Leaf spring question - sub van for trav springs?

[jbrush]

Hi all - I've got a traveller that will have a permanent ~300lbs in the boot, behind the axle. I'm looking at options for uprating the rear suspension.

I note on ESM the availability of 8-leaf springs for van/pickup, which I imagine give some additional load capacity over the traveller's 7 leaf (which itself is heftier than the saloon's 5).

1. Do folks think this would be adequate to compensate for the extra weight, or would I still need some form of "helper spring" (e.g., airbag over axle)?

2. Are the spring length/widths even compatible (i.e. same size for trav and van but for the extra leaf)?

Many thanks in advance! -Jason

[surfergirl]

Hi,
I replaced the springs on my van a couple of years ago and as I recall the front mounting eye is bigger on the van spring to allow it to fit to the chassis mount on vans.
You may be able to come up with different bushes to get around this for a saloon. Whats in the boot?!

[taupe]

Hi

you could probably fit another 'second' spring and a longer dowel bolt ...I would be more worried about reinforcing the floor and chassis with that weight carried all the time..

You may be able to find leaf spring assister's which bolt on to the existing springs

Taupe

[bmcecosse]

I agree - just add a leaf (or two) - and possibly 1" longer rear shackle plates which will lift the car 0,5". Also cut 1" off the bump stop rubbers so you still have some travel. It's quite a weight to have at the back - keep it as far forward as possible !

[jbrush]

Thanks for the feedback. The extra weight is lithium ion batteries. I'm converting to electric drive. 500 lbs overall with half the modules in place of the gas tank, and the other half under the bonnet. It would be better to get the weight *between* the axles, of course, but there is limited opportunity (space) to do so.

BMC, if advice is to add a leaf, would not the van spring do the trick? I'm in California, and 1.5" wide springs are not readily available (nor are bolt-on "helper" springs that small). My options, it would seem, to maintain the leaf spring system, are either to have custom springs forged (est. $500 from an outfit in Colorado, which is actually not too terrible), or import the van springs via ESM (if indeed that'd do the trick). The latter would be cheaper but may still require supplementation. I was also starting to investigate airbag helper springs...

In the front, I'm looking into the JHL coil over conversion (very spendy, which is part of why I'd like to minimize costs in the rear). Would like to get the front suspension shifted outboard because those lever arms are taking up valuable under-bonnet real estate.

[IslipMinor]

The van rear spring mounting is different and you could add an additional leaf, or 2, from a standard Traveller rear spring. the 'U' bolts are probably long enough, but you would need to make up some new clamps and the centre pin that hold the spring together.

[bmcecosse]

Just import a set of Traveller springs... and double up with your existing springs. The coil spring conversion doesn't eliminate the 'inboard dampers' which also function as the top suspension arms....... My advice is to just stay with the torsion bars at the front. Very interested in your electric conversion - let's have all the details of how you are doing it - please!

[jbrush]

Thanks guys! The link to my conversion thread is here:
http://www.diyelectriccar.com/forums/sh ... hp?t=94145

and resto thread here:
http://www.mmoc.org.uk/viewtopic.php?f=28&t=54543

Both only started, and not very well updated, I'm afraid...

How does one measure the weight the springs can take? When under load, how far out of normal curvature is acceptable? And by "double up" do you mean double thickness (14 leaves??), or a second full set in parallel, cheek to jowl on the axle with the first?

Space is an issue everywhere, and the rear is no exception. The battery box is 36" wide, so I'd widen the fuel tank aperture about as far as I dare. The space between the rear chassis rails (and springs) is just over 37." So side-by-side springs won't do.

Another consideration is weight. Solving problems with the lightest (yet affordable) materials is preferable for an EV, so a full extra set of steel leaf springs is moving the wrong direction, if avoidable...

[jbrush]

ESM reports today that a custom bush is all that's needed to mount the van springs on the traveller, and that they may have some. Apparently they had these larger bushings made for a customer a while back and had to order 100 of them (!).

If the best answer is to add a few leaves worth of thickness, and the bushings are available, I'm thinking I'd order the van springs and if necessary, supplement them with a leaf or two from my originals. That'll cost me about half what the custom springs from CO will cost.

Still concerned about what happens up front...torsion bars will handle the additional 300 lbs? Is there no alternative that eliminates the lever dampers? Would not the telescopic damper, mounted at the top, also act as the upper arm?

[bmcecosse]

Most of the weight is going to be at the back....so don't worry about the torsion bars - they can be adjusted easily to gain extra suspension movement if necessary. If ESM have the bushings - then go that way with van springs. The idea I suggested was to use a NEW set of Trav springs - with an extra leaf or two from the old springs added in to the pack......not 'double' springs! But the van springs will be easier. Putting the box in place of the petrol tank doesn't sound too good - that's BEHIND the axle - it will be much better directly above the axle - or as far forward as possible - right up against the rear seat - or even better - in place of the rear seat!

[jbrush]

Thanks. Actually, most of the weight will still be up front, as there's an equal amount of batteries there, PLUS motor and controller (net of maybe 150 lbs greater than the stock motor). In the rear will be just battery pack plus 50 lbs or so of charger and other fiddly bits. So overall, the weight distribution will be much more even than it had been, but certainly chubby all around.

But you are right that the cantilevered weight behind the axle is...sub-optimal. Hence my quest for suspension solutions that can minimize the problem. Many EVS sacrifice interior space for the sake of batteries,but I'm not willing to do that. A primary goal for the project is to have the car appear and have the same utility as our beloved Bonny had bopping around the Highlands. That includes having a fold-down back seat.

[bmcecosse]

Hahahaha -'Giovanni' seems determined you should wait 5 years.... Great project - I suggest you keep it as simple as possible at first, and then improve it later, as you find necessary. Why carry the 'charger' around with you - can it not stay at home? What's the pressure to have an electric car in SF...is it financial or just about being 'green'? Last time I checked - petrol in USA was cheap as chips!! I've been in SF twice before - great City! Will your Traveller be able to climb California ????

[jbrush]

The incentive to do an EV conversion is to be awesome.

The "charger" is a distinct piece of equipment from the EVSE (power supply, plug and cord). It’s true you could build an EV without an onboard charger, but it's not a very good idea. Effectively, not having one cuts your range in half, because you can only charge at home, so every mile logged is one you must save for the return. The (relatively) nominal weight is more than worth the range and anxiety.