What did I do On Kevin's, Houston's, Ian, and Alexs' rally Volvo 240s today?

eyesoreracing Wrote:
--
> It looks like I'll have 6.25mm clearance between
> the tire and front spring with the 626 wheels,
> Only 1.25mm with Millenia wheels.
>
> Bigger problem with putting 50mm struts in is the
> fact that the strut clamp is only 52mm. So even if
> I keep things straight, I'm still going to have to
> make some extension that welds to the bottom of
> the strut tube and lifts the functional bits above
> the clamp.
>
> -Dave

Remember that the combined offset/clampy thang is for cars having old school "tube welded to spindle" designs like old Datsuns , old Maz-dogs, BMW theu the 90s, Fiat and Volvo,
For cars already having the plug in, or "socket" style fitment then all that's needed is the bottom offset thang. Here's a photo of some Ford Proflex or something silly expensive, crappy phopto but I think you can see;


What are you thinking about for suspenders?

And weren't you going to post some piccies of the rear of the car set up?
>

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

john vanlandingham Wrote:

> Remember that the combined offset/clampy thang is
> for cars having old school "tube welded to
> spindle" designs like old Datsuns , old Maz-dogs,
> BMW theu the 90s, Fiat and Volvo,
> For cars already having the plug in, or "socket"
> style fitment then all that's needed is the bottom
> offset thang. Here's a photo of some Ford Proflex
> or something silly expensive, crappy phopto but I
> think you can see;

Reason I like the clampy thang so much is the built-in gusseting. From what I could gather so far, the weld-on bottom offset thang is a relatively unproven design with a really high stress concentration at the offset.

Now, clearly I might be wrong about the "relatively unproven" part of my assumption. This picture looks pretty proven. If you can tell me these gussetless offset guys have been on lots of fast cars and have never broken, I'll drop my gusset obsession.

Even if they don't have that much track record yet, there's still no reason gussets can't be welded to the tube to stop my worrying anyway...


> What are you thinking about for suspenders?
>
> And weren't you going to post some piccies of the
> rear of the car set up?

Depends on what you mean by set up... I haven't done any rally prep to the suspension yet, so there's nothing to show there. If you just want to see what stock Mazda3 rear suspenders look like, I can do that in a jiffy.

And while we're talking about struts and stuff, here's another question for you:

I've got a perfectly good set of DMS front suspenders that have survived around 10 rallies and have kept me perfectly happy so far. I'm planning to modify their housings to fit the Mazda3 and continue being happy. Some day, though, they'll either break or wear out, and then I'll want something more locally serviceable, like a Bilstein insert. In your experience, is there any reason why I couldn't just slide out my DMS 50 when it finally dies, and slide a Bilstein 50 into the same housing?

-Dave

eyesoreracing Wrote:
-------------------------------------------------------
> john vanlandingham Wrote:
>
>
> Reason I like the clampy thang so much is the
> built-in gusseting. From what I could gather so
> far, the weld-on bottom offset thang is a
> relatively unproven design with a really high
> stress concentration at the offset.
>
> Now, clearly I might be wrong about the
> "relatively unproven" part of my assumption. This
> picture looks pretty proven. If you can tell me
> these gussetless offset guys have been on lots of
> fast cars and have never broken, I'll drop my
> gusset obsession.
>
> Even if they don't have that much track record
> yet, there's still no reason gussets can't be
> welded to the tube to stop my worrying anyway...

Well I think aside from modelling the things on some nice program to do stress study or FEA, you might just have to write Proflex.
>
>
> > What are you thinking about for suspenders?
> >
> > And weren't you going to post some piccies of
> the
> > rear of the car set up?
>
> Depends on what you mean by set up... I haven't
> done any rally prep to the suspension yet, so
> there's nothing to show there. If you just want to
> see what stock Mazda3 rear suspenders look like, I
> can do that in a jiffy.

Yeah, that's what I'm saying. I'm wondering just how Focus-y it is in design and execution, so please put up photos of what the sunframe, mountings , links etc look like.
>
> And while we're talking about struts and stuff,
> here's another question for you:
>
> I've got a perfectly good set of DMS front
> suspenders that have survived around 10 rallies
> and have kept me perfectly happy so far. I'm
> planning to modify their housings to fit the
> Mazda3 and continue being happy. Some day, though,
> they'll either break or wear out, and then I'll
> want something more locally serviceable, like a
> Bilstein insert. In your experience, is there any
> reason why I couldn't just slide out my DMS 50
> when it finally dies, and slide a Bilstein 50 into
> the same housing?

The DMS use some lame taper seat on the shaft which passes thru the bottom of the strut body and gets a nut run down---the nut holds the whole shebang together.
Bilstein inserts typically are threaded longer and straight, the strut bottom is threaded, and the insert shaft is screwed into the bottom till it seats (the end of the shaft is usually finished with a internal hex or a slot so you can snug it), and the the nut is run down as a jam nut---it is a far more secure system.

And yes of course with a little zip zap its easy to convert the bottom of the DMS body to become the Bilstein design, and I did that for a guy who had some DMS with a whopping 160mm travel. It was tricky and took at least two or three minutes to come up with the design.
Here's the threaded part:



And the part in position where it gets zapped in:



The problem with the whole Bilstein 50mm insert thing is they are simply "quite full with our Nascar and Baja programmes" and uninterested to spend a few keystrokes to order in the things. Overseas they are available but it's nuts with the way the exchange rate has been manipulated by the Bush Crime Gang to 50% of what it was just 5 1/2 years ago, and the things have become stupid expensive, stupid to the point that I have to consider alternatives if people are going to have affordable suspension.

And there are some alternatives already in the negotiation stage.
>
> -Dave

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

john vanlandingham Wrote:

> > Depends on what you mean by set up... I
> haven't
> > done any rally prep to the suspension yet,
> so
> > there's nothing to show there. If you just
> want to
> > see what stock Mazda3 rear suspenders look
> like, I
> > can do that in a jiffy.
>
> Yeah, that's what I'm saying. I'm wondering just
> how Focus-y it is in design and execution, so
> please put up photos of what the sunframe,
> mountings , links etc look like.

I'll try to get some pics up by the end of the day.


> The DMS use some lame taper seat on the shaft
> which passes thru the bottom of the strut body and
> gets a nut run down---the nut holds the whole
> shebang together.
> Bilstein inserts typically are threaded longer and
> straight, the strut bottom is threaded, and the
> insert shaft is screwed into the bottom till it
> seats (the end of the shaft is usually finished
> with a internal hex or a slot so you can snug it),
> and the the nut is run down as a jam nut---it is a
> far more secure system.

The DMS system is perfectly servicable as long as you never get any dirt or corrosion in the threads. And why would you ever get dirt or corrosion on threads that hang out in a rally car's wheel well?

Took me a month to get mine apart...

The Bilstein system looks much smarter, and the conversion looks simple enough to keep me on my current plan.


> The problem with the whole Bilstein 50mm insert
> thing is they are simply "quite full with our
> Nascar and Baja programmes" and uninterested to
> spend a few keystrokes to order in the things.
> Overseas they are available but it's nuts with the
> way the exchange rate has been manipulated by the
> Bush Crime Gang to 50% of what it was just 5 1/2
> years ago, and the things have become stupid
> expensive, stupid to the point that I have to
> consider alternatives if people are going to have
> affordable suspension.

"Manipulated" implies intent and competence. I think the word you're looking for is "bungled". Dipshits...

> And there are some alternatives already in the
> negotiation stage.

can't wait to see what you come up with...

-Dave

Ok, Mazda3 rear suspension pics, as requsted.

Rear view: Lower control arm with everyone's favorite spring perch.


Bottom view, top of the picture is the front of the car.
First link is the toe control link.
Second link, up high, is the camber control link.
The lower shock mount, which is single-shear on the Ford, is double-shear on the Mazda.
Ford also doesn't have the tray/subframe brace under the center of the subframe.


View from the front.
Toe control link is front and center.
The really skinny blade looking thing coming forward and disappearing behind the little plastic aero tray is the "control blade" or giant stamped steel trailing arm/hub carrier.
I've seen this criticized for its thinness, but I haven't seen if they actually have a problematic failure mode. Seems the three lateral links should support all lateral loads, and its perfectly strong in tension. Go off backward, though, and its sure to fold up.
If anyone has seen this fail, speak up!


Finally, a sad attempt at photographing the forward mount of the control blade. It's quite long and tucked up in a dark corner.


This is basically the same as the last Focus I looked at (that was a European Focus RS, but I think U.S. cars are fundamentally the same back here).

-Dave




Edited 1 time(s). Last edit at 02/19/2008 12:04AM by eyesoreracing.

Hmmmm....I had to think about this overnight. I only see one reasonably priced scenario, one expensive and good, and one mildly ridiculous variation.


1) Box the trailing arm blade and add a spherical bearing, change the short links to tubes with spherical rod ends, change the shock out for something better, and hope for the best.

2) Cut the shell a la Burmeister and go huge.

3) Do some sort of elaborate new crossmember with rocker arms that will let you lay the coilovers down at an angle. Maybe they can fit horizontally behind the crossmember? I don't like this idea very much I just thought I'd throw it out there for the sake of argument.

Overall it looks like they did a fine job of optimizing the design for maximum interior space in the car. If it were me I would already be cutting up the shell. I think you already stated that your goal was "cheap" G2 (please correct me on this if I got your intent wrong) car so that leaves option one.

Tim



Edited 1 time(s). Last edit at 02/19/2008 10:59AM by Tim Taylor.

What exactly are you trying to accomplish with these scenarios? Coil-overs?

I'm working on scenario #4: no coil overs at all...

A rally suspension needs the right spring rate, the right ride height, and lots of damping. None of these require the spring to be anywhere near the shock, nor do they require ride height adjustability. Coil-overs are a great way to get one set of springs and one perch design to fit a huge variety of cars and applications, but when all you need to do is get one type of car to work, they aren't strictly necessary.

On my 510, which has springs in the middle of the semi-trailing arms and shocks at the ends, I simply found a spring with the right rate and height that would fit in the stock perch. I have never once wished I could change the ride height.

In that case, it was simple because I managed to find the specs for the 1969 East African Safari 510 springs and just found a spring that matched the rate and free length on Nissan's old spec sheet. This time I have to figure it out myself, but I'm reasonably confident I'll nail it in the first few tries.

Oh, and don't box that trailing arm. It HAS TO bend as the toe control link jerks the toe around. If it doesn't bend, the suspension doesn't move.

-Dave

eyesoreracing Wrote:
-------------------------------------------------------
> What exactly are you trying to accomplish with
> these scenarios? Coil-overs?
>
> I'm working on scenario #4: no coil overs at
> all...

On 2 and 3 yes, the end game would be inexpensive and durable coilovers or struts. Every stamped link on that suspension looks awfully thin. Option 1 was just plating/replacing the existing links so they survive a little longer and replacing the existing spring and shock with ones that have a more appropriate rate.



>
> A rally suspension needs the right spring rate,
> the right ride height, and lots of damping. None
> of these require the spring to be anywhere near
> the shock, nor do they require ride height
> adjustability. Coil-overs are a great way to get
> one set of springs and one perch design to fit a
> huge variety of cars and applications, but when
> all you need to do is get one type of car to work,
> they aren't strictly necessary.
>
> On my 510, which has springs in the middle of the
> semi-trailing arms and shocks at the ends, I
> simply found a spring with the right rate and
> height that would fit in the stock perch. I have
> never once wished I could change the ride height.
>
> In that case, it was simple because I managed to
> find the specs for the 1969 East African Safari
> 510 springs and just found a spring that matched
> the rate and free length on Nissan's old spec
> sheet. This time I have to figure it out myself,
> but I'm reasonably confident I'll nail it in the
> first few tries.

No argument from me it's dead simple to calculate the motion ratio and turn spring rate into a wheel rate.


>
> Oh, and don't box that trailing arm. It HAS TO
> bend as the toe control link jerks the toe around.
> If it doesn't bend, the suspension doesn't move.

I missed that actually. I've never seen one in person and it was hard to tell from the pictures. That makes it a crappy tension only member. Cutting it off and sticking something like this to the front of the knucke stamping might be a prudent precaution. Easy to make, no binding, and it works in tension and compression. Not that you would ever go off the road backwards like me but it seems like easy insurance.

Tim

Tim Taylor Wrote:
-------------------------------------------------------
> eyesoreracing Wrote:
> --------------------------------------------------
> -----
> > What exactly are you trying to accomplish
> with
> > these scenarios? Coil-overs?
> >
> > I'm working on scenario #4: no coil overs at
> > all...
>
> On 2 and 3 yes, the end game would be inexpensive
> and durable coilovers or struts. Every stamped
> link on that suspension looks awfully thin.
> Option 1 was just plating/replacing the existing
> links so they survive a little longer and
> replacing the existing spring and shock with ones
> that have a more appropriate rate.

Tim, you're spot on about the stamped things being thin, way thin, and designed to accept minimal force in one plane.
Here a fellows arms who thumped into some stuff sideways:



>
>
>
> >
> > A rally suspension needs the right spring
> rate,
> > the right ride height, and lots of damping.
> None
> > of these require the spring to be anywhere
> near
> > the shock, nor do they require ride height
> > adjustability. Coil-overs are a great way to
> get
> > one set of springs and one perch design to
> fit a
> > huge variety of cars and applications, but
> when
> > all you need to do is get one type of car to
> work,
> > they aren't strictly necessary.
> >
> > On my 510, which has springs in the middle of
> the
> > semi-trailing arms and shocks at the ends, I
> > simply found a spring with the right rate
> and
> > height that would fit in the stock perch. I
> have
> > never once wished I could change the ride
> height.
> >
> > In that case, it was simple because I managed
> to
> > find the specs for the 1969 East African
> Safari
> > 510 springs and just found a spring that
> matched
> > the rate and free length on Nissan's old
> spec
> > sheet. This time I have to figure it out
> myself,
> > but I'm reasonably confident I'll nail it in
> the
> > first few tries.
>
> No argument from me it's dead simple to calculate
> the motion ratio and turn spring rate into a wheel
> rate.
>
>
> >
> > Oh, and don't box that trailing arm. It HAS
> TO
> > bend as the toe control link jerks the toe
> around.
> > If it doesn't bend, the suspension doesn't
> move.
>
> I missed that actually. I've never seen one in
> person and it was hard to tell from the pictures.
> That makes it a crappy tension only member.
> Cutting it off and sticking something like this to
> the front of the knucke stamping might be a
> prudent precaution. Easy to make, no binding, and
> it works in tension and compression. Not that you
> would ever go off the road backwards like me but
> it seems like easy insurance.

Well your piccies are way pretty, way prettier than what I can draw, but I've been staring at these things for a while and was thinking an easy solution might be, as usual, to see if we can see something already used and i came up with this idea with the rear link turned 90 from yours and the front link sorta offset so the rod end is adjustable from the rear by merely loosening the jam nut at the front and turning the hex at the back. This modest picture might show better than words:



Maybe you can make a prettier piccie with your fancy CAD things
> Tim
>
>
>
>
>
>

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

> > In that case, it was simple because I managed
> to
> > find the specs for the 1969 East African
> Safari
> > 510 springs and just found a spring that
> matched
> > the rate and free length on Nissan's old
> spec
> > sheet. This time I have to figure it out
> myself,
> > but I'm reasonably confident I'll nail it in
> the
> > first few tries.
>
> No argument from me it's dead simple to calculate
> the motion ratio and turn spring rate into a wheel
> rate.

Dead simple if you know what you're trying to accomplish. That's the trick. What should the spring rate be? There's always a little trial and error...

> > Oh, and don't box that trailing arm. It HAS
> TO
> > bend as the toe control link jerks the toe
> around.
> > If it doesn't bend, the suspension doesn't
> move.
>
> I missed that actually. I've never seen one in
> person and it was hard to tell from the pictures.

Well, if you were to unbolt the front of that long trailing arm, toe-in would shift the arm inboard and toe out would shove it outboard. Anchor that point, and suddenly the trailing arm has to bend to absorb with that side-to-side movement.

> That makes it a crappy tension only member.

Indeed!

> Cutting it off and sticking something like this to
> the front of the knuckle stamping might be a
> prudent precaution. Easy to make, no binding, and
> it works in tension and compression. Not that you
> would ever go off the road backwards like me but
> it seems like easy insurance.

That seems like a really good idea. How to you propose to anchor that to the remaining portion of the arm?

-Dave

John,

I can't tell you how happy I am to finally see some broken parts. You've been holding out on me! Any idea what happened to the rest of the arms when those bent? Any idea how he went off? Did the tires get hit from the rear (I've seen them bend that way when cars get rear-ended), or did the arms get smacked from the side?

> something already used and i came up with this
> idea with the rear link turned 90 from yours and
> the front link sorta offset so the rod end is
> adjustable from the rear by merely loosening the
> jam nut at the front and turning the hex at the
> back. This modest picture might show better than
> words:

Brilliant. Took me a while to figure out what your weld-on double-shear mount was, but I see exactly what you're donig now.
The rear-adjustable rod end is a nice touch.

In the interest of taking some shock loads of the mounting points, I'd be tempted to put some rubber at one end of the triangle or the other. Using something similar to the original bushing up at the trailing arm mount would more than do the trick. Might simplify installation too.

-Dave

Tim, John,
I just cross-posted your brilliant idea on the Mazda3 thread on Special Stage, since we were just talking about this and coming up with much worse ideas. Hope that's kewl with you.

-Dave

eyesoreracing Wrote:
-------------------------------------------------------
> Tim, John,
> I just cross-posted your brilliant idea on the
> Mazda3 thread on Special Stage, since we were just
> talking about this and coming up with much worse
> ideas. Hope that's kewl with you.
>
> -Dave

Fine with me...guess I should go over there and look at that thread too. I never post on SS. Does that make me a JVL sympathizer? Guilty by association...





Edited 1 time(s). Last edit at 02/20/2008 10:44AM by Tim Taylor.

Okay, still just a rough cut at it, but above crayon level. This about what you were thinking John?

Tim Taylor Wrote:

> Fine with me...guess I should go over there and
> look at that thread too. I never post on SS.
> Does that make me a JVL sympathizer? Guilty by
> association...
>

Even JVL has been on the SS Mazda3 thread. I think that makes you the instigator now...

-Dave