Ares: E30-LS1 - Removable Core Support

Welcome to the second installment of the E30-LS1 Build.

Here we discuss a topic that is on every E30 enthusiast’s mind – How to effectively make the radiator core support removable. And this is just the first of 2 parts discussing this very in-depth topic.

To start, we’d like to quantify this discussion. Let’s list out the requirements:

1. Must be easy/quick to remove – Mechanically & Electrically
2. Must be relatively simple to construct
3. Must look stock
4. Must maintain stock functionality

Historically, an easily removable assembly, whether it be a subframe, engine, radiator, or any other subassembly of a rally or race car is key in order to get it back in the race. Here, we try to replicate that to the best of our ability in Ares. Below is a rough list of the pros and cons to doing such a modification. Also are a small list of items that could make/break your effort. This write-up is designed to de-risk your project and execute a professional looking E30 Front Subframe:

 

How to cut the core? We performed a combination of drilling out existing spot welds with cutting and re-welding our own support structure to maintain stability and strength of the assembly. See below for cutting/drilling locations:

There are certainly many methods to incorporate a removable core support while maintaining to all of these requirements, but we will show you at a high level how we plan to execute that with Ares.

Here we have our documented main attachment points. These points must be, strong and somewhat concealed, while maintaining ease of accessibility with hand tools. Below you’ll see the basic structure of Garagistic’s go-forward approach when constructing to all of this criteria.

The prototype modifications have been made as shown below. You can see where it was decided to make the connections. Each of these mechanical connections shall have either weld nuts attached or the holes tapped for ease of installation/removal. All tapped holes shall have at least 3 threads to meet the minimum torque requirements for a thread of that size.

   

Above are some pictures of the entire assembly after construction has been conceptualized.

Now let’s go back to our criteria – our requirements for our removable subframe. See below for the responses to our self-induced requirements.

1. Must be easy/quick to remove – Mechanically & Electrically
   1. 6 Bolts, assembly pulls out by pulling toward the front of the car. No binding occurs
   2. C101/X20 style connector mounted directly on the fender wall near the ABS Pump
   3. Removal/installation of the core support and supporting structure will take no more than 10 minutes, including bumper, valence, core support, headlights..etc.
2. Must be relatively simple to construct
   1. Basic welding knowledge, making steel brackets, and welding nuts or tapping for ease of remove/install.
   2. Need die grinder, angle grinder to make brackets and sheet metal bracing
3. Must look stock
   1. Utilized existing support with modifications.
   2. Holds factory E30 radiator or an aftermarket Moshimoto with stock mount locations
4. Must maintain stock functionality
   1. All electrical signals maintained
   2. Mounting points easily accessible.
   3. Maintains stock strength

More info to come in the second installment as we finalize our electrical routing! Because many of the signals require 10-12 gauge wire, we cannot use a simple aftermarket connector. Therefore, we plan to use a lightly used C101/X20 style connector and mounting it bulkhead in the side of the fender, thereby concealing the routing of the wires from the fuse box to the front end of the car. This helps the project remain inexpensive, available connectors, and no special pin/depin tools. The signals involved are:

Want more detail? Stay tuned for the official write-up of the E30-LS1 through Macalent LLC. There’ll be much  more detail with step-by-step instructions on how to on the construction of the removable core support, hardware listing, hole drilling for spot welds, measurements,  and suggested wiring for the one-connector hookup, making this super easy for the shady-tree mechanic.

Thanks for reading and continue to stay tuned for regular updates on this amazing project!