Amazon: Brake System Upgrade

[rrktmn]

http://www.kartek.com/product/Brakes/CNCPedalsnmc.htmlThe CNC brand dual master pedal w/balance bar is about $160, they also make a dual bore master cylinder in one casting.

[dheming]

Spent some time after work today measuring the frame rails. I wanted to see exactly where the holes would end up on the outer side. So first step was to make a scale template from thin plywood. I buy this stuff from art stores specifically for this purpose since it's super flat and is a pleasure to work with:





Traced the holes:





Now to figure out where they would be on the other side with as little error as possible. The other day I thought up a simple tool that would do this easily. The square tube spacer is the same width as the frame rails, about 2 1/8" (5.40cm) on my estate:





Now to transfer the holes to the other side:









So this is what it looks like on the other side. They're very close to their positions on the inside plate. Due to some inevitable error in my transfer tool I wouldn't be surprised if the spot welded flanges are indeed exactly the same on both sides of the frame rail:






On the inside underneath the wagon the holes are way too close, 5/8" (15.88mm), to the floor to be able to use a hand drill. I don't even think an air drill would be able to pull that off. Either way drilling while underneath would be super awkward and it would be hard to keep everything square.

It would be incomparably easier to drill the holes from the outside in. Looking at the pic above you can see that the upper left hole is edge on with the lip that hangs down. So that hole and the bottom hole would be do-able as is. However the upper right hole is completely shrouded by the lip. Of course I could just drill an access hole through the lip there, but that's not a very elegant solution. I want to drill and cut my wagon as little as possible.

The other thing to consider is that I want the bolt heads facing outward since that would look cleaner than a nut and cotter pin. To do that the hole would need to be moved down away from that lip enough to clear the 1/2" wide hex head that's on a 5/16" bolt. That way it can slide in from the outside.

Next up is designing Mk 4.1 using all this info gathered today. I took careful measurements of that lip and will be playing around with a new layout:

[dheming]

I've been taking various chassis measurements and working on a lot of drawings lately. Just merely adding coilovers to the rear of an Amazon estate would be relatively easy from a fabrication and packaging standpoint. The biggest complication for me is also wanting to do the 3" (7.6cm) drop since I love how it looks. Since I want my estate to handle corners as well, the problem is coming up with a system that has enough adjustment range to preserve proper suspension geometry at both stock height and 3" drop. I really don't want to have to cut into the floorboard underneath the rear seat to make room for a dropped 4-link bracket. As always I have more measuring and drawings to make.


I ordered some parts last week to make a tester control arm. Since I have little experience welding chrome-moly I want to play on a few pieces before I start welding the real parts that will go into my estate. Got some light duty 1/2" (12.7mm) spherical rod ends and 4130 threaded tube inserts from McMaster-Carr:





The 1" x 0.095" (25.4mm x 2.4mm) 4130 tube was from Aircraft Spruce:





Tacked together:




Finished product:







I'm happy with how it turned out. The other reason this arm was built is so that it can be used as a length tester for the coilover. The specific QA1 coilover that I want to use has a recommended ride height of 14" (35.6cm) so I'm designing everything around that. I don't want to drop $600 on the coilovers just to find out they aren't going to work. So I spent $30 to build this control arm instead.

[rrktmn]

this thread was started 11/2009

[Bartezz]

Originally Posted by rrktmn

this thread was started 11/2009

...and still going stong!

[dheming]

Originally Posted by rrktmn

this thread was started 11/2009

And I still really haven't "done" anything to the actual estate yet. Crazy huh? I was just thinking about this the other day while on lunch break. All the real work so far is in my 3-ring binder full of notes and drawings as well as the pile of templates I've made trying out different ideas. Of course being a full-time student kinda complicates a full-on car rebuild both financially and time wise. Not to mention taking a few years teaching myself how to weld good enough to do all my own fabrication and trust my life to the parts that I make.

All in all though, it's easy to make excuses for why things happen. Honestly there have been times where I didn't even work on my Amazon for months at a time. Being such a giant project I think that's just the nature of the beast, at least for real world build projects.

[dheming]

Here's the revised side bracket (Mk 4.1) that should be the final design. This shows details for both inner and outer brackets on the same drawing:





And here's a top view of the intended crossmember detailing its construction:

[Bartezz]

Originally Posted by dheming

Here's the revised side bracket (Mk 4.1) that should be the final design. This shows details for both inner and outer brackets on the same drawing:

Wouldn't that (double) cross member make the car more rigid. I suppose there is normally some horizontal flex between the frame rails which isn't possible with the double cross member. But the forces the come in to play must go somewhere so something's gotta give right?

I don't know crap about suspension so I might very well be wrong, but I thought it might be word checking?

This might be interesting to read!

Cheers

[dheming]

Originally Posted by Bartezz

Wouldn't that (double) cross member make the car more rigid. I suppose there is normally some horizontal flex between the frame rails which isn't possible with the double cross member. But the forces the come in to play must go somewhere so something's gotta give right?

I don't know crap about suspension so I might very well be wrong, but I thought it might be word checking?

This might be interesting to read!

Cheers

This is actually a good question and it's smart to think about these kind of things ahead of time. It looks like when he added that steering brace to his Jeep it caused the stress to be concentrated on the frame rail right where the steering box mounts. Considering how much that area usually moves around under load it's not surprising that happened. Especially since he said he did 350 miles of high speed dirt road driving. I can only imagine the forces created due to the side to side movement of the steering box combined with large tires in that situation.


I wanted to take this picture before replying on my application:




In this entire area the only real side load is from the panhard rod bracket. As you can see Volvo integrated that directly into a stamped cross member that also ties the two frame rails together. This is an ideal load path for the stresses created by hard cornering. Due to this I feel that adding a tubular cross member in the proposed area will not create any major stress concentrations. Especially since the sheet metal of the floor board also ties the frame rails together over a large area here.

That's the way I see it at least. Only time will tell if that's true.

[Colonel Froth]

It eyeballs ok to me too. The only loads you're putting into the crossmember are vertical, and they're going into the frame pretty close to the original spring perch, so that shouldn't bring any surprises. You're not triangulating anything so you're not moving or concentrating forces anywhere. The monocoque should still be able to flex almost as much as it did before.