Author Topic: Parachute Sizing  (Read 1032 times)

Offline lake_harley

  • Sr. Member
  • ****
  • Posts: 259
    • View Profile
  • Your Best Time: 7.06 @99.58 - 1/8 mi.
  • Your Engine: Carbureted, gas mild 305 Chevy
  • Your Track: Jeffers Motorsports Park - Sikeston, MO
  • Your Vehicle: 145" FED
  • General Location: SE Missouri
Parachute Sizing
« on: May 08, 2022, 10:51:35 AM »
Just how bad would it be to use a parachute on a car about 2/3 the weight of the specs on a manufacture's sizing chart. The car would also be slower than the speeds listed for the heavier car chute as well.

The reason I ask is that I fully intend to put a chute on the FED I'm building, but at the races last night at my local 1/8 Mi track I never saw a single car deploy a chute and they were running much faster MPH and much quicker E.T.'s than what my car will be capable of. I read of "soft" and "hard" opening chutes, but I would think that any particular chute would open softer at 100 MPH than it would at 140 MPH or more.

I don't want to disregard a manufacturer's recommendations or safety. I was able to pick up a nice chute but was told it's for a heavier car and wouldn't be suitable for my FED. I can fully understand the danger of using too small a chute for the speed and weight of a car, but it seems a chute a bit too big to not be as critical, especially at slower speeds.

Thanks, in advance for advice from a user's standpoint.

Lynn

Offline wideopen231

  • Hero Member
  • *****
  • Posts: 1910
    • View Profile
  • Your Best Time: 1/8 3.70@ 198 1/4 5.78@245
  • Your Engine: Hemi 526 ci alcohol
  • Your Track: Piedmont
  • Your Vehicle: 225 CMC FED
  • General Location: NORTH CAROLINA
Re: Parachute Sizing
« Reply #1 on: May 12, 2022, 07:28:50 PM »
WIth weight of FED's being less than most cars and speeds you are talking about any chute will work. I am looking fo get rid of two big chutes I have and get smaller because don't need big ones and big weight savings at same time.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline lake_harley

  • Sr. Member
  • ****
  • Posts: 259
    • View Profile
  • Your Best Time: 7.06 @99.58 - 1/8 mi.
  • Your Engine: Carbureted, gas mild 305 Chevy
  • Your Track: Jeffers Motorsports Park - Sikeston, MO
  • Your Vehicle: 145" FED
  • General Location: SE Missouri
Re: Parachute Sizing
« Reply #2 on: May 13, 2022, 05:47:01 AM »
When I sent the chute to Stroud, they said it was a Model 430 Std. 32. I was told the correct size is a model 410. I got it back from them as-is, still set up to be "launched", rather than having a pilot chute. Is there a chance that the chute is so big that it wouldn't even "bloom" at my lower 100-ish MPH 1/8 Mi. speed? I had considered buying a pilot chute and chute pack to convert/complete the chute for pilot deployment.

I don't think I'll even have to use the chute where I plan to run the car, but if it was needed in an emergency I want it to work even if the deployment would be hard with the cars much lighter 1650-ish expected weight. I still have time before the car is completed but I hate the indecision about things like this clogging my brain.

Here's a link to Stroud's sizing chart. The chute I have is the one shaded in yellow in the left hand side chart. https://stroudsafety.com/racing-parachutes-and-launchers/#size

Lynn
« Last Edit: May 13, 2022, 05:51:40 AM by lake_harley »