Rules for 2013

[Grippy]

I have issue with the displacement increase points. On my car I went from 2.0 to 2.5l adding 25% which gained me 20HP and cost me 12 points.
I think it should be calculated on displacement increase not % increase. Someone with a 5.7l V8 gains 1.425l to get the same 25% increase as my .5l increase. HP comes from displacement so the V8 has the potential to gain 3 times as much power with the same penalty in points. Does that make sense?

[Georgethefierce]

Theoretically, the cutoff for Super B is high because if you have more than 100 touring class points, you are rocking a very well prepped car...or a mildly prepped modern super car.

The cars that slip through the cracks are things like spec racers, the dwarf car, FV, etc. IF there are a good number of these cars that warrant another look at the Super classes, we will do that. However, after creating some mock results, the top Super B car at WGI this year ran a 2:07 with the top T100 car running a high 2:08. At South Oval it would have been 1:12 in Super B AND T100. That's less than a 2s gap at WGI and 0s at NHMS between those 2 classes, meaning the addition of another class would be redundant from a performance potential perspective. However, we will look at mock results for NHMS-4 and the season to determine if too many cars are falling between the cracks (un-classable in Touring, too slow for Super B)...which is a different problem...and consider implementing one of the possible solutions.

Valid points and I agree that there is really no need for the 3rd Super class if it'd be undersubscribed and/or create an overlap

[962porsche]

the average my car turned at nhms3 was a 1:16 were jonh spain was turning 1:17 in my car when he drove it .there is so much more than what the HP and tork numbers are in a car that makes it turn a fast lap . my car has a short wheel base there for it does not like long fast corners like nascar's turns 1 and 2 at NHMS . so i add in more wing and the lap times are the same because i lose speed on the straights .

[blindsidefive0]

I have issue with the displacement increase points. On my car I went from 2.0 to 2.5l adding 25% which gained me 20HP and cost me 12 points.
I think it should be calculated on displacement increase not % increase. Someone with a 5.7l V8 gains 1.425l to get the same 25% increase as my .5l increase. HP comes from displacement so the V8 has the potential to gain 3 times as much power with the same penalty in points. Does that make sense?

Gordon - because the basis of much of the system is on the ratio of weight/power, the % increase in power is more important than the actual gross increase in power. Accordingly, we used % increase in displacement, not gross increase in displacement, as the measure. As a benchmark we looked at NASA which handles this similarly. With your example, the v8 may get 3x the power increase you get, but could be a similar % increase overall.

Regardless, if your engine modification points aren't yielding you enough engine modification power...you have the option to request a scrutineer-provided engine modifications assessment based on actual power/torque figures. This may be the best option for you - the process for this is outlined in the latest rules Word Doc if you would like to try it out.

[brucesallen]

My super class p/w would be 14.33. However I currently can squeeze into the top of T100 even on the super fat tires.

my diasio would also be classed in super B . Power to Weight ratio of 8.84
how ever the clamed HP and TORK in my suzuki work shop manual is at the counter shaft . now the gearing of the rearend and sprockets will change the tork out put at the rear wheels . so because i change my gearing from track to track how in the hell do i ajust for that tork rating ?

Gearing is your problem. Take the crank HP/Torque and calculate a standard driveline loss.

Torque at the rear wheels is meaningless. Want three times the torque? Use first gear. Want less torque? use overdrive.
Furthermore, I don't think dynos show actual wheel torque because even if the trans is set to 1:1 ratio, the diff is giving around three times the torque multipication. So I presume the dyno is ratioing the real wheel torque back to shaft torque by dividing by the diff ratio. And if we use manufacturer specified horsepower and torque, the are talking engine shaft numbers. How much torque loss should we figure in the trans/diff? Maybe we should forget about factoring in torque and stick to shaft horsepower.

[paultg]

Nick, I have some questions concerning engine swaps.

I'll use the Miata 1.6 - 1.8 swap as an example. We have a few in the club.

1. Can I use the 10-20% increase in displacement (4 points) then add any mods like headers, exhaust, non stock cat, ECU, cold air etc? (probably not)

2. Or, can I give Tom a Dyno number and get an assessment number and not have to claim headers, exhaust, non stock cat, ECU cold air etc because that is what made the dyno numbers?

3. Or, can I use the stock 1.8 numbers from the car list, give to Tom, get an assessment number and add header, exhaust, non stock cat, ECU, cold air etc?

I have been confused by this also. I have not dyno'd my car but am pretty confident my 1.8L will result in power/tq numbers of a 94-97 miata. On my sheet under the engine tab I am also taking a few points for bolt on items, and then including the % increase of 12.5%. I was assuming I had to do either
#1 in your post, or #2, didn't think #3 was an option.
Another concern is when using the equation for the dyno sheets some cars with many bolt on items and programmable ECUs will actually produce less hp ratings (with a dyno sheet) than a stock 1.8L car.
IE: Stock 94-97 1.8L crank hp rating 128 hp / 114 tq. A rear wheel dyno output resulting in 100 whp-112 whp still works out to be less than or equal to 128 crank hp (with 15% drivetrain loss added in).

I have issue with the displacement increase points. On my car I went from 2.0 to 2.5l adding 25% which gained me 20HP and cost me 12 points.
I think it should be calculated on displacement increase not % increase. Someone with a 5.7l V8 gains 1.425l to get the same 25% increase as my .5l increase. HP comes from displacement so the V8 has the potential to gain 3 times as much power with the same penalty in points. Does that make sense?

I agree something has to happen. My 1.6L - 1.8L is a 12.5% increase, and my car is being hit with 4 points for this item alone, and it's ~11-12 hp delta.

Paul G.

[McMahonRacing]

" However, after creating some mock results, the top Super B car at WGI this year ran a 2:07 with the top T100 car running a high 2:08. At South Oval it would have been 1:12 in Super B AND T100. That's less than a 2s gap at WGI and 0s at NHMS between those 2 classes, meaning the addition of another class would be redundant from a performance potential perspective "

Nick .... if you already have this data how about you share ?

Would really like to see the variance between the top SB car & the bottom SB car ?
How about some info on SA as well, I know a couple of the cars there & they won't be very competative SB w/o a real world "factor".

[paultg]

I have issue with the displacement increase points. On my car I went from 2.0 to 2.5l adding 25% which gained me 20HP and cost me 12 points.
I think it should be calculated on displacement increase not % increase. Someone with a 5.7l V8 gains 1.425l to get the same 25% increase as my .5l increase. HP comes from displacement so the V8 has the potential to gain 3 times as much power with the same penalty in points. Does that make sense?

Regardless, if your engine modification points aren't yielding you enough engine modification power...you have the option to request a scrutineer-provided engine modifications assessment based on actual power/torque figures. This may be the best option for you - the process for this is outlined in the latest rules Word Doc if you would like to try it out.

Cool, didn't see this before posting. I'll read up on it and let you know if I have any other thoughts.

Thanks - Paul G.

[dradernh]

Would really like to see the variance between the top SB car & the bottom SB car ?

The part that interests me is how you can put two drivers in the same car & get very different results. Example: On fairly fresh rubber, I ran my SB car to a 2:08.3 at the Glen last week. Later, another driver got in & ran 2:01.6 on some much-more-used rubber (RR had the most with 24 HCs on it).

Since this exercise is classing cars, and not drivers, I have trouble looking at TT results that include drivers at all skill levels & all car-tuning/prep levels, and then drawing firm conclusions as to the merits of the car-classing system from those TT results. If a car has the bells-n-whistles to run a 1:18 CC at NHMS, then it should be classed with other cars whose capabilities are in that ballpark, unaffected by driver skill level, a set of poorly-matched components, an inability to tune the components to work optimally together, etc., etc.

Depending upon how all this shakes out, as well as who shows next year, the SB spread at the Glen will be a good 10 seconds. Michael Fuchswanz will win in 2:02, his dad will be right behind him, and the rest of us will trail behind. Maybe it's time for that LS3!

[Foosh442]

This is certainly interesting to read, many good points being made. Just went through the classification tool with 2 cars and it seems about right. Our '02 C5 Z06 all stock with the exception of sway bars and tires came to 99.20 (T100) and my race car came to 9.90 (Super B). Curious to hear the mock results at NHMS-4, thanks for all of the thought and time put into this!

[nateh]

To me it sounds as if we ought to try a figure a way for underpowered race cars to be classed with the high Ts.

[kfoote]

To me it sounds as if we ought to try a figure a way for underpowered race cars to be classed with the high Ts.

The problems with doing this are at Watkins Glen and Mosport. I crunched some numbers, and though a heavily modified low power car may be competitive with a high powered car (think SPC vs SSU) at NHMS, and Summit Point, (and also LRP and both NJMP tracks) it will be significantly slower at Watkins Glen and likely Mosport because of how those two tracks heavily favor higher HP cars.

[962porsche]

My super class p/w would be 14.33. However I currently can squeeze into the top of T100 even on the super fat tires.

my diasio would also be classed in super B . Power to Weight ratio of 8.84
how ever the clamed HP and TORK in my suzuki work shop manual is at the counter shaft . now the gearing of the rearend and sprockets will change the tork out put at the rear wheels . so because i change my gearing from track to track how in the hell do i ajust for that tork rating ?

Gearing is your problem. Take the crank HP/Torque and calculate a standard driveline loss.

Torque at the rear wheels is meaningless. Want three times the torque? Use first gear. Want less torque? use overdrive.
Furthermore, I don't think dynos show actual wheel torque because even if the trans is set to 1:1 ratio, the diff is giving around three times the torque multipication. So I presume the dyno is ratioing the real wheel torque back to shaft torque by dividing by the diff ratio. And if we use manufacturer specified horsepower and torque, the are talking engine shaft numbers. How much torque loss should we figure in the trans/diff? Maybe we should forget about factoring in torque and stick to shaft horsepower.

tork at the wheels is meaningless is just what i'm saying ! tork numbers at the wheels change greatly they are for the most part are taken in top gear but on cars were you can change out your gearing at the rear axle at any time in the matter of minutes it becomes a plus if your playing with numbers and how you want your car classed . on the other hand for motors on motorcycles and snowmobiles the tork and hp numbers are taken at the counter shaft not the crank .

[Chrispy]

tork at the wheels is meaningless is just what i'm saying ! tork numbers at the wheels change greatly they are for the most part are taken in top gear but on cars were you can change out your gearing at the rear axle at any time in the matter of minutes it becomes a plus if your playing with numbers and how you want your car classed . on the other hand for motors on motorcycles and snowmobiles the tork and hp numbers are taken at the counter shaft not the crank .

You can change the rear-end all you want, it shouldn't alter your dyno results significantly on a modern load sensing dyno (Mustang, Dyno Dynamics etc). The dyno is only measuring HP, torque is just displayed as a factor of HP over RPM.

[Chrispy]

Nick, I have some questions concerning engine swaps.

I'll use the Miata 1.6 - 1.8 swap as an example. We have a few in the club.

Can I use the 10-20% increase in displacement (4 points) then add any mods like headers, exhaust, non stock cat, ECU, cold air etc? (probably not)
Or, can I give Tom a Dyno number and get an assessment number and not have to claim headers, exhaust, non stock cat, ECU cold air etc because that is what made the dyno numbers?
Or, can I use the stock 1.8 numbers from the car list, give to Tom, get an assessment number and add header, exhaust, non stock cat, ECU, cold air etc?

Les,

According to the proposed rules, engine swap cars do not use the change in displacement formula, that is reserved for engines that have been bored & stroked. Engine swap cars are required to be re-classed based on new power/torque figures, the competitor is required to provide dyno sheets and supporting documentation. I'm not sure how dyno variance will be dealt with yet, but some conversion factor for dyno type may need to be considered.

You can estimate your new base points by using the formula's in the rule book.