Rear Shock Turrets For Volvos

dammit John, I KNOW what your answer is.
Besides, your answer is exactly why NOT go to the floor, which just fucking confuses shit, because that's the EXACT OPPOSITE of the question that I asked.

---

Monika Hawkinson
Seattle, WA

Sofa King Wrote:
-------------------------------------------------------
> dammit John, I KNOW what your answer is.
> Besides, your answer is exactly why NOT go to the
> floor, which just fucking confuses shit, because
> that's the EXACT OPPOSITE of the question that I
> asked.

I wuz jest tryink to correct your question, ya snows?
Precisera som man säger på svenska.
>
> Kevin Hawkinson
> Seattle, WA
> 83 Volvo 240 Gp5 (in progress)
> 34-ish

---

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.

Sofa King Wrote:
-------------------------------------------------------
> dammit John, I KNOW what your answer is.
> Besides, your answer is exactly why NOT go to the
> floor, which just fucking confuses shit, because
> that's the EXACT OPPOSITE of the question that I
> asked.

John is right, the angle is most important.

As for going to the top of the suspenders.. It seems to make sense you would want to connect there.

What's stopping you from putting in a dog leg to the top of the tower? Will that make a real world difference?

Don't forget the spring is doing work as well.

As for the comments about putting the cage to the reinforced area of the shell, I believe that was for the benefit of tying it in to the bits of the car that are doing a lot of work and to make the cage less likely to punch through in a roll over.

---

Andrew M
Onterrible
30ish

Hey Kevin,

#1 consideration for the cage for SAFETY is to go to a strong point in the car.
- Don't go the wheel wells in this type of RWD car; they're amazingly flimsy. (I just add that note in case someone was thinking to follow the old way of putting the backstays to the wheel wells that was common in the days of bolt-ins.)
- The structrual member under the floor that I mentioned is there to carry the original spring loads under the car; it's a strong place. Look at the under side picture; see that approx 2" x 2" box reinforcement under the floor just inside where the lower edge of the wheel well meets the floor?
- These strut towers are decent, but not as strong as the floor over those box reinforcements. Any severe fore-aft load on these towers through the backstays will tend to bend them. (Just compare these to the rear strut towers in a Golf, for instance.)

#2 consideration is to transmit the suspension load. This has to be done for car survivial, but the number one place where these towers should transmit the suspnsion laod to the car is along the lower edges of the towers, where they weld through the floor and tie to the original underfloor box reinforcements. Run braces from the backstays to the towers to help transmit that vertical suspension load in to the backstays, and which wil help stabilize the towers in the fore-aft direction. Run the backstays plates from the floor, up the side of the wheel well, and alos on the front surface of this new tower to tie them together and further spread loads.

These towers (for a RWD, solid axle, originally with coil springs) are set futher inside the location where you would typically find the strut towers for an independent, strut rear for a FWD or AWD car. The integration of these struts to the floor and wheel wells is not as close as for those other types. And, the original under floor box reinforcements in this car are much stronger than those in those other types. It makes sense to go to the towers in the rear of a FWD/AWD car; this car is like my Opel and the main strength is on the ends of the axle tunnel, where the original spring perches are/were located.

If the main hoop gets pushed so far in the car that the angle between the main hoop and the backstays is less than 30 degrees, THEN it's time to do things differently.

Hope that makes sense! Regards,
Mark B.

Mark,
Does it make sense? well, yes and no.
Here is picture of what my plan is, and what I think you said:


You said brace the top of the turret to the backstay. I drew what I understand that to mean. You never mention closing the triangle (putting the third side on it), and from the way you are talking, it doesn't seem like you had it in mind.

So is this a reasonable representation of what you have in mind?

---

Monika Hawkinson
Seattle, WA

Kevin,

Your plan seems to be heavy and inefficient. What are you trying to achieve with that design? If you're concerned about rigidity of the tower, I'd suggest using a variant of Marks plan... instead of having that horizontal bar.. which, if it is doing anything, will put ugly loads into the backstay. Put in a bar that's 45 degrees from the vertical back to the backstay.

This is all my opinion of course.

---

Andrew M
Onterrible
30ish

The horizontal bar (in green) is not my plan, it's an approximate representation of what I think Mark said. He said run a brace from the top of the turret to the backstay. That's what I drew.

Here's what I think you said:


Are you saying the drawing in orange is heavy and inefficient?

Edit: on first read, I misunderstood Andrew's suggestion, and came up with this, which is NOT what he said to do:



This is getting confusing.

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Monika Hawkinson
Seattle, WA



Edited 3 time(s). Last edit at 04/20/2008 10:55PM by Sofa King.

Yes, you got what I said right.

I'm worried that your plan won't achieve much for the weight of it. Also I wouldn't trust it in a roll over (for several reasons).

The real question is how much is the shock tower going to want to move? And should we care about it if it does?

If we care, then you can add gussets or bars as needed.. but they don't necessarily have to be part of the cage.

Again, as always.. my opinion.

---

Andrew M
Onterrible
30ish



Edited 1 time(s). Last edit at 04/20/2008 10:58PM by hudson.

You've changed the picture.. I was saying the second one (now). How does the first one make sense?

Time to bust out photoshop apparently

---

Andrew M
Onterrible
30ish



Edited 1 time(s). Last edit at 04/20/2008 11:05PM by hudson.

Oooohhhh ok.
See? I said I was getting confused.

Here is an un-adulterated copy of the picture:

---

Monika Hawkinson
Seattle, WA

This is what I would recommend if you want to stiffen the towers fore and aft.

The gussets can be anything, tube, sheet, whatever.

The picture isn't what I was saying initially as I've added the rear gusset, whatever you want to call it. All angles if optimized are 45 deg.

---

Andrew M
Onterrible
30ish



Edited 1 time(s). Last edit at 04/20/2008 11:26PM by hudson.

hudson Wrote:
-------------------------------------------------------
> Kevin,
>
> Your plan seems to be heavy and inefficient. What
> are you trying to achieve with that design?

Something like this:


or


or
This more or less:













If
> you're concerned about rigidity of the tower, I'd
> suggest using a variant of Marks plan... instead
> of having that horizontal bar.. which, if it is
> doing anything, will put ugly loads into the
> backstay. Put in a bar that's 45 degrees from the
> vertical back to the backstay.
>
> This is all my opinion of course.
>
> Andrew McNally
> Hamilton ON
> 28

---

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, I hear you there. That's what cages look like on high level competition cars. Part of the problem is we're doodling in mspaint.. just how high is the tower? Just what is the angle of the backstay if it is going to connect to the top of the tower?

I'm not saying it's a stupid idea. I'm saying from the mspaint representation that the angles don't look right.

That first cage looks sick.. It also looks like the back stay is a perfect 45 degrees from the vertical.

EDIT:: CAN WE ALL AGREE THAT A 45 DEGREE ANGLE IS THE MOST EFFICIENT AT HANDLING LOADS?

---

Andrew M
Onterrible
30ish



Edited 1 time(s). Last edit at 04/20/2008 11:46PM by hudson.

hudson Wrote:
-------------------------------------------------------
> just how high is the tower? Just what is the angle of the
> backstay if it is going to connect to the top of
> the tower?

From Timm's earlier pictures (and from preliminary measurements made by John and I on my car), the top of the turret is going to be just below and in front of the bottom edge of the rear window.

> EDIT:: CAN WE ALL AGREE THAT A 45 DEGREE ANGLE IS
> THE MOST EFFICIENT AT HANDLING LOADS?

NO!!! You gotta qualify that! I say an equalateral triangle totally kicks your 45 degree angle's ass up and down the street!

Also, how do you define "efficient" in this context. I know definitions for thermodynamic efficiency, but I've never seen any definitions for structural efficiency.

Last edit: the towers in the Fords are going to be a lot lower, because the bottom of the shock connects to the trailing arm, which is UNDER the wheel centerline. In the Volvo, the bottom of the shock will attach to the axle housing, ABOVE the wheel centerline.

---

Monika Hawkinson
Seattle, WA



Edited 2 time(s). Last edit at 04/21/2008 12:35PM by Sofa King.

Sofa King Wrote:
-------------------------------------------------------
> hudson Wrote:
> --------------------------------------------------
> -----
> > just how high is the tower? Just what is the
> angle of the
> > backstay if it is going to connect to the top
> of
> > the tower?
>
> From Timm's earlier pictures (and from preliminary
> measurements made by John and I on my car), the
> top of the turret is going to be just below and in
> front of the bottom edge of the rear window.

Well maybe.
>
> > EDIT:: CAN WE ALL AGREE THAT A 45 DEGREE
> ANGLE IS
> > THE MOST EFFICIENT AT HANDLING LOADS?
>
> NO!!! You gotta qualify that! I say an equalateral
> triangle totally kicks your 45 degree angle's ass
> up and down the street!
>
> Also, how do you define "efficient" in this
> context. I know definitions for thermodynamic
> efficiency, but I've never seen any definitions
> for structural efficiency.


YEAH! So there! And I say a 43.5* is way bitchin-er, but not as good as 46.38*
46.38* FTMFW!!!

> Last edit: the towers in the Fords are going to be
> a lot lower, because the bottom of the shock
> connects to the trailing arm, which is UNDER the
> wheel centerline. In the Volvo, the bottom of the
> shock will attach to the axle housing, ABOVE the
> wheel centerline.

Yeah but if'n the Fords are down there, and the Volvo are say 2" above it may still be somewhat lower than the cutsie drawing.
I do like the colors tho.

>
>
> Kevin Hawkinson
> Seattle, WA
> 83 Volvo 240 Gp5 (in progress)
> 34-ish
>
>

---

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.