2012 Superlight R400 SV

[Scott_]

On September 5, 2026, I went to Cars & Coffee in Morrisville with no intention of buying another Caterham.  I was a approached by a fellow after he saw me next to my '99 Caterham.  He and I started talking about Sevens, and he mentioned that he had a  Caterham R400 that he was selling.  He had my attention.   I had plans for my '99 but I came to learn that the car he had for sale checked all the boxes for me.  

 

He showed me photographs of the car and told me the history.  It was a genuine Superlight R400 SV with the 210-horsepower 2.0-liter Duratec, Caterham six-speed gearbox, limited-slip differential, wide-track suspension, uprated brakes, carbon dashboard and front wings, cage, race seats, etc. He was the first owner and had built it at the end of 2012.  He said he had all the maintenance  and purchase records from new.  The cage was built off the original track day roll bar by a race shop.

 

After talking more and talking numbers we worked out a deal on the spot. Later that day I sent him a deposit subject to inspection on pickup.  After that I listed my '99 for sale.

 

Over the next few weeks I was able to sell my '99 while the seller of the 2012 sent me copies of some of the paperwork and answered my questions as we worked to arrange a pick up date at VIR.  

 

The car had led an unusual life. Although completed in December 2012, it had seen very little ordinary road use and was road legal for only about a year. Most of its life was spent in garages/storage at Virginia International Raceway. It came out for track days and an autocross or two.  

 

My father shares my interest in cars so he and I left early for VIR from Raleigh on 9/25 to inspect the car and (hopefully) complete the purchase.  It was special to have him with me because when I was young he and I went on long trips to collect hot rods and other cars.  

 

The car was what I expected and wanted so we closed on the deal and my father and I were back in Raleigh by noon.   With the car unloaded I was then off to the DMV for title work and temporary tag followed by an afternoon drive.

 

[Scott_]

One of the things I really like about this car is the paint.   The order sheet says Lotus Anniversary Paint Scheme.  It matches the Caterham F1 cars of the time.  The number on the car is an homage to Group 44/Bob Tullius.  I had originally planned to take the numbers off but for now plan to leave them on... I like them.   

Edited October 2 by Scott_

[theDreamer]

I love the image of your new to you 7 as seen in the rear view mirror.

When I picked up my MV Agusta F3 in 2012 I had the same view every time I looked in the mirror. For nearly four hours I was staring at that gorgeous red upper fairing. I could not help myself from thinking about the opening line of the Richard Thompson song “1952 Vincent Black Lightning”:

Oh, says Red Molly to James, That's a fine motorbike…

So I called her Red Molly.

(I do not know when we started anthropomorphising our possessions but all my guitars and our toys, (both motorcycles and cars) have names.)

[Origin7]

She's a beaut! Congrats! 

[Scott_]

I purchased a set of RBTB's originally made for a 485 with the idea of using them when I installed the Haltech R3 which supports drive by wire.   Now that I have the R400, I decided to see if I could convert them to cable actuation since I have a MBE 9M4 on order.   It helped that I have a spare head, throttle cable and some other bits to work with off the car.

 

The 485 uses a remote DBW actuator mounted on the side of the engine that uses a short throw to achieve the 90 degree rotation of the barrels.  I had originally considered a bell crank arrangement to get the cable pull ratio right but the extra complexity of adding that below the manifold did not seem worth it after studying the throttle bodies and taking measurements.  

 

I have a tig welder and came up with a solution so I could use the stock throttle cable without alteration and avoid the need for a separate bell crank arrangement.   Initial testing is fine but I need to make sure the return spring is strong enough.   

 

Edited October 5 by Scott_

[Scott_]

Finally finished the installation of the Caterham 485 throttle bodies and MBE 9M4 on the Superlight.  I switched over to 440cc injectors which, after testing, appear to closely match the initial setup of the SBD basemap that came on the 9M4.  I went ahead and replaced the coils and sparkplugs so I knew I was starting from a good known baseline on the ignition.

 

I'm using an Innovate LC2 wideband o2 and had to adjust the voltage curve in Easimap. The SBD/MBE lambda target table appears very conservative and am just leaving it this way for now.  I still need to balance the airflow in the throttle bodies and have ordered an air flow meter. 

 

Initial road testing and logging indicated the short term fuel trim was adding about 10% so i updated the main TPS fuel map accordingly and the trims are, in most places, now hovering around +- 2% of the target Lambda map.  I did update the throttle site curve and still think I need to give that more attention.  I did some fourth and fifth gear pulls on the road while logging and everything appears good.  Throttle response is good.

 

Cold and hot starts are fine and the coolant fuel enrichment trims seem to work well as is.

 

Curiously the SBD basemap came set up for a Ford coolant sensor and when I switched it to work with my Bosch unit the map disabled the aux pinouts to the fan relay and fuel pump relay.   It took me a while to figure out what was going on but I knew there was an issue with the fuel pump not priming.  Initial thoughts were blown fuses but I traced it to the ECU and that was an easy fix. 

 

 

 

Edited Sunday at 03:20 PM by Scott_