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irs or solid mk2 type? either type the angle isn't important, the more straight up the firmer the ride will be and vice versa if laid over at an angle.
neil.
 

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Consider arc of travel from the pivot point on the lower arm when deciding upper mount location. This will aid in preventing potential bind up on the coil over, as it will be aligned and perpendicular during travel.
 

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Not so much cause bind as increase rge spring rate . As you lay the shocker at an angle so the effective rate of the spring declines , roughly by the same amountas the inclanation ie 30' lean is aabout 30% derate of spring rate . Depends what model the spring shocks came from.

Also is chnaging to aftermarket coildover shocks the bushes need to be replaced with Jag specific items as they are larger pins than standard aftermarket.
 

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If on a budget and using the factory coilovers will almost certainly be the wrong pondage springs unless installed at the same angle and weight of the Jag they came from,
A band aid for years if using the stock coilovers is to create 2 or 3 positions for the top with outer being upright and the others going closer to the diff to jn effect soften the spring rate.
 

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Vertical will cause bind thats what makes the stiffer ride. They do need some angle on them to perform correctly.
you're wrong about there being bind causing a stiffer ride in this case, as fitting the coilovers vertical will not cause any bind as long as the top and bottom pivot bolts are kept parallel. as kev says it just alters the effective poundage of the springs by laying them over more or less.
to keep the stock jag ride quality what you need to know is does the panel van weigh the same as the jag at the rear wheels, if so the stock mount angle will be fine. if it's less then lay them over more than stock, if it's more mount them more upright. that way you can keep the stock jag springs.
neil.
 

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Discussion Starter · #10 ·
If the bottom of the shock moves on a arc the top of shock needs to be on that plain. when the shock is at the right angle spring ratings can be changed to suit the ride.
I would not fit them upright as the suspension looses its effectiveness as the shock cannot work properly.
 

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Also depends what ride height you are aiming for and the angles of the driveshafts . Most rodder like to set them straight ( to aid lowering ) but more correct with an incline down to the wheel . Better to raise the crossmember in the chassis to get it lower and work more as designed.
 

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If the bottom of the shock moves on a arc the top of shock needs to be on that plain. when the shock is at the right angle spring ratings can be changed to suit the ride.
I would not fit them upright as the suspension looses its effectiveness as the shock cannot work properly.
that's why i said the top and bottom shock blots/pivots need to be parallel. plus what everyone seems to forget is the coilover only has 2-3 inches of travel so saying it swings in an arc is really really nit picking, it's a tiny amount to be fair. either way there's no bind, no issues and either will work just fine. you just need to decide what works best for you, both functionally and aesthetically. be aware that stock jag fitment coil springs are few and far between in different poundages, the coilovers can be swapped out for aftermarket ones with 2 1/4" springs and then spring choice is vast but buying 4 coilovers and springs can get spendy. again it's what works best for you.
neil.
 

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Discussion Starter · #13 ·
that's why i said the top and bottom shock blots/pivots need to be parallel. plus what everyone seems to forget is the coilover only has 2-3 inches of travel so saying it swings in an arc is really really nit picking, it's a tiny amount to be fair. either way there's no bind, no issues and either will work just fine. you just need to decide what works best for you, both functionally and aesthetically. be aware that stock jag fitment coil springs are few and far between in different poundages, the coilovers can be swapped out for aftermarket ones with 2 1/4" springs and then spring choice is vast but buying 4 coilovers and springs can get spendy. again it's what works best for you.
neil.
I've managed to get some info from a jaguar specialist. The distance between the top shock mounts on my xj6 axle should be 30" the distance between the bottom mounts is 38". So that's a 4" difference between top and bottom mounts. With shocks mounted this way the axle movement is at it best. 1 inch either way is also ok. Having them vertical stops the axle movement as the bottom mount wants to go inwards on movement not up wards. Mounting shocks this way is on a live axle will work better. But even on a live axle the still need a bit of an angle to perform well.
 

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glad you got the info you needed to get it where you wanted.
as i mentioned with the small overall travel of the coilover the 'inward' movement of the lower mount you mention may be as much as a few mm which will in no way 'stop' axle movement, it just won't happen. if the lower arms are angled down at ride height as per stock jag, when the suspension is compressed the lower mount will actually go outwards until the arm is horizontal then it will go in so negligible changes from one extreme to the other. i don't know who told you they'd 'bind' if vertical but they're simply wrong.
as i say i'm glad you're sorted now though.
neil.
 

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In reality,coilovers dont really care what angle they are mpunted at.

They all work. Upright is fine. Ive fitted them in just about ever configuration,due to packaging.even mounted them facing backwards slightly will no ill effect.
 

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In reality,coilovers dont really care what angle they are mpunted at.

They all work. Upright is fine. Ive fitted them in just about ever configuration,due to packaging.even mounted them facing backwards slightly will no ill effect.
exactly wayne, as long as the bolts at each end stay parallel during travel it can't bind. (y)
 

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i also mount a lot with the top and bottom mounts at 90 degrees to each other. again it affects nothing over a suspensions travel.they actually move very little and any movement is taken up by the bushes.

one thing i do with just everything i build here,is to cycle suspension,through its full travel. you gotta do something majorly wrong to make a coilover bind up. youre run into more issues using them with bearings,and having one seize.ive seen snapped bearing ends,as once they lock up,there is no movement
 

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i also mount a lot with the top and bottom mounts at 90 degrees to each other. again it affects nothing over a suspensions travel.they actually move very little and any movement is taken up by the bushes.

one thing i do with just everything i build here,is to cycle suspension,through its full travel. you gotta do something majorly wrong to make a coilover bind up. youre run into more issues using them with bearings,and having one seize.ive seen snapped bearing ends,as once they lock up,there is no movement
Just something else to consider.Most after market coil over shocks usually have about 3 inches of travel from fully compressed to fully extended. The normal rule of thumb is that at ride height your shock should be about 30% compressed,this is normally referred to as sag.This gives your approximately 60% Of travel for compression(downward travel) and 30% for rebound.Because stock jag shocks have no adjustments it’s sometimes difficult to get your ride height correct but with aftermarket you have some adjustment by turning the bottom collar.I would recommend you spend the extra money although this can be considerable because obviously there are four. I have seen lots of vehicles that have only two but this is normally on a very light vehicle such as a T Bucket,not on a van especially if you want to carry anything in the back.As I am sure you are aware there are many variables when installing a Jag IRS.Normally any binding is caused by the bars that extend forward from the lower arms especially if the bushings are polyurethane as they have very little give in them unlike rubber that the factory jag ones are.About the only way you can elevate this totally is by making the bars point in towards the driveshaft and having there pivot point on the same axis as the Inner fulcrum points on the jag axle lower wishbones.Just something to think about when your carrying out your fabrication for the install.
 

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Discussion Starter · #19 ·
Great info chaps. I will be setting mine up they way jaguar do theirs. I'm looking for the best ride and their way seems to be the way
I will be fitting 4 new adjustable coil overs when complete. I will speak to gaz about them and spring poundage . Lastly the bars that go from the lower wish bone to chassis ( can't think of their name) will be nice and long and as near as possible to the wish bone pivet points
 

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Good sounds like you have everything under control,if you get time post some pictures, always enjoy seeing other people’s projects and how they overcome any problems they may encounter.Good luck with your modifications.
 
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