Garage Ramp Maximum Incline Angle
 

Good Morning. I have a 2004 C5 and just bought a 2-car garage for it.
The floor of the garage is 8.5 inches above street level.
Being a better driver than carpenter, can anyone suggest how long a ramp should be to allow driving into the garage without scraping the spoiler? I plan to build the ramp from pressure treated lumber.
Thanks.

scrape
 

Just for the record the spoiler was designed to be scraped a little,but 8'' is a lot

Follow the guidelines for wheelchair/handicap access.

27 inches long @ 17* degree angle.

you can look at my ramp design:
http://mikemercury.home.att.net/ramp.htm

My 2002 non-lowered non-Z51 coupe could only tolerate a 9 degree rise to avoid touching the rubber air blade. Once the car was tilted 4 inches high in front , the angle could increase to 15 degrees.

That;s why I did two angles on these ramps. If I maintained the 9 degree angle of rise, the ramps would of needed be (around) 8 feet long to get the desired 10" lift. By changing to 15 degree at the 4 inch lift mark, I cut down on the overall length of the ramp.

Like others stated, making contact with the flexible air dirverter is not a negative thing... it's made to flex.

Thanks everyone for the input.
Since I am custom building these, I want to avoid the need to have the spoiler use it's hinge.
The dual angle design looks good, but since I will be using these to enter a garage the rear wheels will be following the same path. I am concerned about mid-chassis hang-up if the front wheel are going level before the rear wheels get enough incline to clear the "hump" where the ramp stops inclining and becomes level.
Anyone ever do this or design it?

My garage has 2 levels 12 inches different in elevation, my concrete ramp is 12 feet and I don’t come close to hitting anything. So a inch per foot and your in, no worries

Thanks, love the ramps, hope to build this weekend !

Final Product Garage Ramps
 

This is how the ramps worked out. The 1 foot per inch of rise was the trick. I have no less than 2 inches of body clearance at anytime. These ramps worked out to be 8 feet long for the 8 inches of elevation to the floor of the garage.

http://www.erols.com/marksr/garageramp.jpg

WOW; nice work. Looks professional.

:cheers:

Looks nice, but I'm just curious; If you built the garage knowing you would be parking cars inside, why wouldn't you build the ramp into the equation with the asphalt instead of the wood? (or potentially having the building match up with the current asphalt)

Either way, still a nice setup. :yesnod:

The space I put the garage was already asphalt. It is really a double shed and does not attach to the ground but rather just sits on top. I save on property taxes that way.