S2's Build Thread


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Mesa, I think you're talking about 2.5 above, but with the black side scoops. Below are three renderings with increased vent heights:

A: requires no changes to the front vent

B: provides room for the aero catches in the standard location;

C: IMO this version looks best. As you point out the visible fiberglass is easier than B because there is no need to maintain the thin section of body or the panel gaps above the vent. The big question is how to get the aero catches to work. I think the rear one could be slid back and hid in the vent. The front will be a challenge.

I'm traveling until the end of August so I can't look at the car to see how complex it would be. If you have any pictures of how you solved the problem, please post them.

I have a custom C&R radiator/shroud up front, so I'm not going to consider moving the cooling to the rear.


Dan Carter


After pondering the drawings some more, 3.1 or 3.4 are my favorites. I see following the front wheel well does add to the front better but the symmetry of the angles looks impressive as well. Are you planning to make the mod? How will you maintain structural integrity?


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I took a six-week vacation with the family and, fearing build withdraw, I made a man bag to bring some electronics along. Needless to say my wife wasn’t happy — something along the lines of “NFW are you bringing that!”.

Joel made a bench harness so that I could start to get my brain wrapped around the MoTeC display, Power Distribution Module (PDM), keypad, rotary keypad, Dual Half Bridge (DHB) and CAN bus. The test harness is first rate; Deutsch connectors, Raychem DR-25 sheath, labels on everything and detailed documentation.

My plan is to focus on the basics and leave all of the complex ECU and tuning stuff to the pros. Even so, MoTeC isn’t geared for DIY’ers, so Joel is providing tutoring lessons via a remote desktop application— my kids think it’s hilarious that the old man still needs tutoring.

One of the primary objectives with a MoTeC setup is to replace as many physical fuses as possible with PDU outputs which have configurable current limits, automated retries, logic and logging. For this reason, the harness powers the display via a PDU output. The first step was to configure the name of the output. Like software, it’s a good idea to provide robust names. Since it’s part of the bench tester and it powers the C127 display, the keypad and a spare power connector, I named it “Output.BenchTester.C127/Keypad/Spare”. To power it, I simply created a condition as can be seen in the snippet from the PDM Manager below. When then PDM has power, the display, keypad and spare power connecter have power.


I didn’t get very far with things, mostly because I had a poor internet connection which made the remote sessions difficult. However, I was able to get the keypad buttons to activate turn signals, the hazard and to activate the DHB.

Now that I’m back home, I’m going to get things kicked into high gear!


Lifetime Supporter
Are you planning to make the mod?
Dan, I'm going forward with variant 2.6-A3, which looks the best, but requires the most work. Funny how it always seems to work out that way.

Today I made some initial cuts to implement the front vent… there’s no going back now! The AeroCatch and rear locating pin (A) were completely removed. Filling the curved vertical section (D) will be easy. I just need to bolt a curved non-stick piece of plastic to the outside and patch from the inside.
IMG_7712 Annotated.jpg

I left a portion of the flange that the nose sits on in place because the bottom side of the nose flange needs to clear the door hinge and the side of the spider when it is raised and lowered and something needs to seal the nose from the exterior. This flange will likely get cut back further and I’m wondering if I should create a large fillet to blend its underside into vertical section D.

The AeroCatch will fit into section C if it’s oriented transversely. However, that orientation places the pin more inboard than desirable which may cause the strike pin to scrape the side of the spider. The factory body fitment had that issue on the right side and the scrapes can be seen in B. For this reason, I’m going to replace the AeroCatch with a Quick-Latch QL-35. Even if I trim the flange off of the end of the AeroCatch, the center of the pin is 1.5” from the edge whereas the Quick-Latch is 0.9” with the flange in tact. In addition, the Quick-Latch installs with a single 1.25” hole saw whereas the AeroCatch requires a more complex oblong cutout and six mounting holes. Each Quick-Latch is rated for 500 pounds, so they should be more than strong enough.


The biggest question at this point is what to do with piece C. If left as is, I will need to reinforce it (glass it to the curved vertical piece) and close the curved back edge (red lines). IMO it will look bulky and getting the back edge finished properly will be tricky. Another option is to raise piece C. The Quick-Latch requires a minimum depth of 1.2” which would allow me to reduce the distance to the part line by at least half. Getting the curved back edge to look right would be easier because it’s smaller and less visible. That said, I’d need to make a simple mold. I ordered a set of Quick-Latches and I’m going to reflect on things before cutting any more.

The door consists of an inner and outer shell which are bonded together at the factory. Fortunately, there is a fair amount of space between the two pieces which allowed me to cut the outer shell. I ground the dark-gray adhesive on the front edge because I assume that epoxy/fiberglass is stronger and I’m not sure how well the adhesive would blend with fiberglass or hold paint. As can be seen in the profile picture, there is plenty of room for epoxy/fiberglass to add strength and micro balloon mix to create the profile. The top edge of the door is thin near the top of the cut, but I can easily add fiberglass to the inside of the door there.


Lots of adhesive on edge


Most of adhesive ground off


Room for epoxy/fiberglass and micro ballon mix


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I spent a lot of time looking for a fuel pump with the following requirements:
  • 1,000+ HP; it’s gotta have the juice.
  • Brushless: Heats the fuel less and consumes less power.
  • PWM’able: No way do I want to be sitting at a light with the pump pushing over 120 gallons / hour at 42 psi. That will heat the fuel and if something comes loose I want to be flowing as little fuel as possible.
  • In tank: Reduces external plumbing and keeps the pump cool.
  • Flange-mount: No brackets, clamps, hoses or wires dangling inside of the tank.
  • Ethanol Compatible: More power and lower operating temperature.
While many pumps met most of the criteria, the brushless/PWM’able combination was the limiting factor. At some point during my search Radium announced a surge tank designed for the FUELAB 92902 which met all of my criteria. It’s rated to 1,800HP and has an integrated motor controller. This allows me to simply connect it to one of the PDM’s PWM outputs.

Great! I immediately ordered one… not so fast. Apparently FUELAB, chasing bigger HP numbers, changed the height of their pump twice which required Radium to change their surge tank twice. So, after over a year of waiting, I finally received the pump and the surge tank.


Radium provides a filter which bolts to the bottom, an o-ring and a retaining ring with bolts — so about three minutes to install it into the surge tank.

I fabricated an aluminum bracket for the surge tank and attached it to the 2” x 2” tubes with six 1/4”-20 nutserts, two of which capture the surge tank. Four additional 1/4”-20 nutserts mount the surge tank to the bracket. I will fabricate a heat shield to protect it from the exhaust manifold.


I also mounted my super trick fuel filter which I posted about here. Man, it feels good to get that out of the box and mounted to the car!!! If you’re wondering what the trio of holes are to the right of the fuel filter are, they are specifically designed to reduce harmonic engine vibrations from disrupting fuel flow through the filter OR I mounted the filter in the wrong place and now need to weld the holes shut;-)


Joel K

Very nice setup Scott, how are you going to control the PWM pump, with Fuelab’s electronic regulator, the engine ECU, or some other way? Just curious.

Ian Anderson

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Neat looking setup.
What GPH / LPM is the pump rated at in order to support their 1800 hp?

What Low pressure pump will you run to keep the radium unit full?



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how are you going to control the PWM pump
Joel, I will control it via a MoTeC ECU. If I wasn't going in that direction, I'd take a serious look at Fuelab's motor controller. Since the motor driver is integrated into the pump, the controller is small.

What GPH / LPM is the pump rated at in order to support their 1800 hp?
Ian, their marketing indicates:

190 GPH at 45 psi
720 LPH at 3.1 bar

However, every pump has a serial number and comes with a printed certification sheet. Here's a scan of mine:

Looking at the results, my pump flows enough fuel for 1,800HP at around 75 psi, assuming that gives you enough boost headroom.

What Low pressure pump will you run to keep the radium unit full?
Ian, I'm a little over 1,000HP so I don't need to worry about feeding a 1,800HP monster. Assuming a Brake-specific Fuel Consumption (BSFC) of 0.65 at wide-open throttle (WOT)

GPH at WOT = (1,000 * 0.65) / 6 = 108.3

I used a Holly 12-125 because it worked well for my layout (it's vertical) and it seems to have a good track record. It is rated at 125 GPH free flow and 110 GPH at 7 PSI. So, In theory it can keep pace with WOT consumption if the pressure is in the surge tank is around 7 PSI. That said, I can't imagine applying 1,000HP for long in a SL-C, particularly in a sweeper that starves the low-pressure pump.

Radium's documentation "generally recommends a [lift] pump with a rated flow of 400+ LPH." That's 106 GPH which a little less than the Holly's spec.
The next step is to wire it up and test it. Apparently you need both calipers plugged into the ECU for it work.
Awesome build and write up.
How did you get on with the HiSpec EPB in the end, did you get as far as wiring up ? also on caliper mounting the clearance looks tight to the disc, is it threaded (M10?) or does it need a nut on the disc side of the fitting?