The engine bay in my Rx7 gets dusty as hell. I think it's partially from the Samberg fans blowing down in my driveway. I wanted some kind of undertray. No one makes one specifically for v8 swapped Rx7s, especially when there are different setups that could alter fitment. My current setup:
I bought the tray directly from LRB. They were nice enough to not cutout the Rotary triangle that is normally cutout for the rx7 radiator drain. I don't need this since I have an LS2 motor. Plus having a rotary symbol would be ironic. I'm still in the process of fitting it, but below are my notes.
So for starters the Samberg v2 kit sits slightly below the bottom of the bumper. The R1 lip hides it nicely. However the LRB undertray is mean to bolt to the underside of the bumper. Since the radiator hangs down a tad, it interferes. So I had to change the angle of the LRB splitter. I did this by adding 3 washers under the front bolt of each side piece.
This shows the underside of the radiator. With the front sidepiece bolts spaced down it gives me a little bit of clearance. If you had the v1 Samberg radiator I bet this would not work as I hear it sticks down even farther.
Here's a picture with the big piece slid on. It actually looks pretty good, all things considered.
The front part of the tray will have a small gap underneath the bumper. This is because the side pieces are angled more to provide clearance to the Samberg radiator shroud. Any front lip will hide this gap. I'm going to need to make spacers though to accommodate the gap and probably get some longer bolts too.
The side pieces do hit the AWR sway bar brackets. I'm not sure they would interfere with the oem brackets or not. I didn't want to run the OEM brackets as people have had issues with them twisting. Now I think I could grind out some material on the LRB side pieces to provide plenty of clearance. My only concern is on the passenger side where there is a valley cut out. I believe this was for OEM Rotary oil cooler lines? The passenger piece already feels flimsy. If I were to grind out some material it would be even worse. Maybe LRB could cut one without this valley, or I could weld a plate over it. The LRB under tray comes with an extra metal lip piece that is meant to direct air up to the factory rotary radiator. I won't be using that piece, but I could repurpose some of the material.
Now the back side is where I expected to have problems. Obviously the LRB undertray is meant to fit the rotary subframe. It won't bolt directly to the Samberg frame. I think that I could make 4 slits though creating 2 little tabs that I could bent up slightly and drill. Then the front bolts that hold the power steering rack on could go through the holes. On the edge pieces I could cut them off completely or there is a flat spot I could drill into on the Samberg rack. I'm leaning towards cutting them off.
I'll update this again once I have it fully fitted. I also made a quick video that goes over the areas described above.
I chopped off the back ears of the undertray. I grinded out space on both side pieces too so that they don't interfere with the AWR sway bar brackets. I bought some nylon spacers for the front bumper bolts that I think will work. Now I'm just stuck on what to do with the rear.
I got it mounted today using some brackets I made. I bought a piece of 1"x4' aluminum that was 1/8" thick from Tractor Supply. I cut 2 small pieces out of it, and gave them each a slight bend in the vice. I drilled a hole in one side so that the front power steering bolt could secure it. On the other side I drilled an M8x1.25 hole for a 12mm bolt. This gave me a spot for the rear undertray to bolt to. I took it for a ride and everything seems great. I made 1 last video of it. I'm going to share what I did with LRB. Hopefully they will end up offering a kit specifically for swapped Rx7s. If not it wasn't too difficult to make their kit fit the Samberg Subframe.