pros, simple enough. Off a 4x4?
cons, would need bracing as they would be the driven wheels. maybe ugly. spring rate.
Just wondering, has someone used McPherson struts for the rear suspension of a 7?
[Edited on 22/6/04 by gys]
would have thought finding springs soft enough may be a problem,
maybe not ?
dunno, bit big n ugly though, all IMHO.
well, it offers 4 wheel steering at least...
pros, simple enough. Off a 4x4?
cons, would need bracing as they would be the driven wheels. maybe ugly. spring rate.
You should look up user TheGecko. He's building a middie with struts.
id almost recommend it with a car-engined middy, theres more weight to spring and the donor struts will save a lot of effort. Plus more height at the back.
Could you be all be talking about the Chapman strut? Now, I wonder why it's called that ...
Cheers,
Neil.
Who was McPherson then?
quote:
Originally posted by Mark Allanson
Who was McPherson then?
quote:
Originally posted by Mark Allanson
Who was McPherson then?
) is a McPherson strut without the rotation bearing. In
a rear application it then must be 'Chapman Strut' (or you add a rack)... GM cars were originally design-bound by accountants.
Not much changed then
I seem to remember that a Chapman strut uses the drive shaft as part of the linkage somehow. Wil check when i get chance unless someone beats me to
it.
At least I was right about Mr McPherson!
The original Chapman strut appeared on some of the early Lotus sports racers. In simplest form, it contained:
The driveshaft to locate the wheel laterally (and drive, of course)
Spring & damper unit
A single trailing arm to locate the wheel longitudinally.
So it obviously puts a lot of load on the driveshafts. Lotus strengthened the system later to include a bottom wishbone to take some of the load.
As Pete Bura said, I'm building a middy struts at the rear. The following picture shows the drivetrain with the (unmodified) struts in place.
The biggest problem is the size of the spring seat. However, kits to convert to coil-overs are common. Here's a pic of an unmodified strut
(different type to mine) and some conversion sleeves (the blue and gold bits).
And here's the same strut with the factory spring seat removed and the sleeve in place (and a nice new paint job).
Those sleeves (ACME thread alloy body with alloy collars) are AU$38.50 each (about GBP14.50) so hardly expensive.
The biggest problems could be the height of the strut and the need for a fairly rigid top mount. The height isn't as big a problem as you might
think - my Corolla struts tops (at normal ride height compression of the strut) are 850mm off thr ground. That's only ~100mm higher than the
normal rear bay in a book Locost (from memory - I'm at work and The Book is at home).
The frame strength is a seperate issue and important because the strut is providing suspension location in three directions. In the back of a front
engine Locost it would be fairly straightforward to brace I would think.
Strut rears have been used on plenty of performance cars since Chapman's efforts too. Obvious examples are Lancia Stratos, Lamborghini Urracco,
Toyota MR2 etc etc.
The ubiquity of struts also makes than a very inexpensive choice now. On the weekend, I also decide that I will reuse the Corolla front subframe
which has two engine mounts and the suspension arms all attached. Will need about 10 bolts to hold it to my chassis and then most of the rear
suspension is built and aligned for me
Best regards,
Dominic
I Could you be all be talking about the Chapman strut? Now, I wonder why it's called that ...
The 'Chapman strut' (yes, after the guy that invented those funny sportcars ) is a McPherson strut without the rotation bearing. In a rear application it then must be 'Chapman Strut' (or you add a rack)...
Good grief... that mount above will have terrible bending loads in bump.
if its good enough for lotus , then ..........
Has anyone used the Macpherson's on the front? perhaps replacing the top wishbone?
Robin Hood use a 'mini McPherson strut' on there cheapest kit.
Below is a pic of as much of the strut as they show on thier website.
[Edited on 19/3/05 by clbarclay]
Rescued attachment robin hood 2b.JPG
The Robin Hood set up is actually sliding pillar much as used by Morgan. RH called a mini McPherson strut either because sliding pillar has such a
(justfied) bad reputation or I suspect more likely (having seen examples RH suspension expertise) they didn't know any better.
McPherson didn't invent strut suspension the inventor was a Rolls-Royce and later GM engineer Maurice Olley. MacPherson took it with him to
Ford GB (then almost entirely seperate from the main Ford company)and symplified combining the anti-roll bar and track control arm to form the lower
wishbone. For obivious reasons Ford dubbed the revised aranagement a McPherson strut.
Olley along with Fred Lanchester was the foundng father of automotive suspension and a major influence on Colin Chapman.
On aircraft landing gear struts are still called after Olley.
As in one of the pictures the original Elite and Elan used struts. The Elite had a fixed length drive shaft the Elan rotoflex joints.
The lower end of the strut was a special alloy casting to accomodate the wheelbearing --- The height of the upper mounting wasn't much
different from the upper shocker mount on a Locost because Chapman did a very clever wheeze and didn't put the strut centre line in line with
the wheel bearing axis but moved it forward by about 4 inches, this was enough to allow the bottom end of the damper tube (from a Ford Anglia) to
sit alongside the wheel bearing and drive shaft, this being the key difference between a Chapman strut and MacPherson strut. This of course allowed
the strut top mount to be several inches lower and suitable for use in a small sports car. Elans were great handling road cars but could be a
handful on the track much I suspect due to the strut suspension.
I have seen Elan struts transplanted on to the rear of a racing Imp (John Fyda's "Agra Imp" and can't say it gave any
advantage over the more usual semi-trailing arm Imp suspension.
Also Davrian tried using Fiesta struts on the rear of the Davrian Dragon (a Fiesta power Davrian Mk8) but Adrian Evans concluded they didn't
work and reverted to using semi-trailling arms.
[Edited on 19/3/05 by britishtrident]
quote:
Originally posted by rusiq
I Could you be all be talking about the Chapman strut? Now, I wonder why it's called that ...
The 'Chapman strut' (yes, after the guy that invented those funny sportcars ) is a McPherson strut without the rotation bearing. In a rear application it then must be 'Chapman Strut' (or you add a rack)...
quote:
Originally posted by britishtrident
The Robin Hood set up is actually sliding pillar much as used by Morgan. RH called a mini McPherson strut either because sliding pillar has such a (justfied) bad reputation or I suspect more likely (having seen examples RH suspension expertise) they didn't know any better.
quote:
Originally posted by kb58
Good grief... that mount above will have terrible bending loads in bump.
quote:
Originally posted by MikeRJ
quote:
Originally posted by kb58
Good grief... that mount above will have terrible bending loads in bump.
Exactly what I thought. The suspension tower is extrememly robustly made with considerable triangulation and it's them mounted on a couple of bits of unsupported RHS. Should flap around nicely, perhaps it's a cheap way of reducing spring rate (until it fatigues and falls off).
quote:
Originally posted by Volvorsport
if its good enough for lotus , then ..........
How many F1 drivers did they kill Steve?
quote:
Originally posted by stephen_gusterson
quote:
Originally posted by Volvorsport
if its good enough for lotus , then ..........
i disagree.
lotus and chapman desings have killed more F1 drivers due to mechanical failure than any other team. addinf a brace would have added 8 oz of weight in that design, so thats why it wasnt fitted.
atb
steve
more
Rescued attachment road_n_track_63_1_4a.jpg
The early Datsun Z-cars were very similar in design.
