loftygoals wrote:


Rule is in place to limit the effectivness of ballast as tool to change weight distributon. We do not intent guys who run ballast due to either a light car or light driver to have a significant edge on weight balance on the car.

However there are ways to be creative in how to strip a chassis to leave the weight where you may need it.

BTW... Fuel to make weight works, but is problematic in long races. You could run out of fuel and be DQ'ed for being underweight. Personally I set-up my car to try to be at minimum weight with zero fuel. This should I run out of fuel I will not be DQ'ed.

loftygoals wrote:


In the interest of full disclosure.

I run ballast in my 944 spec. I have it the legal location, however I also run with a passenger seat. I used to use full stock seat in the stock location. The rules do not required me to remove the seat. These things are 40lbs or so.

However I could not safely mount a harness for passenger rides so I mounted race seat instead.

Behind the set in the rear seat foot well I mounted my fire bottle. This a perfect spot for two reasons. It is low and sort of to the rear, and it is also in well protected spot. In wreck I may crash first and then need to pull the fire system. So I want it where it may be survivaable.

So those are 2 things that are extra weight, but are not techically ballast and can be placed wherever they fit.


Now the cool suit cooler. I considerered the spare tire well. Alot of guys use that space, but I rejected it. My reason is that my car drifts to understeer with too much rear weight. On a full tank of gas I have a bit too much understeer. Now I could re-align the car for a better balance with more rear weight, but I don't run the cool suit all year. In fact I don't even run it for and entire event. I mostly run it at race time. So I found that add it where the legal ballast is located works best. It is easy to fill and install and has the least impact on the overall chassis balance. So my car has the same feel with or without the cool suit.

So just somethings to consider.

joepaluch wrote:


Ah, this makes sense. I like the rule a lot better now that I understand the logic behind it.

joepaluch wrote:


Man using fuel as ballast is an all around interesting proposition. I've been reading up on "slosh dynamics". It is extremely interesting--there are entire books dedicated to developing models to predict how a fluid will slosh in a container.

I'm not as familiar with the late tanks as I am the early tanks, but the early tanks are some of the best designed stock fuel tanks I've seen. Fuel slosh is much less an issue on our cars than on many others. Based on the models I've seen and the G levels of our cars, I think the maximum effect will be displacement of 6-12 lbs. Now with inertia, this effect is slightly amplified, but still we are talking a minimal difference.

I'm going to calculate the volume of the part of the tank that sits on the passenger side from just below the peak above the transaxle to the fuel pickup on the bottom. This volume will be my maximum fuel load. If the fuel is kept in this location slosh is almost totally eliminated.

Whatever this volume is, I'm going to subtract out the fuel volume for a 40 minute race. This will leave me with the minimum fuel weight.

joepaluch wrote:


I won't be able to add enough fuel utilizing the passenger side of the tank to make weight, so the additional weight will be made up in accessories and ballast.

I'd like to add a cool suit. If I get the massive 24 qt unit, I can add up to 50lbs with it. That alone would remove the need for ballast or extra fuel and keep me nice and comfortable on those hot Texas days. The biggest challenge with this solution is getting the wife to let me spend more money on the race car...

Thanks for all the feedback guys. This has been a great thread for me to work through this issue!

-bj

One more thing to consider... If you add something back in and make it much heavier than needed such that it acts like ballast... Well it needs to be in the right location. So if you make a cool suit cooler from 80lbs of steel... well it will probably be ruled as "ballast" rather a cool suit. It has been done before where guys make certain parts quite heavy overly so and get DQ'ed for illegal ballast. I have never seen it inthis class, but it has happen in others.

Heck running 50lbs of cool suit on a 40 degree day may approach using a cool suit as ballast. Of course your fellow racers would probably just force you to turn it on while they add extra ice as your "punishment" so to speak.

joepaluch wrote:


40 Degree day? Don't have many races days here that cool. If It's that cool, I might fill the cooler with chicken noodle soup to keep me warm and nourished.

A 24 qt cooler isn't that big. It's a standard off the shelf size that Cool Shirt sells. I'd probably mount it in the floorboard against the rise of the rear seat. The 24 qt would be really nice to have for enduros, anyway.

-bj

We have cold days at the track here in Az. We start running in January and first session is often run at 40degress. Some days it only gets to 50F. These days are great for HP, but cold for us desert types.

So 24Qt is a commong size, but that 60Qt cooler is a little bigg for a cool suit.