Brunton Stalker XL #22 Build

[toedrag]

Horn is now installed, circled in yellowhttp://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28191&g2_serialNumber=3:

 

I finally found a suitable location for the inertia switch that meets the following criteria:

 

• Mounted to the frame
  
• Oriented as upright as possible
  
• Accessible to the driver while seated
  
• Out of the way of knees & feet
  
• No wiring visible to the occupants
  

Circled in green:

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28189&g2_serialNumber=4

[toedrag]

...The shorter the wires to the chassis the better. A wire won't conduct as well as the entire chassis even if copper is a better conductor, unless you way oversize all your wires..

 

Revisiting this one since I'm starting to run wires now...I feel the need to try to put some numbers to it, with the full understanding that my numbers are likely very wrong. Read on to be misinformed

 

The frame tubes are 16 gauge steel, which is .06" thick. Most of the tubes are 1.25" square, so that makes the cross sectional area 0.075 sq in per face of the square. If I take the generally applied idea that steel is 20% conductive as copper, maybe I can say the equivalent surface area is 0.075 * 20% = 0.015 sq in, which is smaller than 6 gauge copper wire & larger than 8 gauge copper wire. But, if the ground currents flow on more than one face of the frame tube (my physics on this is quite rusty), then obviously the cross sectional area increases. If, at best, it's 4x, then steel would have an equivalent cross sectional area of 0.015 * 4 = 0.06 sq in (ironically), which is close to 1 gauge copper.

 

I suppose this means that 16 gauge 1.25" steel square tube is [approximately?] electrically equivalent to copper somewhere between 8 & 1 gauge. Sooooo, maybe for ground wires smaller than 8 gauge copper, it's preferable to use the chassis for ground instead of a wire. For anything larger than 1 gauge, it's probably better to run a ground wire. In between, it's anyone's guess.

 

Obviously, there are complexities here that I'm not smart enough to comprehend. However, to me, the notion that the 1.25" frame is equivalent to, at least, 8 gauge copper passes my "smell test". For 1" square tube, the smallest equivalent also seems to be 8 gauge. For 3/4" square tube, the smallest equivalent seems to be ~10 gauge.

 

On a related note, earlier I mentioned that I would like use the block as the ground distribution point. I now find myself wondering what, if any, long term impacts there are of putting sustained current (50A) through the block? When that number (50A of ground current) finally dawned on me, I started having second thoughts about using the block for ground distribution.

 

For the smaller ground wires in my system (for 20 & 14 gauge circuits), looks like I'll use the chassis as the ground connection, unless there is a compelling reason not to on a specific circuit.

 

What I'll also do once the electrical system is up & running is to try measuring the drop from the various chassis ground points back to the battery.

 

Sorry to meander all about in this post, but I'm stuck inside the house with 3 sick ppl...going a bit :willy_nilly: and I needed something else to occupy my brain today.

[xcarguy]

. . . . it's preferable to use the chassis for ground . . .

 

Sorry to meander all about in this . . . . .

 

Chassis for ground........yes. :seeya:

[HOTTTCAR]

Ground to both= less to worry about.

[toedrag]

Wiring has been going well, or so I think. I keep waiting for the "oh &$%!" moment that forces me to re-do a bunch of it, but knock on wood that it hasn't happened yet. The way I'm doing things is to run all the individual wires along some common paths, seeing where the natural groupings occur, and once that's done, I'll bundle them and put them in some split loom tubing. I'm debating on testing as much of it as I can before housing it inside the split loom.

 

The wiring for the front half of the car follows the frame along the passenger side, then around the front frame tubes. The wiring for the rear of the car goes down the tunnel and then splits left & right.

 

I thought briefly about doing multiple wire colors, but in the end, decided not to.

 

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28197&g2_serialNumber=3

 

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28210&g2_serialNumber=3

 

I'm taking a brief pause from wiring to finally work on the rear body. It took a while to talk myself into this because doing the rear fiberglass body requires that the 3-piece aluminum cover panels are also done simultaneously. I had been kind of dreading working on the 3-piece aluminum covers on the rear because I haven't found any instructions, either in text or build video form. Happy to say that those aluminum panels are now done, and I'm quite tickled with how they turned out.

 

What is so tricky about this, to me, was getting the profile correct on the outer pieces where the fiberglass turns the corner, and ensuring that the edges of the two outer pieces & center hinged door are perfectly aligned.

 

I started by marking the center of the 3/4" circular frame tube which is just under the fiberglass lip. I marked the center by measuring from the fiberglass lip to the edge of the tube, then added 3/8" (3/4 divided by 2). The hashed line represents the 3/4" tube.

 

Then, I took a couple of scrap 1/4" shims & taped them together, offset by about 2". This allowed the outer shim to ride the contour of the fiberglass body. Then, the inner shim rested on the horizontal edge of the fiberglass and I put my pencil against that inner shim. That allowed me to generate the smooth line you can see in this picturehttp://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28216&g2_serialNumber=3.

 

Once I did the other side in the same way, I used a straight edge to connect the two, and this told me where the front edge of the center door needed to be.

 

Moving over to the piano hinge, I centered the piano hinge on the door, marked it and cut the hinge to size. I wanted the piano hinge to be as invisible as possible, but still needed to open fully. And, the center door obviously needs to be flush with the 2 outer pieces. Here's how I did it:

• Lay the door (not yet trimmed to size) on top of the opening, one end laying on the frame and the other end laying on the fiberglass lip
  
• Center the door left to right in the opening. For me, this was 2 3/8" inward from each roll bar diagonal support. (refer to picture above)
  
• Position the piano hinge the under door & against the frame.
  
• Clamp the hinge to the door.
  
• Clamp the hinge to the frame.
  
• Remove the clamp holding the hinge to the door, then remove the door. This should leave just the hinge clamped to the frame. Mark & drill the frame and cleco the hinge in place.
  

 

Next, the door needs to be again centered in the opening and positioned so that it can open fully. Here's how I did it. This part required some trial & error, i.e. re-clamping & adjusting

• Figure out which edge you want facing outward (toward the rear of the car).
  
• If you want the factory machined edge facing outward as I did, flip the door over so that it's front and rear edges are reversed. Left & right edges should be unchanged.
  
• Lay the door in the "open" position, i.e. vertically, resting against the roll bar.
  
• Rotate the free part of the hinge into place against the door and clamp the hinge to the door.
  
• Close the door
  
• Check that the closed door is still centered between the roll bar supports. If not rotate the door open and re-clamp.
  
• Don't be tempted to drill & cleco yet if your door is still flipped over.
  

 

Once the door (flipped) is centered & clamped to the hinge, you can now mark the door for trimming. I used a straightedge to join the two lines from an earlier step:

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28218&g2_serialNumber=3

 

Now that the door is trimmed to size, flip it back over so that the cut edge faces the hinge. Repeat the previous steps of putting the door in the "open" position, then clamping to the hinge, then closing to check if it's centered. Once it is, mark, drill, and cleco the hinge to the door.

 

Now, comes the hard part....the side pieces. Continuing on next post....

[toedrag]

Continuing from the previous post, starting work on the side aluminum panels for the top of the rear bodywork:

 

First, I had to determine where the back edge of the panel would end up. I arbitrarily chose 5/16" inwards from the edge of the flat steel back there.

 

Next, I had make a u-shaped channel for the roll bar supports. I measured from the door edge to both sides of the roll bar support. For the curve of the roll bar support, I used some spare 12-gauge solid wire as a form and transferred it to the side panel.

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28220&g2_serialNumber=3

 

Next, I had to notch the outside to fit around a little fiberglass lip on the side of the rear bodywork. No picture, sorry.

 

Some light filing was required to get the proper fit and to get the back edge to line up with my 5/16" reference line. After it was in the right place, I grabbed some thick-ish paper to use as a shim between the door & side panel, shooting for a finished gap around 1/32ths.

 

Once that was done, I opened the door and clamped the side piece to the fiberglass & frame. Next, I scribed a line onto the underside of the panel (used painter's tape so that the pencil mark would appear), following the profile of the rear bodywork.

 

Then, I removed the panel and cut it with the jigsaw. This got the initial shape I needed onto the panel. Once verifying that the shape matched properly, I used a compass and set it to a width equal to the difference between the edge of the door and edge of the rough-cut of the side panel, which was ~1/4". Then, I used the compass to scribe another line onto the panel and cut it again, ensuring to cut it slightly larger than I needed. After that, I got out the belt sander to make final adjustments. Lather, rinse, repeat for the other side.

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28222&g2_serialNumber=4

 

To now drill the side pieces, I transferred the marks I made earlier where the frame tube travels under the fiberglass and continued that line around the panel. There are two holes on each side which don't go into the tube. I'll probably epoxy some scrap squares of aluminum to the underside of the fiberglass to give the screws something to bite into.

 

Phew....now the majority of the rear bodywork is attached to the frame....But, I wasn't done yet.

 

--

 

To keep the door closed, the Shopping list calls for two pop-up latches that rotate to release the door, to be installed at each rear corner of the door. I had another idea of using a single keyed lock and two magnetic catches.

 

Why use a key lock? I don't know, seemed like a good idea since my car will see public streets.

 

I had originally purchased a generic weatherproof cam lock from McMaster, but turned out I couldn't use it. I needed to be able to use the key as a handle to actually pull up to open the door since the door has no other pull/handle. The cam lock I bought from McMaster allowed the key to slide out no matter what position the key was in. So, I found my way to the local big box hardware store and browsed their cam locks in the mailbox accessory section. Turns out, what I needed was, in fact, called a Mailbox cam lock. This type of lock retains the key unless the lock has been engaged. I suppose what I had originally purchased might be classified as a "cabinet" or "drawer" cam lock since those applications always have a separate pull.

 

In order for the cam bar to make contact under the 3/4" frame tube, I needed to locate the lock about 1/4" rearward which required notching the fiberglass. I also had to slightly adjust the angles of the bend of the cam bar.

 

To keep the corners quiet, I grabbed some magnetic catches in the cabinet section of the hw store. I used JB Weld to attach the strike plates to the underside of the door and used some spare aluminum panel right angle pieces to mount the magnets. (The one on the left was slightly skewed when I snapped the picture)

 

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28232&g2_serialNumber=3

 

All finished

http://www471.pair.com/stalkerv/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=28234&g2_serialNumber=3

 

Next up will be to install the rear fenders so that I can call the rear body work done.

[Twerd68]

Tremendous work. I hope we save this for whenever I get around to my build, maybe in five more years.

 

Also tremendous toenail polish on the last picture in post #265. ;-)

[xcarguy]

Tremendous work. I hope we save this for whenever I get around to my build, maybe in five more years.

 

Also tremendous toenail polish on the last picture in post #265. ;-)

 

First, MightyMike gives Brit s$#^t about his garanimals (see first page of this thread) and now he's catching grief about his toenails. Brit, I'm really starting to think your forum handle 'toedrag' has much more to do with a personal chooice in attire than with the game of hockey. :jester:

 

Sorry, Brit; just couldn't pass on that one. On a more serious note, the build is looking fantastic. Here's to getting together on track in the not-so-distant future. :cheers:

[toedrag]

Like any vice, it started innocently enough...ya know, getting toenails painted with my 4 yr old. Harmless, right?

 

We started micro-painting faces & little landscapes on our toes after that (kind of like those artists who paint the heads of pins) - we tried people, animals, etc...This made for a much more realistic, "This little piggy" game. Again, harmless, right?

 

I started exploring other stories/plays using these new toe characters in my private time. Eventually, I started making up complex plot lines & characters. Sadly, I began to realize over time that always having bald characters was stifling my creativity. Naturally, the solution was to find miniature wigs to fit my toes. The sky was now the limit with what I could do.

 

Now, things get a little weird....

 

As a gag, I made a video of one of my plays and temporarily posted it to youtube. It went viral, much to my surprise, but hey, the interwebs have some weirdo's I guess...

 

Anywhoo, and after a fair amount of back and forth with an individual known only as "BigToeny", I'm now contractually obligated to produce videos exclusively for [him/her?] BigToeny happens to prefer all-female toe-centric theatrics, so I suppose that, technically, you could consider that my "toes are in drag" on occasion for that.

 

:jester:

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Or, maybe the reflection you're seeing in pic 265 is from the shiny insole of the sandal

[xcarguy]

Like any vice, it started innocently enough...:jester:

 

 

 

And now, back to the build. :jester:

[subtlez28]

:jester:

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Or, maybe the reflection you're seeing in pic 265 is from the shiny insole of the sandal

Well played sir!

 

I have been jumping in and out of your thread, so I may have missed this if you detailed it earlier.

 

Can I get more info and maybe a source for that inertia switch? That was something I intended to incorporate, but did not yet put in, during my rush to get racing in the fall.

 

I remember my step brother's old Temp had a resettable inertia switch in the trunk. Literally the worst car anyone I know has owned (unbelievably slow, and yet still horrible mileage) , but I liked that little bit.

[toedrag]

Can I get more info and maybe a source for that inertia switch?

 

Sure thing. Got 'em from Summit, SUM-890145 is the switch, and PCO-5756PT is the pigtail for it. The actual p/n stamped on the switch is XF32-9341-AA, and it looks like you can find them a little cheaper on ebay using that p/n.

 

It's a 3-wire connection, Common, N.O., and N.C. On the pigtail, the Common & NO terminals are 12 gauge wires, but the NC terminal is 14 gauge for whatever reason. I chose to wire it such that the inertia switch is in series with the coil side of the fuel pump relay vs putting it in series with the pump directly.

 

I have the Common terminal connected to the control wire from the ECU (12V = On), the NC terminal connected to the coil side of a relay, and the NO terminal feeds a indicator light on the dash.

[toedrag]

I had been working on fitting the rear fenders for the last couple of days. It's funny how something so seemingly simple like fender installation can uncover new dependencies:

 

The outer lip of both fenders was a pretty rough circle, and the width of the lip varied up to 1/2" all the way around. To fix it, I traced the profile of the fender onto the lip and gradually re-shaped it. It took a while to complete both fenders. I think I spent maybe 4-5 hours on each one. [statement of the obvious]: It's hard to get a perfect circle by hand . It's now infinitely better than it was originally, and I'm happy with it. I'll do pictures once they are on the car. I don't have any 'befores' though...

 

When I tried to place the fender onto the car, it dawned on me that because the rear fender will be attached to the body of the car, it meant that the car needed to be, more or less, at its final ride height since I wouldn't want to set the fender, then increase the ride height and screw up the nice gap I had worked so hard to obtain.

 

Such began my odyssey into trying to set the ride height on this car. Keep in mind that this M-Spec version of the Stalker differs from previous Stalkers & many other se7evn variants in that the M-Spec has double-wishbone control arms with pushrod/rocker actuated inboard single adjustable coilovers on all 4 corners, which is a lot of fun to say, by the way.

 

The car currently sits with the front roughly 0.5" too high, and the rear roughly 1.5" too low. After a quick call to Brunton, the guidance was to just add 3/4" of spring preload to the rears and that would raise it up enough.

 

Not having any idea what spring preload was or why a person would want more or less of it, I set about to educate myself, and I think I understand it now. Feel free to correct me if any of the following sounds off:

 

'Spring preload' is a fancy way of saying, "raise the lower spring perch until the spring is compressed X number of mm or inches." The main purpose of preloading a spring is to change the starting/statically loaded position of the damper stroke. Preloading a spring also has an interesting affect, therefore, on ride height. For some suspension systems where there is no separate ride height adjustment, changing spring preload is the only way to change the ride height, which is I think where some people get the slightly misguided idea that [the purpose of preload is to change the ride height]. I personally think that's an oversimplification, but since it's also application-specific, it's hard to blame people for coming to that conclusion if that was their experience.

 

I found an Internet Rule of Thumb (be warned) for a street car that states when then car is statically loaded (resting on its wheels on a perfectly level surface), the damper should be compressed approximately 1/3 it's total stroke. For example, if you have a damper with 3" of total stroke, when the springs & damper take the weight of the car, you should still see 2" of the damper stem. Going further, if you had soft springs that allowed the car to compress the damper such that you could only see 1" of damper stem, then you could use some spring preload so that the damper isn't compressed as far. In contrast, if you could see 2.5" of damper stem, you could reduce spring preload so that more of the damper is compressed.

 

The good news is that at my car's current state of being, it does compress the front & rear dampers to ~1/3 it stroke with basically zero preload. If I adjust preload any further, it'll be because extra weight added to the car during the remainder of assembly caused the dampers to be compressed more than 1/3 their stroke. Outside of that, I have no interest in using spring preload to adjust the ride height. So, I find myself, once again, deviating from the Stalker playbook.

 

My logic is that with the pushrod suspension, it's the total length of the pushrod + heim joints that dictate the ride height (or so I think). That's what I'll be messing with to lower the car in the front & raise it in the rear. After remembering how trigonometry worked, I've determined that I need to reduce the front pushrods by 1" and increase the rear pushrods by 1", and using the heims to fine tune things. This should allow me to get to the 6" ride height I'm after and allows zero spring preload.

 

So, new pushrods are now on order (at a pleasant ~$10 ea), so it'll be back to wiring for a few days while waiting for the new pushrods to come in.

Edited January 16, 2015 by toedrag

[jevs]

For the final height adjustment and corner weights you will want to get it on some scales. You may also want to sandbag the seat for your weight when you do it...However for doing the body work, you can just get the ride height about where you want it and then try to tune it back to about that on the scales with your weight in there.

Personally I would not put a bunch of effort in figuring out the preload amount and all that because it is going to need tweaking once you get it on some scales and put your weight in it and finish adding weight to the car.

This is why the front is nice, no fender placement to worry about regardless of what happens. You can move the front suspension anywhere with no worries.

I have not messed with the rear fenders yet, but if you could somehow slot them or leave larger holes and use fender washers or something and leave yourself some adjustability for final tune, that would be nice...

[toedrag]

For the final height adjustment and corner weights you will want to get it on some scales. You may also want to sandbag the seat for your weight when you do it...However for doing the body work, you can just get the ride height about where you want it and then try to tune it back to about that on the scales with your weight in there.

Personally I would not put a bunch of effort in figuring out the preload amount and all that because it is going to need tweaking once you get it on some scales and put your weight in it and finish adding weight to the car.

This is why the front is nice, no fender placement to worry about regardless of what happens. You can move the front suspension anywhere with no worries.

I have not messed with the rear fenders yet, but if you could somehow slot them or leave larger holes and use fender washers or something and leave yourself some adjustability for final tune, that would be nice...

 

Right, I'll wait on corner balancing w/ballast weight until later, once the car is all put together. The interesting thing (and I'm a neophyte w/corner balancing btw) is that ride height seems to be the parameter of interest during corner balancing, which means preload won't be a consideration, unless one adjusts ride height via preload.

 

Good idea on the slots to accommodate changes!

[degoetz]

Be careful using only shock preload for ride height. I use shock preload to center my travel in the shock and the adjuster rod to determine ride height. For example if the the ride height is too low and you preload the spring you might end up with the spring only compressing at 1/2 or 3/4 of an in. What I do is preload the spring and let the car down and measure how much the shock has compressed. I have 3&1/4 in of travel so I want my spring preload set so the shock settles about 1&1/2in. then I set my ride height with the adjuster rod and now I know I have range on both sides of the shock travel without it bottoming or topping out.

[HOTTTCAR]

degoetz

Thanks for the post..very simple and concise.

Gale

[toedrag]

Be careful using only shock preload for ride height. I use shock preload to center my travel in the shock and the adjuster rod to determine ride height. For example if the the ride height is too low and you preload the spring you might end up with the spring only compressing at 1/2 or 3/4 of an in. What I do is preload the spring and let the car down and measure how much the shock has compressed. I have 3&1/4 in of travel so I want my spring preload set so the shock settles about 1&1/2in. then I set my ride height with the adjuster rod and now I know I have range on both sides of the shock travel without it bottoming or topping out.

 

Thank you for this. Yes, that's what I was trying to say, but with 1000 or more words...the only difference between what you're saying is that I will end up with a 33/67 ratio instead of 50/50.

 

My dampers (front & rear) have 4 3/4" of travel, and with zero preload, they end up around 3 1/4", which is right around 68%. If I were to get more travel to end up closer to 50%, I'd either need to use softer springs or I'd have to lower the spring perch such that it loses contact with the spring at full droop, which would lead to a frightening 'clang clang' sound on the street as the spring & perch lost and then resumed contact. I suppose I could find some large diameter washers to use as a shim, or if the gap was big enough, use something called a 'helper spring'.

 

I'll stick to this 1/3 to 2/3 ratio and see what happens.

[toedrag]

I suppose I also glossed over a fairly important detail with the pushrods & heims on my car. Because the rear needed to come up 1.5", that simply couldn't be done by just turning the pushrod to extend the heims. Well, you could, but it would leave the heim with only about 1/2" or less of thread engagement in the rod, and that's not quite enough thread engagment, imo.

 

For the fronts, the heims were already threaded in all the way, which meant I couldn't lower the front the additional 1/2" that I wanted.

 

To correct this, I'm replacing the rear 8" rods with 9" ones and replacing the front 19" rods with 18" ones. These should get the ride height where it needs to be and still allow plenty of heim thread engagement & adjustability when it comes time for corner balancing.

 

---

 

As an aside, I'm using 6" for ride height because of the following: The lowest part of the car is the bellhousing, which protrudes 2.5" below the bottom frame rails. Then, if I stick to the 1/3 rule for the damper compression (at a total stroke of 4.75"), that means at rest, the damper has another 3.25" of compression before it bottoms out. I reason that I need as much ground clearance as is remaining in the damper compression stroke, which means 3.25" to the bellhousing. Add 2.5" to that, and I end up at 5.75" from the ground to the frame rails. I rounded up to 6".

 

[EDIT]: It's now occurring to me that I didn't take into consideration the motion ratio with my little ride height formula above. I had been assuming that 1" of wheel travel = 1" of damper travel, and that may or may not be correct. Brunton has the motion ratios listed in a doc somewhere, I just need to go find & study them. [end EDIT]

Edited January 16, 2015 by toedrag

[degoetz]

[EDIT]: It's now occurring to me that I didn't take into consideration the motion ratio with my little ride height formula above. I had been assuming that 1" of wheel travel = 1" of damper travel, and that may or may not be correct. Brunton has the motion ratios listed in a doc somewhere, I just need to go find & study them. [end EDIT]

I did my own on a 2014 AXR but this might not apply to all Stalkers

http://i644.photobucket.com/albums/uu163/degoetz/Cars/MotionRatioChart_zpsf471b449.jpg