creating new susp for the monster, going dual A setup front and rear |
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creating new susp for the monster, going dual A setup front and rear |
byndbad914 |
Mar 31 2010, 02:19 PM
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#21
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shoehorn and some butter - it fits Group: Members Posts: 1,547 Joined: 23-January 06 From: Broomfield, CO Member No.: 5,463 Region Association: None |
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 |
May 15 2010, 01:20 AM
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#22
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shoehorn and some butter - it fits Group: Members Posts: 1,547 Joined: 23-January 06 From: Broomfield, CO Member No.: 5,463 Region Association: None |
hopefully it is back together by then (IMG:style_emoticons/default/dry.gif)
Got the right rear fully tacked in and mocked up both sides today and got the right front in with the longer brackets I had made to reduce scrub - the left front will come out and the longer brackets put in - measuring right to left with all tacked in everything was under 1/16" on the wheelbase so pretty amazing how just being anal can work out with a tape measure. The measure from the trans flanges to the uprights are also almost identical for axles lengths. When I redo the left front I will get the cross and wheelbases set exact - I didn't work too hard at it since the left side is coming out anyway. With adjustable upper As I can get it perfect but am shooting for perfect at the lower As with both sides all the same dimensions. I set the car up to be pretty tune-able such as I will be running 3/4" wheel spacers in the back to shove the tire up to the fender, but also if the car doesn't want to turn, tho' it might look funny, I can run narrower and narrower spacers to reduce rear track width and just have the tires tucked like a tubbed drag car. I don't want to run spacers on the front for tuning as that will increase scrub again. Now for the bummer - talked to Kodiak today (finally, been a process to say the least) and they have the outers I want but not the inners. Since everyone likes big heavy wheels, the 16" diam isn't so popular so they weren't even going to give me a lead time, just wait until they get an order for a couple more 16s... shit, that could be a year, so I offered to throw an extra $200 at the total to pay for setup time and that would help, so they might get to them in 3-4 wks. He said to call in 2 wks and didn't take a credit card # so who knows how this is gonna roll but at least this guy seems like he is trying to work with me. So the car is going to be together and waiting for wheels. I really wanted to hit the track first week of June but that ain't happening now. I will pull the nose off and run my current wheels just to test drive it around the block and hope I don't get a ticket for driving a car with no signals or fenders on the front (IMG:style_emoticons/default/huh.gif) |
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