Suspension, Up travel or downtravel?

[Rainbow Warrior]

Say you have 3 factory coil sprung vehicles each with 10 inches of travel per corner.

No1 natrually sits at the half travel position
No2 sits 3 inches above centre
No3 sits 3 inches below centre

Beside the obvious ground clearance issues, would there be much difference in crossups or perhaps the lower one would be more stable at side angles or road use?

How would shocks effect them if they were biased in one direction like koni's or Rancho's?

There would also be the bottoming out issue I suppose leading me to believe the best position is halfway and ideally an air bag option to lift higher for clearance in some situations would be good but only where bottoming out of chassis was an issue.

[ISUZUROVER]

The best suspension system will be one where the static ride height is the middle point of the suspension travel, so you have equal droop and compression. It will be the most balanced in terms of travel and the most stable offroad.

Although this is a hypothetical example, in a real case - the one that is lifted 3" will usually not get the same travel as the centred suspension because it will need higher rate springs to get it 3" higher. And the one that is too low may not get full droop offroad.

Of course the one with lower ride height will have a lower CofG.

I doubt shock absorbers will have a significant effect on overall travel and stability between the 3 cases.

[Slunnie]

Whats it going to be used for?

In my unedudecanted upinion remembering you did say apart from ride height issues etc.

I would have it naturally sitting for more bump travel for touring to carry the weight via stiffer springs and more up travel will absorb a lot more of the bumps and ruts before smashing you into the bumpstops.

Offroading I tend to think for more drop travel to keep the cofg low, it also means softer springs to keep even weight on the wheels and when you stand the thing on its tail, especially with a side angle the travel wont go too far before landing on the bumpstop and stopping it all from getting too exciting.

Now shumbodi who nose more may refute this.

Oh, and all shocks are stiffer in rebound, not just Koni/Rancho etc.

[Rainbow Warrior]

The best suspension system will be one where the static ride height is the middle point of the suspension travel, so you have equal droop and compression. It will be the most balanced in terms of travel and the most stable offroad.

Although this is a hypothetical example, in a real case - the one that is lifted 3" will usually not get the same travel as the centred suspension because it will need higher rate springs to get it 3" higher. And the one that is too low may not get full droop offroad.

Of course the one with lower ride height will have a lower CofG.

I doubt shock absorbers will have a significant effect on overall travel and stability between the 3 cases.

You suspect it may not get full droop offroad because the springs fall out or in case they were fixed in place to prevent this they would cactually lose weight over the wheel concerned?

The 3" lifted unit would have more pressure on the wheel at near full droop perhaps, but then also more opposition to full upward travel on the opposite wheel?

So perhaps with soft suspension that sat below middle ride height you would have better upward travel and downward, but lack wheel pressure?

[Rainbow Warrior]

Whats it going to be used for?

Probably latenight hypothetical/imaginary ramp tests & dumb questions. May even put fluro lit bonnet tachos on all 3 of them

[bruiser]

I had my 6 inch suspension lift put in 6 months ago and I can tell you that I have way more upward travel and more downward than at standard height.
Don't understand how anyone can say a vehicle at standard hieght has maximum travel.
Steve

[MY45]

Have a look on pirate, ive seen a few interesting theads on there.

[bruiser]

Take your springs and shocks out and jack your car body up and then let it fall down to bump stops.
The mid point of travel is way beyond standard height

[Slunnie]

I assume we are working within the 10 travel on the shocks though. I'd assume this is more theory developement than suspesion designing.

[ISUZUROVER]

I had my 6 inch suspension lift put in 6 months ago and I can tell you that I have way more upward travel and more downward than at standard height.
Don't understand how anyone can say a vehicle at standard hieght has maximum travel.
Steve

This is a theoretical system we are considering with all things being equal. I am sure when you did your lift you modified shocks, springs, bump stops, link angles, castor, etc... So of course you have more travel over stock.

If your suspension is not limited by: shock length, bush/link binding, tyres rubbing the body etc... then the balanced suspension (halfway between up and down travel) will always work best offroad.

[bruiser]

Yes I agree half way is best. but halfway is still a long way off standard height even without moding the arms, links etc.
(on most vehicles anyway)

[bogged]

Don't understand how anyone can say a vehicle at standard hieght has maximum travel.

By not having matched shocks, springs, bumpstops, linkages, swaybars, etc etc many variables..

You could have a 3000ft lift, and no travel.

[Shorty40]

Don't understand how anyone can say a vehicle at standard hieght has maximum travel.

By not having matched shocks, springs, bumpstops, linkages, swaybars, etc etc many variables..

You could have a 3000ft lift, and no travel.

It would be a little bit tippy aswell

[Rainbow Warrior]

I assume we are working within the 10 travel on the shocks though. I'd assume this is more theory developement than suspesion designing.

That is correct, just bouncing ideas around, I have noticed stock vehicles on sagged soft springs on occasions outperform lifted rigs because they were too stiff.

[bruiser]

yes if the shocks are not geting replaced and have only 10" of tavel then the mid of this is the best.
Sorry thought you were talking about getting maximum up down travel from new springs, shock.
If your not replacing the shocks then you will want to stay at there mid point.
Option no 1 is the go dude.
when you say 3 inches above/ below centre of travel what are you taliking about?
Shock travel or the whole axle link system?
Rainbow warrior

[zzzz]

Now throw a 2" body lift into the mix and re-think everything

[Slunnie]

Why does the body lift change the way the suspension operates apart from raising the CofG?

[bruiser]

Body lift will do nothing suspension wise unless the body is the limiting factor. ie the tyres are hitting wheel arch.

[zzzz]

Why does the body lift change the way the suspension operates apart from raising the CofG?

The main benefit of a BL is that it allows you more uptravel without increasing your COG by as much as a spring lift.

So with a BL you can either raise the bumpstops or fit larger tyres as they wont hit the body as early.

[muddyperils]

Why does the body lift change the way the suspension operates apart from raising the CofG?

The main benefit of a BL is that it allows you more uptravel without increasing your COG by as much as a spring lift.

So with a BL you can either raise the bumpstops or fit larger tyres as they wont hit the body as early.

Larger tyres maybe after spending on custom rims that are offset $$$$ but rarely reducing the bump stops !!!

[Rainbow Warrior]

yes if the shocks are not geting replaced and have only 10" of tavel then the mid of this is the best.
Sorry thought you were talking about getting maximum up down travel from new springs, shock.
If your not replacing the shocks then you will want to stay at there mid point.
Option no 1 is the go dude.
when you say 3 inches above/ below centre of travel what are you taliking about?
Shock travel or the whole axle link system?
Rainbow warrior

I'm refering to the dhocks parked position due to spring set height differences, softer/stiffer springs or load.

[Rainbow Warrior]

Now throw a 2" body lift into the mix and re-think everything

Actually all 3 of my hypothetical vehicles have 8" body lifts & red slurpee injection

[Rainbow Warrior]

Why does the body lift change the way the suspension operates apart from raising the CofG?

The main benefit of a BL is that it allows you more uptravel without increasing your COG by as much as a spring lift.

So with a BL you can either raise the bumpstops or fit larger tyres as they wont hit the body as early.

Just raising/removing the bump stops doesn't necessarily gain more travel, does wonders for shock sales though.

[Rainbow Warrior]

Why does the body lift change the way the suspension operates apart from raising the CofG?

The main benefit of a BL is that it allows you more uptravel without increasing your COG by as much as a spring lift.

So with a BL you can either raise the bumpstops or fit larger tyres as they wont hit the body as early.

You may also punch the guts of your shocks out on upward travel, unless you raise them too. You can also find the spring bottoming out on its coil compression too.