Ground clearance at full bump discussion

[Scott_F]

I have heard many theories on this, and would like to see some opinions.

Underground at bump:

Pros: lower CG, better handling
Cons: high risk of slamming chassis into ground and back injuries

The underground system can work if you only bottom out one end at a time. Flat landing a jump where both wheels touch down at the same time could be a problem.

4"+ clearance at bump:

Pros: helps clear the "crown" in rutted out two track courses
Cons: higher CG, more body roll

Ground level at bump:

Split the difference above.

What is your preferred ground clearance with the suspension fully compressed?

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[Josh_K]

Man this could really fire this up here so let me get in early. If it doesnt thou some one will have to ask "whats the best way for the bolt to be located in a 3 link, veritcal or horizontal.

I am not the expert but I think the trend now is not to scoop dirt. I personally wouldnt what it but what do I know.

[ChuckH]

My vote is underground at bump if your trying to go fast or want a cool looking car-truck

Dalton, ok i will bite, if your talking about the top link like in a 4 link but the top is a one piece link then i vote for a vertical bolt because one of the major loads is sideways, the other load is from acceleration and braking and with that is doesn't matter how its mounted, people have done it the horizontal and it still works.

[singlehanded]

neither do it the right way and 4 link it.

[matt_helton]

My vote is underground at bump if your trying to go fast or want a cool looking car-truck

Dalton, ok i will bite, if your talking about the top link like in a 4 link but the top is a one piece link then i vote for a vertical bolt because one of the major loads is sideways, the other load is from acceleration and braking and with that is doesn't matter how its mounted, people have done it the horizontal and it still works.

roger that!

[Brandon_Charley]

Are their any trucks setup for underground at bump? It seems like such a bad idea to me. Is their some kind of other trick to keeping your spine in one piece, do trucks that use this setup have a really drastic front or rear weight bias. Is it maybe a short track thing for groomed dirt only?

My vote is for on the ground at full bump, I intend to get my Explorer as low as possible.

[Josh_K]

Are their any trucks setup for underground at bump? It seems like such a bad idea to me. Is their some kind of other trick to keeping your spine in one piece, do trucks that use this setup have a really drastic front or rear weight bias. Is it maybe a short track thing for groomed dirt only?

My vote is for on the ground at full bump, I intend to get my Explorer as low as possible.

There are some tt's and possibly a few buggies that will hit ground if they ever fully bottomed all 4 corners at the same time. The theory is that bottoming all 4 corner during a race never happens so they do this to lower the overall ride highth.

Now keep in mine that the only cars/trucks that can get away with this are cutting edge vehicals that have so much thought put into there design, constuction and shock set up that it would be all but impossible for any one but the elite fab shops to put to practical use. For all the rest of us that dont know what we are doing, we should stick to more convetional designs

[Allen Bolt]

I always believed that as a minimum, the tire's sidewall height should be the clearance between the ground and the frame at full bump - on cars with non-bypass shocks. The tires act as emergency air springs and save the spine from hurt. Personally I wouldn't like to rely on just the urethane stops to save my spine.
Dalton8driver has a point that for any course, the car should be set up for the worst scenario, a bit like selecting gearing.

[John_Bitting]

I think my blazer is built with 4-5" of frame clearance at full bump. I did not want to bottom out and hit frame.

[MNGSX]

I really dont think handeling characteristics while at full bump are something to worry about...

I would build around a 4+ clearance setup and look at the truck at normal ride height trying to lower the CG and roll center other ways... Its spends alot more time near normal ride height.. Make it handle there.. Concentrate on making it stay in one piece at bump instead..


Mount heavy things like the battery lower in the frame...etc..