Ok so from the advise i have been given on my suspension setup I ideally need longer shocks all round.
between the mount points for the dampers the i measure a range of 275 - 350mm so if i fit a 14" shock with open length of
356mm when on full droop in theory the suspension will hit a hard point before max travel is this ok? or should i go for a shorter damper
and have the damper as the limit to travel?
Thanks
ArA
quote:
Originally posted by ArAKern
Ok so from the advise i have been given on my suspension setup I ideally need longer shocks all round.
between the mount points for the dampers the i measure a range of 275 - 350mm so if i fit a 14" shock with open length of
356mm when on full droop in theory the suspension will hit a hard point before max travel is this ok? or should i go for a shorter damper
and have the damper as the limit to travel?
Thanks
ArA
I know that on OEM suspension, you can have what is called a 'rebound buffer'. I don't know if this is common in the aftermarket though.
Shouldnt really matter as no force is ever put in to droop, unlike compression. However shock lengths should be set to match intended swing, and governed by the manufacturers guidance.
In rebound the unsprung mass is accelerated by the compressed (and now extending spring). Unless this is reacted by the tyre on the road, the force will be taken up by the damper piston/tenon and therefore also the suspension upper bush/clevis.
quote:
Originally posted by james h
In rebound the unsprung mass is accelerated by the compressed (and now extending spring). Unless this is reacted by the tyre on the road, the force will be taken up by the damper piston/tenon and therefore also the suspension upper bush/clevis.
In the dim and distant past I had a Marstro 2.0L efi, faster than an Escort XR3l which I had stolen.
The Meastro has this really weard and troubling problem of the front shocks bottoming out on full droop, now I’ve got air in a number of cars but the
thunk of shocks reaching the end of travel is unnerving, I just don’t like it.
There is nowhere on a shock to put a negative bump stop, I have heard of straps that stop the shock reaching full droop because a strap is cheaper
than a new shock, but you’ll still feel an unearthing thid
quote:
Originally posted by snapper
An Escort XR3l which I had stolen
On full droop the front springs are loose on my car, it looks unsettling on the trolley Jack as the retainers could move although in practice its not been a problem or I would replace with shorter shocks or longer springs.
quote:
Originally posted by jps
quote:
Originally posted by snapper
An Escort XR3l which I had stolen
Despite the passing of time it's always best not to openly confess ;-)
quote:
Originally posted by loggyboy
quote:
Originally posted by james h
In rebound the unsprung mass is accelerated by the compressed (and now extending spring). Unless this is reacted by the tyre on the road, the force will be taken up by the damper piston/tenon and therefore also the suspension upper bush/clevis.
Yes but only if you in a rally car going from one extent to the other over a jump - unlikey to happen in track/road car. So unless your crashing, in which case is probably the last of your worries!
Its also damped, reducing the acceleration, so Even if you get to full lift on track due to high cornering forces or kerb hopping, the load will not be travelling far to gain momentum.
Only track exception for jumping I can think of is cadwell park, but even then the road drops away slowly giving suspension a chance to extend with reduced force.
quote:
Originally posted by ArAKern
Ok so from the advise i have been given on my suspension setup I ideally need longer shocks all round.
between the mount points for the dampers the i measure a range of 275 - 350mm so if i fit a 14" shock with open length of
356mm when on full droop in theory the suspension will hit a hard point before max travel is this ok? or should i go for a shorter damper
and have the damper as the limit to travel?
Thanks
ArA
Insufficient travel in droop is never good on the rear. You will get frequent knocks as the dampers ‘top out’ which can eventually cause premature
failure.
It can also give a loss of traction as the unloaded wheel is lifted from the road in roll, exiting a corner. Protech do extended top eyes that fix
this quickly.
However, for track use, front dampers with restricted droop can be a trick to restrict roll. As mentioned by James H, the inner spring extending
assists in pushing the sprung mass outwards and upwards. If the droop is limited, the roll moment adds more load onto the outer spring and further
motion lowers the front of the car not raising it as normally happens.
Protech can add an internal buffer to dampers used as droop stops. Its purpose is to prevent internal damage.
quote:
I had my Orion injection Ghia stollen.
very common in the 4x4 world, called suspension limiting straps
All series landrovers had these as standard on the back, although using much beefier fabric than just seatbelt stuff that's the norm these
days
As demonstrated in this pic it's not the damper that is at risk but joints and driveshaft CV's. Although for road cars going full droop is
going to be very rare
[Edited on 15/12/17 by Mr Whippy]
quote:
quote:
I had my Orion injection Ghia stollen.
Was that a German cake shaped like an Orion?
Sorry.
Ah the venerable Austin Maestro that takes me back, first car I had access to (my parents) which I wrote off 
did it properly mind rolled it every
panel and every piece of class smashed 
So thanks to the responses so in conclusion (i will not be fitting straps) Should I option:-
1, select a shock open length longer than the physical suspension travel.
or
2, select a shock open length shorter than the physical suspension travel.
2
My ex-military 1967 SII LR has straps running around the axle from mounting points on the chassis above. The spring hangers are all lower on these
military variants, giving a considerable ride height and articulation (even with the horse cart spring architecture).
However - I wouldn't do this on my 7 or race car. On the race car, I shortened the shock pushrod (eye end) - which is what you might be able to
do in this case?
Desmond Tweeks do spring assistors, just light poundageflat coils that take up the skack
In model car racing, droop stop adjustment is as critical/important setting as is spring rates/damping/camber/castor etc etc. Adjusted to within 0.1mm
lhd/rhd if your racing at a reasonable level (national, euro's or world championships).
Ian