S2's Build Thread

Scott, are you also installing column mounted power assist?

Do you have a certain date by which you want to be at Go Kart stage?

Are you targeting any specific race event rules while building?
 

Scott

Lifetime Supporter
How much is the rack? The power steering?
The rack is $1,499. Hill will provide a $50/unit discount if a group orders 3 and a $100/unit discount if a group orders 5.

I’m going to the DEC Motorsports Pro Street EPAS system. The Raver car uses the Pro Race System which isn’t rated for the street and is much more expensive. I’m planning on replacing the column because I’m want both a quick release and an OEM steering wheel and the stock column won’t support that. The EPAS, collapsible column and the universal joints will run about $1,600. If you reuse the stock column and universal joints it would cost less.

why didn’t you build yours first so I could have copied your ideas.
The details take time (i.e., I'm slow!) and I needed to learn from all of the other great builds.

are you also installing column mounted power assist?
Yes. IMO a faster ratio requires power steering and given that I have dry sump system there is no room in the engine compartment for a mechanical one.

Do you have a certain date by which you want to be at Go Kart stage?
My wife has been asking that question for quite some time. I plan on getting it to the go kart stage next year. The scheduling challenge will be getting the custom harness and MoTeC configuration done.

Are you targeting any specific race event rules while building?
I plan to use car on the street with some track days so I'm not targeting any specific race/event rules. I want to build a supercar-ish interior so a fuel cell is out (no way do I want to tear the car apart every 3-5 years to service the tank), I want to drive on the street so a full cage is out (but I went with the removable side-impact bars), I have an active wing which isn’t allowed in most rules, etc.
 

Scott

Lifetime Supporter
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As expected, I ran into some issues installing the new rack. Specifically, the housing OD is larger than and the section where the steering shaft connects protrudes lower than the stock rack. Compounding this, my chromoly tube frame prevents the rack from sliding upwards. To get it to fit, I had to scallop the top of the extended foot box and enlarge the opening in the vertical face of the monocoque. I’ll add a close out panel when the rack’s location is finalized. Most builders don’t have a nose frame, so I assume they won’t need to scallop the top of the extended foot box.

The pillow block holes were sized for M6 bolts and at Agile’s suggestion I enlarged the holes to M8 (future pillow blocks will be predrilled). I was hoping to reuse the stock rack’s top mounting holes in the monocoque, but that would result in a loose fit. So, all four holes will be welded shut and re-drilled. I don’t have the tie rods yet and I want to check bump steer before I finalize the mounting.

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To keep the bellows from rubbing the monocoque, 1/4” spacers are needed. I fabricated some temporary ones and I’ve asked Agile if the manufacturer can provide pillow blocks that are 1/4” taller. The factory ships the car with washers and nylocs on the backside of the pillow blocks. I added backing plates out of 1/8" steel.

Once the rack was in place I was able to determine where to locate and weld the crossbar on the top of the nose frame in front of the foot box. Due to ongoing changes, the Penske shock reservoirs have been kicked out of every location they’ve had and the crossbar provided an ideal place to mount them with some trick brackets from Joe’s Racing. Pull the pin and it pops open. Push the cam down, replace the pin and it’s locked. A simple design that works really well.

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Scott

Lifetime Supporter
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I finally got the oil cooler mounted. The first step was to trim the wheel well liner so that I would know where to locate the oil cooler. The flange that goes against the body needed a lot trimming! Fitment was complicated by the air jacks and the liner was in an out of the car at least 20 times to get it right.

I bought a MHX-520 oil cooler and a MHX-520-FSS shroud with mounted SPAL fan from Improved Racing. The cooler has a high-quality, made-in-USA core and the shroud has four rubber grommet vibration isolators that are very similar to the ones that I used on the intercooler brackets.

I designed the upper and lower brackets to achieve the following:
  • Allow the body to be removed / installed without touching anything
  • Robust without adding too much weight
  • Provide upper and lower mounting points for the rear tire liner
  • Stiffen the bottom body flange in front the rear tire
  • Cover the fan, the lower backside of the tire liner and the fiberglass body
  • Provide mounting points for a panel that will eventually cover the upper backside of the tire liner
  • Look cool — because that’s the way that I roll LOL
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I made the brackets out of 6” wide x 4” tall x 1/4” thick 90-degree aluminum (the structural stuff with a fillet on the inside corner). When the three-foot-long piece arrived in the mail I thought “that’s bigger and heavier than I thought!” After rough cutting it with a bandsaw, I used an end mill to clean up the edges. I then used a 3/4” end mill to cut six slots in the top and two in the vertical face. The slots on the top were milled parallel to the 2” x 2” chassis rail (62.5 degrees) to give it a custom appearance. This significantly lightened the piece and created a lot of chips!

Having enough of the fancy slots, the bottom bracket just got two big windows.

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Upper and lower bracket plus support rod

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Cooler mounted

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Ignore the intercooler lines which haven't been finished

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Good fit with top of wheel well liner

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Good fit with bottom of wheel well liner

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1/8" backer plate mounted to bottom of 2" x 2"

Each bracket has 1/4” screws that mount through the 2” x 2”, a 1/8” aluminum backer plate, a washer and a nyloc. The backer plates are held in place with a 10-24 button head. The vertical support rod was made from 5/8” stainless tube with M8 stainless flange nuts welded into the ends. The result is a very robust structure.

In the future, I’ll fabricate mounting tabs for the liner, a closeout panel to hide the upper portion of the wheel well liner and a bracket to stiffen the lower body flange in front of the rear tire.
 

Scott

Lifetime Supporter
Dan, it’s a It’s a Sharp 9” x49” vertical knee mill.

Joel, it came out nice but as “H” mentioned it’s probably a few pounds heavier than it needs to be. I hear this a lot from my wife LOL I might put a few more holes in the bracket and work on the stomach starting January.
 

Scott

Lifetime Supporter
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Morimoto has released Aventador-inspired tail lights for the 2014-2019 C7 Corvette. They’re DOT-compliant and feature optional sequential turn signals. I’m not sure why they’re not listed on their website, but I purchased a set from Vette Lights.

In the image above, the right tail light is a 3D scan of the stock C7 tail light and bezel with the “fang” removed. The tail light on the left is cut from a photo I took of the Morimoto light. While my graphics hack job is pretty bad, I think I like the Aventador style a lot more. I asked my daughter which she preferred and she responded “the one on the left because it looks meaner” — that’s my girl:)

The one wrinkle is that they placed the backup light in the “fang” which I plan to cut off. I have two options:
  1. Put the backup lights somewhere else.
  2. Modify the fang so that it’s flush with the bottom of the tail light. That might provide enough space to retrofit some backup LEDs into the lower outer corner. Filling in that corner may also make the lights appear more fit for purpose.
Thanks to some help from Ken regarding the connector pin mappings, I was able to get them wired up on the bench. I’m sure there’s a way keep the lights from blurring the video, but it escapes me.

 
Those tail lights look great Scott. Any progress on the body vent mods that you can share?

I noticed that you CNC'ed the radiator plates, were they too large for the Wazer to cut?
 

Scott

Lifetime Supporter
Any progress on the body vent mods that you can share?
I want to work through the entire process on something small before doing the side vents or the tail which are large projects. The first body part will be a radiator outlet similar to what Allan has done many times. I’m working with him and Kevin to come up with a more refined design since the plug will be CNC machined.

I noticed that you CNC'ed the radiator plates, were they too large for the Wazer to cut?
The Wazer has a 12" x 18" (305 mm x 460 mm) cut area and I’ve cut ¼” cold rolled steel, so it’s certainly capable of doing the job. However, there are several challenges.

(1) Like most water/laser/plasma cutters it operates in 2D (i.e., the material being cut is flat). With this piece, the section that isn’t being cut is 90-degrees to the cutting plane and it must be positioned so that it doesn’t collide with the cutting head / gantry. If I pointed it up, I wouldn’t have been able to get as close to the edge of the material next to the vertical section as I wanted. If pointed it down, I would have had to notch the cutting bed. Not a huge problem, but one leg was 6” and I’m not sure if I would have had enough depth in the water tank to accommodate.

(2) There is no good way to precisely indicate / locate the cutting head over the material and once you have a third dimension you need to precisely indicate the starting point. In addition, you need to ensure that the material is perfectly square which is hard to do when your screwing the material to plastic cutting bed and there is no way to measure run out. None of this is an issue when you’re cutting a shape from a flat piece of material because your only worried about the cut going outside of the boundaries of the material.

(3) It would have used a LOT of abrasive due to the number of slots and ¼” thickness.

For these reasons, I didn’t waze it. I could have CNC’d it, but I didn’t need exact dimensions, it would have cost a lot more and it would have had a much longer lead time (I don't have access to CNC machine). I kept the design simple (i.e. the slots were cut in one pass with a 3/4" end mill) enough to do it on a manual mill. Using a a DRO made it easy to do.
 
Thanks for the thoughtful answer, it sounds like the Wazer is better suited for flat plate materials. Also, the parts turned out great, with consistent shaping on each of the slots. Your manual mill skills are impressive.
 

Scott

Lifetime Supporter
I appreciate the compliment, but any knuckle head with a mill could do this (i.e., me). I designed it to service multiple purposes and to be easy to manually machine. All of the slots and one of the end cuts are at the same angle as the chassis rail (62.5-degrees). So, I sprayed the piece with layout dye and scribed two lines to indicate the start and stop of the slots (see dashed lines on image below and orange arrows on the picture below). I then oriented the vice (dark gray) 62.5-degrees from the table (light gray) and clamped the piece (light blue). This oriented the slots so that they were parallel to the Y-axis.

I measured where I wanted the first slot to be on the X-axis and dropped the end mill through the piece near the closest scribed line. Since the end mill (orange circle) was the exact width of the slot I just needed to crank the Y-axis until I reached the opposite line. Cutting a slot that is parallel to an axis and the width of an end mill is about the simplest thing you could do on a mill. I cranked the y-axis back to the starting point to clean up the sides. When making a second pass like this the end mill isn't under any stress and it will smooth the cut edges.

I then cranked the X-axis the desired distance (DRO made this very simple) and repeated. I had to reposition the piece in the vice once, when I ran out of room, but that was easy because I wasn't worried about precision with this piece.

If the slot wasn't parallel to an axis or if the slot was wider than the end mill, then I would be doing etch-a-sketch and I’m horrible at that.

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Scott

Lifetime Supporter
I finished installing the steering rack by using the stock top hole to clamp the rack in place while I located and drilled the bottom hole. The rack was removed, both of the stock holes were welded/closed, the top hole was drilled and 1/8” steel backer plates were fabricated.


Agile sent me taller pillow blocks which allowed me to ditch the spacers. Rack-to-steering-arm alignment looks good so I‘m not expecting any bump steer issues. Agile also sent me beefy tie rods with Auora heim joints which are higher quality than the ones provided in the kit. In addition, they have a misalignment mono ball which removes the need to use misalignment washers — two less things to lose!

I also noticed that the uprights were binding on the sway bar drop link brackets about 8 degrees before full lock. I had previously fabricated 1/4” spacers to allow the brackets to clear the top of the shock pins. This extra height was exacerbating the binding. It then occurred to me that I could clip the corner of the shock pin. This resolved the binding so I tossed the spacers. This also enables me to remove the shocks without removing the brackets. Duh, I wish I had done that sooner!

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