creating new susp for the monster, going dual A setup front and rear Options

[byndbad914]

Car currently has RSR front struts with custom lower arm setup (sorta like a 935 front end) and the rear is a 5-link setup that is much like any old school 60s-80s open wheel car, GT-40, etc all attached to my tube chassis setup.

Decided I wanted to lower the car more and fix a couple issues with the rear 5-link geom so I started laying out some parts, then decided F it, time for a whole new update (IMG:style_emoticons/default/laugh.gif) I can't leave anything alone.

So I measured various available pickup points on the current chassis and whipped up this stuff in Pro/Engineer. The lower A is already a bit different than I have assembled in here, but close enough for convo - and JP was asking to see what I have going - I am sure so he can raz me about whether or not I actually win at DEs (IMG:style_emoticons/default/happy11.gif)

I used Pro to lay out the geometry so I could measure camber gain, get zero toe positions for the toe link (which will be adjustable in case I want to put some bumpsteer into the rear), RC height and motion, etc.


Is this perfectly optimal on all points? Hell no, but much better than what I have and works with existing structure - I am not about to really hack into this car. I can get tabs waterjet cut and welded into place, but not bending/notching tubes in my near future. Besides, it leaves me a little bit of excuse for why I am slow on the track cuz it certainly isn't my driving abilities hahaha (IMG:style_emoticons/default/driving.gif)

So here is the rear design - it will be built using the stock trailing arm cut down to not much more than a bearing carrier. yeah, yeah, use this other thing, make that, blah blah - the stock rear bearing assy has worked for a few years now so it is fine. I intend to replace that big bearing every few years regardless of upright used anyways.


I did the same layout stuff for the front and even am going to be able to use the exact same billet lower A front and rear so that is nice. I can have them waterjetted for about $170 each including the 1.5" plate material, so not bad at all.


I bought a couple front strut housings from Carquip last week and had my machinist buddy endmill out that monster weld so gonna work on getting them apart down to the stock knuckle, then I have 2" diam chromoly I just got yesterday that I will have him machine down to make the front "upright". Note the two surface colors in the above image - the blue is turned down to fit in the knuckle (50mm) and the green is the stock 2" diam of the tubing - that ridge will be used to exactly place the tube relative to the knuckle so I get both spindles left to right in the exact same spot.

The upper forward link will be made on the fly so I didn't bother modeling it. I need to get this stuff in the car with the right pickup points placed, then place some dual adjustable coil over assys which might be tough on the front, then build the forward link around the shock assy. At some point you stop fisting the design and just build it (IMG:style_emoticons/default/shades.gif)

Being a structural analyst I also have access to finite element code so I fully analyzed the lower A designs (I have 5 of 'em now hahaha) to make sure they are structurally sufficient. If I get off track in a big way I will likely bend them, but that you can't design for without having a 10lb A arm. These are just over 5 lbs per the modeling software.

[byndbad914]

CCW has an offset that I would prefer too... argh. The real selling point was the looks of these wheels, I really like the centers and they tend to be pretty unique in the 3pc wheel world. CCWs look like every other BBS copy... I dunno. I really try to keep some level of form in the function equation on this car, and I really think these wheels look great on the car.

But the CCWs are damn tempting... to the point of getting a set, then telling Kodiak when they get around to it, make me new halves whenever and have the backup set. If anything could put a more DOT legal tire on 'em for the street (IMG:style_emoticons/default/shades.gif) I currently just blast around the neighborhood main roads with the slicks when I test drive, but if a cop were a tool he could tow the car as it wouldn't be considered "road worthy" on the slicks, even if I were only a block from home.

Meanwhile, more of this coming (IMG:style_emoticons/default/welder.gif) I now have the lower As so fricken square you can't even measure the difference in cross or wheelbase on a tape, so less than 1/32", so the heims are locked down and I started building the upper As in the rear last night.

Rear wheel spacers are down to .350" thick with the bias plys, will be thicker with radials if I go back to them as the top comes way in, around 3/4" like I mentioned before. Nice thing about the thin spacers is I can use the hub centric feature on the hub itself, not the spacer, so less tolerance stackups which is what I am really after.

So now I don't feel so bad letting the cat out of the bag - this car was NOT square before by any stretch of the imagination or tape measure. I spent two days after I picked it up, one weekend before I moved to CO, with my circle track friend Scott trying to set this car up. He has built track cars on the floor of his garage in Moreno Valley and decades of racing means he knows his shit. We fought this car, gave up and got it as close as possible after a 15hr Sat and 12hr Sunday. The two of us can square a car within a couple of hours typically. Right off the bat we realized that somehow the whole rear end is shifted over 5/8" (!) and why I had all the new custom brackets waterjet so I can get everything where it belongs - the right side brackets in the rear are 5/8" longer at the lowers, same length at the uppers as the left.

Before I had different length tubing right to left, all sorts of shit just trying to get by, so now you guys all know why I decided to just hack in so deep and really redo everything.

So for guys like Brett - imagine what my RCs and ICs were like before! Certainly not symmetric and would have wandered like a mofo. And if I lowered the car 1" it would start bump steering in the rear to the tune of 1/8" in the next inch... PER SIDE.

Embarrassing to admit since this is stuff I caught and would have had fixed, but unfortunately I was moving out of state by the time it was in finishing stages, so I had to accept what I got.

Car bodywork is within 1/16" on all corners now with lower arms at exact same adjustment - damn fricken tight for a garage job (IMG:style_emoticons/default/laugh.gif) I had to square the rear body work a little (it was out a bit as I fudged it to make the previous stuff seem ok) and now am plumb bobbed exactly the same fender to hub on the front and 1/16" out on the rear so a little more squaring, but everything is where it should be.

Finally. Need :smiley with poor bastard wiping sweat from his brow:

Feeling pretty good as it should be a much nicer car to drive now. It was a handful before when it wasn't squared up - makes a car freakin' DARTY, 'specially at speeds around 150-160mph when things aren't square. I need to knock on wood to remove the coming jinx, but I am really looking forward to seeing how this thing drives with the new stuff.