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Is GTS a Power to Weight or HP to Weight Series?

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cstreit911
Guy have and are building cars to the current rules. Guys have and are spending lots of money and time developing packages based on the rules. Major philosophical shifts in the rule - and this would absolutely be one - penalize people who did good work with lost time and increased cost.

 

I fail to see how this would penalize anyone and increase their cost, can you please explain that thought?

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Chris F

It's only an average if your Torque is higher than your RWHP. If not then classing is based on RWHP.

 

My Honda Prelude is gonna DOMINATE GTS1 with 0 RWHP.

 

Just passing through...

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dillehayd
Guy have and are building cars to the current rules. Guys have and are spending lots of money and time developing packages based on the rules. Major philosophical shifts in the rule - and this would absolutely be one - penalize people who did good work with lost time and increased cost.

 

I fail to see how this would penalize anyone and increase their cost, can you please explain that thought?

 

Simple. Guys who have gone out and spent 10K+ to develop engine packages with intakes, cams, pistons, and headers, and software that produces engines with hp and torque numbers that are very close to each other will have to go back and change that package to find the new sweet spot that produces the fastest weight/power ratio car. Don't kid yourself; changing the way the ratio is calculated will change where the sweetspot is and people will have to spend money and time to find it.

 

Now, I'm not in the most competitive region or anything, but in 08 my car was pretty competitive when my health allowed me to race. There are a couple new cars so maybe that will change in 09...but...an example.

 

A guy I raced with has a dyno that shows something like 265hp and 240torque. He's on DOT's in GTS 3 so he has to weigh 2915. I've got 219.65hp and 191 torque on slicks so I have to weigh 2636. He and I had a pair of close races, I won one and he won one. Under a (hp+trq)/2 system, his min weight would drop 137.5lbs and mine would drop 172lbs.

 

1 - If we're already competitive why should I get a 35lbs advantage? The change in weight is a much larger % of my car than his.

1b - If that weight reduction in both cars means that he has to spend less time managing tires I lose much more relative speed than I gained with 35lbs. Indeed, if my car was that much lighter, I'd probably have to go to a smaller slick just to get temperature into them. The net effect is the exact opposite of what you're going for! [This is how rule changes usually work out - unintended effects are much larger than the intended ones.]

 

2 - How much would it cost you to take 137.5 lbs out of your car? What if the weight just isn't there to be taken out? I am running about 30lbs of ballast. I honestly don't think I could take another 150lbs out of the car w/o tube framing it. It just isnt there to be taken out. I'm already running CF hood, doors, trunk, lexan everywhere, and have gone to town on the car with a 4" cutting wheel. I'd have to add power to the car. I could do it pretty easily...a set of cams for 2k, 1k headers to make the cams work, and another 1k tune plus the time to do it. Why should I have to spend 4k to keep my car competitive? Sounds like a penalty to me and I've got exactly the type of car that would benefit most from a calculation change.

 

3 - Lets be real here. None of us are getting phone calls from Flavio Briatore or Ron Dennis. There is a lot more competitive advantage to be found by tightening up the loose nut behind the wheel than there is anywhere else in our cars. Bench racing on the internet is great, but when we get in our cars there are just way too many variables behind the wheel for us to come to a certain conclusion that the current setup is flawed deeply enough to tinker with a really successful series.

 

4 - I know people who have decided against racing with other organizations simply because the rules keep changing. It's not that they dislike the new rule or the old rule, but that they don't want to spend the time and money chasing a moving target. Let's not be that series. Stability will bring a lot more fresh meat into the series that tinkering will!

 

5 - There is a matter of intrinsic fairness here. GTS has set the rules. Some guys have done a better job of putting together engine packages than I have. The result is that they have a competitive advantage coming out of corners or at the end of the straight over me. I guess I could be bitter about this because I just don't have the money to spend or the setup expertise to equal their cars. Why would I be though? We were all given the same choices in chassis, engine, suspension, etc. NASA did not issue me a package and say that I must run it. I choose to run a BMW. Maybe I should have chosen a different BMW or a different marque. Nowhere in the rules did NASA promise me that if my car hit the ratio number perfectly (mine does) that I'd have a chance to win nationals. I made my choice and I have to race it. I can always change my mind and race something else. As long as that is the case, I have no right to whine when somebody does a better job of building to the rules.

 

6 - If you want to change rules, start with ones that wont hurt anyone first. Anybody running a sucker fan car yet? Personally, I dont want to run with a fan car throwing boulders at my windshield! (But, those are the rules and if a fan car shows up, I'll just learn to dodge better!)

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dillehayd

It's only an average if your Torque is higher than your RWHP. If not then classing is based on RWHP.

 

My Honda Prelude is gonna DOMINATE GTS1 with 0 RWHP.

 

Just passing through...

 

I propose a new rule: rice may not be used as a fuel in gts.

 

Prelude problem solved.

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911.racer
Guy have and are building cars to the current rules. Guys have and are spending lots of money and time developing packages based on the rules. Major philosophical shifts in the rule - and this would absolutely be one - penalize people who did good work with lost time and increased cost.

 

I fail to see how this would penalize anyone and increase their cost, can you please explain that thought?

 

Simple. Guys who have gone out and spent 10K+ to develop engine packages with intakes, cams, pistons, and headers, and software that produces engines with hp and torque numbers that are very close to each other will have to go back and change that package to find the new sweet spot that produces the fastest weight/power ratio car.

 

Ok,

 

That statement confuses me.

 

So, what are we talking about changing the rule to.

 

The fastest car out there would currently be the one where the torque and hp numbers equal each other per the current rules. Actually, per the current rules, the fastest car would be one where tq and hp are equal and from 5454 all the way up to redline the hp stays perfectly constant.

 

So, the guy who has perfectly developed his car has one that has a razor sharp constat hp from 5454 all the way up to redline.

 

How does any rule change that has been discussed not still make him the king of the tuning.

 

If we look at the tq+hp/2 number in all cases, not just where tq is higher than hp, then this guy is still king of the power and his effective power number does not change.

 

Really, you want a POWER to weight series, then you would take the tq curve, calculate the area under the curve to find it's area, and then that area would become the POWER number. Not some tq OR hp number.

 

To remind everyone Hp is nothing more than a calculation that uses the torque and calculates in RPM. By doing tq+hp/2 you are now averaging the power number since in many cases hp is higher than tq. to say that a car that a car that has a higher hp number but a lower torque number than another car has more power than that car is absolutely incorrect. The car with a higher Hp number has power that comes on higher in the rpm band range than the car with higher torque. That does not necessarily mean he would be the faster car. It could, but the only way we would know is to compare the area under the torque curve.

 

My tow vehicle makes 425 tq and 300 hp. It is a great stump puller. The max POWER is around 2500 rpm far below the magic 5454rpm number where tq and hp equal each other.

 

My vote is still a calculation of the area under the curve, or tq+hp/2 across the board

 

This being said. This needs to be researched and discussed far more widely than just the dozen or so people on this board. It is also a good consideration for next year or the year after. It would be nice to see a rule change like this at least a year in advance.

 

Thanks

 

Ed Baus

233 tq 234 hp. (many $ and dyno hours to get it there)

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scottbm3

It's only an average if your Torque is higher than your WHP. If not then classing is based on WHP.

 

My Honda Prelude is gonna DOMINATE GTS1 with 0 RWHP.

 

Just passing through...

 

Chris,

 

Thanks for pointing that out. It's been fixed....

 

-Scott B.

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B.Watts
Personally I think that TQ should be factored into the equation always.

 

A 200HP car with 199# of torque is going to be faster all things being equal to a 200HP car with 100# of TQ.

 

Why stop there? Might as well take into account gearing ratios and the area under the curve. A car with 199 ft lbs. of torque that peaks only for 50 RPM could very easily be slower than a car with only 180 ft lbs. torque from 2000-7000 RPM. And then we need to take into account the aero advantage of some cars over the other...

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B.Watts
YES...YES...YES Car classifications should be based on industry standards. NO one else, I repeat, No ONE Else classifies on this basis.

 

I am, of course, concerned with my car. With the current classification, I run against ITS and ITR cars with SCCA classification. I have no chance. All I want is a relatively level playing field.. to be able to be competitive in my class. Chuck

 

If someone actually built a GTS2 car that even approached the "limit" of the rules (that's hard to define in an open ruleset), your car and the ITS/ITR cars would be a few seconds too slow to be competitive anyway.

 

Crossover cars from strict rulesets of SCCA, PCA, BMW CCA, etc are very "basic" cars compared to what the rules allow.

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cstreit911

A guy that developed a TQ=HP car is not losing a thing under this. The reality is this, the current formula favors certain engines over others. (edited out comment for poor math)

Edited by Guest

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B.Watts
I'll be more direct, a BMW engine will almost ALWAYS make more TQ than a 911 will. The current forumla penalizes the 911's in favor of the Bimmers, plain and simple.

 

How so? 911's have more displacement to work with than the BMW's for most of the cars I've seen running in GTS. How are these BMW's magically making so much more torque when they have less torque and displacement from the factory and why can't your Porsche guys do the same?

 

1996 BMW M3, 3.2 liters, 240 hp, 236 ft. lbs.

1996 Porsche 911, 3.6 liters, 270 hp, 243 ft. lbs.

 

2006 BMW M3, 3.2 liters, 333 hp, 262 ft. lbs.

2006 Porsche 911, 3.6 liters, 325 hp, 273 ft. lbs.

 

Now, if you're trying to "compare" your 38 year old Porsche to a more modern 10-13 year old BMW, then we may have a problem. It worries me a bit when a GTS Regional Director starts making claims about an open rule set showing an obvious bias to one car over another. There's nothing in the rules keeping you from driving a newer car or placing a more modern engine into your current car. It's a wide open ruleset...what penalty does the 911 have? If you don't make as much torque, you can make less hp and run less weight. Isn't that the entire point of using power/weight to begin with?

 

On this thread, we've learned that BMW's always make more torque than Porsches and on THIS thread, we've learned that Porsches will never be as fast as BMW's in GTS3. It's a wonder that Porsche has ever beat a BMW in any race series...

Edited by Guest

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cstreit911

I speak as a competitor and having built over 40 engines, not as a Series Director.

 

I suppose I opened myself up with a vague statement, "I'll retract that comment your honor.". I understand your points. I did is look at numbers for cars running in GTS rather than internet statistics. I made that statement based on the cars that I have data on. My statement came from a simple mathematical calculation. I leveled out the HP/WGT ratio's for the cars that I have in my lists and then looked at who had more torque for leveled hp/wgt. That was the essence of what I stated there... Disagree, fine. Talk to some engine builders and ask them their opinions and perhaps I'll change my tune.

 

 

EDIT: Just so we're entirely clear, I don't believe that the HP/TQ discussion gives a huge advantage in GTS, things like suspension design, tires, setup, etc.. are much more pertinent. Yes, my 40 year old P-car lacks many of those and still manages to do a fair job with the bimmers. And now with my Series Director hat on, I think the formula should be looked at but Mr. Watts if you knew me you'd know that I'm one of the strongest opponents to changing our simple rules unless there is a VERY compelling reason to do it. ...but you don't know me...

Edited by Guest

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cwbaader

Chris, the main thing everyone is missing is the applied hp or torque to the rear wheels.

 

My motor as an example. BMW 325e. Max rpm 5600, map hp 144, max torque 180. Process hp 162. GEAR RATIO 2.73.

 

Typical 325i makes 170/165, max rpm 7000. GEAR RATIO 4.27

 

Now take that 180 times the 2.73 gear (for this we will assume a 1 to 1 trans ratio) and you come up with 491ft-lbs APPLIED torque.

 

Take the 325i at 165 times the 4.27gear and you have 705ft-lbl APPLIED torque at the rear wheels.

 

None of this was taken into account in averaging hp/torque. Simply put, my 144hp motor (162 process) will never run with a 170hp motor....there is a basic inequity in the assumptive process. People don't seem to realize that low torque motors gain torque through gear ratio, where high torque motors, intrinsically being low rpm motors, loose. Chuck

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cstreit911

Chuck you've put me on my ear there... I don't think you're suggesting that we take gear ratio's into account... ...are you?

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JSG1901

Reference the last four pages of conversation to appreciate why the CURRENT rules are rather brilliant. There are a million things you can do to any of these cars. If we wanted every car to be absolutely evenly-competitive with all the others, we should start a spec series.

 

Unless I'm missing something, that's not what we're looking to do. Read the rule book (it doesn't take long), pick your car, make your mods, try to catch the guys at the front. If you don't like where you end up, re-evaluate the whole system, starting with the nut behind the wheel.

 

No offense intended, but I'm willing to bet nearly all of the cars in GTS have the ability to go several seconds faster than they are--probably to win--with, say, Lewis Hamilton behind the wheel.

 

There's more to it than the size of your pistons.

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cstreit911

Hey, lets not start talking about the size of our pistons okay? Besides rod length is at least as important and piston width when it comes to torque, seriously.

 

So I went back and classified as many cars as I had data on from the last two years and compared the percentage of torque to horsepower. I then cut out any serious statistical outliers and averaged out the TQ/HP numbers. As it turns out once we cut out the outliers the numbers per car manufacturer are suprisingly close. Literally within 1-2% for the cars actually running (non BMW/Porsches having the TQ advantage). I imagine if we classified models we'd probably see a disparity but I don't have enough data to support an analysis on that.

 

I guess the question we'd have to answer to consider this, is there a REAL performance advantage for a car using one formula over another. I'm not sure I can answer that question.

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cwbaader

Chris, no I am not suggesting using gear ratios in the calculation. I am suggesting that the average of torque with horsepower puts the cars with more torque than hp at a disadvantage.

 

Referencing other series (I understand this to be a no no) SCCA, BMW, PBOC, etc. I run cars that have very similar speed capabilities to mine. Only in NASA am I at a distinct disadvantage. Case in point...last Road Atlanta race for NASA I ran basically a 1.44 flat. 944S2 Porsche (an ITS car per SCCA) ran a 142.xxx and even that is slow for a ITS car. (Kip Vansteinberg turned 140.xx at the ARRC in ITS and his car would be a GTS 2 car.)

 

All I am asking for is a level playing field. Averaging hp/torque prevents that. Chuck

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jakermc

1996 BMW M3, 3.2 liters, 240 hp, 236 ft. lbs.

1996 Porsche 911, 3.6 liters, 243 ft. lbs.

 

 

A stock 1996 3.6L VarioRam 911 engine should dyno around 220-230 ft lbs for torque, not as high as you stated. RWHP is in that neighborhood though, I dyno'ed at 246 rwhp. Torque, unfortunately, is much lower.

 

I would not recommend a change to the rules though.

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B.Watts

1996 BMW M3, 3.2 liters, 240 hp, 236 ft. lbs.

1996 Porsche 911, 3.6 liters, 243 ft. lbs.

 

 

A stock 1996 3.6L VarioRam 911 engine should dyno around 220-230 ft lbs for torque, not as high as you stated. RWHP is in that neighborhood though, I dyno'ed at 246 rwhp. Torque, unfortunately, is much lower.

 

I would not recommend a change to the rules though.

 

I'm not quoting dyno numbers...I'm just quoting stock manufacture's listed numbers for the motors. If it dynoes around 230 ft. lbs. at the wheels, it probably has quite a bit more than 243 at the crank. In truth, none of it matters...the rules specifically allow you to modify and tune your motor to make the power curve that YOU want to run and then to adjust your weight for that power. There is no inherent advantage to the BMW over the Porsche when you can clearly do ANYTHING you want to the car to give it the power curve and weight that you want it to have.

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ELEPHANT1

I can never understand why someone who builds a car specifically for one series expects another series to change their rules to accomodate them. GTS is pretty much open and simple and has worked. People build to that or they decide to compromise. If you're compromising then that's your choice. Why should those of us dedicated to the current ruleset be forced to change? It was the same in BMW CR. Seems selfish to me.

 

I guess I don't read the forums enough, is there really a big problem with the rules now?

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cwbaader

Jack, you being in the same class as me is the perfect example of the limitation of the rule set. No mater what series I choose to run (and my car is set up for SCCA ITA) I run comparable cars except NASA. That oversight is based on one rule that requires motors that make more torque than hp must average and multiply by 14.5 to get minimum weight. Please see my previous post for numbers.

 

Yes, I am lobbying for my own benefit. Whatever happens I will continue to run NASA until I can no longer be remotely competitive. HOWEVER, I have no intention of tearing apart a podium SCCA car to meet the minimum hp/weight allowances of NASA. Chuck

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ELEPHANT1
Jack, you being in the same class as me is the perfect example of the limitation of the rule set. No mater what series I choose to run (and my car is set up for SCCA ITA) I run comparable cars except NASA. That oversight is based on one rule that requires motors that make more torque than hp must average and multiply by 14.5 to get minimum weight. Please see my previous post for numbers.

 

Yes, I am lobbying for my own benefit. Whatever happens I will continue to run NASA until I can no longer be remotely competitive. HOWEVER, I have no intention of tearing apart a podium SCCA car to meet the minimum hp/weight allowances of NASA. Chuck

 

Well, I have no doubts that my car is not the best choice for GTS2 as well. But that is my choice. I will do what I can to make it as competitive as I think it needs to be. You are choosing to not make your car competitive, how is that a fault or limitation of the rules? Sorry, I fail to see this. It's an open ruleset and any attempt to limit it by way of someone not wanting to prep their car to a certain level is a horrible idea. Granted, with a reasonable number of mods one car may be better than another but again, how is that a fault of the rules? My car engine costs more to modify than some others, should there be something in the rules which makes the cost of gaining equal power a factor? Of course not.

 

You are asking for the rules to be changed to accomodate a car you built specifically for another series and will not change from that ruleset. Why should those of us dedicated to this series change perfectly fine rules for someone not dedicated to them? If you're running in ITA there is a lot more you could do to make your car competitive in GTS. But you choose not to, that does not dictate a fault in the rules and I don't see why the rest of us should change for that. I don't recall that GTS says it will make all cars competitive.

 

Sorry, I just can't see any validity to this request personally. I think it's just selfish.

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cwbaader

Won't argue about the selfish...what I am asking for is a level playing field. You have a JP car...would you want to run for points against an IP car of the same level of prep? That is the basis for my request... And by the way, my car was optimized for GTS1 before the rule change moving me to GTS2 (It just happened that way when I built the ITA car). Chuck

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ELEPHANT1
Won't argue about the selfish...what I am asking for is a level playing field. You have a JP car...would you want to run for points against an IP car of the same level of prep? That is the basis for my request... And by the way, my car was optimized for GTS1 before the rule change moving me to GTS2 (It just happened that way when I built the ITA car). Chuck

 

It is level. You can do what you want to make your car competitive. If you choose not to then so be it. If I had a JP car and had to run against IP cars directly - and was allowed to by the rules - I'd make my car competitive with an IP car or I'd go somewhere else. Or in your case, I'd focus on running the series that my car is built for and dedicated to. Your car may have been optimized in weight/hp sense but that does not make it an optimized GTS1 car, particularly if it was still a legal ITA car. You are absolutely allowed equal prep, you choose not to take advantage of it.

 

Cheers.

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Michael Dayton
You have a JP car...would you want to run for points against an IP car of the same level of prep? Chuck

 

A JP & IP allow same prep except motor...maximize hp/wgt (add ballast, chip, restricter plate, etc.) and then it's up to the drivers. We all have to tweak our cars some since most of us crossover from other series. Just wait until someone decides to build a car for GTS then none of us will be competitive.

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Damon in STL

Having been through the ITR/JP/GTS2 decision making process last year....I came to one conclusion. If you don't build a car to a specific class and a specific series, you will have to make compromises to all the classes you want to run in.

 

I could have gone ITR...then put cams in to be competitive in JP....but, then I can't run ITR....but, wait....I'm overweight for GTS2...so, I lighten the car. Wait! Now I'm DM! There is no "one car fits all" mold.

 

For me it was a decision based on:

 

1. What organization runs at tracks close to me?

2. What organization has the most competition in my class?

3. What organization(s) do I like to run with?

 

So....I'm now building my car more towards one class for a specific organization....NASA GTS2. And, yes, I'll be way out classed for DM with the CCA. But, that is the choice "I" am making.

 

Damon in STL

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