Hello, I'd like to find a place in SoCal (preferably Los Angeles) which can do center of gravity height measurements to calculate the Static Stability Factor (SSF) as described in:
https://dk1xgl0d43mu1.cloudfront.net/us ... s-1-12.pdf
This is for my Chevy Bolt EV, which fails the 1:1 track width:height relationship, but has a floor-mounted battery weighing over 900 lbs (like a Tesla Model S/X/3). For the Model S, it's only 18", so I think the Bolt would be similar.
I've never competed in anything before, and the Bolt is the only car I'd compete in, but it's ineligible unless I can get an independently verified SSF and submit it to SEB. I haven't seen the exact measurement posted on any websites, and I don't think it's been disclosed by GM.
So, is there an independent shop/lab which can do this? Thanks.
Place to measure center of gravity height
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- Bill Martin
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Re: Place to measure center of gravity height
Here's how it's done with race scales:
http://www.longacreracing.com/technical ... item=42586
http://www.longacreracing.com/technical ... item=42586
Re: Place to measure center of gravity height
Yes, it requires scales, a tall lift and solid shock links; so probably not a lot of places have these. I don't even have the tools or skills to replace MacPherson struts, myself.
The center-of-gravity-height will also be different with windows rolled down, and I noticed most folks had both front windows down today, some only had the driver side down; but most had rear windows up. I suppose the front being down is for safety and driver extraction and the rest of the windows were up for aerodynamics?
The center-of-gravity-height will also be different with windows rolled down, and I noticed most folks had both front windows down today, some only had the driver side down; but most had rear windows up. I suppose the front being down is for safety and driver extraction and the rest of the windows were up for aerodynamics?
- KJ Christopher
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Re: Place to measure center of gravity height
I'd posit no where near that much thought went into their window positioning.Eric Wong wrote: I suppose the front being down is for safety and driver extraction and the rest of the windows were up for aerodynamics?
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Use the email link. I don't read nor get notified of PMs.
Former No$ Club Rep | Former SCCA Area 11 Director |Former CSCC Solo Chair
Caged Z Motorsports - automotive consultation
The ACME Special Now with Super Speed Vitamins
Re: Place to measure center of gravity height
It looks like GM published the center-of-gravity height as 20.7" at some point on their media site:
http://media.chevrolet.com/media/us/en/ ... .tab1.html
It wasn't in an earlier copy from 2016, and archive.org has not crawled it this year so I'm not sure when it appeared:
https://web.archive.org/web/20161214162 ... .tab1.html
Nor is it on chevrolet.com without "media".
The 20.7" center-of-gravity and 59.1" track width gives the SSF as: 59.1 / (2 * 20.7) = 1.4275; more than the 1.3 required.
Somebody else also submitted this info to SEB already, so it should be classed in the December Fastrack (out Nov 20) and I should be able to finally run my Bolt at the December events.
I was going to wait for the NHTSA to test the car and then submit an FOIA request to get the raw data with the SSF, but now I won't have to wait as long
Somebody else also went this route with the Nissan Leaf to get it classed.
http://media.chevrolet.com/media/us/en/ ... .tab1.html
It wasn't in an earlier copy from 2016, and archive.org has not crawled it this year so I'm not sure when it appeared:
https://web.archive.org/web/20161214162 ... .tab1.html
Nor is it on chevrolet.com without "media".
The 20.7" center-of-gravity and 59.1" track width gives the SSF as: 59.1 / (2 * 20.7) = 1.4275; more than the 1.3 required.
Somebody else also submitted this info to SEB already, so it should be classed in the December Fastrack (out Nov 20) and I should be able to finally run my Bolt at the December events.
I was going to wait for the NHTSA to test the car and then submit an FOIA request to get the raw data with the SSF, but now I won't have to wait as long
Somebody else also went this route with the Nissan Leaf to get it classed.
- Q V
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Re: Place to measure center of gravity height
That's awesome Eric, I'm glad you were able to follow through with this! I hope they class it asap.Eric Wong wrote:It looks like GM published the center-of-gravity height as 20.7" at some point on their media site:
http://media.chevrolet.com/media/us/en/ ... .tab1.html
It wasn't in an earlier copy from 2016, and archive.org has not crawled it this year so I'm not sure when it appeared:
https://web.archive.org/web/20161214162 ... .tab1.html
Nor is it on chevrolet.com without "media".
The 20.7" center-of-gravity and 59.1" track width gives the SSF as: 59.1 / (2 * 20.7) = 1.4275; more than the 1.3 required.
Somebody else also submitted this info to SEB already, so it should be classed in the December Fastrack (out Nov 20) and I should be able to finally run my Bolt at the December events.
I was going to wait for the NHTSA to test the car and then submit an FOIA request to get the raw data with the SSF, but now I won't have to wait as long
Somebody else also went this route with the Nissan Leaf to get it classed.