2010 Rules Clarifications and Feedback Thread

[Micks 41]

No kidding!!! The resemblances are amazing.

[Pat L.]

Very good news, John!

[firehawkclone]

For those who were wondering, from L to R, that's Todd, JWL & Al.

 

[

 

-=- Todd Covini

That kills me

 

Good luck sticking it to my car JWL, it has no metal on the outside

[Aaron B]

Very good news, John!

 

 

 

 

Yes, Very Good News!

[pederb]

We are constantly working on improving the ways we are enforcing the rules and the GPS that JWL mentioned has been tested for years and could very well make dyno's at the track something of the past.

 

Happy Holidays

[GTO1]

Pederb, please explain!

[gbrown8439]

We are constantly working on improving the ways we are enforcing the rules and the GPS that JWL mentioned has been tested for years and could very well make dyno's at the track something of the past.

 

Happy Holidays

 

I don't like the sound of that at all!

[ST#97]

Todd, I applaude your efforts along with everyone involved. It's clear that you guys are investing a lot of your valuable time and effort into the series which is exactly what it needs. The thing is, and I'm trying not to sound like an ass here, without ways to level the playing field and to enforce compliance... the "better" teams, for lack of a different word, will look for other series to showcase their talent. And "better" isn't defined as having a larger pocket book, but rather talent and exceptional preparation. I just saw this happen in World Challenge as we lost a manufacturer due to lack of enforcment of the rules as well as a lack of communication. AI is an amatuer series, but that's no reason for the directors and participants to expect an "amatuer" level of officiating or racing. We should all raise our expectations a little. Afterall, it's free.

 

You guys did an amazing job at Nationals and I wish all the regional events were officiated that well. The sad truth is that'd be very difficult because of the way we are forced to comply with the weight:power levels. It just doesn't work and it won't get better until the rules change.

 

Funny how many offline conversations, emails and PM's I've seen this statement in lately....Pat, you and I actually agree on something here! LOL!

[JWL]

For those who were wondering, from L to R, that's Todd, JWL & Al.

 

[

 

-=- Todd Covini

That kills me

 

Good luck sticking it to my car JWL, it has no metal on the outside

 

Duct tape, Wheelie, duct tape. It held Lightning together for many years so it ought to stick the limpet on there real purty like.

 

As to the picture above, I certainly am one sexy beast, no? I also think Al is ready to deliver the Max Mosley style discipline to those who do not meet ze number.

 

-JWL

[92MNstanger]

I am not against the idea of GPS enforcement. I am a complete novice for GPS and it's about to show.

 

 

How does the rotating weight of the drivetrain effect these GPS calculated power numbers? Does a light weight set of wheels and a button clutch show up as more power when compared to cheap wheels and an OEM flywheel/clutch?

 

Also how are aerodynamics input into the model? Surely a 4th Gen firebird is more slippery than a fox body mustang.

[Pat L.]

I am not against the idea of GPS enforcement. I am a complete novice for GPS and it's about to show.

 

 

How does the rotating weight of the drivetrain effect these GPS calculated power numbers? Does a light weight set of wheels and a button clutch show up as more power when compared to cheap wheels and an OEM flywheel/clutch?

 

Also how are aerodynamics input into the model? Surely a 4th Gen firebird is more slippery than a fox body mustang.

 

Rotating weight or "driveline loss" wouldn't show on the GPS because that's already accounted for in your dyno number. Aero is factored as a single input in the setup; just plug in frontal area which can be a standard number for each make/model/year. We don't go fast enough to warrant any major calcs on drag cf or anything... all that should be within the margin of error. I had the AIM software calculating HP during every session at Nationals and it was about 10hp lower than the actual dyno. We came to the conclusion that the difference was probably attributed to the dyno correction factor. We tried changing the frontal area in the software on the off chance the car was getting through the air cleaner than we thought, but that didn't make much of a difference. We were only seeing 134mph (race) and 137mph (qualy) on the front straight. Given, we were running heavy during the race.

[92MNstanger]

I am not against the idea of GPS enforcement. I am a complete novice for GPS and it's about to show.

 

 

How does the rotating weight of the drivetrain effect these GPS calculated power numbers? Does a light weight set of wheels and a button clutch show up as more power when compared to cheap wheels and an OEM flywheel/clutch?

 

Also how are aerodynamics input into the model? Surely a 4th Gen firebird is more slippery than a fox body mustang.

 

Rotating weight or "driveline loss" wouldn't show on the GPS because that's already accounted for in your dyno number. Aero is factored as a single input in the setup; just plug in frontal area which can be a standard number for each make/model/year. We don't go fast enough to warrant any major calcs on drag cf or anything... all that should be within the margin of error. I had the AIM software calculating HP during every session at Nationals and it was about 10hp lower than the actual dyno. We came to the conclusion that the difference was probably attributed to the dyno correction factor. We tried changing the frontal area in the software on the off chance the car was getting through the air cleaner than we thought, but that didn't make much of a difference. We were only seeing 134mph (race) and 137mph (qualy) on the front straight. Given, we were running heavy during the race.

 

 

So what you're saying is I should dyno with heavy wheels then run the light ones while racing. Perfect.

 

Can you show me the tech reference that says a lightweight rotating assembly (either clutch or wheels) will show up as hp on a dyno, please?

 

The few books I have relate them to static weight so I don't know how they relate to hp.

[nape]

So what you're saying is I should dyno with heavy wheels then run the light ones while racing. Perfect.

 

Can you show me the tech reference that says a lightweight rotating assembly (either clutch or wheels) will show up as hp on a dyno, please?

 

The few books I have relate them to static weight so I don't know how they relate to hp.

 

Do you have a copy of Chassis Engineering? If so, look in there. There isn't a rule of thumb because mass and diameter are a big part of it.

 

I'll attest to it across the board from rotating assembly weight to wheels/tires. I know Jay Andrew has seen the difference in wheels and I'm sure many other competitors have as well. If you want a way to test, ask your dyno operator to do a coast down at the end of the pull and check drivetrain loss. Change the wheels and strap it back down and do another pull. The numbers don't lie as long as you can qualify your data.

[King Matt]

You can see a difference in power by changing rotating mass on an inertial dyno like a Dynojet because what those machines calculate is the time and rate of acceleration of a known mass (the roller) and extrapolate that to a horsepower number and then back calculate torque. So if you change the mass that is accelerating the roller (like change the wheel weight) it would show up as a change in calculated power. Similarly, you can get a different HP number depending on the transmission gear used for the run.

[92MNstanger]

 

Do you have a copy of Chassis Engineering? If so, look in there. There isn't a rule of thumb because mass and diameter are a big part of it.

 

Yeah, I have it. That's what I was talking about.

 

 

You can see a difference in power by changing rotating mass on an inertial dyno like a Dynojet because what those machines calculate is the time and rate of acceleration of a known mass (the roller) and extrapolate that to a horsepower number and then back calculate torque. So if you change the mass that is accelerating the roller (like change the wheel weight) it would show up as a change in calculated power. Similarly, you can get a different HP number depending on the transmission gear used for the run.

 

OK, good to know. I wasn't sure that the dynojets were capturing rate of change and use that to calculate power. I didn't know how they worked at all. I thought it calculated sticker area and used an SAE smoothing factor of 5 to come up with HP.

 

GPS sounds like a pretty good method, then.

[King Matt]

The GPS systems are essentially using the same principle as a Dynojet by calculating the time and distance to accelerate a known weight (car) to a given speed. I think the GPS is a great tool to help police the field, but using it to replace the dyno is another matter altogether. It only takes a small error in data assumptions to make a pretty significant change in calculated HP. How many cars have been caught out over the years by small changes in dyno numbers that skewed their required weight enough to cause a DQ? Now you are introducing a dynamic measurement system whose accuracy can be affected by even more variables. Plus, someone has to be responsible for gathering and interpreting the data, which isn't an insignificant task.

[nape]

I think the GPS is a great tool to help police the field, but using it to replace the dyno is another matter altogether. It only takes a small error in data assumptions to make a pretty significant change in calculated HP. How many cars have been caught out over the years by small changes in dyno numbers that skewed their required weight enough to cause a DQ? Now you are introducing a dynamic measurement system whose accuracy can be affected by even more variables. Plus, someone has to be responsible for gathering and interpreting the data, which isn't an insignificant task.

 

Holy crap, I agree with Matt King. How do you know when to throw out the data with GPS? I know we aren't Spec Miata, but I would think getting a bump from someone would skew the data.

 

I'm not saying I don't like the GPS idea, but I don't know enough about it to understand it.

[tacovini]

Deep breaths....calm...inhale....exhale....inhale....exhale....

 

Remember...think long term...3-5 year plan. It's something that will be phased in...we're not going to pick a date and no longer use dynos after that date.

 

GPS is a tool, like dynos are a tool.

These tools are just a few of the many things your series directors will have in their tool bag to ensure compliance.

 

Now Matt...this is where my quote comes in....

"...and we've got our best people working on it!"

 

Merry Christmas everyone!!!

-=- Todd

[ssfab]

Todd didn't you say you were going to give a reason behind each rule change or were we supposed to forget about it and act like it was never said?

 

dash (what the hell)

no mustang SS's what is the advantage? (just to get rid of Pat and I?)

we have to prove our car is legal? i thought it was the tech director's job to prove it was illegal '

the dyno tech sheet,what is all that about? jet size,timing,restrictor,exhaust,

 

why not use the gps and dyno. the gps is obviously a good tool for picking out who is a good candidate for dyno and im not just talking about us the gps on everybody. If your going to make the racers spend money on something make us spend it on something worth while.

[ST#97]

Todd didn't you say you were going to give a reason behind each rule change or were we supposed to forget about it and act like it was never said?

 

dash (what the hell)

no mustang SS's what is the advantage? (just to get rid of Pat and I?)

we have to prove our car is legal? i thought it was the tech director's job to prove it was illegal '

the dyno tech sheet,what is all that about? jet size,timing,restrictor,exhaust,

 

why not use the gps and dyno. the gps is obviously a good tool for picking out who is a good candidate for dyno and im not just talking about us the gps on everybody. If your going to make the racers spend money on something make us spend it on something worth while.

 

 

Give em' hell Troy!

[tacovini]

I'm in Daytona at the moment and can't take your call. If you'd like to leave a msg...

 

 

I prepared the "Director's Cut" on the 2010 rules and sent them off to the webmaster before I left. Ill check on them and be back in town late Sunday site.

[tacovini]

See the "Director's Cut" post in the Announcement section for more clarifications.

The rules were written for the long term with the big picture in mind.

My goal is to include ALL racers, pro & novices, technical & non-technical...outspoken & soft spoken in the series provided it is in the greater good of all.

 

If you've got further questions after reading the DC...let me know.

 

-=- Todd

[DHarsay]

I've read the rules many times over the years, and watched things develop. Director's cut is great. There are a couple of things I struggle with regarding the wording of the AI rules... it seems like over the years I have figured it out by looking at all the cars out there, but when I'm actually reading the rules, I wish it was clearer.

 

The most significantly questions for me are the ones dealing with modifying factory sheetmetal. This falls into two categories it seems.

 

The first one is the section 7.3 "Frame" - it talks about tub/floorpan/firewall/cowl/windshield-frame... which may be a misleading title for this section, but the intent is fairly obvious... and there are definitions to clarify what means what... got it, and unless it's spelled out, it's not allowed, says so right there very clearly.

 

No problem so far, but it's a segway into the next section, and read along with me on the next section, 7.4 "Body/Interior". Seems pretty straight forward at first, no definitions needed here perhaps, and none are given. Seems all of the structural metal parts outside of the ones covered under "Frame". It talks about a few things that can be changed, and that seems to be clear. The term "Body Panels" is used throughout, and I'm starting to wish this was a little bit more defined. It mentions that body panel lightening is not allowed in AI. Acid dipping is straight forward, but body panel lightening? Hmmm. Maybe it means the the primary structure? But wait, much of that is covered under 7.3 "Frame" isn't it... so we're left with the remainder... the rest of the structural paneling, or body panels, interior structural panels and components. It mentions "All Interior Modifications Allowed"... okay, that makes sense... but then it goes to say including dashboard and wiring? Wait a minute. Is that the kind of stuff "Interior" stuff we're talking about? ... then "provided that they don't conflict with other rules"... uhm... what about the interior "body panel lightening is not allowed in American Iron Class"? So what can I remove or modify here exactly? What is meant by lightening? What does "Interior" mean exactly? AIX it mentions unrestricted in body panel modifications... what about AI? What are the restrictions? Do all the people who install lightening holes or cut away part of the interior paneling or structure, are they allowed to do this? I would say yes, just look at the extremes, look at the Paul's Automotive car (running AI this year), most of the interior paneling is gone. And the Wilson/Tone car, there are dozen's of lightening holes, b-pillar is gone, much of the interior structure is gone... Pat Lindsey's car, actually a lot of the well thought out cars. Is that what it means by all interior modifications are allowed? How about sheetmetal forward of the strut tower? Many have removed this. How about the doors? I've seen parts of them trimmed for access... great idea, but is this allowed per the rules?

 

Then there are the front fenders... first it mentions "free as to venting, louvers, and other modifications"... then it mentions "may modify wheel openings for the purpose of tire clearance only... some cars have wheel opening modifications for aero, can this be done?

 

Alright, in list format, here are some questions I have regarding sections 7.3 and 7.4, on a 2000 model year Mustang; some of it is common practice as many of you will notice, but it's not clear to me with regard to the rules:

 

1. Can the interior sheet metal stuff be removed? Talking about a lot of the double wall stuff towards the upper rear, around the decklid too... can this be trimmed? Can the passenger door opening perimeter be trimmed also?
   
2. Can I remove the trim panels surrounding the a-pillar_roofline_rear-quarter-windows? And do a little bodu work to clean up the holes and indentions left behind? And trim the roof panel pinchwelds a bit?
   
3. Can I remove the B-pillar inner structure?
   
4. Can I install lightening holes in footwell area below the A-pillar?
   
5. Can I install lightening holes in the rear panel on the aft side of the trunk?
   
6. Can the firewall pinchwelds be trimmed and seam welded to clean them up a bit? (specifically in the front wheel well area, and cowl area)
   
7. Can the door entry threshold AKA rocker panel pinchwelds be trimmed and seam welded to clean them up a bit? Or is this part of the floorpan which cannot be modified?
   
8. Can the front bumper support "accordian box" be removed from the core support and the frame rail or is it considered part of the frame rail?
   
9. Can I modify the shape of the wheel openings to cover the front tire better on the forward side, and using the opposite method relieve the high pressure air on the aft side?

 

Anyway, I've asked for clarifications on a few of these back in November, with regular follow ups. Hope some of you can show me the way around these questions.

 

With appreciation,

Dave

[Raznkane]

I am interested in item 8 also, these were missing on my car when I got it.

[DHarsay]

I am interested in item 8 also, these were missing on my car when I got it.

 

Lot's of AI cars don't have that. Per the definition offered in 7.3 Frame, it's part of the frame. For the shotgun rails on the other hand, that's a little bit tougher to interpret, and the definition offered is a little weak in this regard.

 

Sorry about the large pictures, they are linked as Icannot attach any (the quote for the site has been reached)

 

Tone/Wilson car...

 

 

Lindsey's car... there are a few things there that I would like to understand exactly what part of the AI rules allow us to do, such as bracing passing through the shock tower (as caled in the rules, aka strut tower), the accordian box (#, shortening and modifying the shotgun rails, and the sheetmetal forward of the shock tower being removed, etc. Maybe I just don't understand.