Last 111, First Street Legal K20 Swap? (Part 2)

Tub Swap

Before doing anything K-swap related to the new chassis, we started by transferring parts over from the original tub to the new one. Since this was a low mileage car, it wasn’t difficult selling the drivetrain. Timing worked out perfectly as there was another Elise in our shop needing a motor due to a failure.

Once the motor was out, it was time to move the car next to the new tub and start transferring things over. We started off with the suspension and brakes so that we could bring the new tub to a body shop to get painted. While we were at it, we replaced all of the control arm bushings, installed BWR Ultimate Uprights, and JRZ RS PRO3 coilovers. From there, we took everything else off the car. We wanted to take some time to thin out the chassis harness and remove what won’t be used, so a lot of parts could not go back in until that was was done and routed through the car.

Manual window conversion

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We installed the doors so that the body shop had panels to match against and towed it over.

While the car was being painted, we worked on removing all the wiring that wasn’t needed from the chassis harness. This included the ABS, alarm, CDL, power windows, stereo, TPMS and rear fuses (replaced by Motec PDM). The instrument cluster connector was replaced with a Deustch connector since we’re going to use an AiM MXP dash. All of the unused front fuses (windows, ABS, radio, etc.) were routed to an AUX connector by the cabin fuses.

When we were done with the old tub, it was taken back to the owner. Our good friend, Kiyoshi was nice enough to convert his trailer into a stacker and bring it down to SoCal since he was headed there for a track day at Willow Springs. Between five of us, we were able to lift the tub onto the trailer. We’re not sure what’s going to happen to it, but we hope it turns into a race car or maybe a racing sim?! And if you’re wondering, yes, the cars made it down safely.

Back to the Donor Car

It was time to start isolating the original engine/chassis harness and remove everything that was not going to be used in the Elise. This was a long and tedious task because it meant removing some sections, then checking with the scan tool to make sure that no fault codes popped up in the ECM. Once we had the harness down to the bare necessities, we learned that the Honda factory scan tool would no longer connect and communicate to the car. This was a really big problem, because that meant that we wouldn’t be able to run the EVAP test like we did in Part 1. It also meant there was no way to register or program any new immobilizer components if they failed.

Luckily, our Snap-On rep had a demo scanner to try out and it was able to connect to the car and had all the capabilities of the factory scanner. It was time to update our current scanner anyway, so we bought one for the shop.

Engine Prep

It was time to remove the engine and start prepping it for the Lotus. Before getting it on the engine stand, we sprayed it down with degreaser and wiped it clean. The only modification that we plan to do to this motor is the baffled oil pan to help with oil starvation. The rest of the work is purely preventative maintenance.

In order to install the baffled oil pan, we needed to delete the balance shaft assembly that comes on the K20Z3. To do this, we simply needed to convert to the K20A2 oil pump from the RSX-S. We worked with Unit2Fab for making a version of their Elite oil pan to fit a Honda swapped Lotus.

For preventative maintenance, we replaced the timing chain, chain guides, timing chain tensioners, water pump, thermostat, seals, gaskets, clutch, and adjusted the valves.

With all of that done, we were finally able to move to the next step and put the motor in the car!

What’s next?

With the motor in, we’re going to tackle each section of the drivetrain one by one. Coolant system, shift linkage/axles, oil system, fuel system, exhaust, electrical etc. Stay tuned!

Looking for Part 1? Go here.

Looking for Part 3? Go here.