Jump to content
JSG1901

2015 GTS Rules changes

Recommended Posts

Cobra4B

Rather than have a highly-regulated points system like the ones used to assess modifications in NASA’s PT and ST classes

Hey... don't lump ST in with PT for having "high-regulated points systems". That's just not the case. ST is quite simple at power/weight with a few modifiers for tires and some specific tube-chassis cars.

Share this post


Link to post
Share on other sites
Michael G.

Jerry,

 

I can only tell you that all of the RDs recognize and respect the value and the spirit of the open rules format and no one is trying to convert it to the spec series. Don't take it as an indication for future restrictions or slippery slope. After long discussions and considerations we simply agreed that considering the values of the average HP is better representing the true parameters of the car than the peak HP. I am sure people will try to maximize the new rule as well as they did before, but we still committed to trying.

 

Michael G.

NE GTS Dir.

Share this post


Link to post
Share on other sites
cstreit911

Folks I think many of you are distorting the intent of this.

 

The idea is not to penalize one curve or the other, one car or the other, but to better represent the acceleration of a car in GTS. After all the entire idea of power to weight is to represent the acceleration capabilities of the car. That is, at its heart, the intent of the current calculation.

 

I don't think that anyone would disagree that that current calculation is flawed as so many have woefully or gleefully pointed out over the years. Is there any arguement that a car having 300 peak HP over a 500rpm band will not accelerate as well as a car with 300 HP over a 3000 RPM band?

 

So with that in mind, a formula which better represents a cars acceleration capabilities is a more accurate application of the spirit of GTS.... ...which is to provide a racing showcase for cars that are classed based on a few simple factors such as tire choice and power to weight. This has not changed.

Share this post


Link to post
Share on other sites
J Smith

So where is the actual data that supports a "detuned" car with a "flat" dyno curve accelerates faster than a car with a peak hp that only happens at redline. Apparently the difference is "enormous", even though anyone I know has yet to see that actually happen on the race track.

Share this post


Link to post
Share on other sites
mjmccoy

GTS was very simple in principle. Weight vs HP. Peak HP.

That is all that really defines the maximum potential of the car.

Optimizing total power has always been a goal in racing. Changing the rules a little won't change the goals of making the fastest car possible for the class.

The open-ness of the class has lead to diverse approaches in aerodynamics, suspension, and engine tuning. I don't see any reason to try to quell any of that creativity.

 

Much like limiting detuning wouldn't help, averaging selected points won't help either, IMO. Making a "total power" number that is the integral across the entire power band might help, but then we have the option of severely detuning the unused power band to lower that total number. Again, the more the rules change, the more they favor the flexible.

 

Limiting detuning was brought up before as well. That would only mean that I can't get rid of X hp, and thus will tune the power band (but flatten, and not increase the peak), and then need to reduce weight by the target amount. This could mean I now need carbon hood, trunk, doors, fenders, and to spend dozens of hours with a dimple die and an air body saw. In cases like this, *just* detuning would have been a substantially more cost effective approach that will ultimately yield a very similar result class/performance wise.

 

Since the GTS2 issue was brought up again, we should also clarify in the rules that GTS is a weight to power class. This means compliance is based on weight, and horsepower. (peak horsepower in 2014.) Compliance should thus be determined based on weight, and horsepower. Not by comparing cars to other cars "in class". To do so would be saying that the "reference" car is as fully optimized in every way possible, and driven to the limits, which will never be the case in club racing. When using data, it should be used, mathematically, to validate the weight... and the horsepower. Nothing more, especially in such an open class with so many variations on the "theme".

With that said, I am still a bit appalled that a car was disqualified in the fashion it was. Moreover, that car did not exhibit the highest weight/power ratio per the data, as it did not have the highest peak acceleration rate, points to either misunderstanding of the principles at play, or a purely political decision not based on fact. To me, and a few others, this is a more alarming issue than the possible disparity between those who built their car to the limits of the class and those who didn't.

 

This change is heading in a possibly positive direction if the goal is parity in the field. The methods for calculating will be a lot more complicated though, and that also opens up the issue of possible technical infractions. No longer does the racer need to only worry about the peak number vs weight. They need to do on-the-fly math to validate the required weight, and there is always the worry about some minor change.

Find a leaking HG, pull the head, put it back together, get the cam timing close, but not quite right, lose peak HP, but gained some down low, and now your total power number is off, and possibly high? This is now a concern for the restrictor plate people. Get the intake cam too advanced and you gain where you shouldn't. Too retarded and you lose everywhere because top end gains are fighting the restrictor plate.

 

The car with more total power should always be faster... as long as that total power is in the used power band....

 

To me, the easier fix is to mandate a plug in the car that has TPS and RPM present. Something the NASA compliance loggers can plug in to quickly and easily. RPM gives us the ability to calculate power.

 

Ideally though, the human factor would be removed. Compliance should be a simple pass/fail, without need for interpretation, special glasses, or decoder rings.

Share this post


Link to post
Share on other sites
JVR127

Not a fan of the new rule, I think it complicates things and I think that at the end of the day the end result will be the same... As far as detune cars having an massive advantage I have to disagree, when I ran my E36 with an S52 in GTS3 the only disadvantage I felt I had vs the E46's was grip level that's it, I never had any of those cars walk away from me from mere acceleration so in my opinion this is just a waste. I've had more problem passing the "back markers" cause the pulled me every single time, no one ever checks or dynos the guys on the back and I can assure you they make more HP than the front runners. I think if people focused more on making their car work and handle properly we wouldn't be having this discussion.

Share this post


Link to post
Share on other sites
Alan_Wolfe
This is switching GTS from a "peak power to weight" class over to an "average power to weight" class. One can either agree with that change or not. I think it's a good change. But then I haven't spent kilobucks on a detuned S65! It's a bummer for those people who have made the investment - they're just going to have to drive it harder

 

The proposed scheme for implementing "average power to weight" seems pretty good and sufficiently simple. I think the "every 1000 RPM" thing should be made more fine-grained. That's only like 3 data points - having to type in 5 or 10 numbers is not too onerous.

 

The detuned engines will still have some advantage - it's better to make your max power over a 5000RPM band than over a 2500RPM band. But the advantage is less.

 

My thoughts exactly, so I quoted them instead of typing them out again.

 

Any rule which equalizes cars makes GTS more of a driver's series. That's great!

Share this post


Link to post
Share on other sites
braknl8

Wow.....this is going as smoothly as the demise of PTA/TTA.

Share this post


Link to post
Share on other sites
hamflex

So maybe I missed this or no one has made mention....

 

30% if my power band will be the determining factor while my TQ level is unrestricted?

Share this post


Link to post
Share on other sites
hamflex

So maybe I missed this or no one has made mention....

 

30% if my power band will be the determining factor while my TQ level is unrestricted?

Share this post


Link to post
Share on other sites
911.racer

I am in support of the rule change. I have always felt that 'area under the Hp curve' is where we need to measure power. There are always going to be loop holes and people trying to exploit those loop holes. One would hope that most of the racers just want good, clean, fair, racing.

 

As one person pointed out, they felt that they actually had more power with a normal tune with a normal peak Hp rather than a flat line tune. It may come out that this would be the best tune for the fastest lap. Who knows.

 

Thanks

 

Ed

Share this post


Link to post
Share on other sites
cstreit911
However, the goal of this rule is to stop people using 2-15 year old BMW V8 engines because they have a torque curve advantage.

 

...the goal of the rule is to fairly represent the true power/acceleration of a car rather than an inaccurate calculation. It does not target a car, engine, or class. ...or are you stating that peak horsepower (in the current formula) is the most accurate representation of the acceleration capabilitites of the car? If so, please document how so we can better understand.

 

 

So where is the actual data that supports a "detuned" car with a "flat" dyno curve accelerates faster than a car with a peak hp that only happens at redline. Apparently the difference is "enormous", even though anyone I know has yet to see that actually happen on the race track.

 

Are you saying that all these tuners are just selling a bill of goods? Why are teams doing this then?

Share this post


Link to post
Share on other sites
Grifkylian
When I ran my E36 with an S52 in GTS3 the only disadvantage I felt I had vs the E46's was grip level that's it, I never had any of those cars walk away from me from mere acceleration

 

I can vouch for this. The bigger tire does allow the car to do things you wouldn't normally be able to. Yes, suspension setups have a major effect on the car's performance, as well as the nut behind the wheel but as far as grip goes, you cannot do the same things. I agree that it will give some boost to older cars or cars without detunes, but I don't think that's the answer.

 

Look at some GTS cars at Hyperfest at Summit Point (not mentioning names but you can probably think of some). You will see the in-car vids of E36's in GTS3 being dead even in the straights with E46 M3's and even coming out of some of the turns at the same speeds... but entering the twisty bits (such as the turn 3 and the turn 4 down curve right hander), you can clearly see that there is an advantage with the tires (and possibly the chassis and aero work). An E36 with 245 tires may not be able to stay stuck to the pavement the same way an E46 M3 with 275's would... it all depends on the driver of course, but I am guessing that the E36 would get out of shape far quicker than the E46 would if strung out in the turns. Having detuned, "flat" power curve cars carrying more weight may help close the gap, as tires can only do so much until they lose grip. I don't feel that the new rule is targeting detuned car drivers as the "bad guys" necessarily, but using these average hp calculations will allow more weight to be added to slow what is really helping cars go quicker in the turns. THE TIRES. As we know, NASA isn't about turning left and going in circles and isn't about straight drag racing. It's road racing It's a complicated matter to implement these new rules but hopefully it will be executed in a professional manner.

 

I would've thought to have a ballast added for the width of the tires to make the whole transition more simple for everyone, but hey, I'm not in charge.

 

-G

Share this post


Link to post
Share on other sites
Michael G.

Griffin,

 

I understand your point, but remember that the core principle GTS based on is power to weight. We are not trying to equalize the grip levels or the downforce limits. We are not looking at the brakes or gearing. Ballasting tire width becomes very difficult for number of reasons - primarily the variety of set ups in different platforms, especially once you start looking into staggered 911s, all wheel driven Audis... Mo question some newer chassis are better developed and have better starting point, but again, we never intended to equalize across the board.

Regarding the proposed change - again, we simply agreed that reading averages with in usable band is better representing power than the peak value. It is not about GTS2 or 3, and it is not about E36 vs E46 or BMW vs P cars.

The question is how to fine tune the calculator.

 

Michael G.

NE GTS Dir.

Share this post


Link to post
Share on other sites
7VO-VOM
However, the goal of this rule is to stop people using 2-15 year old BMW V8 engines because they have a torque curve advantage.

 

...the goal of the rule is to fairly represent the true power/acceleration of a car rather than an inaccurate calculation. It does not target a car, engine, or class. ...or are you stating that peak horsepower (in the current formula) is the most accurate representation of the acceleration capabilitites of the car? If so, please document how so we can better understand.

It is to target people detuning. The biggest complaints are about S54s, S62s, and S65s, not the new Porsches, so I guess I could have said 2-15 year old BMW M engines. Since the S54 guys are also complaining about the S62 and S65 swaps, we're back to this rule being about the V8s (it's all about the 8's, no turbos). You as much as admitted that when you called me out for being against the rule because my car will have a V8.

 

You are correct, area under the curve is probably the most accurate estimate without testing the actual car on track. The current peak HP is not. The best system would be figure out the fastest straight and the slowest corner a GTS car will go through, then run through the gears over that speed range, and measure the area under the curve (skipping the time spent shifting). Arbitrarily saying the area under the curve in 30% of the rev range is not an improvement. Why not 10%, 20%, or 40%? Maybe a change should be made, but this is not it.

Share this post


Link to post
Share on other sites
J Smith
...Any rule which equalizes cars makes GTS more of a driver's series. That's great!

And there's my rub. If you want a "driver's series", there are plenty of Spec classes out there that are very strict about what you can and cannot do to the car. It places everyone out there in race cars that are similar in every way. GTS is not that kind of series. You want $15K dampers? Totally allowed. How about a $12K custom geared transmission just to get the most out of the engine you picked/built for your car? Yep, that's allowed too. Want to spend $30K on a true race sequential with close ratio gears? (and take the tiny .2 penalty, I guarantee you it's worth it) No problem...absolutely legal. Show up with a full blown DTM car? Have fun in GTS, because that's legal too. But detune your engine? Now you're getting penalized. Makes no sense.

 

 

...As one person pointed out, they felt that they actually had more power with a normal tune with a normal peak Hp rather than a flat line tune. It may come out that this would be the best tune for the fastest lap. Who knows.

Exactly! No one knows! So why the rush to implement this before any kind of testing/actual data gathering has taken place?

 

 

[Are you saying that all these tuners are just selling a bill of goods? Why are teams doing this then?

"All these tuners"? Lol. Sure there are a few guys out there that can detune a BMW, but everyone knows there is one guy who is the best at it who does 95% of the GTS BMW detunes. This penalty is aimed directly at those customers. And guess what? Not all of Randy's customers are winning every weekend. There are plenty out there who haven't seen the podium yet. Wonder why that is? Could there be other factors involved in winning races besides this "unfair but legal" advantage of detuning?

Why are teams doing this? I tell you why I did. First, because the open rule set allows (allowed?) us to. To he honest, I was hoping I'd see a noticeable difference in acceleration between my new car in GTS3 trim and other GTS3 cars that aren't detuned as much or at all. Truth of the matter is that, I see absolutely no difference. So the advantage on paper is not there on the track. Second reason for detuning is engine longevity. There is no doubt that detuning reduces the stress and strain on an engine. Who wouldn't want that? Engines and rebuilds are expensive. In GTS, I'd rather spend my money elsewhere on the car where is actually makes a real performance difference (aero, suspension, brakes).

Share this post


Link to post
Share on other sites
hamflex

Im not opposed to change especially if it increases car count, but as mentioned..... has this been tested?

 

For example, the national gts2 fiasco happened based on a new system used to monitor the cars and at the track their system failed. Sure it looked great and they deemed he won by shifting really fast and super wheel bearings or something ridiculous. When I asked my director about the system he said it had been tested but I arose the question, was it tested on a known car that was cheating to see beyond doubt that yes this system works.

 

I mention this because the level of testing was not there and it potentially is not here. Is there any plan put in place to revert back to what once was if this goes to hell and people stop racing, will the inventors of this system admit failure in this case? Or would this system stay in place through out the entire 2015 season potentially hurting the series more then if it had just stayed as is.

Share this post


Link to post
Share on other sites
JVR127

Like Josh said... Just because you have a detuned car it doesn't mean you are gonna win... Guys that are complaining about this should spend the time to develop the cars. Just because you buy the same shocks the guys up front have doesn't mean you will be going just as fast as them. I know guys that have the same or better equipment than the guys up front and can't close the gap and think that the front runners are cheating. If this rule is aimed at helping other brands get to the front it will still not work unless they have a purpose built GTS car, if they plan to run for example some GTS events and some PCA events that car will NOT be a front running car in GTS, those days are over.

 

 

I also think that this rule should have been brought up for discussion, at the end of the day we are customers and we should have a saying/vote on this. Without us what would you have?

Share this post


Link to post
Share on other sites
Brad Waite

I have a lot of respect for what Josh has said. He's one of the best racers I know and certainly gets the most out of his car in all respects, tune, setup, driver skill etc. If he is right, that a detune provides no competitive advantage, then I don't think we have any controversy. If the only reason to detune is to increase engine longevity, then this rule doesn't change that. Tune your car to an average hp you want to run to maximize both your wt/hp ratio and achieve your desired engine longevity goals and we're all good. Everyone is running on average hp, so no one is at a disadvantage. Not sure what I'm missing here.

Share this post


Link to post
Share on other sites
ILIKETODRIVE
...Any rule which equalizes cars makes GTS more of a driver's series. That's great!

And there's my rub. If you want a "driver's series", there are plenty of Spec classes out there that are very strict about what you can and cannot do to the car. It places everyone out there in race cars that are similar in every way. GTS is not that kind of series.

BINGO!

 

As someone who has raced Honda Challenge, I can offer up this: Spec classes are a drivers series, GTS/HC/AI/etc are a builders series. I know for a fact that's exactly why Honda Challenge started.

Share this post


Link to post
Share on other sites
peterc
...Any rule which equalizes cars makes GTS more of a driver's series. That's great!

And there's my rub. If you want a "driver's series", there are plenty of Spec classes out there that are very strict about what you can and cannot do to the car. It places everyone out there in race cars that are similar in every way. GTS is not that kind of series........

 

THIS!!!

Share this post


Link to post
Share on other sites
Michael G.

Josh,

 

You are absolutely right about what makes it win and what makes GTS fun. I just wanted to remind that in the history of GTS we had few times when the formula of calculating power was changed. Initially it was only peak HP. Once we changed to peak HP + peak TQ/2 for the cars with TQ>HP, many folks screamed that this was an attack against Turbo cars, and many tuners made sure not to exceed TQ values over HP. But many others argued and still do that this is not a correct way of calculating power. The discussion was always there and unlikely to go away.

I can simply say that we consulted with many experts and the majority of opinions agrees that taking the averages under the curve is a better way to calculate power relevant to capabilities of the car.

Once you will see the calculator - it will be clear that the numbers will not change much at all, considering the adjustment in ratios.

I am sure we will continue to have discussions and may need to modify the formula more than once in the future if the data will support it.

 

Hamflex,

 

I hope you aware that the "fast shifting" guy was DQ'd later, based on the analysis of the data from the Black Box in his car. So the technology does help at times.

 

Many argue that measuring acceleration with data recorders is a better way to judge and we may arrive to that point sometimes in the future, and will need to change formula again, who knows, time will tell...

 

Michael G.

NE GTS Dir.

Share this post


Link to post
Share on other sites
mjmccoy

What is the end goal of these changes to how power is calculated?

How will this be policed? (now we not only need to repeat the peak value, we need to repeat a part of the curve.) For those who are running restrictor plates, be careful with your cam timing if you need to replace a bad VANOS unit at the track. The restrictor plate may keep the peak power number capped where it is, but a little too much advance on the intake cam and you might bump some area below that and skew the total power number.

 

Who are you trying to appease with the rule changes?

 

Total power is a better measure of how fast a car should be. it is not an absolute though.

 

I think a bigger problem is in proper compliance checking.

That also applies to the new tire rule. How do you verify chain of custody on a tire? I buy 8 tires from tirerack. they show up at my door. I put them on the car. I show up at the track. someone protests. Now what?

For the power rule, since the GTS2 thing from nationals has been brought up a number of times, what is being done to make sure that doesn't happen again?

From what I can tell, this is a weight/power class, but was not enforced as such. It was enforced not by calculating the power of the car in question, but by comparing it to other cars. Doing that tells us that you have KNOWN cars that are 100% optimized in every way possible for the class, and nothing could ever be faster, ever. Yet, at the start of this thread it was discussed just how much of a difference optimizing the powerband can make in comparison between LEGAL cars for the same class. So, I'm confused as to how we are where we are.

Share this post


Link to post
Share on other sites
hamflex
Josh,

 

Hamflex,

 

I hope you aware that the "fast shifting" guy was DQ'd later, based on the analysis of the data from the Black Box in his car. So the technology does help at times.

 

Many argue that measuring acceleration with data recorders is a better way to judge and we may arrive to that point sometimes in the future, and will need to change formula again, who knows, time will tell...

 

Michael G.

NE GTS Dir.

 

Yes I know he was DQ'd at a later date but, all I was pointing out is that certain methods of testing and regulating should be thoroughly tested before implemented. When its all said and done I hope it makes the class stronger and increases car counts!

Share this post


Link to post
Share on other sites
J Smith
Josh,

 

You are absolutely right about what makes it win and what makes GTS fun. I just wanted to remind that in the history of GTS we had few times when the formula of calculating power was changed. Initially it was only peak HP. Once we changed to peak HP + peak TQ/2 for the cars with TQ>HP, many folks screamed that this was an attack against Turbo cars, and many tuners made sure not to exceed TQ values over HP. But many others argued and still do that this is not a correct way of calculating power. The discussion was always there and unlikely to go away.

I can simply say that we consulted with many experts and the majority of opinions agrees that taking the averages under the curve is a better way to calculate power relevant to capabilities of the car.

Once you will see the calculator - it will be clear that the numbers will not change much at all, considering the adjustment in ratios.

I am sure we will continue to have discussions and may need to modify the formula more than once in the future if the data will support it.

 

Hamflex,

 

I hope you aware that the "fast shifting" guy was DQ'd later, based on the analysis of the data from the Black Box in his car. So the technology does help at times.

 

Many argue that measuring acceleration with data recorders is a better way to judge and we may arrive to that point sometimes in the future, and will need to change formula again, who knows, time will tell...

 

Michael G.

NE GTS Dir.

 

So, you consulted "experts" and came to the conclusion that this is the best thing for GTS? No discussion period allowed for the racers to take part in? Because this rule change was certainly not in topics up for discussion a few weeks ago.

 

And you say that discussions will continue and most likely the formula/calculator will change in the future if data supports it? So I ask again...where is the "data" that supports this proposed change? Show me. Prove your point. It's data right? Should be black and white.

 

And I keep hearing that this will be a minor weight adjustment for most. Well, I'll believe it when I see it. So where is this calculator? Having that accessible to racers before this rule is actually in place may be a smart thing to do so we can discuss how it affects us differently and discuss its "fairness". Because from what I understand, I'll be adding quite a bit of weight to my car to penalize an advantage that I don't think exists and that no one can actually prove exists with actual data.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...