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Volvo 122S Build Thread: Scope-creep the Sequel

Bummer about that pedal box! Shame it can't be fabbed up after the rails are in. By the way, I don't know if you said and I missed it or if it wasn't stated, but were the new frame rails modified in any way from the stock curve? or were they just replaced with new steel? I assume it's the former, but I was curious so I figured I'd ask!

Good question. I only changed the width and the gauge of the material. The originals were 16 ga and the replacements are 10 ga. The old ones are a little over 2.25" wide (if memory serves or something random anyway) so I made the replacements 2" to fit the tube.

The angles are all stock.

I've had the floor tilt verified, and my floor is extra tilty - no clue why. I literally matched the bends and weld locations with the floor replacement. One side is on the tunnel and the other sits right on the sill. I only replaced the front 1/3 when I did it. so not sure why I've got about 3/4" more angle than everyone else. Maybe a Monday in Sweden?
 
Craig, I watched your last video with the frame rails. I found you this tool, I know how much you like good ones. Maybe you can find one on your list!:);-):-P

<iframe width="560" height="315" src="https://www.youtube.com/embed/c2RlM6FcOcU" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
 
Canuck;5758098 I've had the floor tilt verified said:
IIRC you peeled all the old front floor out and just left the channel stamping? Did you add braces while the car was without floor pans? So you think that the rockers could possibly be closer together, accounting for the steeper angle? Just a dream in a dream:wtf:
 
Craig, I watched your last video with the frame rails. I found you this tool, I know how much you like good ones. Maybe you can find one on your list!:);-):-P

<iframe width="560" height="315" src="https://www.youtube.com/embed/c2RlM6FcOcU" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

That's the same sort of laser that cut the tubes for the front clip. I'm having a hard time trying to find some space for an English Wheel let alone one of those monstrosities!

IIRC you peeled all the old front floor out and just left the channel stamping? Did you add braces while the car was without floor pans? So you think that the rockers could possibly be closer together, accounting for the steeper angle? Just a dream in a dream:wtf:


When I cut the front of the floors out, I did not brace the rails. I did not remove the entire floor pan. Only the front 12" of flat by the tunnel, over at an angle to about half way, then about 8" off the sill, just enough to remove all of the rotted material (basically over the out rigger). When I did that job, the engine and transmission were removed and I had nothing (suspension etc) on the front of the car. I was supporting the A-pillar with jacks. I'm pretty sure nothing could move.

The mistake was probably removing the frame rails around the same time. They would have given me a bottom reference. I did fashion the panels to match the ones that I cut out. So I'm a bit stumped. I also recall that for my car at least...that's just the way it looked. Tilted.

<digging up pictures>

Old floor.

40475906132_9d31c58fde_b.jpg


New floor.

39755275374_baa3076b00_b.jpg


As I look at the pictures, it does appear that I may have moved that angle (the bend up to the firewall) back towards the A-Pillar a bit (it's at the bend point in the A-Pillar closing panel. I also made the part differently (it's one piece not two). So I'm sure this accounts for the error - a little off over a longish distance is a lot off. I'm not changing it now. No point really.

Let's call it a signature!
 
Whew - what a stupid weekend. It took all day on Saturday to get the pedal box sheet metal to fit perfectly again. Sure I could have just welded and smashed it into place, but that's not how I roll. I didn't take pictures. It fits - enough said.

Next up was pulling the frame back out of the car and onto the bench to fit up the K-member. Took all day Sunday. All damn day. Never would have believed it. Would have gone a lot faster if, say for example, the damn clip could come out of the jig without having to lift the frame every time.

26752656908_11b6e06133_b.jpg


Again, not snapping a lot of photo's of the process. You grind and fit until it's perfect in every dimension.

26752656178_e58121c0d2_b.jpg


26752655408_f300af123d_b.jpg


26752657548_623455672a_b.jpg


26752659038_3d51ca6980_b.jpg


No joke...this clip came in and out of the jig at least 30 times today. I'll tack it in when my head's back in the game.
 
The attention to detail you have for this stuff is mind boggling. That said, I drove on some really fun, but sometimes rough roads last weekend in California. I spent a lot of time following E30s around, and the whole time I was thinking about your car and its IRS. It's going to be awesome.
 
In typical fashion, another great build on the way. Also, in typical fashion, it's great to see someone with the skills and dedication to take a usually unloved (by the rest of the world) 122 and turn it in to a work of art. Keep up the great work, and we'll see you at IPD, right? (!):omg::roll:;-) 900 hrs left...piece o' cake!:omg::roll::lol:
 
The attention to detail you have for this stuff is mind boggling. That said, I drove on some really fun, but sometimes rough roads last weekend in California. I spent a lot of time following E30s around, and the whole time I was thinking about your car and its IRS. It's going to be awesome.

Thanks - the BMW/Audi crowd were part of my motivation.

In typical fashion, another great build on the way. Also, in typical fashion, it's great to see someone with the skills and dedication to take a usually unloved (by the rest of the world) 122 and turn it in to a work of art. Keep up the great work, and we'll see you at IPD, right? (!):omg::roll:;-) 900 hrs left...piece o' cake!:omg::roll::lol:

Planning on making the show...in 2020. Love the PNW. Funny, the 122 has been on my "dream car" list since I was a kid. I've just always thought they had a cool vibe.

It's motivating just to know that people are following along.
 
25594555087_3ddaf58cf3_b.jpg


Have you modeled the front suspension design?

My calibrated eyeball says that in this pic the upper arm inner pivot is too high. (even with the crossmember raised to the finished position)

vsusp.com

and the anti-dive is backwards?
 
As meticulous as Craig is I really doubt he has overlooked anything in his suspension design, besides, trying to make a judgement on whether the pivot is in the wrong position from a photo on the innernut is (um, how do I say this without seeming rude?) uneducated.

I checked out your VSup link. Have you figured out how to use it?
 
Anti-dive geometry positions the front pivot of the UCA higher than the rear pivot...exactly as seen in the picture above and below.

fig-13.gif


The suspension geometry was modelled by me, then checked by Ron Sutton Link - Ron's a race engineer and he did the final optimization. No stone unturned etc.

As for how it all looks - well, the pivots are what matters and I'm responsible for the design. The idea was to place the UCA dog bone as close to the frame rail as could be tolerated to reduce the bending moment on the UCA bracket.

As it sits, the LCA cradle is not sitting on the frame and the UCA is just plopped in place for show.
 
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I got up in the marbles there a bit! :oops:

Can you tell my project chassis design is still in the wrinkled bar napkin stage? :cool:

What yanked my chain at first was the arm angles in the pic.
(After I started my post I realized that the crossmember was not in position.)
And the aggressive anti-dive angle spun me out.
I'm going to have to model that and figure out why it set off my mental alarms.

Is that not a stiff spring setup?


Fantastic workmanship!
 
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As meticulous as Craig is I really doubt he has overlooked anything in his suspension design, besides, trying to make a judgement on whether the pivot is in the wrong position from a photo on the innernut is (um, how do I say this without seeming rude?) uneducated.

I checked out your VSup link. Have you figured out how to use it?

The only stupid question is the one that is not asked.
As a student of suspension design I have blundered a bit.
I rely strongly on my visual measurement abilities to analyze what others are doing and ask questions why if things don't appear "correct".
Once I really irritated a racer who I was assisting in a "between rounds" crash repair when I observed that the replacement RF upper control arm that was being installed was bent.
The rules did not allow non-OEM A arms nor was it allowed cut or weld an arm or relocate mounts.
So he had put the arm in a press and purposely bent it to make it shorter for camber gain.
My calibrated eyeball had exposed his Top secret "cheat"!

Then there was the Quarter Midget chassis I built where I copied from pictures some designs Gary Stanton was experimenting with on a car Ray Evernham drove. That QM chassis reset track records up and down California, my phone rang for weeks from racers who wanted to buy one every time a record fell.

So as a Track Champion and a Rookie of the Year and with my hand in more than one National event win under my belt, among my other achievements I find it hard to classify myself as uneducated. Thankfully I am much more often right, than wrong. ;-)

Stay tuned, I'll be asking more stupid questions.
 
I got up in the marbles there a bit! :oops:

Can you tell my project chassis design is still in the wrinkled bar napkin stage? :cool:

What yanked my chain at first was the arm angles in the pic.
(After I started my post I realized that the crossmember was not in position.)
And the aggressive anti-dive angle spun me out.
I'm going to have to model that and figure out why it set off my mental alarms.

Is that not a stiff spring setup?


Fantastic workmanship!


This amount of anti-dive is actually a little less than the stock Corvette C4 that it's based on!

Here it is tacked in place - not that this angle helps matters. I'll take some more explanatory pictures later.

40673833411_2cf27256b5_b.jpg


In the picture that tossed you - I should also mention that the frame is tipped forward a couple of degrees (i.e. it is not level)...but it still looks like a lot.

Here't a good factory drawing of the stock geometry.

1984-Corvette-side-view-outline-A_a.jpg



The UCA also has the ball joints located to take some of the apparent angle out.

Just to review (and I'm not an expert) but conceptually, the idea of anti dive or anti squat geometry is to transfer the weight associated with motion (either + or - acceleration in this case) through the suspension links and not just the springs. In the stock suspension (with no anti dive) the only option you have is to increase the spring rate to counteract the weight transfer associated with the acceleration. So two methods, one desired outcome - reduce the vehicle attitude change under acceleration conditions.

So you can then set spring rates based on other dynamics instead of just the desire to not drive a barge.

The cost is that this angle impacts wheel bump characteristics...a load is a load so if your links are preventing you from moving weight excessively under braking, the converse is also true - if the wheel is bumped, it will resist the movement. In anti squat, it works for you as the location of the links (and the geometrically constructed "virtual link") are favourable to say a bump in the road. On the front, you get the opposite effect. So you don't generally design in a lot of anti squat as the associated cost is a rough ride.

So with the right balance of anti dive you should be able to run less spring rate for a little more driver comfort with improved "handling".
 
Thanks. I have been looking at this for a day now and still can't wrap my head around it.

Help me here, is it the rotational torque from braking that causes the anti-dive reaction, or the thrust of the wheel being pushed back by braking forces?

I am thinking the thrust forces are greater so that would be the forces in play. But with the rear upper mount below the ball joint I see the chassis levering under the ball joint, not pushing down on it.
I am obviously not looking at this right.....

I am a fan of softer spring setups because, "Any suspension design will work if you don't let it"
It seems to me that Lighter springs have more stored energy and unload less within a given travel.
 
Load transfer causes the change in attitude in response to acceleration. Make a free body diagram to work out the basic kinematics. There are a few good YouTube videos (some not so good) but there is no need to overly complicate the topic. The Mechanical Engineering folks at University of San Diego https://www.youtube.com/watch?v=7QZ5z66PhdU have done a good little video series that is better, in my opinion, than many.
 
Dirty Rick, congratulations on your racing success. I found this for you:

<iframe width="560" height="315" src="https://www.youtube.com/embed/qAbHbGgFWJs" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

I also stared at the silhouette that Craig posted. I was scratching my head, too! The vid sorted it out pretty well, although somehow I think (?) it also has something to do with trying to compress or twist a quadrilateral. By that I mean the box formed by connecting the four pivot points created by the UCA and the LCA around their perimeter. Hope that's clear. Wishing you continued success!

Thanx for the Ron Sutton link, Craig. I've been thinking about building one so doing some research on Locost 7's and his site will come in handy.

DR, I see Craig posted a U tube while I was slowly typing!
 
I typically like EE's version of things...this is one that I don't like. Not "go to YouTube and tumbs down" don't like, but he's super rushed and just not giving it enough detail to power home the idea. What I'm left with is "you want this, but not too much" - speaking as a scientist, it's just a bit mushy. Now in one of my original videos, I bumbled my way through why I picked the suspension I picked and just said to go read up on it. That's not really very satisfying either.

The lecture I posted is much better - reading Thomas Gillespie's "Vehicle Dynamics" and the classic by Milliken and Milliken "Race Car Vehicle Dynamics" if you're a person that learns by reading.

What I can say is that looking at these things in 2D is difficult as they are 3D systems...so for a simple suspension (say a stock 122) - a 2D diagram or model works fine...it just won't work for what I am doing. When I first started studying this stuff it was a challenge as I wanted to know what "optimal" was for a car. More engineering than physics (no slight to my engineering colleagues) - you know, something to get my design started and get me into the ball park - somewhere past a Radio Flyer.

Nothing.

It doesn't exist.

Every car is a different system.

This caused more reading.

I'm drawing a histogram.

with words.

So, as I was already committed to stuffing an IRS and changing the IFS (as I had determined that fixing it (whatever that means) wasn't in the cards). Now I had sold parts, bought parts, started building jigs and still was as clueless as they come. I had, however, read all the books (yup - all of them - JK - most of them...I have a shelf with many books). Then I started with what I had to see what it would do (in software) and I'd started racing and modifying my 242. Racing works to sharpen up your understanding. I had 4 different suspensions in my 242 in a CANADIAN race season.

Then I got nervous - I'd crush my 242 if it came to that...I wouldn't crush my 122, I love that car. I just like my 242. So I'd done what someone with only book learning does, asked a few stupid questions got a few things right and many wrong. Then I emailed Ron after a frustrating conversation with a guy who wouldn't sell me race coil overs (looking at Penske's at the time) because I was building it myself and for sure was nuts and an idiot. Seriously, he was never going to custom valve a set of coil overs for some garage engineered death trap (his characterisation of what I am doing). Ron was just the opposite. Very helpful. He basically just checked my math.

Things that he said to change were:

1. Get the Howe Racing lower ball joint that is 1/2" taller. It effectively makes the spindle taller. This improves camber curves.
2. Reduce the "Stock" anti dive of the front suspension that I had by lowering the front PIVOT by 1" and keeping the stock lower pivot location. I high light pivot because you don't lower the mount hole by that much in relation to the pivot.
3. Move the UCA back in relation to the wheel centre by 1".

That's it - the rest was as we found it. Now, I put "stock" in quotes as this was not in reference to what GM planned, but the suspension that I bought. I contacted that guy and asked him about why it was the way it was and he said it was what GM engineered and best not to ask questions. Turns out what we optimized is pretty close to what GM engineered (latest edition of the C4) not what should have been there. The UCA mount was all wrong from the start. That led to a quick redesign, which I couldn't square -> how come I did my own design.
 
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