I've never seen shocks and springs mounted with the tops facing outwards. Was this done on purpose to eliminate some problem your foresee? Looks as though it will bind.
I've never seen shocks and springs mounted with the tops facing outwards. Was this done on purpose to eliminate some problem your foresee? Looks as though it will bind.
I just did that for packaging, but I see what you mean. I was thinking the panhard bar would take care of all lateral forces. Maybe the opposite spring angle will affect roll characteristics? It's not too late to mount the shocks vertically if there is concern.
edit: Looks like I didn't think about the arc of the axle movement when one side is compressed. The line of the coilover from end to end should follow that arc, instead I have them at an angle, so as the axle rotates during cornering or single-side bump, the effective spring rate could change a lot. I think I have some re-working to do...
I think I can re-mount the bottom of the shocks at the LCA mounts, as drawn in red. The cross-member and shock towers are only tacked in. This angle would straighten out during a turn, making the spring "progressive" as the body rolls. Less angle = more stiffness. Thoughts?
Seems legit, it would correct the current falling rate induced by body roll
You're going to want that panhard bar (yellow) level at ride height, the angle you show will shove the axle sideways when the suspension moves. I would put the shocks/springs more vertical like your red lines show.
In reply to ¯_(ツ)_/¯:
Sorry that picture is misleading. The yellow bar is the rotation of the axle during cornering. I agree, panhard will be level at ride height.
Last night I chopped out the cross-member and shock towers. Looks like I can re-use all the pieces I already made, so I'll probably do that and panhard bar this weekend.
I figured that there was probably something I was missing 
This thing is going to be so berkeleying cool!
I like ending my posts by saying what I'll do next time because it keeps me accountable. In this case it actually worked!
First I cut the old shock mounts off. They turned into nice little "ptero-scrap-tyls"
Then I made new ones, basically by cutting up some 1x2 and welded a 1/2" bolt to it, probably going overkill on the welding.
I broke all the tacks, separated the shock towers from the cross-member, flipped it upside down, and tacked it all back up. Then I tacked the new lower shock mounts to the lower link mounts on the axle.
Also built the panhard bar mount out of the same stick of 1x2. Cut one of the faces off, drill some holes, and round the edge for looks. Kept it straight while tacking by clamping it with some house trim that happened to be the right size.
And here's how it turned out
I expect the panhard bar angle to flatten out once it's loaded up with engine and body and I dial in the coilover settings.
For fun I played with the full range of motion of the axle. Here is max height, AKA "rock-crawler mode", or most accurately "welding service position"
Here is minimum height, AKA "spark show". Theoretically, with bags, I could technically lay frame without the chassis interfering anywhere with the axle.
I don't know what's next so I won't finish this post with any plans. I suspect it has something to do with the engine, transmission, and one more cross-member to build.
Looking good! What gauge plate is that axle side panhard mount made from? Do you think it's suitable? It doesn't seem very robust, but I don't really know one way or the other.
I lol'd at the ptero-scraptyls and was mocked for it when pressed to explain. Thanks.
With no math to back me up, I want to make the chassis mount for the upper link beefier.
Everything is 1/8". It's beefier than it looks, and like the other 3-link mounts was actually built by Georgia Tech students (including me at the time) for our $2012-$2015 Challenge car, the turbo 2JZ MG Midget. Wait, that probably makes it worse! I graduated and later bought the axle from them at the $2016 Challenge swap meet after they retired the MG and parted it out.
Fun story regarding the panhard bar mount...it is definitely stronger than the MG's "structural" unibody we welded the chassis-side of the panhard bar too. During some shake-down testing, the cornering forces actually ripped a chunk of MG sheetmetal off the chassis where the panhard was welded, allowing the body to shift relative to the axle, and much carnage ensued. The axle-side mount was completely intact. The driveshaft and transmission...not so much.
NOHOME - agreed on the upper link mount. It will be connected to the lower link mounts via triangulation of sorts. Also a convenient way to put a loop on the driveshaft, not that I'll probably need it.
Also, here is some anti-squat math. The largest ? is around the CG height, which I approximated at the height of the cylinder head.
Oh, OK. It looks more like 12ga based on perspective and was just curious.
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maschinenbau wrote:Then I made new ones, basically by cutting up some 1x2 and welded a 1/2" bolt to it, probably going overkill on the welding.
No worries about the extra welding... this is like mazdeuce building the Grosh with a hammer instead of a nailgun. There's probably a good debate to be had about which will be more awesome, the RiceRod or the Grosh.
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maschinenbau wrote:And here's how it turned out
I expect the panhard bar angle to flatten out once it's loaded up with engine and body and I dial in the coilover settings.
{... ...}
I don't know what's next so I won't finish this post with any plans. I suspect it has something to do with the engine, transmission, and one more cross-member to build.
For whatever reason (beer?)... those two combined made me think back to my questioning the strength of the frame. Do you have enough friends and 'dead weight' to have them stand on the frame to approximate the weight of the engine, trans, cab? Plus, with the (now) wife, you can get a reading on how the suspension is reacting (measurement, or photograph, or both)
I just had to see what it looked like. Also, added a few member to finish off the rear of the frame.
The GSXR shocks seem to work well, after jumping up and down on the frame. They're easy to install and don't contact the arms or chassis (though just barely at full droop). It's definitely stiff, like sports car stiff. Front wheel rate should be right around 200 lbs/in, rear is just under 225 lbs/in. I expect the fronts to compress a bit more as I remove lightness, hopefully leveling out the control arms.
Starting to feel like a real car 
Looking good 
I feel like I did a lot more work this weekend on the rod than I actually did. I welded the rear link tubes, ground all the frame welds flat in preparation for fish-plating, and spent some quality time with a brush, hose, and a bucket of degreaser getting the engine, trans, and front end clean. I was going to build a trans cross-member, but I ran out of beams long enough and the metal market doesn't open til Wednesday. So I was going to start fish-plating the frame, but I ran out of 1/8" plate. Then I ran out of MIG gas. So I tiled our friggin bathroom instead. Happy 4th of July!
I had to look up "fish plating". Apparently there are two meanings.
I learned a new term today. (Oops, maybe that belongs in the "TIL" thread.)
Built the cross-member last night. It's pretty simple. 4 studs on the factory Lexus trans mount, 2 of which go through the beam, which has larger 12mm socket-sized holes on the bottom for tool access.
Ta-da! I tacked it in place with the jack supporting the beam, so that the mount cushion was fully compressed.
Its going to look like a car in no time at all!
I added a cut-out in the trans cross-member to help tuck the exhaust up under the body. Yes it will have a full exhaust, mufflers and cat, in addition to some sweet side-dump headers with a cap. I do plan to actually drive this thing a lot.
Then I devised a method for assembling the cab so I can build the floor and trans tunnel.
A little of this
A little of that
Turn it in into this
And some of these
And put them all here
CAD method, including frame fish-plates and mock fuel tank. I really need a plasma cutter, because my angle grinder is dying
Surprising amount of leg room. The driver side is worse thanks to the clutch slave cylinder.
Bonus: Milwaukee angle grinder rehab. It stuttered to a death with lots of arcing and heat. The carbon brushes were fine, but the brackets holding them broke apart. $11 and a week later its fixed, but still has quite a shake, builds up heat, and arcs a lot even after cleaning the copper rotor. I think the rotor part is deformed and out of balance, and its only a matter of time before this failure repeats again.
Anyone have a favorite death wheel they can recommend? Almost tempted to buy this exact model again. It's a really powerful 6" model I got (extremely) used at a thrift store 2 years ago, and ya'll know I haven't been easy on it.
Harbor Freight, buy 2 at a time.
I love my dewalt 4 inch. Buy the tw0 pack at lowes for 75
I use the mid level harbor freight.
I bought 3 of them 5 years ago. I setup 1 with flapper wheel, 1 with cutting disc, and 1 with grinding disc.
All 3 are still going....
I waited until they went on sale for sub $20.00.
They have lasted through building 3 chumpcars...
I've had the same Wel-Bilt (or something; Northern Tool brand) for the last 4 years, and I've used it for damn near everything. Not quite the volume of work as you, but it cost me $30 and I've put it through everything with no protest - still going strong
The guys in the field in my industry love the big boy Metabo, but it's not cheap. I bought one used.
I'm a big fan of Porter Cable. DeWalt and Black and Decker are also good, and share parts. Either way, I recommend finding one you like (trigger style, not switch or paddle for me), and sticking with it. I burn up a couple a year, and having a boneyard helps keep em working.
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