JohnCh

x Sorry, your tangent threw me and I assumed that was a generalization. I should have read it more closely. I took the car for a longer drive today and can confirm that vibration is now reduced to inconsequential levels. When it did vibrate, it wasn't enough to distort the view, and the rest of the time, it was rock steady. After more than 25 years of se7en ownership, this is a first.

Light from bright headlights immediately behind you will still reflect into your eyes. The extent that bothers someone or impacts their night vision for the road ahead is specific to the individual. Given the plethora of LED headlights and trucks/SUvs on the road, I find this issue more problematic today, and of course, it is compounded when the person travelling just a few car lengths behind doesn't realize their high beams are on. Been there/done that even with a day/night mirror fitted. As mentioned earlier, the convexity of this mirror is quite low. Much closer to a flat mirror than a traditional convex side mirror.

I've done touring through very hot areas and recommend a small, insulated hydration pack with straps like this one, which is thin enough to stow behind the seat and hangs from the headrest. Fill it up with mostly ice before you leave the hotel in the morning, and you'll have cool water later in the day when you need it. The bite tube makes easy to hydrate while driving, and the location keeps it out of the way. https://www.amazon.com/Hydrapak-HydraSleeve-Insulated-Shape-Shift-Low-Profile/dp/B0BRBR82BG

yep, the same setup @Outbound mentioned earlier. Zoom ships via Japan Post who handles the tariff payment and bills through Zoom, which simplified everything. The mirror was $115.23, the mount another $28.81, shipping to Seattle was $28.55, and tariffs were $20.03 for a grand total of $192.62.

It's not a badge, it's the horn button. I had it laser engraved with the logo.

I installed the Zoom Compact mirror today. I had previously lowered the factory mirror to the base of the windscreen to reduce some of the annoying vibration, but the Zoom takes things a noticeable step further. While shake isn’t completely eliminated, it’s no longer objectionable. The mirror is slightly convex and, despite its small size, provides a good field of view between the seats. There’s no day/night function, but the surface is coated with a blue tint to help reduce headlight glare. I was concerned the coating might be too dark during daytime use, but it seems fine. My only complaint is that adjustment requires loosening and tightening a set screw. This isn't a big deal unless you regularly share driving duties, but with a wider channel machined into the socket housing, and a Belleville washer to apply constant tension to the ball, it could operate like a conventional mirror.

420R SV on BaT: https://bringatrailer.com/listing/2023-caterham-seven-420r/

Piling onto this comment, another place where people go wrong -- including Caterham -- is the sensor mounting orientation. Sensor manufacturers recommend positioning it at least 10 degrees above horizontal to minimize the condensation pooling on the tip.

I may be using TPU for a tricky airbox to air hose connection in another car. I'll be interested to hear how things go for you.

Very nice! For under bonnet items, check out PET-CF. Prints just as nicely as PETG-CF, but can handle very high heat.

He has a problematic Zetec that is getting horrid mileage. Someone with a 420 should be able to chime in with their typical street mpg. As proxies, my Westfield, with a taller (3.62 vs. 3.92) final drive returned ~25 mpg when it had 420 cams with ITBs, and about 1-2mpg worse after changing to more aggressive cams. Highway consumption when touring was much better. The 2.4L Duratec in my Caterham is pretty thirsty, barely breaking 20 mpg in normal (back roads/around town) street use. Something would need to be wrong for you to go through 5 gallons in just 40 miles of street use in a stock 420.

BTW all the suggestions above are assuming your car is running well and you aren't getting @Vovchandr-like fuel consumption.

Caterham doesn't offer smaller fuel tanks, so even if they somehow managed to install the slightly smaller S3 tank in your SV, you would still have 9.5 gallons less ~1.5 gallons the fuel pump can't reach. That doesn't mean the tank wasn't crushed, but you that would be pretty obvious from beneath the car. From the owner's manual: It seems there are only two possibilities: The way you checked earlier that the tank was full was done incorrectly, or you have an issue with the tank. Although it's a little tricky to do because of the flap and the curvature of the filler neck, you could make a curved dipstick out of thick single strand wire or thin rod to confirm the fuel level. I have done this before when troubleshooting, but it took several attempts to get an accurate reading. I found putting painter's tape on the rod was helpful to see the actual level. Another possibility is repeatedly tapping the front of the tank going from bottom to top to see if you note a change in the thud that delineates the transition from fuel to air. I've never tried this myself, so the difference may be too subtle to hear. If you do attempt it, avoid the middle of the tank where the baffle is located. If you think the tank should be nearly full and the dipstick or thump test shows about half, then you know the issue is with filling it. If not, then there could be a blockage, or possibly an issue with the baffle, which divides the fill side and pump side of the tank. The foolproof method to confirm the fuel level is to remove the floor and pull the fuel pump/sensor assembly and do a visual check. However, that isn't easy as an uncut floor can be very frustrating to remove, and you need a special tool to remove the fuel assembly's locking ring. Fortunately, that tool is readily available and isn't expensive. My boot floor is currently removed, so let me know if you need pictures of anything.

I'm not sure how @Croc will feel about losing top billing

Yep! The MAP sensor is really just there for barometric compensation. A TPS controls the tables. I can share my map that was done on a dyno for my 2.4L. I'll shoot you a PM.

@redursidae welcome to the world of se7ens where Alpha-N is the norm. Even the MBE in new Caterhams employs this older strategy with time-based injector control. It's certainly not as good as a VE-based PID control, but it's certainly possible to achieve good behavior with these less sophisticated ECUs. Over the last 22 years, I've run Emerald and MBE on Duratecs with ITBs and have never had running issues related to the mapping strategy. Your advice is spot on when it's time to replace the Pectel, but I suspect @Vovchandr's issues run far beyond his map or mapping strategy. Fuel milage doesn't plummet by 40% unless there is some kind of failure. He needs to address that first. I suppose it's possible that the Pectel has a driver failure that is intermittently holding open an injector, but other than that, I'd start by looking at all sensors that can trim the injection map, run a compression and leak down, then check injector flow to see if one or more is bad. If the AFR numbers provided above are accurate, I'd be very concerned about bore wash. Given all the issues with this particular engine over the years, I suspect there are multiple things going on. Occam's razor won't apply.

If your totals and fill procedure above are accurate, and assuming your car wasn't used to smuggle anything into the country via a hidden compartment in the fuel tank, I wonder if you experienced a fuel delivery issue, that is discrete from your gauge accuracy? Either some kind of blockage in the tank or the fuel pump cutting out? Has this only happened once?

I'm having trouble correlating your last two posts. Nearly 6 years ago, you wrote: Now you say: Did you make map changes in those intervening years, or does the Pectel have a self-mapping function that would have altered it without your intervention? If not, and if the supplied data is accurate, then something else has occurred to account for the significant drop in mpg; leaking injectors, fuel pressure has increased, TPS is out of adjustment, O2 sensor feeding the closed-loop mode has failed, compromised cylinder(s), etc. Changing the map to compensate for an unknown issue is just kicking the problem down the road. You need to identify the root cause(s).

The latest issue of Avants magazine has a nice article on Caterham that was pulled together with the help of some Seattle-area owners and features some very nice photography. https://www.avants.com/magazine/the-benchmark-for-lightness?

Per Caterham, S3 fuel tank capacity is 9.5 gallons (36 liters), and the SV is 10.8 gallons (41 liters). In both cases, the last 1.5-2 gallons isn't accessible due to the shape of the tank and the relation to the fuel pump pickup. It might be worth starting a separate thread on this if you need troubleshooting advice.

@Vovchandr is wrong. Now add that to your signature!

I don't know how the loom was set up in those days. I wouldn't expect it to matter, but it's always possible that the grounds were daisy chained and the connection at one of those missing points failed (e.g. they crimped those grounds together to complete the circuit and the crimp weakened over time). My understanding is that because LEDs draw far less voltage, they tend to expose weak grounds earlier than an incandescent bulb. I'd start by replacing the incandescent lights one at a time to see if the issue persists or goes away as a means of potentially narrowing down the location of the issue. You may get lucky. If not, then start methodically checking and cleaning all the ground connections in the circuit until you find the culprit. Don't forget to hit the grounds at the switch and relay.

I had something very similar happen with the Westfield many years ago. It turned out the ground on a rear taillight was bad.

Just to add onto my earlier post, that hose next to the filler might act like a secondary vent. Although it enters the filler neck below the flap valve, if that's not particularly airtight, then air could escape through it and join the main vent system on the other side. @CBuff, I hit it with compressed air before taking photos

I was curious, so popped out my floor to take a look how my recent build is plumbed. The only vent is the one in the filler neck above the internal flap valve (shown roughly by the white line). The hard tube at point A connects to a rubber hose that loops around to the red rollover valve, then continues down to the bottom of the tank where it’s zip‑tied to the clamp rod (red line). From there, it follows the rod back up to the top of the tank and vents to atmosphere.