t.j.
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 posted on 21/1/06 at 08:42 PM |
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ground clearance
Can anybody tell me which height is normal needed as ground-clearance between ground and frame?
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kb58
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| posted on 21/1/06 at 09:44 PM |
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You need to add more conditions to your question.
For what type of car, what suspension, where will it be driven? If we assume a Locost 7 with a straight axle, it's already defined by the
fenders.
If you mean "in general" for a street-driven car, I went and measured a few speedbumps and came up with 4.5" minimum.
It all depends what you are doing with your car and where you drive it. Also be aware ground clearance is designed in from the very start, you
can't just crank the shock perches down to lower it without also messing up the camber curves.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
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MikeR
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| posted on 21/1/06 at 10:11 PM |
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everyones cars are different but ......... most people try to aim for the engine to be 1" below the chassis and for the chassis to be 5"
above the road giving 4" clearance.
HAving said that i know people running 3" clearance on the road.
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t.j.
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| posted on 21/1/06 at 10:20 PM |
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quote:
Originally posted by kb58
You need to add more conditions to your question.
For what type of car, what suspension, where will it be driven? If we assume a Locost 7 with a straight axle, it's already defined by the
fenders.
If you mean "in general" for a street-driven car, I went and measured a few speedbumps and came up with 4.5" minimum.
It all depends what you are doing with your car and where you drive it. Also be aware ground clearance is designed in from the very start, you
can't just crank the shock perches down to lower it without also messing up the camber curves.
Sorry,
I'm building an tiger avon by "the book" or better said inspired by the book.
I'm using an Sierra 20 DOHC.
it's gonna be 10 cm longer, front track 141 cm rear 150 cm. caster 6.30 degr. using cortina uprights. rollcentre now at 15 mm. ground clearance
callcullated at 14,7 cm. If lowering my roll-centre also drops as my bottom wish-bone is horizontal now.
Bumpsteer is zero, instant centre is complete.
grtz
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cossey
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| posted on 21/1/06 at 11:10 PM |
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also for flat bottom cars the front ride height should be lower than the rear to stop air ramming under the car and causing lift. 1" is normal.
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JohnN
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| posted on 22/1/06 at 12:39 AM |
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wrt ground clearance, measure up your engine, if it is a 1992 dohc, ie pre Zetec, it's both tall and heavy, compared to other engine options.
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JB
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| posted on 22/1/06 at 08:14 AM |
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Ground Clearance
I run around 120mm on my Minor and it is OK, however what I find more critical are the overhangs front and rear. The only time my car catchs the
ground is at the rear.
On my Reliant the sill was so low just behind the front wheel I could not get my foot under it and that rarely caught.
You should be fine with 14.7cm
John
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mranlet
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| posted on 22/1/06 at 10:09 AM |
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Also depends on how stiff the suspension is.
On my street car (98 Legacy Wagon) I only have 3". That is for a car with coilovers and full 3000lb of up and down bounding curb weight. I would
imagine that 3" would be ample for a light car on relatively stiff suspension.
If you're worried baout scraping you could always build yourself a skidplate for the motor and weld on some small and long longitudinally
mounted skid beams on the underside skin.
I forget who it was, but a few years ago someone had posted pictures of their skidbars. If I come across it I'll link it.
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britishtrident
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| posted on 22/1/06 at 12:10 PM |
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It clearance under the sump and bellhousing that is critical --- in the UK you need 4" with the driver onboard or every speed bump will get
you.
Generally best if front clearance under the frame is slightly lower front than the rear --- helps high speed stability and reduces drag slightly.
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