KnifeySpoony

I can't recall exactly what my choices were - I'd reach out to Bruce for details.

I bought from Bruce, and I had options on when to lock in payment/exchange rate.

You can also get them from Caterham. I bought a set from them as well and price after shipping was virtually identical to price from Roger Kraus. They were delivered in something like 2-3 days as well.

Also hadn't realized they were bought by Goodyear last year. https://www.tyrepress.com/2022/10/cooper-to-close-melksham-factory-2023-consultation/

It's this one https://caterhamparts.co.uk/seatbelts-harnesses/7526-seatbelt-4-point-quick-release.html They are 4 point, no sub strap.

Awesome build. TC on a 7 though... doesn't that kind of defeat the purpose?

https://www.caterhamlotus7.club/forum/chitchat/cooper-tyres-melksham-factory-danger-closure I guess it's just the uk manufacturing closing. Hopefully the zz line will move manufacturing overseas (and maintain quality).

My understanding is the xr4 was a ford sierra in the uk, and our rear calipers are indeed sierra calipers. However i think they are modified slightly to clear the radius arm or something else if I'm not mistaken.

Avon is no more it seems. All us aficionados will be switching to toyos I guess?

Never installed, new in box pair of 4 point harnesses, dated 2020. These are 200gbp each from Caterham (plus UK shipping). SOLD

Drove Sonoma yesterday. Had zero leakage. Between the thin paperboard ring and being careful not to overtighten, problem solved. I did a double thick towel over the top and a full diaper system underneath, and everything was bone dry.

I paid $7k to have my kit delivered in 2021... (to port of Long Beach, then trucked to a warehouse in Bay Area).

My fluid is rated for 617F boiling point. True, as pads wear thin, fluid will be more likely to boil. I would just expect to feel a change in pedal feel. But maybe that's an incorrect assumption.

Front locks up first. I put higher friction pads on rear to move the bias rearward, as the front were overbraked with the uprated front calipers/larger rotors. I previously did the calculations on brake bias but don't have the numbers anymore. The stock system is heavily front-biased. A prop valve will not help without first upgrading the rear setup to overbrake the rear. A dual master/balance bar setup is ideal for sure, but I'm not ready to take on that project at this time.

I think CC sells a kit to convert? I had intended to change to flexible lines soon after my build but haven't, as the rigid lines don't seem to cause any issues. The calipers are easy to lift up for pad changes (my calipers have been off at least half a dozen times for various reasons), and both pads wear evenly (something I read about as a potential issue with the solid lines). If a line fatigues/cracks/leaks someday, then I may change my tune lol...

Will do - Is this something that could change/develop over time? Or something intrinsic to the master cylinder?

No vibration. I did check hub/caliper temps with IR gun after several sessions on Thursday, as I had just replaced the RR caliper due to a leaking piston seal and wanted to make sure I was getting equal braking on both sides. Both rears were equal in temp- back of pads was about 450F on both sides hot off track iir. Fronts are less than half that but I figure that's to be expected with a solid disc and no airflow.

Fluid is fresh rbf 660. Pedal rock solid all day, don't think it's boiling.

I have the AP Racing "race" cap with the bellows and no sensor- installed from new, as recommended to reduce/eliminate leaking from stock cap. It didn't leak a drop until last trackday it was leaking something fierce. Not sure what changed. I have a towel zip-tied over the cap as a precautionary measure to absorb any seepage. After each session on track Thursday, the towel was fully saturated and there was mist/spray around the area under the bonnet (presumably flinging off the wet towel). Changing out for a new towel each session would just result in another saturated towel. Made sure it was quite tight (can it be too tight?). Made sure the bellows was well-seated into the cap before screwing it on. Tried putting the bellows down into the reservoir, and then applied the cap. Nothing helped. I know some people on some cars recommend running much less fluid in the reservoir (say, only 50% full) to minimize leaks. I have always kept it topped up to "full", however over the course of the day, it ran down to about 75% full with no less leaking. Just now I cut a small ring of paperboard (cereal box lol) to fit into the ring groove in the cap to give just a little more downward pressure on the bellows flange to see if it helps seal more. Maybe something thicker would be of more help. Won't know until next time out on track next Saturday. It doesn't leak with street driving. Anyone dealt with this issue? Any hot tips?

interesting

TPS swapped thanks to @sltous - seems to have fixed this issue. Only did a short drive, but similar to my last neighborhood test drive that clearly elicited the issue. I think issue is solved. So it would seem that as the TPS got hot (remember on a RBTB car, it's attached directly to the roller barrels which are attached directly to the head, so it gets quite hot), it would malfunction over that part of its range. I don't know enough about how potentiometers work to explain that, but that's what I'm going with. Hopefully it was just a dud TPS and I won't have to replace every ~3k miles, but it may just be a hazard of being mounted to the rollers, as opposed to being more isolated on a plenum setup.

Going to swap tps today thanks to a very generous forum member. Will report back.

What were your tps symptoms?

Ugh, new problem... so did a trackday yesterday, no engine issues all day, though I was struggling with a leaky brake reservoir cap. Will have to make another thread for that issue. Driving back from Sonoma, started getting a severe hesitation at partial throttle - basically from 0-5% throttle, tip in feels normal, however it's like from 5-20% throttle, no fuel is being added, and the car hesitates severely/will not accelerate at all. If I keep gradually opening the throttle, once its gets past about 20% or so, then it's like it catches, I get a surge, then the rest of the throttle travel is normal. Car pulls hard and smooth to redline. When I get the hesitation, it's interesting in that if I keep the throttle depressed at that position, and press in the clutch, the revs do not climb at all as they normally would when the load is removed. Today I test drove around my neighborhood - when engine is cold it's not doing it at all. Even when the water got up to temp it wasn't doing it initially, but as I continued driving for more than 5-10min, it started up again consistently. No popping from exhaust. No smoke that I can tell. I checked the TPS (FWIW I'm on CC roller barrels) with easimap - idle voltage is correct, and it seems to be sweeping/responding normal with throttle. Jiggling wires to the TPS while connected did not show any voltage fluctuation. I swapped out the sparkplugs and no change. Plugs I ran yesterday seem to look OK but 2 of them look different than the other 2. Any thoughts? Bad 02 sensor? Bad TPS? Something else?

Mine is a 2020/2021 build - not sure if you have the newer style "race" oil cooler or the older style that mounts in front of the water rad. That could be a factor. Also, I have the 420R "race" nose cone with extra opening for the oil cooler. This could be contributing as well. On cold morning drives to the track I block off the opening, which does bump up oil temps about 10deg F on the freeway. However, on a particular cold fall AM drive to Laguna I was seeing 108F steady state on the freeway at 70mph. That's COLD. Cold enough for me to fear for my engine. 2 days ago AM drive to track was seeing 125F on freeway in about 55deg ambient. These temps are in the oil tank, btw- I'm not sure of the delta before/after the cooler. I can only hope oil is 50deg hotter in the bearings. I have read about people putting inline thermostats to the oil rad with little change in temps, so I abandoned that idea. My water temp runs rock solid at 197F when underway. Not sure which thermostat I have- it's the one that came fitted as standard. The reality is I think the car is cooled for racing. And in particular, drafting. The 420R race cars (now called UK championship) run the exact same nosecone and cooler setup AFAIK. They have to run nose to tail and not overheat. This means that in any other situation, the car will be overcooled. I'm ok with that as I only drive my car on the street to/from the track and I'm ok with the compromise. However, for a pure street car, I think a oil/water (modine) style cooler is superior.