2005 rules - Ground clearance/ride height

[mwilson7]

I don't know what the number is but I think that there needs to be a minimum ground clearance/ride height identified for at least CMC and AI cars.

 

Any thoughts or how it should be measured?

 

I want to add that I believe exhaust should be excluded from any measurements.

[Admiral]

Yeah, if we could do something at the frame rails perhaps? I don't want my LT headers being the measuring point, but maybe a minimum like 3" at the outer sides of the car?

[onralz]

Wilson, you are reading my mind. I am just too busy making the french fries to post that much here.

 

I like the three inch idea as well. Long acre makes a guage that the directors could use to walk around the car and ensure that it is legal. This would have to exclude exhaust, and torque arms.

 

This is a simlar rule as is in World challenge and that is how they do it with success.

[Black Horse]

Question - would the front splitter be included as part of the height check?

 

Statement - I for one could care less about ground clearance, as long as its not dragging, it's good to go in my opinion.

[swhiteh3]

Mark Wilson and I had talked about this earlier.... Thanks for bringing it up Mark, it should be in the rules - no doubt.

 

First of all, I suggest that the number is more like 4". This would be measured at the perimeter of the car, all around, and would include the splitter, undertray, ground FX, etc.

 

I do think that the exhaust should be excluded, with the obvious note that if it's dragging during the course of an event the car can be black-flagged.

 

Other suspension components would also need to be excluded, such as very low panhard bars or under-the-axle watt's links.

 

Another exception I would include would be the STOCK UNMODIFIED lower radiator spoiler. This is the black plastic piece that extends down from the rad support to increase airflow through the radiator. This is an important piece to keeping cars cool, and should be allowed.

 

I know Longacre makes a nice (and expensive) gauge, but a simple 4"x4" wood block on a pole does the job nicely. It's a simple go/no-go gauge.

 

In the interest on not DQ'ing existing after-market-available bodywork, does anyone have a car with 2000 Cobra R front bodywork on it that would have vioated the 4" rule? Mark Luna???

[RichardP]

I'm in favor of a minimum ride height for the chassis but not for other appendages like spoilers.

 

I have the Ford Ranger air dam on my car that replaces the stock air dam. It's certainly not a radical modification. On my "normal" ride height AI car, the Ranger air dam leaves just under 3" to the ground.

 

It's also fairly common for various aerodynamic appendages to get a bit beat up and sag during hard races. It could get a bit sticky in impound to determine whether or not someones car was "illegal" or just sustained some minor damage in a race.

 

Set a number to the bottom of the chassis (excluding pinch welds and such) and call it good. With a minum ride height number, the advantages to radically hacking up the car to get decent suspension travel along with a low center of gravity go away.

 

 

Richard P

NASA TX AI #91

[onralz]

Mark Wilson and I had talked about this earlier.... Thanks for bringing it up Mark, it should be in the rules - no doubt.

 

First of all, I suggest that the number is more like 4". This would be measured at the perimeter of the car, all around, and would include the splitter, undertray, ground FX, etc.

 

I do think that the exhaust should be excluded, with the obvious note that if it's dragging during the course of an event the car can be black-flagged.

 

Other suspension components would also need to be excluded, such as very low panhard bars or under-the-axle watt's links.

 

Another exception I would include would be the STOCK UNMODIFIED lower radiator spoiler. This is the black plastic piece that extends down from the rad support to increase airflow through the radiator. This is an important piece to keeping cars cool, and should be allowed.

 

I know Longacre makes a nice (and expensive) gauge, but a simple 4"x4" wood block on a pole does the job nicely. It's a simple go/no-go gauge.

 

In the interest on not DQ'ing existing after-market-available bodywork, does anyone have a car with 2000 Cobra R front bodywork on it that would have vioated the 4" rule? Mark Luna???

 

That splitter the way I run it leaves 3" of space. I bring up the longacre guage because I don't want Eric Meehan to hurt his back having to shove wood under the cars.

[mwilson7]

Could we just check ground clearance between the front and rear wheels? That would exclude front splitters and their location either before or after the race and also exclude panhard bars, torque arms or any other low hanging suspension piece in the back or front for that matter.

 

I do agree though that asking Eric to kneel over for each car might be taxing. It's bad enough he has to bend over slightly when reading the scales

[swhiteh3]

Preventing splitters that need to be replaced after every race is exactly part of my point in supporting this rule. I could go for 3" (although I still believe that 4" is more than sufficient), it should apply to the entire car. Otherwise, why bother?

[mansier]

As a racer, I would vote for a minimum ground clearance, but something much lower than 3". Looking at Grand Am DP's or ALMS racers, the cars are extremely low. The benefit is certainly downforce, and creating aerodynamic benefit was one of the reasons we chose this racing category to build a car for. Taking away the underbody benefit of a race car would take a lot of the creativity out of the class, and in my opinion would be a step in the wrong direction. There really isn't a safety issue here, unless the chassis contacted the pavement, thus causing a meatball flag and bringing them in to fix it. However, with a bit of creativity, the cars could go just that much faster, with just a bit more grip. What is the downside of a 2" or 1.5" minumum?

 

LM

[Jim P.]

I agree w/Lawrence on this - the minimum should be non existent - most cars have to clear enough obstacles at many tracks just to get on grid!

 

As long as there are no sparks then they should be allowed on track.

 

 

 

 

posted as a racer and NOT a regional director

[mwilson7]

Lawrence - Those classes you mentioned also allow belly pans and many are custom built race cars which benefit from being close to the ground. Those race cars are about as far from an AI car as possible. We have production based vehicles with exhausts that run under the car and unmodified floorpans. The amount of aerodynamics that can be gained from underneath the car amounts to a hill of beans, a VERY small hill.

 

Jim - Would that mean that most of the AI cars at Nashville would have been illegal? EVERYONE was throwing sparks going into turn 1.

[mansier]

Is there something that I am missing about the bottom of the car? I don't see a restriction on the bottom of the car?

 

So, as you say, if there isn't any theorectic aero benefit to having a very low ride height, then what is the problem? Why would a minimum ride height be necessary?

 

LM

[mwilson7]

Because some people are afraid that IRS cars could be lowered substantially lower than solid axle cars.

[racercosmo]

Because some people are afraid that IRS cars could be lowered substantially lower than solid axle cars.

And we have proven that blue cars can be lowered even more.

[EFisher12]

Yeah LM.... get in the game here....

[swhiteh3]

Simply put, we're get farther and farther from our class intent of being "production based".....

 

No production mustang came with 1.5" of ground clearance.

 

Requiring something like a 4" ground clearance will restricit ridiculous aero development, and keep the cars recognizable.

 

Pretty soon, AIX cars will be a floorpan hung inside a Daytona Prototype car.....

[ChuckMM]

I do not think there should be a rule concerning ride height. With the non-tube frame cars we race there is a practical limit to how far a car can be lowered, and still maintain good handling characteristics. With AI cars, and the limits placed on chassis modifications by the rules, we have less flexibility in lowering a car than a purpose-built tube frame race car. Those that go too low will suffer the consequences of bottoming out their suspensions. Creating a rule on ride height will stifle creativity, and cause enforcement problems—how do you measure the variety of chassis that may race in this series? It is easy to measure ride height on a tube frame car with flat bottom, but not on our production sedan based cars.

[Admiral]

Just saw the new rules, 5"?? That seems a little high for a full-race car guys. I didn't see that number being batted around here, I thought 4" was the highest number I'd seen.

[coupe331]

Quote from Admiral

 

Just saw the new rules, 5"?? That seems a little high for a full-race car guys. I didn't see that number being batted around here, I thought 4" was the highest number I'd seen.

 

 

 

I just checked my car and it is 6 1/2 inches in front and 7 inches in the rear with the fuel level at post race level. This is from the ground to the ROCKER PANEL. My splittter is much lower than that but that does not matter. My car is a MM car so it is not as low as some of the Griggs cars but 1 1/2 inches should be enough space for a Griggs car.

 

Ryan Walton

[racercosmo]

I just want to clarify where this is measured. The side of the car quits being vertical and starts being horizontal, this is the area, correct? Is the pinch weld that hangs down an additional inch counted? At its lowest point, #40 is 5 1/2" to the bottom of the pinch weld and 6 3/8" at the flat portion. So I don't see any problems, but I want to make sure.

[trackboss]

That's the way I read it.

 

6.1c:

Minimum ride hieght is 5 inches (AI), to be measured at the lowest point of the rocker panel, but not to include welded seams or fasteners. This does not include splitters, exhaust, torque arms, or other components.

 

Side skirts I assume fall under the "other components." I take it as basically the factory original, steel rocker panel structure. Anything added on like the above appears to be ok.

[Rustic]

Ok... here I am with the odd-ball body on frame car.

Will I have to measure at the lowest point of the frame or any particular place.