JohnCh

I upgraded my old Westfield from the standard Girling 0.7" master cylinder to the AP Racing unit. The mounting lugs differ slightly from the Caterham version to suit Westfield-specific packaging constraints, but otherwise the assemblies are effectively identical—including AP’s practice of individually shimming each unit to account for production tolerances. Both cars use the same rear calipers and feature four‑pot fronts, but the piston layouts differ slightly: the Westfield setup uses four 1.5" pistons, whereas the AP calipers use a staggered configuration with 1.5" and 1.625" pistons. So while the brake systems aren’t identical, they’re very close. The difference between the MCs was immediately noticeable—firmer pedal feel and easier modulation. Zero regrets despite the price and 6 month wait for AP to do a small run. Here are the AP and Girling 0.7" side-by-side: I also played around with brake pads on that car and found feel differed wildly. My assumption is the non-assisted nature tends to exacerbate differences in initial bite. @KnifeySpoony how is the dust with the Pagids? Is it just a little worse than the stock pads or is it excessive?

I finally got around to reading @chrisp993's blog. It's well worth checking out if you haven't already done so. It's brought back a little trauma from my build, but other than that, I've really enjoyed it.

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.