KnifeySpoony

Looking forward to your AR1 report - I figure I will switch to these after my ZZR supply is used up (I have sets of A24, A64, and extreme). Definitely curious to hear about differences between running the 205 vs 235. Also surprised to hear they overheat within a few laps on such a light car. I figured the opposite would be the case (ie hard to get heat into).

looking proper racecar now

yes

Nice car

OK it's working now. That looks like a lot of travel - obviously I can't test the total range on my car right now, but there is not a ton of travel in the master. Too me it looks like you're hitting bottom. You must have a massive amount of air somewhere in the system.

Video not working for me

Not sure, but if it's just still some air in the line, you should be able to "pump up" the system and get harder/higher pedal. If it's really no resistance, then hitting a brick wall, it sounds like bottoming out. Maybe 5cm is not enough though. I'm honestly not sure what my total travel is. Thinking about it, maybe it's more like 10cm.

Based on your description of the pedal, it sounds like you're not building any pressure in the system at all, and what you are feeling is the pedal/MC bottom out. I have found the brakes very easy to bleed on this car, so I wonder what is happening for you. If indeed you aren't building pressure, you would need to either have an opening in the system or a ton of air hiding somewhere. I'm not an expert on master cylinders, but some people tout the need to bench bleed masters. I don't know if something with the MC could cause your symptom or not.

Most trackday wall inspections I've seen (in person or on video) involve oversteer. Rarely do people just terminal understeer into a tire barrier. Any car, though especially a car like a 7 (with even weight distro front/rear), can be easily balanced to the driver's tastes with spring rates, ARBs, and tire widths. IMO ideally a good car with good setup allows it to be adjustable at any phase of a corner depending on my inputs.

Yes and 34nm for the mounts to the engine block.

This is the take home for me. Will be watching any fasteners on painted/coated surfaces closely.

Presumably due to fretting of the powder coat on the engine mount brackets, these seem prone to loosening up. I had been checking my paint marks regularly since my build in 2021 and trusting them, but they lied to me. Best put a wrench on them frequently imo. First tested them just recently and needed tightening. After a single track weekend a few were slightly loose again.

I have a CDI 1/2 wrench that goes up to 250ft lbs or so for bigger fasteners. No complaints. Seems high quality and can go in both directions for torqueing rear hub nuts which is basically what I bought it for. I have been using a Husky brand 3/8 wrench (20-100ftlbs), which has served me well and remained accurate for >10 years, but i recently "upgraded" to a gearwrench 120XP for the 120 tooth gear. There are various situations in which the coarse (many even high quality wrenches only have 30ish teeth) ratchets make operating the wrench challenging. I'm hoping the the 120 tooth makes tight situations less annoying.

Great pic - seems like something like that is my issue. Something causing the float to stick down. Some type of progressively increasing resistance/friction. While I look at the pump I want to see if I think the pickup can be modified to help reduce fuel starvation in left hand corners.

I'm well aware of the poor fuel gauge accuracy/linearity with these cars. I actually thought I was a lucky one, with a decent gauge compared to others. My car is almost 4 years old and it'd been doing OK - definitely a bit non-linear. It stays at full for the first 1/4 of a tank, then started to go down pretty predictably. However, starting yesterday, it doesn't register full anymore after a fill up. I was at the track so did 5 fillups in one day. At first it only went to 3/4, then a bit less each time, now it barely shows half a tank after a fillup. Any thoughts?

I use that industrial strength clear velcro stuff.

Starve was much worse at Sonoma this weekend. Could only run 7 laps on a full tank before starve would happen in T6 (long left) on the 8th lap. This behavior was consistent all weekend. I am on new stickier tires and carrying much more speed through there, but it seems odd that I could previously run 2 whole sessions, now can't even get through one full session. I'm looking into solutions to help the fuel pump pickup get to lower down or more central in the tank. Trying to avoid a more complex surge pot setup with secondary pump, return line, etc.

Hmm it felt secure (ie no wiggle to it), but i could see well to see if it had backed out of the engine itself. I think i saw a couple screws holding it in... Just nip them up?

Sensor is clipped in securely but I will fiddle with it.

Not that I'm aware of. And I'm on a dry sump so that seems unlikely. I will review my video though monitor the oil pressure gauge.

Interesting, someone else mentioned a possible sensor issue too. I will have a look over the sensors. Aren't they clipped in though?

In my duratec powered 420r, I Believe the fuel pump pickup is on the left side of the tank. However from all my googling I'm only reading about people getting fuel starve in right handers (maybe those are different setups?) Today at Laguna, twice in turn 2 (long left hander after downhill long hard braking zone) with about a third of a tank (can never tell with these gauges, but was only the second session after a fillup), I got a very brief but severe hesitation. No popping, which I've heard in other cars during fuel starve. No issues elsewhere on track. Otherwise, car flawless all day. Could this be starvation or should I be looking for other causes? I've always run two 20min sessions on a tank without issues, but maybe burning more fuel today from pushing harder with sticky tires. (New set of A24 ZZR, PR day)

Oh also i have a decat pipe on mine, that's a decent weight loss right there.

Do you know the spring rates on the cup dampers? re: weight. I weighed mine (420R, roller barrels, trackday rollbar, no heater, CF aeroscreen/mirrors, CF tillets, CF front wings, CF interior panels, OEM Banner battery, about 2/3rd to 3/4 tank of gas) and it was 1230lbs. I have since gone to an antigravity battery, so I think that was like 15lbs savings. So I assume with half tank of gas it's under 1200. 540kg wet is a fantasy by Caterham.

Ah ok doesn't sound too bad. With the s3 and tillets, the tunnel top is locked in by the seats. So much so that i never bothered with the aft fixing screws during my build.