KnifeySpoony

Put in the amount that you took out, then check the level- simple as that. Top up as needed. Re: oil burning - my car (also a 2.0 duratec) is primarily track driven and burns/blows-by very little oil. I typically top up maybe 100ml every track day. Next time, check your oil level prior to changing it so you know where you're starting imo.

The 420R has racecar cooling. ie it has enough oil cooling to keep oil from overheating while driven flat-out in a draft, with poor airflow to the coolers. In any other situation (yes even on hot trackdays), it is overcooled in my experience. It's awesome that Caterham have built such a race-ready machine with dry sump and cooler, but it's not really ideal for a dual purpose car. A water/oil cooler would have been better for 99% of buyers. In an ideal world, they could supply either cooling setup as an option. Although to be honest, I would have still chosen the current setup, as my car is primarily driven on track, and even here in Northern California, 90-100F (~32-38C) trackdays are common. I still drive my car to/from the track which makes me cringe at the temps sometimes. I have found that cruising on the freeway at 70mph, with ambient temps around 4C (which sounds like you were in today), even with my cooler blocked, my digital oil temp shows 41C in the tank!

On my recently built 420R, I put in a Spa designs dual digital gauge that displays both water and oil temps. Very convenient. The factory location for oil temp sender is in the tank, which is the coldest place in the circuit. Be ready to see some scary-low oil temps. Many advocate tapping the sump but I haven't gotten around to it.

Velcro if carpet, double sided tape if not. That would be my vote.

Yes, it feeds from the bottom of the tank. I have read about some people having issues with oil siphoning back into the sump when sitting, but I haven't seen that issue. At least, if I look in the tank after the car has been sitting a while, there is still a fair bit of oil in the tank. No issues on cold start.

I didn't notice that the radiator was being twisted on its mounts, and it was free to move on the rubber bobbins. I am running Zerex G-05.

The radiator on my 420R developed a tiny pinhole leak in the upper/LH side corner, which apparently is a common failing point from my reading here. Car has about 3k miles on it, mostly track. I have read the theories about excessive vibration transmitted from engine and/or uneven mounting points putting stress on the radiator. I ordered a new standalone radiator from CC. They list only the combined water and oil radiators for the 420 road model: https://caterhamparts.co.uk/radiators/7114-radiator-and-oil-cooler-seven-420-road-model.html However, you can get the water rad alone. It says its for the 420 race model only, but mounts up just fine. You just don't need the two little upper drop brackets anymore: https://caterhamparts.co.uk/radiators/5755-radiator-only-420-race.html I put on the new rad, and copied the idea of a user here to try to reduce transmitted vibration by replacing the distal segment of the top coolant hose with the 620R top coolant hose: (https://caterhamparts.co.uk/hoses/5758-cooling-hose-top-seven-620.html). The hose isn't perfectly shaped, but it's pretty close. Side benefit is that the hose is flexible enough that I can now pull it out of the way enough to pull out the oil catch bottle to drain it, and will no longer need to suck it out.

DO NOT remove the other bolt/plug on the side. You will grenade your transmission - you will need to pull the box and have it reassembled. The turret oil doesn't need frequent refreshing. It is separate from the main fluid and doesn't degrade rapidly. I think most only do it when rebuilding the transmission.

Calls for bIue loctite too.

CC sells the uprated race-style rear rotors and 2 pot calipers. This sacrifices the handbrake, so you would need to find a solution for that if you needed one.

I'd just plan to replace them frequently - it's just a function of the solid disc and heat. Going to the vented rears will make your pads (and rotors) last forever apparently.

According to Mazda - either GL4 or GL5 fluids are specified. https://www.mazdausa.com/siteassets/pdf/owners-optimized/2000/mx5-miata/2000-mx-5-miata-owners-manual.pdf

No need to suck out - there's a drain plug on the bottom. Most of the noise you're hearing is the diff, not the trans, so fluid won't change anything there. One of the local spec miata gurus here in California who has rebuilt countless MX5 transmissions swears by Swepco 201 for syncro life, so that's what I'm using. It's a dino oil so needs more frequent changes presumably. I'm ok with that.

Keep in mind those dyno pics are from US owners - in the US, dyno sheets are pretty much always given with uncorrected WHP/WTQ numbers. I notice UK dyno shops tend to show corrected numbers, from my time here.

here's a dyno for a 420: https://usa7s.net/ips/uploads/monthly_2022_01/9312106_orig.jpg.d307494d9b8b2fc6372da4a66729ba26.jpg And a 420 on RBTB: https://usa7s.net/ips/uploads/monthly_2022_01/image.png.aeaa158f334d5025484fda86e9a30a68.png (tiny image but you can make out the numbers) Can't find any 360 dynos

All the new motorcycle communicator sets allow this. I used to use Sena, but recently changed to the top line Cardo units and have been pretty happy with performance.

I have a Spa digital gauge - It runs at a rock solid 92C when underway. In traffic/idling, the fan comes on at 98C. Based on the numbers you guys are seeing, I wonder if my gauge reads low, or the OEM gauge reads high.

re:#23 - I could revert, but I was getting very uneven tire wear on ZZS. I did the ear swap when swapping to ZZR, figuring the wear would be even worse. The car felt fine on 1.5rear but i would be giving up something like 40% of potential tire life I feel. re: #24- I don't think that standard radius arms would change anything, as the interference I am getting is with the forward link, which is essentially in the same position as the radius arm would be. re: #25 - thanks for the info. I would just run without handbrake.

The problem arose after changing my DeDion ears from 1.5 to 2.0 deg. This apparently brought the calipers in closer to the linkage. Before the upgrade there was no contact. I'm not sure how/why Caterham sells the 2.0deg plates if they cause this issue, but I guess Caterham gonna Caterham. related thread: /forum/techtalk/rear-brake-caliper-contacting-radius-armwatts-link

My initial interest (pre-build even) was to improve braking performance. Then, after upgrading rear pads I was content. Now that I'm having the clearance issue, I'm considering the upgrade again, as apparently that would eliminate the issue as well.

The caliper is a CP5119 with 44.5mm pistons (unless the Caterham piston spec is something different somehow). The standard Sierra rear is a 42.8mm piston, so minimal increase in size. The rotor does go from 232mm to 254mm, so there is some additional torque there. I'm kinda surprised it needs a prop valve tbh. https://caterhamparts.co.uk/15252-thickbox_default/brake-caliper-rear-race-10-lh.jpg https://apracing.com/race-car/brake-calipers/formula-car-range/2-piston-fia-f4-cp5119

10" vented discs. Which is the same as the factory option for uprated front 4 pot brakes. But it uses a 2 piston (fixed) caliper.

Yes, the whole assembly lateral to the DeDion tube changes with this setup. I just didn't realize that the track changed so much. I already get some tire rubbing on my rear wings, so I'm not sure how things will all fit if that track width change is indeed a thing.

Hmm interesting that it increases the rear track by so much. I wonder if that would affect handling balance enough to require change in other setup.

I guess CC refers to them as "uprated" brakes. https://caterhamparts.co.uk/calipers-pads-discs/2976-rear-brake-upgrade-kit-race-only-no-handbrake.html?search_query=brake+pad&results=251