• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Volvo 122S Build Thread: Scope-creep the Sequel

Time for an update. The IRS subframe has become a bit of a gong-show in this build. It's been in and out of the car so many times. I cover the details in the latest installment on my YouTube channel (https://youtu.be/mvSg3Plb5nE) but let's just say that I thought it was OK last spring when I finished it up and put it in the car. I just didn't put the control arms and uprights and tires on to check. Mind you...I didn't weld the sheet metal in either. So it turns out not only were the passenger side brackets just a little out, but when I installed the frame, the bushing alignment pins at the front caught on the bushing sleeve and pushed it out of position. This, unbeknownst to me, racked the subframe. I should have double checked...but it looked fine. It was off, and I used that racked alignment to weld in the rear cross member. So the entire thing was borked - causing 1/2" more wheel base on the passenger side.

It was really noticeable when I installed the suspension and tried to locate the front end.

So I cut that junk out and we're doing it again.

39299208194_b8bb5feb44_b.jpg


A few brackets and gussets will also help.

39110680705_54e00f6682_b.jpg


Back together - basically dead on the angle I was looking for.

39110680405_9c94bacbc3_b.jpg


Here's the other side...the crappy level is good to 1/10? (I prove this in the video).

39299207664_e34a3b5ce3_b.jpg


Caster side to side.

39110680205_1718c394f2_b.jpg

39299207314_f26a826ca2_b.jpg


Weld it back together.

39110679955_e56e94a2c0_b.jpg

39299206584_bbffa45a71_b.jpg


Drill out and remove the rear bushing alignment pins.

39110680085_ecde33cb97_b.jpg


Make new pins.

39110679765_22ef89344f_b.jpg


Quick dust of paint so it won't rust while I finish the rest of the build.

39299206034_f12a066c6e_b.jpg


And back in the hole - this time everything is perfect.

39299205714_430623c148_b.jpg
 
Glad to see that worked out finally! I'll have to update my progress in the forum soon, but I did have a question I figured I'd ask about the tubular front end. I'm gonna have to do one in my car because of the crack of death and suspension subframe swapping that'll be taking place. Have you given any thought to how far outward (toward the tires/doors) a plate could be welded against the firewall to tie in the stress of the suspension forces to the a-pillar? Seems a bit tight and off-center to me without basically removing all the sheet metal, including the bits that the fender bolts to. I've seen a 122 that had a tubular front end but the pictures aren't specific as to how it was tied in and I believe it had a full tube chassis as well, meaning they could tie in whatever tubular front to whatever tubular cage in the cabin whereas I'll have to worry about transfering that load to the existing 1965 body. Hoping to avoid a full cage because I don't plan on racing it, but if I can't feel good about the way it'll come together I don't want to get caught halfway through and THEN decide I have to add a whole lotta tube to the rest of the car for rigidity.
 
Glad to see that worked out finally! I'll have to update my progress in the forum soon, but I did have a question I figured I'd ask about the tubular front end. I'm gonna have to do one in my car because of the crack of death and suspension subframe swapping that'll be taking place. Have you given any thought to how far outward (toward the tires/doors) a plate could be welded against the firewall to tie in the stress of the suspension forces to the a-pillar? Seems a bit tight and off-center to me without basically removing all the sheet metal, including the bits that the fender bolts to. I've seen a 122 that had a tubular front end but the pictures aren't specific as to how it was tied in and I believe it had a full tube chassis as well, meaning they could tie in whatever tubular front to whatever tubular cage in the cabin whereas I'll have to worry about transfering that load to the existing 1965 body. Hoping to avoid a full cage because I don't plan on racing it, but if I can't feel good about the way it'll come together I don't want to get caught halfway through and THEN decide I have to add a whole lotta tube to the rest of the car for rigidity.


Heck, I'm glad someone's reading this thread! I'll be going over this in detail soon as the front end gets done. The short version would go like this.

I worked for a long time to work out why the "Crack of Death" happens. What I came up with was the sheet metal that supports the frame is not adequate for the job over the long haul (I shudder even saying this...brickboard flash-backs). I've looked at a lot of modern cars and all have much more substantial material joining front suspension upper parts to the A-pillar. Regardless if they are strut or SLA suspensions.

So then when I looked at my car I tried to work out a reasonable load path. I tried some cardboard mock-ups.

36887224316_db928ec440_b.jpg


Didn't like it, but thought it would work.

Ended up mocking up some tubes and tape to see how silly it looked. Wasn't silly.

36299486313_3ac87731c9_b.jpg


36941894642_65eb67306f_b.jpg


Did up this straw model (have I shown all this before?)

37036898302_447673a15b_b.jpg


Then how to implement this...well the box that joins the inner fenders was always coming out as it gets in the way of where I need the engine. The firewall can then be doubled up (ie either a box section (most likely) or tube (if needed) inside the car and can stretch all the way across the firewall not just ending at the inner fenders.

I haven't done that part just yet as I'm waiting to see where the engine ends up and how much of the front of the tunnel I need to take off.

So if you didn't want the tube solution (which is dramatic) then I would go with a variant of what I have shown in cardboard. There is room to do this without fouling the fender stiffening panel and you can always add to the fire wall inside the car to help out there. Then I would bridge the frame where it goes under the car and turn it from being a dirt/leaf trap into a more useful structural piece.
 
Yeah, I read and watch everything too, but your pretty far above most peoples ability to comment, including myself.
Wish I could offer food for thought type comments, but above my pay grade here.
 
I'll add my name to this list of people who watch all the videos but can only provide superlatives for commentary. "Incredible."
 
Thanks Guys - didn't mean for my comment to sound like I was fishing for a complement. I'm only putting the effort into the video stuff to take the heat off keeping this thread going. It's also a great motivator to keep on top of the project. I'm happy with the 50 guys that tune in! I've learned (and continue to learn) from this forum all the time - just trying to pay back a little.
 
Then how to implement this...well the box that joins the inner fenders was always coming out as it gets in the way of where I need the engine. The firewall can then be doubled up (ie either a box section (most likely) or tube (if needed) inside the car and can stretch all the way across the firewall not just ending at the inner fenders.

I haven't done that part just yet as I'm waiting to see where the engine ends up and how much of the front of the tunnel I need to take off.

So if you didn't want the tube solution (which is dramatic) then I would go with a variant of what I have shown in cardboard. There is room to do this without fouling the fender stiffening panel and you can always add to the fire wall inside the car to help out there. Then I would bridge the frame where it goes under the car and turn it from being a dirt/leaf trap into a more useful structural piece.

Gotcha. Makes sense. I'll be doing tube to ensure my own freedom since I'll be putting the subframe of an entirely different vehicle under it. Just to be clear is this what you mean:

 
Yes, that tube would be behind the firewall...it's just a straw model - and while scaled, it is only approximate. The vertical straws are the A pillar. So some of this is sort of fictional in the model which was created as a test of structure.
 
Yes, that tube would be behind the firewall...it's just a straw model - and while scaled, it is only approximate. The vertical straws are the A pillar. So some of this is sort of fictional in the model which was created as a test of structure.

Makes perfect sense to me. That's similar to be what I was thinking. There might be a temptation to bend the tubes that go from firewall to grill, but other than that, I had in mind the same sort of idea minus that firewall trick. I think I'll do that. It makes me feel much better about the stresses under hard cornering going into a structural tube and the body rather than just the body. I would feel much safer.

Keep it up!
 
I guess I forgot to take pictures when I was welding up the UCA brackets. I did take this one. Note the 3/4 aluminum plate I'm using as a heat sink...I don't want this sucker to warp. And it didn't (well, not much).

38518860400_b976b4472a_b.jpg


I added the front side supports to provide registration on the frame rail and add some strength to the part. The backside of this bracket has 3 - 1/4" thick brackets.

The K-member has been vexing me all week. It was just missing something. So with it all mocked up for welding, I got some inspiration last night and came up with this idea.

39430477295_30a26a1129_b.jpg


The part I was fretting over was the front mount point. It only went to the bottom of the frame. I need it to get some method of registering it to the side of the frame rail. This will allow me to ensure that things are going to stay square and parallel.

So I just added this bracket.

39430474815_c3a2894f6e_b.jpg


It fits like this.
40282771742_476ca9e9a1_b.jpg


Then settled in for a long dime stacking session.

40282772552_33823a670c_b.jpg


40328096391_c4a2b22f2a_b.jpg


And done! Had to stretch it a little post weld to get it all back straight. I'm happy with how it all turned out.

40328100631_ef2b7d7c93_b.jpg


Next up. Steering bracket. I'll probably mock this up on the frame first then get it fitted into the car...then dick around with this weldment.

40328097431_5a2abe0f05_b.jpg


39430473985_57075bdc7c_b.jpg


Moving on to this next mock up tomorrow.
 
Ever have one of those weeks where you're out in the garage daily working your tail off and seem to get nowhere? That was this week. With the frame tacked together, it was time to make the reference jig to get the thing grounded on the frame table. This next phase is critical as getting the subframe square and centred in the car is important.

I designed and build that basics of the jig and just couldn't get the level of precision I think I need with the tools that I have. So I had to spend a few nights working on some tools.

I needed some big squares...like really big.

25594553617_f08009cea8_b.jpg


This of course means a trip to get steel and the usual fiddling around to get the parts square. So it took 3 days.

That got me these done - the larger of the two is 12" tall (smaller is 8") and they can be used like a planar gauge or a set of right angles. I needed these to get the uprights positioned on the beams across the jig - they have to be dead square to get the correct measurement at the top. Now, normally, I'd just cut a top bar - but with the stuff in the way, that wasn't going to work.

39755277724_f44152255f_b.jpg


Started the first quick mock up - pretty clear that there was some pull during the welding...had to take a night to straighten that out.

39755278754_95046c85d7_b.jpg


Looks like it will work once I figure out how much of the back bar to cut off.

25594555087_3ddaf58cf3_b.jpg


With the rails up and level...a new problem.

38655285330_cb88de101b_b.jpg


38655284280_9e60386d9c_b.jpg


The rail went a little further up than planned - I double checked, but once installed, this is what we have.

So the pedal box has to go up the firewall a little...good thing I haven't welded it in yet. It does need to be welded in before the rail goes in for welding.

That caused the former complex shape to bind and cause problems.

That gap isn't going to work.

39755276124_ca4b6b57b1_b.jpg


The gaps to the floor are worse.

25594550167_0967d4396b_b.jpg


So that's going to need some work. So I grabbled my flow-forming tool and bashed the floor sheet metal around a little to get some relief.

39755275374_baa3076b00_b.jpg


Make up a cardboard template and get some sheet metal bent up.

25594549247_6713374bbb_b.jpg


Then I'll mod the front to fit better.

39755274494_d29b6ebc40_b.jpg
 
A little cutting and folding later and we had this.

40443773692_1c9c8e993f_b.jpg


It fits like this.

38676210360_de1f3ecb8f_b.jpg


And with the pedal box front lip all fixed up...it all goes together like this.

40443772922_98d14545eb_b.jpg


That's where the weekend went. Still have some final trimming to do on both parts and then workout where it all fits. I'll get that worked out this week.
 
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!
 
Back
Top