendiary posts. If you have a problem with the classification, make a suggestion and we'll consider it. If you simply want to indulge in personal attacks because the rules don't agree with your vision of the world and you're looking to call someone a cheat or a liar because things did not work out for you, please do it elsewhere or best not at all.

 

Thanks.

 

-JWL

 

John Lindsey

Chief Divisional Director

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If you simply want to indulge in personal attacks because the rules don't agree with your vision of the world and you're looking to call someone a cheat or a liar because things did not work out for you, please do it elsewhere or best not at all.

 

Thanks.

 

-JWL

 

John Lindsey

Chief Divisional Director

 

I read only one maybe two people that've made these personal attacks. I'd like to think the blatant offender did it in jest, but I'm glad that you made this post to nip it in the bud. Most of us are trying to point out rules that don't make sense.

 

I hope the tire width rule is reviewed and amended. The weight of the car has a direct bearing on traction with a given tire width.

 

It is a mistake to set a tire spec based on what class you run, because within some classes there is as much as 1500 lb difference in weight between the cars. You can't expect the heavy cars to wear the same size tires as the light cars, or does NASA really think all cars put the same force on the contact patch regardless of weight.

 

Now for the light cars, they don't have to wear wide tires, they acctually get rewarded (points DEDUCTED) for wearing the tire size optimal for their performance, while the heavy cars get penalized for wearing their factory sizes.

 

Example: Dodge SRT-4 in TTC base class TTE, stock size 205, normally running 225, increased tire size 20mm for free.

Pontiac WS6 in TTC Base class TTC, stock size 275, running 295's gets +15 points for increasing tire size by the same 20mm!

 

He is correct. The physics and real world results show the problems with this rule. I propose three different options:

 

1)Cars are re-classed based on their OEM tire width. This will negate the penalty points for having OEM tires that are bigger than the class size.

 

2)Add a sliding scale for tire width based on weight for each class. For example a TTC car weighing 2700lbs would have a base tire width of 245. Another TTC car weighing 3600lbs would have a base tire width of 335. In this example, 100lbs would equal 10mm of tire width.

 

3)Remove the base class tire width rule and re-class vehicles that were previously classed wrongly to address that problem individually instead of instituting a blanket rule.

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Greg worked very hard on these rules with my direct supervision and there is no plot afoot to make the RX-7 or the SRT-4 into the ubercars as some of the previous posts imply.
I am the one who brought up the RX7, and I didn't suggest any such thing.

 

There were reasonable metrics applied to arrive at the base classes and this involved many hours of hard work and careful research.
Of that I have no doubt. The problem is that "reasonable metrics" don't always reflect real cars on the race track, and the GTI Cup vs Pro 7 is a prime example. The RX7 is a stronger car in every category except weight, yet is classed lower than the GTI.

 

SCCA classes The RX7 one class higher in both Improved Touring (ITA for the Mazda, ITB for the VW) and Production (E-Prod for the Mazda, F-Prod for the VW), yet here they are reversed.

 

Honestly, it doesn't really matter. When we had spec classes, we raced with ourselves. Now our classes are gone, the Pro-7s will race each other in PTE, and the GTIs will race each other in GTS, the only difference is we lost our Toyo Bucks, making racing a little more expensive.

 

It really is too bad, I know the GTI guys were looking forward to competing with the Pro-7s, but as it stands now it isn't going to happen.

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