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JSG1901

2015 GTS Rules changes

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7VO-VOM
So, how about a third option. One that would be 30% or 2000 min. That way you would have 2000 if the car had a redline under 6700 rpm, but would be measured on the 30% scale if it had over 6700 rpm ?
You would see a lot more turbo diesels. Tune it for GTS2 average numbers over 2000 rpms with GTS4 power in the 500-1000rpm actually used.

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JSG1901

So, gentlemen (I presume you're both male...and both gentlemen, for that matter), this is a much more productive conversation. Thank you for that.

 

Before I answer your questions, though, I do have one request. There are a lot of people involved in this thread, including yourselves, whose signatures do not include their names. I would consider it a big favor if everyone weighing in would add their names so we all know who we're talking to.

 

As to the question of why we settled on 30% of the powerband as the area to measure, that would be based on my influence. While I will grant you that folks can build crazy gearboxes with incredibly short gears, most of us are using more or less stock transmissions. Researching those transmissions--primarily those from BMW and Porsche as those two marques constitute virtually all of our racers--I found that the average drop in RPM from a redline shift, in the gears that cover the range from 50 to 150 mph (the range in which we race), varies from about 25% to 40% and that, usually, the bigger drops are from the higher revving cars.

 

That's why I'm not wild about the idea of a fixed-size RPM band. On an 8500 RPM engine, 2000 RPM is a lot less than it is on one that peaks out at 6200.

 

In a perfect world, we'd know your specific car's gearing and make up a special percentage just for you--which would get around the very narrow gearbox issue--but that seems way too onerous to me.

 

Given that, if you accept the premise that a big wide band of horsepower is more advantageous than a tall narrow peaky one, as I do, then you have to find a balance of what to measure. If you measure a very narrow sliver--5%, let's say--of the peak power, pretty much all cars are going to look about the same. Functionally, that's pretty much what we have today.

 

Go to the opposite extreme and measure 50% of the powerband and you'll find that the peaky cars have averages that are incredibly low in comparison to those with the wider power curves. But given what we know about gearing (above) and what we all know about how you actually drive on a race track--in other words, that you keep the revs high pretty much all the time--measuring deep down into the powerband isn't representative of the reality on the track, which is what we should care about. You don't drop down to 50% of redline on the track (or if you do, you have bigger problems to deal with).

 

So, after spending countless hours playing with models and numbers, I came to the conclusion that something around 30% was a fair compromise. It's within the RPM drop from redline for most cars--so it's realistic in that regard--yet it's also wide enough to pick up some of the differentiation between power curves.

 

So, that's the logic that got us to 30%.

 

Personally, I have no particular objection to Ed's suggestion of the greater of 30% or 2000 RPM, but the biggest beneficiaries of that will be the cars with the lowest redlines because they will be measured over a wider (as a percentage) band, which will naturally give them a lower average horsepower value.

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7VO-VOM
As to the question of why we settled on 30% of the powerband as the area to measure, that would be based on my influence. While I will grant you that folks can build crazy gearboxes with incredibly short gears, most of us are using more or less stock transmissions. Researching those transmissions--primarily those from BMW and Porsche as those two marques constitute virtually all of our racers--I found that the average drop in RPM from a redline shift, in the gears that cover the range from 50 to 150 mph (the range in which we race), varies from about 25% to 40% and that, usually, the bigger drops are from the higher revving cars.
The two factory trannies I am looking at have drops mostly in the 15-20% range. The more modern cars that you are trying to penalize are the cars with more and closer gears that allow them to get around the rule.
In a perfect world, we'd know your specific car's gearing and make up a special percentage just for you--which would get around the very narrow gearbox issue--but that seems way too onerous to me.
I think you would see mass exodus and/or a lot of hidden part swapping if that was even suggested. ST fields would grow drastically or somebody would create an European Touring Series off the old GTS rules.
Given that, if you accept the premise that a big wide band of horsepower is more advantageous than a tall narrow peaky one, as I do, then you have to find a balance of what to measure. If you measure a very narrow sliver--5%, let's say--of the peak power, pretty much all cars are going to look about the same. Functionally, that's pretty much what we have today.
Without a narrow sliver, there is way too much room for people to take advantage of the rules. With a narrow sliver, you eliminate people bending the rule, but we're not far off from what we have.

 

That brings us back to the 2014 rule being far more fair and far easier to administer than the proposed 30% average. Does the 2014 rule measure acceleration/power as well, probably no. Is it fair and equal across all cars no matter how they are setup, yes. Is it fair to the drivers and builders who were expecting complete and final rules 4 days ago, yes.

 

To the points Josh has been making, has anybody tested to see how much advantage a flat detune has over a standard/stock tune? I know it has been claimed that driver skill and car setup make that impossible. magnetic1 has a fleet of E46 M3s, including his detuned race car. Put a couple cars on a load capable dyno, do some 50-150 runs through the gears in each car, and see how the data looks.

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mjmccoy

I suspect my previous comments have been buried. My concerns with the revised rules are numerous. The change in landscape this will present is one facet, but I think my bigger concern at the moment is in the "enforcement" side of things.

 

This thread started with three rules changes proposed.

The gearbox ones is somewhat trivial. Easy to check/enforce. Premise behind it being "it makes the car faster" seems simple enough too.

So we have "has good reason" and "enforceable".Reasonable combination for a rule.

 

Next we have "All tires, whether DOT-approved or not, must be commonly available to all competitors from typical national retailers (for instance, Tire Rack), or directly from their respective manufacturers. This is to be interpreted to mean that special compounds not generally available to all competitors are not permitted."

Ok. seems like a decent enough rule at face value. Everyone should have equal access to the tires on which we compete. But how is this enforced? If Goodyear is playing with compounds on a tire in an existing mold, how/where do they mark that? Is it even marked in a discernible way? or just a change in digit on a "product code" laser etched inside the tire or some such?

more importantly, how does one defend against a claim of this?

 

Lets say I order a set of goodyear tires from TireRack. They show up at my house already mounted to new wheels. I put them on my car. I arrive at the track. For some reason or another I show up at a race track for a race and I go fast. I get protested for having "special tires". Maybe I have a friend that works for Goodyear. Maybe my aunts neighbors cousin works for Goodyear. Maybe my wife works for goodyear. Maybe *I* work for goodyear. Maybe I don't work for goodyear or know anyone who does. Now what? The tires impounded? A sample taken and sent to the manufacturer for testing? We start bringing scales, a dyno, *and* a GC to the track?

I don't see how this can be cleanly enforced.

 

Now on to the new rule for classing.

well, we've seen all the commotion of the classing method itself....

How is this enforced though? How do we know the car makes what it is stated to make? This has been a problem in the past apparently, and that was also not handled appropriately.

We've now discussed how cars in a class (legally in that class) can have very different approaches to power delivery, gearing, etc. This means that cars at the top of a class can have very different acceleration profiles... legally.

We have had attempts at compliance checking in the past with data, but didn't look at data as just data. it was compared between cars. We have very clearly established that massively different results can be had from cars in the same class legally. If the classing is now some average power figure, doesn't that further complicate things?

Before, we had a "peak" hp number that was "known". we also had weight. We also, by knowing most of the cars in play, had gearbox ratios as likely knowns. We can make assumptions on diff ratio, and tire size is also easily "known". We could easily calculate the maximum peak acceleration we should see at a specific speed/gear... but we didn't. We compared cars A, B, and C, who were varying levels of "different".

 

Now we will have the same problem, but with a "fuzzy" number for power.

 

I see a need for proper procedures for these rules. All of them.

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scottbm3

Just had them run the numbers using my current Dyno sheet and with the proposed "new formula" with higher weight ratio's(Which I didn't even see reading through it the first 5 times) for the classes and I will have to add another 120 lbs just to make min weight for GTS3 at the end of the race. Starting weight would be much higher. That's not counting a fudge factor for impound at the dyno. That's a pretty big penalty considering I've done nothing else to my car. I already carry aprox. 80lbs of ballast and adding another 120+ pounds will be a pain not to mention completely change the setup on my car and a safety factor. This might be ok if it was known it was coming for a while and giving everyone time to do the things they need to do to their cars to comply, but to have it just tossed on us at the last second is unfair to many racers no matter what make car you're running. That's my .02

 

 

 

-Scott B.

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cash7c3
Beginning at the bottom of the known rev range, it adds up the first 22 consecutive values and saves that total as the current-highest-horsepower value. Then, it starts over at the next-to-lowest increment and adds up 22 consecutive values, then compares that to the previous high hp to see if the new number is larger. If so, it replaces the current-highest-horsepower value with the new value. If not, it leaves it alone.

 

Thanks for further explaining the algorithm. Sounds good, that solves any issues with easily taking advantage of the new rule.

 

Only way to really maximize it is to spend (relatively) large amounts of cash to rev high and have the perfect ratios, if no one ever does then the rule change isn't a big deal, if people do then maybe it wasn't a great move but time will tell.

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braknl8

 

Only way to really maximize it is to spend (relatively) large amounts of cash to rev high and have the perfect ratios, if no one ever does then the rule change isn't a big deal, if people do then maybe it wasn't a great move but time will tell.

 

 

Racers want to win, be guaranteed that it will happen. Not nearly enough do but there are a few in each series that will always push the limits of the rules, and have the resources to do so. It's a snowball effect that leads to a runaway $$ train, if allowed...

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JVR127
Just had them run the numbers using my current Dyno sheet and with the proposed "new formula" with higher weight ratio's(Which I didn't even see reading through it the first 5 times) for the classes and I will have to add another 120 lbs just to make min weight for GTS3 at the end of the race. Starting weight would be much higher. That's not counting a fudge factor for impound at the dyno. That's a pretty big penalty considering I've done nothing else to my car. I already carry aprox. 80lbs of ballast and adding another 120+ pounds will be a pain not to mention completely change the setup on my car and a safety factor. This might be ok if it was known it was coming for a while and giving everyone time to do the things they need to do to their cars to comply, but to have it just tossed on us at the last second is unfair to many racers no matter what make car you're running. That's my .02

 

 

 

 

 

-Scott B.

 

Scotty you won't be the only one penalized... Some how this is "supposed" be better. You will see cars lose tons of weight while the rest get heavier. Or you can retune your car which means spending money, if you don't then you will spend more money because your car is heavier.

 

Great job guys! Watch the series desolve now.

 

Didn't Andrew Say that no one will have to add weight?

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I'm sorry, I can not believe that a 996 or 997 cup car has a box and diff requiring more than 2000 rpm to race.

 

The first look online I grabbed for a six speed from a 997 was:

 

3.91

2.32

1.61

1.28

1.08

0.88

 

Using a 3.91 diff for that shows exactly 2000 rpm gap for 3rd to 4th if redline is 8K or 9K, and from 5-6 its only 1500.

So we are all in the same ball park here.

 

Show me a cup car with gears, diff included where you need another 1000 rpm to drive in.

 

Now, as to how this all pans out for low rpm cars? Again, people are ignoring the basics.

 

In rough numbers, say you have a 5000 rpm redline car.

If you plan on racing, and need to hit 160-170 mph tops, you going to have to gear it a certain way....

 

again, using the most common gearbox which all pretty much have a 1:1 gear near, or just below the top, it looks to me like you'll need a diff around 2.9 or so to get high speeds.

 

Guess what?

 

This puts your used rpm range around 1700 or so at the high end, also reasonable to use my suggestion of 2000 rpm as a range.

 

Nobody needs the 30%, its too large a number, and invites manipulation. (To say nothing about the obvious here...almost any engine can survive a couple dyno runs to well above the shift point we might use, so people will run their engines up to high rpm for the dyno to prove a high redline, but then only drive in a narrow portion, the high power portion, of the 30% graded area)

 

Maybe my spreadsheets are off, and only work for BMWs

Edited by Guest

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ILIKETODRIVE

Using an online calculator at 8K and 275/35R18 (and lazy math rounding):

1-2 ~ 3250 drop

2-3 ~ 2450

3-4 ~ 1650

4-5 ~ 1400

5-6 ~ 1500

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scottbm3
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.

 

Nope, nobody will need to add weight or reduce power because of this change. Because an average cannot exceed the peak.

 

People will be able to remove weight and/or add power because of this change - cars with peaky power curves.

 

Andrew,

 

You are wrong. What you didn't figure is that they're also going to change the HP/Wt ratio's for each class. I just ran the numbers from my dyno sheet using their new guidelines and without doing a single thing to my car to be able to run in GTS3 as I have since day one, I will have to add a minimum of 120lbs more ballast to my already heavy car to run it just as I did a few months ago even though my average HP is now almost 5 HP less. So I'll either need to spend a bunch of money for a new tune/dyno time etc or run a already heavy car, even heavier, or........ST3. It makes no sense to me....

 

 

 

-Scott B.

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JVR127
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.

 

Nope, nobody will need to add weight or reduce power because of this change. Because an average cannot exceed the peak.

 

People will be able to remove weight and/or add power because of this change - cars with peaky power curves.

 

Andrew,

 

You are wrong. What you didn't figure is that they're also going to change the HP/Wt ratio's for each class. I just ran the numbers from my dyno sheet using their new guidelines and without doing a single thing to my car to be able to run in GTS3 as I have since day one, I will have to add a minimum of 120lbs more ballast to my already heavy car to run it just as I did a few months ago even though my average HP is now almost 5 HP less. So I'll either need to spend a bunch of money for a new tune/dyno time etc or run a already heavy car, even heavier, or........ST3. It makes no sense to me....

 

 

 

-Scott B.

 

 

Scott B... I know of plenty of GTS drivers ready to jump ship to ST3...

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flink

Andrew,

 

You are wrong. What you didn't figure is that they're also going to change the HP/Wt ratio's for each class.

 

Yep, sorry, I missed that part. It does make a 2015 rollout more problematic. Saying "hey, you can remove weight if you want" is not a big deal. Saying "if you don't add weight you're DQ'ed" is more severe.

 

Oh well, at least I can stop looking at 5lb alternators.

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mlwbcolorado

Where is the new HP/WT for each class posted? I could not find it.

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scottbm3
Where is the new HP/WT for each class posted? I could not find it.

 

 

It's not posted yet, as they don't have a completed rule yet.... I wanted to see where I stood with my current dyno sheet and sent my info to the director and he did the calculation and sent me back the info. That's how I discovered the change in the class HP/Wt classing numbers, surprise !!

 

 

 

-Scott B.

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RockyRoad1

Made it through all 14 pages...

 

1. I find it laughable that the people yelling about investing "all this time, money, and effort" into tuning their cars will turn right around and claim there is no advantage to it. Then at least one of you goes on about how smart you are. You probably are, but you clearly assume everyone else here is dumb. ...because you expect them to believe that you'll all invest thousands of dollars on these solutions that provide no benefit to you. If there is no benefit to the flat curve, then dispense with it. Sell it. Problem solved. There I just did you a favor.

 

2. You absolutely cannot tell me that A car that makes 300 HP at 5000, 6000, and 7000 RPM is not going to out accelerate a car that makes 120, 250, and 300 HP over the same RPM. For 70% of the operating rev range you have 2-3 times the horsepower. To suggest that having 2-3x the horsepower of the other cars for 70% of your operating rev range is no advantage is not just silly, it's so transparent and obvious that you should be sent to bed without your dinner.

 

3. Despite claiming there is "no advantage" you all have run out and done this... ...and are *freaking out* that you might lose this *not an advantage*

 

Tell me again how all of you sent your money to TRW, Epic, etc.. who likely spent tens of thousands of development costs on these chips for "no advantage". Really?

 

Not a single person here has claimed that the previous formula was accurate.. ...yet you're willing to take your ball and go home if it is changed.

 

So transparent.

 

The calculation is wrong. Has been for years. Start there.

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cash7c3
Where is the new HP/WT for each class posted? I could not find it.

 

 

It's not posted yet, as they don't have a completed rule yet.... I wanted to see where I stood with my current dyno sheet and sent my info to the director and he did the calculation and sent me back the info. That's how I discovered the change in the class HP/Wt classing numbers, surprise !!

 

 

 

-Scott B.

 

Oh, that's lame, maybe they'll modify it to solve that issue . . . and post it sometime soon

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How about a recap?

 

Every year, GTS competitors have the chance to propose new and/or changed rules for GTS. The process is as follows:

 

1) Between now and November 15, 2014, GTS competitors may propose any changes to the GTS rules that they feel are appropriate. That can be done here: http://tsdev85xw.teamsol.com/NASA/GTSRulesProposals.nsf/GTSRulesChangeRequest.xsp

 

2) After the closing date, the GTS Series Directors will discuss the proposed changes, determine those that are appropriate and/or feasible, and post those proposals back here in the GTS Forum for open discussion through November 30, 2014.

 

3) At the completion of the open discussion period, the GTS Series Directors will again meet and determine which, if any, proposals will be accepted. The finalized 2015 GTS rules will be posted by December 15, 2014.

 

So racers submitted proposals. Presumably the Directors got them via the process described in "1)"

Then, the Directors vetted them, or discussed them, and sent back for discussion, as described in "2)"

And last, we assumed that they would REVIEW WHICH, IF ANY, PROPOSALS would be accepted, as in "3)"

 

So next, a new rule is (sort of) posted regarding power/weight calculations. It is not any of the three proposals submitted by the racers in accordance with "1)", nor is it any revised version after vetting as described in "2)", and yet somehow, its presented as if the racers discussed it, got a chance to review it, and that it somehow went through the "due process" we were all expecting, and was presented as a rule change after review by racers as described in "3)"

 

Succinctly? NO. That did not happen.

 

We have this out there:

 

As to the question of why we settled on 30% of the powerband as the area to measure, that would be based on my influence.

So, after spending countless hours playing with models and numbers, I came to the conclusion that something around 30% was a fair compromise.

 

Scott, with all due respect, if those are your opinions, and that is how you feel we should revise the rules, then by your own guidelines, you should have submitted it to be vetted by the Directors, posted to the forum for Racer discussion, and then reviewed it with the other Directors to be published.

 

That did not happen, not even close. You guys are not even following your own rules.

 

I've heard 5 separate comments about how easy it is to "beat" the system and ruin GTS, but no one willing to share input how they think that will happen... ...and then complaining that this was done without racer input.

 

And Chris..... given the above.... you find the complaining somehow surprising?

 

If the Directors believe there is a groundswell of support from the Racers to change the way power is measured, and they've known this for a long time, then they should have created many months ago, a proposal, in all its specifics, which should have been published in advance, discussed by the racers, and then adopted after discussion and review at some point.

 

That would have been fair, as described by our GTS Director.

 

I generally consider myself to be a "Problem Solver" not a "Problem Maker" However......

 

In this case you guys are lying in a bed you made, and it could have been, SHOULD have been avoided if the guidelines you Directors laid out for us were followed in the most rudimentary of fashions.

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Michael G.

Alex,

 

I respect your opinion and agree with many points in general aside of colorful analogies and references at times, which incidentally don't contribute to the problem solving, often times - just alienates. But I'd rather stay off the ping pong route of responding with the insult to the insult.

Unfortunately, the reality of the situation is that we don't have an efficient, functional and productive way to exchange opinions on many subjects, not locally, regionally or nationally. Yes, we have a Forum where selected few express opinions.

Even though we had published guidelines (unlike many other classes where ch

anges often made with very little or any exchange with members), those are suggested and materialized to the best of our abilities. There are also number of other avenues to communicate outside of this Forum, like emails, phone calls, personal meetings, FB, etc, etc. We have about 70 GTS drivers in the NE and with the most I personally keep contacts outside of this Forum. Yes, we appreciate hearing practical and rational opinions, but don't make it sound like not adhering to the 1), 2), 3)s reflects a major violation or disrespect to the membership. Again, membership has other avenues to express opinions.

By the way, there were many times in this series as well as any other racing series, when certain decisions on Rules changes were made by the executive committee based on the factors often outside of the subjects discussed here. Years ago the TQ was added to the HP with no prior discussion, recently we added Black Boxes to the compliance protocol based on what we see backstage. The same with sequential boxes. By no means I suggest that there is intentional disregard, just saying this is not the only stage.

In the ideal world all of that would work and we wouldn't have this argument.

The Rule is not finalized and we are working hard to make it better than the peak power point with which we had number of issues through the years, but, as before Black Boxes, we were very limited in how to deal with.

Ultimately, everyone has a choice to continue or go elsewhere. Sometimes we make mistakes, but as long as we can respond and correct it - that is what the most important.

By the way, the time line of the Rule changes proposed by Scott this year was the earliest in memory. Not to excuse, but I don't remember the Rule changes finalized ever before January. So we are not far off for us or comparing to any other classes.

 

Michael G.

NE GTS Dir.

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flink

If we're reading directly from the dyno data, we have our RPM/hp points. If we are using the manually-input-every-1000-RPM approach, the code takes each of those points, inserts the max hp point where it fits, adds the redline and redline hp where they go, and then pro-rates between all these known points, generating a calculated hp value for every 100 RPM over the full band for which we have data.

 

It then determines how wide the 30% collection band is by taking 30% of the redline. If the car has a 7000 RPM redline, its 30% band is 2100 RPM wide, which is 22 of the 100 RPM increments.

 

Beginning at the bottom of the known rev range, it adds up the first 22 consecutive values and saves that total as the current-highest-horsepower value. Then, it starts over at the next-to-lowest increment and adds up 22 consecutive values, then compares that to the previous high hp to see if the new number is larger. If so, it replaces the current-highest-horsepower value with the new value. If not, it leaves it alone.

 

This process of iteratively totaling all the possible 2100 RPM bands (in this example) continues until it makes it through the band that ends at the redline. Whichever of all those possible 2100 RPM bands generated the highest raw number is the one that is used, regardless of where that band fell in the overall rev range.

 

The resulting high value is then divided by the number of increments in each band (22, in this example) and the result is the highest average horsepower.

 

So I wrote a little program to implement the above. Then I grabbed a random s65 dyno sheet off the internet, extended the rev limit to 9000 and detuned it thusly:

 

s65-out_zps9696a835.jpg[

 

I manually entered this as

 

[email protected]: 100

[email protected]: 100

[email protected]: 100

[email protected]: 100

[email protected]: 330

[email protected]: 100

[email protected]: 100

[email protected]: 100

[email protected]: 100

 

and I get a result of 185HP at 3300->5900 RPM. From an engine which is producing a usable 310HP! This is far, far worse than the 2014 ruleset.

 

Now, this result is mainly from gaming the "every 1000 RPM" thing. If this is made finer-grained then such gross inaccuracies will not occur.

 

 

 

The other flaw I see in Scott's description is that it uses a fixed RPM range (2100) across the entire rev range. This is only accurate at the very top of the rev range. In the middle of the rev range it is twice as wide as it should be. The rev range should be less at lower RPM, to reflect the fact that engine revs drop a smaller amount when you upshift at lower RPMs.

 

In the case of my detuned S65, the rev range according to Scott's design is 2700 RPM, so my engine's peak power band is 3200->5900. So the averaging will include a whole bunch of the 100HP region. The driver will never *use* this region, but it falsely reduces his HP number.

 

 

 

So I suggest two changes:

 

a) Forget the "every 1000RPM" thing and require "every 100RPM", or better.

 

b) Don't use a constant RPM range. Make it a ratio. As I said before, it should be "from N RPM to N*1.43" RPM, to retain the 30% idea (1/0.7 = 1.43).

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7VO-VOM

flink,

 

That only works if they use the 1000rpm approach, and you are using a boosted S65 dyno chart. Your concept is correct, but unless you give a specific example, they will ignore you. Hell, I gave a specific example of how a hard to tune car is more screwed than an easily tunable S65 and there was no response.

 

Michael G,

 

You are missing the fact that the proposed (by the directors with no driver influence) rule is A) less fair, B) is more open to bending the rules, C) is easier to hide cheating, D) will cause a lot of drivers to spend a lot of money to effectively be the same, E) IT IS ALREADY 5 DAYS AFTER THE RULES WERE PROMISED, so we really don't care if this is earlier than usual, F) you have deflected or ignored all criticism (constructive or offensive), G) different directors have made drastically contradictory comments which calls into question the motivation for the change (which we all know is to penalize detuned BMWs) and the ability of the directors to make a fair and enforceable rule.

 

You failed.

 

Admit your failure and push any change to 2016. You will get more help, and lose less cars.

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Michael,

 

I appreciate your reply, sorry you don't like my colorful anecdotes.

 

I'm unhappy about two issues regarding the new rule planned for power/weight calculation.

 

Foremost is the 30% size of the rpm band.

 

I can not wrap my head around why anyone OTHER than the owners of super high redline engines that make increasingly more power towards that redline would want that.

 

The most torque to the ground will have the advantage. The engine that makes the most HP at the highest rpm will allow for a diff choice that is a mulitiplier of torque to the rear wheels that will confer the best advantage in all gears.

 

So, the high rpm engines with rising HP towards the redline are the best engine to race with in their natural state. It is a given that those are the best, that is why you find those in modern 911 variants and all Euro M3 (Normally aspirated) variants.(*)

 

The problem is, that you guys are compounding that baseline advantage by setting up a 30% rule.

 

Anyone with an ounce of energy can (and will) set up a car with modern gearbox and diff ratio to be a close ratio set up... its not just the transmission, but the diff too that determines how quickly you hit that redline, and bounce to the next less advantageous torque mulitplier.

 

On a sloped dyno curve, we have to measure a portion of it that is relatively small unless you want to intentionally set it up to the advantage of the those cars that have a rising curve.

 

Face it, using 2000 rpm still accomplishes the stated goal of more accurately measuring the ability of an engine to accelerate the car.

 

Any more than 2000 ASSURES that the rising hp dyno curves are "gamed" with this new formula.

 

Getting rid of consideration of redline enormously decreases the ability to pad the measured range of rpm to allow close ratio gearing to "game" the system.

 

**********

(*) (BMW made fake E36 US M3's, and now, well, Turbo stuff, as a BMW fanboy, a sad state of affairs)

 

The Second issue I have is obviously the process.

 

Let us not compare ourselves to other groups, or the past. There is no reason we can not set the standard for transparency and be the group other people are jealous of.

 

The Directors will help themselves avoid accusations of bias by following the guidelines that Scott put out in this forum. When they don't, it should not be surprising that there are people caught by surprise, and unhappy at not having had a chance to participate in the process.

 

I would hate to be in the Director's shoes right now. Nobody is perfect, and most people make mistakes. I'm sorry to call it the way I see it, but in this small matter, I think a mistake has been made not just in process, but in content.

 

I think every single racer in GTS would be proud of our Directors, and our Series if they backed off this new rule, and worked out the kinks in the open over the course of the next six months. It is too big a change, and even if the Directors reserve the right to make decisions outside the process outlined by Scott, I think they should do it with our input, in advance, and out in the open.

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flink

OK, let's do something a bit more realistic and assume the every-1000-RPM thing gets fixed.

 

It's a cup car. According to http://www.carreracup.com.au/content/vehicle-specifications, the revs drop by a factor of 0.81 on the 2->3, 3->4, 4->5 and 5->6 shifts. The redline is 8200, 30% of which is 2460RPM.

 

We want to set the working rev range as low as possible, to game the "30% of redline" error. I chose 5000 RPM, so the car's working rev range is 5000 to 5000/0.81 = 6173 RPM.

 

Tune it like this:

 

cupcar-out_zpse90aa575.jpeg

 

You'll see that the "30% of rev limit" rule means that for GTS classing purposes, we average the power over the 5000->7460 range. But the driver only uses the 5000->6173 range!

 

Net result: this 250HP car is classed as having about 200HP.

 

If we were to fix the "30% of rev limit" idea by switching to "N to 1.43*N" then things would get better - this car's power would be averaged over 5000->7150 instead of 5000->7460.

 

However to class this car fairly we'd also need to reduce the 30% to 20% (actually 19%) as Alex suggests. Due to its close-ratio gearbox.

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Michael G.

7VO-VOM,

That only works if they use the 1000rpm approach, and you are using a boosted S65 dyno chart. Your concept is correct, but unless you give a specific example, they will ignore you. Hell, I gave a specific example of how a hard to tune car is more screwed than an easily tunable S65 and there was no response.

 

If we didn't reply to your proposal doesn't mean it was ignored - it may very well being looked at and tested. It is also tough to reply if you still prefer not to disclose your name.

 

You are missing the fact that the proposed (by the directors with no driver influence) rule is A) less fair, B) is more open to bending the rules, C) is easier to hide cheating, D) will cause a lot of drivers to spend a lot of money to effectively be the same, E) IT IS ALREADY 5 DAYS AFTER THE RULES WERE PROMISED, so we really don't care if this is earlier than usual, F) you have deflected or ignored all criticism (constructive or offensive), G) different directors have made drastically contradictory comments which calls into question the motivation for the change (which we all know is to penalize detuned BMWs) and the ability of the directors to make a fair and enforceable rule.

 

You failed.

 

Admit your failure and push any change to 2016. You will get more help, and lose less cars.

 

All of your A to F are highly subjective and mostly incorrect. We will admit the failure once that happens, so far it is nothing more than your opinion.

 

Flink and Alex,

 

I am not involved with writing the algorithm, but assuming the formula could be modified to address the redline and wide band concerns, do you see any other specific technical issues with this approach of calculating HP?

 

In regards to the transparency and open communication - at least 3 proposals for the change in calculating minimum weight or power were made and discussed this time around (and every year prior). Average HP under the curve method was discussed as well there proposed by one of the members and actually received well, so it didn't come from nowhere simply as a conspiracy.

 

If we will adopt the mandatory upload of the dyno sheets for open review, we will be able to see the odd balls ahead of time, which together with black boxes and strict dyno protocol at impound should help with compliance - not that the peak HP has no compliance issues now.

 

Michael G.

NE GTS Dir.

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