ground clearance?
ground clearance?
(OP)
I am interested to know if/what the 'industry' standard for ground clearance is (rule of the thumb) in comparison to suspension travel.
My vehicle i am building for weekend road use has 4" of shaft (mcpherson) with 2" bump rubbers, so I assume 3" of front suspension bump travel.
I currently have 4" of chassis clearance, does this sound good/bad?
My vehicle i am building for weekend road use has 4" of shaft (mcpherson) with 2" bump rubbers, so I assume 3" of front suspension bump travel.
I currently have 4" of chassis clearance, does this sound good/bad?





RE: ground clearance?
Suspension stroke is up to you. On smooth roads, driven very carefully, 2" is just adequate. Stiffer springs mean you can run less stroke.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: ground clearance?
Consumer Reports shows mostly 4, 5 and 7". A few are 2.5" (static measurements).
RE: ground clearance?
You'll also need some travel into rebound.
The more you have the more options you have when tuning the suspension.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: ground clearance?
I think there's is some confusion as to what I require, although I was interested to know the industry standard (thanks Greg).
I have 3" of wheel travel in bump, I have 4" of ground clearance. Is this a reasonable combination for average and light sports driving? I am at rolling chassis stage and can adjust the ride height now if there was some thinking that I could go lower (preferable) or thinking that raising may be required.
My chassis would have about 600mm from front axle center to front protruding chassis low point running 640mm dia tyres (16/205/55).
I have a total travel of about 8.5" (4" up 4.5" down without 2" thick bump rubbers in place).
Thanks again!
RE: ground clearance?
So far as legal standards go generally, sorry that will depend on your jurisdiction.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: ground clearance?
Also it is very desirable that the chassis or body does not strike the ground when you get a flat tyre.
A lot depends on manner of use, how hard the springs are, type of terrain of use and local laws.
There are a lot of compromises in the mix, and you need to decide which trade offs you want to make.
New car designers and marketing spend a lot of times deciding on the trade offs for each model. A luxury model will be different to a family model which will be different to a off road or utility model which will be different to a soft core sports model to a hard core sports/racing model.
Regards
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: ground clearance?
I havent built a roadcar from scratch before (a few racers up my sleeve)and have a 1" chassis clearance at full travel, level car. I was wondering if there was something about this figure that the more experienced roadcar boffins may know about.
Again, thanks for the interest.
RE: ground clearance?
Incidentally, a ground clearance line is a bit of a misnomer, the line is actually a series of planes underneath the car, to cope with kerbs, speedhumps etc. For instance, we can have less ground clearance out near the wheels, because the wheels protect that space.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: ground clearance?
Yes I understand there are area's to be wary, obviously mid belly rearwards isnt a good place to be low for example.
Also I will try to have more clearance at the furthermost point of the chassis.
Of course we have all seen what happens to low cars with a big front spoiler hanging way out front when they negotiate sloping driveways etc.. Of course exhaust shops like the extra business
RE: ground clearance?
And by the way my 41 Willys is just 4" in front. Just clears a small hyd jack so it looks like I'm in trouble already. I worry more about hitting road kill at night than anything. Especially skunks and 'possums.
99 Dodge CTD dually.