Min weight at Tours Q
I have not been to a Tour in several years and SD will be the first time in the FF. How does weighing the car work out. Sups say drive to weight station after running. I presume the last run. And with 2 drivers, how does it work? What keeps you from adding gas before the last run to get up to min? Will they have the scales set up before the event to ck on our weight?
Mark
1990 Van Diemen, the Racing Machine, CM AutoX, 2016 Frontier
You can try to make a street car into an autocrosser or you can do a lot less work and make a race car into a great autocrosser
At Nationals, Tours, and Pro's that I went to last year weighing happens after each driver's final run as they come off course on the way back to grid/impound as applicable. No chance to add weight between drivers. It was all very organized. At Nats Doug Gill even had a really nice drive on system for the scales which made weighing really fast.Originally Posted by mwizard
Dick
CM 85
The scales are usually (always???) set-up before you run, so you can check your weight on the official scales. As far as adding fuel between runs, if you mean "between driver's third runs", what Dick Said, no time for that. If you mean "after 2nd runs and before 3rd runs", I suppose if there's a good reason, like you each got 4 four re-runs and are afraid you're running a little low despite an honest effort to make weight, then that's cool. If the need is "intentional", don't do that :-)
Barry
At the Dixie Match Tour this past weekend the scales were available at tech on Friday to check the weight of the cars.
As each car that was required to be weighed exited the course on that driver's last run, that driver was weighed, then proceeded back to grid/impound. Second drivers were weighed after there last run was completed.
I assisted an FM F500 by standing at the scales to give the impound guys the wheelbase of the car to speed up the weighing process as the first driver reported to the scales. The weighing was done quickly, the car reported back to it's grid spot and the driver change ensued. The second driver needed to add 70 pounds of ballast. There was ample time to accomplish that and to adjust tire pressures.
Always check your weight on the event scales unless you know you are WAY over weight. I weighed 3 to 5 lbs heavier on the scales there than I did on some other scales in the past week.
I was at tech down at Dixie when a competitor who just won his class was 1 pound over minimum weight.there was much rejoycing.
That's why I mark my fuel dipstick in pounds instead of gallons. It makes the math very simple. I target 4 lb over to allow for 1 lb per scale of calibration drift.
Neil, What technique did you use to determine 1 lb increments? And what is your dip stick that you can read it so accurately?
Mark
1990 Van Diemen, the Racing Machine, CM AutoX, 2016 Frontier
You can try to make a street car into an autocrosser or you can do a lot less work and make a race car into a great autocrosser
Gasoline weighs roughly 6 lbs per gallon, so you just need to do some planning ahead of time to know how much to add to your empty tank when calibrating your stick. If you're happy with 6, 12, 18 lb increments you can add 1 gallon at a time. A half gallon at a time will give you 3, 6, 9, etc. If you really want 1 lb increments, you'd need to add 2 2/3 cup at a time. I'd use larger increments and eyeball it
Probably should introduce myself...
Oh and hi gang, I just bought a FF I'm planning on autocrossing. I used to drive an RX-8 in RTR.
http://www.apexspeed.com/forums/show...94&postcount=5
To expand on that, here's my calibration technique. I started with no fuel in the cell and a full fuel jug sitting on a digital scale. My dipstick was complete except for quantity marks. I wrote down the full jug weight, poured a little in the car, measured the dipstick reading with a tape measure, and wrote that down along with the current fuel jug weight. I repeated that process until the jug was empty, weighed it, refilled it, wrote down the before and after weights, and continued until the fuel cell in the car was full. That gave me several weight vs dipstick height data points. I entered that data into Excel, created a curve fit through the data, and used the curve fit equation to calculate the dipstick mark dimension for each 2 pounds of fuel. I removed the clear tube and marked the rod with a V-notch file and an engraving pen. With a mark every 2 pounds, I have the option of eyeballing between the lines to estimate the exact fuel reading to finer increments if I'm in a high-precision mood.
Here's a screen grab of the spreadsheet.
I removed the clear tube and marked the rod with a V-notch file and an engraving pen. With a mark every 2 pounds, I have the option of eyeballing between the lines to estimate the exact fuel reading to finer increments if I'm in a high-precision mood.
Here's a screen grab of the spreadsheet.[/QUOTE]
Neil, What is this clear tube and rod? I use a length of clear tubing and a rod inside, but it doesn't work very well. The gas falls out too fast.
Mark
1990 Van Diemen, the Racing Machine, CM AutoX, 2016 Frontier
You can try to make a street car into an autocrosser or you can do a lot less work and make a race car into a great autocrosser
Look through the links. One of them includes a photo of the dipstick and its seal.
Neil, I don't see your name on the San Diego entry list. No time to waste!
Joey was DQ'd at the Southern Pacific Super Regional last year because of weight. We'll never make that mistake again. I shoot for 1110. With scales variances, I feel that's pretty safe.
I don't see either one of you entered in the Pro Solo. With the new Pro Solo Pax this year, we may actually have a chance against the likes of Kiesel and Huffman. Mark, if you want to leave your car here for the week between events, you can either store it at El Toro for $25 for the week I believe, or I'd be happy to let you store it in my shop, about a 40 minute drive north of El Toro and just off the 405 freeway on your way home.
BTW, The 2013 Southern Pacific Super Regional will once again be at El Toro June 21-23. Be sure to mark your calendars for that one. The surface at El Toro is the closest you find on the left coast to Lincoln.
Thanks, Neil. I was trying to plug the top.
Mark
1990 Van Diemen, the Racing Machine, CM AutoX, 2016 Frontier
You can try to make a street car into an autocrosser or you can do a lot less work and make a race car into a great autocrosser
So a 10lb sand bag only out weighed the fire can by 4 lb. Next I plan on a 10x12x3/4 in iron plate under the seat. If that isn't enough, I will do a custom sand bag in the noise to what ever I need. As a last resort, I could fill the gas tank up more.
I think we are ready
Mark
1990 Van Diemen, the Racing Machine, CM AutoX, 2016 Frontier
You can try to make a street car into an autocrosser or you can do a lot less work and make a race car into a great autocrosser
We weighed in on Fri and added enough fuel(my guess) to keep the same weight, 1112lb. It worked for Sat, but on Sun I really needed to add more fuel as I came in at 1100 even. It looks like fuel tank level is the magic variable.
Mark
1990 Van Diemen, the Racing Machine, CM AutoX, 2016 Frontier
You can try to make a street car into an autocrosser or you can do a lot less work and make a race car into a great autocrosser
Fuel was the magic bullet for me and Jackie codriving.
I used fuel as the final piece of ballast for Jackie. I also made a seat back for her that had 5lbs of weight in the base. Were used bags of lead shot (bought at a Scuba store) to achieve the rest of the ballast. The seat pad and bags were easy to switch between runs. The bags nestled under the seat bottom near the fire bottle.
She ended up 1116 on day one and 1106 on day two (we dropped out one bag). I was way heavy (20lbs) because of a) the fuel load, or b) my fattitude. Depends on who you ask.
When Kelly drove our car we used a few layers of lead sheet wrapped in a towel. The lead sheet was bent to confirm to the curvature of the car's fiberglass seat and she sat on it. Extra 2 part foam insert behind her back made the fit pretty good.
Dick
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