KnifeySpoony

For mostly street driving, absolutely go with any of the modern 200TW tires. They are amazing at street temps. RE71R, A052, etc will all do much better than a 888R on the street and will be stickier on track as well.

Looks so odd without a bit twin hanging off the front.

I think I will try a stronger bolt just to eliminate bolt stretch as a possibility. Although I don't see why re-tightening is a bad thing if it's actually wear on the chassis boss that's causing things to loosen. LOL well, it's in my first post that I already have a nyloc on there. And also, the nut is not loosening, so safety wire will not accomplish anything... I do think this is a distinct possibility, though I don't fully understand the mechanism. At some point I will pull it apart and look. My only goal with this is to prevent catastrophic failure on track which would undoubtedly lead to loss of control. There is a thread on blatchat about the radius arm bolts shearing off or falling out causing crashes. It was from back in 2001. Interestingly, torque spec on those bolts back then the spec was 35FTlbs. Now it's 34Nm.

Yes, there's 2 under the head, and 1 under the nut. The front link bolt is different - the head is on the inside (without a washer), with one washer under the nut, which is in the wheel well. I can only assume no movement, but how can I know for sure? How could could the bolt/nut be properly torqued and not clamp it? And if it wasn't locking it to the chassis somehow, I guess movement there could cause wear that would necessitate periodic re-tightening.

Mine was off but not quite that much. Rather than drill a new hole I just cheated all the holes a little bit from midline and it worked out. In your case I'd consider just drilling another hole.

That's an interesting idea, but I always check the torque (and tighten it), with the suspension at its position with the car settled on its suspension, so it's always consistent. Also, the bolt doesn't turn as the linkage rotates with suspension travel - ie all the movement is within the bushing deflection as designed it seems.

Both sides are behaving the same way, and only on the rear watts links. Front links stay tight. It was never overtightened. These are the bolts specified by Caterham that came in my kit. Do you think that lateral loads on the link could be stretching the bolt? Seems like it would take a lot of force to do that. I suppose I could pull the bolt, then run the nut down the threads to make sure it hasn't stretched. ashyers - What do you mean by relative movement?

It seems either the bolt is getting longer, or the material in between the bolt head and nut is getting smaller. But I don't see how either of those could be occurring. Maybe I'm missing something.

Ok an update. I moved the suspension through its travel and can confirm the bolt is not moving, so that's good. Before my last trackday, I paint-marked the bolt/nut/chassis, and nothing moved. The nut did not loosen. HOWEVER - when I put a wrench on it, I can tighten it about 1/8th of a turn before achieving proper torque. So I am really confused. How is it that nothing is loosening, and yet I can keep tightening the nut over and over?

Interesting, my kit delivered 2021 did not have the earth mod. Also interesting, as my diff came dry.

Bumps or no bumps, the 420R with roller barrels can easily overwhelm the rear ZZS just about anywhere. That's one of the things I'm enjoying about the car. It's so different than my Exige was. Much more playful. My plan is to learn the car on the ZZS and wait until my lap times plateau before "upgrading" to ZZR. Given that I drive the car to the track, I'll be going with the harder of the two compounds.

Sonoma is bumpy for sure, the surface is terrible in places. It's super fun though, very technical and rollercoastery; perfectly suited for a 7 to embarrass more powerful cars. The rear is only lively when I'm hard on the throttle and getting power oversteer. It's very planted and confidence-inspiring on corner entry and mid corner at neutral throttle. I have the very stiff race-rate rear springs, which everyone says are too stiff, so presumably that's hurting my traction. Also I'm on ZZS as well. I'm sure these spring rates are better suited to stickier tires. I'm using RaceChrono for timing.

It was a fun day for sure. My best of the day:

I highly doubt that, but I'm not sure, as I was distracted by someone waving a blue flag furiously at me for some reason.

Plausible deniability is a thing of beauty.

P1, P2 right there.

Not at all. It will rotate with aggressive trail braking, but it takes a concerted effort. Nothing like my Exige that loved to back it in with even light trail braking. I'm ok with the level of rotation I'm getting, thought a little more wouldn't be bad either. I can always rotate the car on the throttle during exit phase. My main goal is to increase overall braking ability/shorten brake zones.

Prop valve to limit front brake bias is considered a big no-no. I would never consider it.

I am trying to increase rear brake bias, so a prop valve won't work for me.

I already have the race master. I had actually considered doing the race rear rotor/caliper set up during my original build, but didn't for 2 reasons - first off it was backordered (and still shows as not available). Secondly, I was worried that I would fail inspections during the CA registration process without a handbrake. It turns out I could have slipped through without a handbrake without issue. If I end up chasing my tail trying to tweak pad compounds, I'll certainly try and do the big rear upgrade, assuming it is still available from CC.

Of course a dual master solution is best, but my understanding is this requires significant pedal box or even chassis modification to implement on a 7. The reality is that countless trackday enthusiasts and amateur racers mix/match pad compounds all the time to improve performance. Keep in mind that these cars (modern Caterhams) are coming from the factory with 2 different pad compounds from 2 different manufacturers, even. They perform adequately, but I am just looking for that last bit of braking performance.

I have seen the Mintex 1144 mentioned on blatchat threads - my understanding is that it is/was a popular choice for standard front (2 pot) calipers to help move bias more to the front for their cars which are overbraked in rear from stock, which is the opposite of my issue with the 4 pot fronts. However, if the mintex is a higher friction pad, I could try it in the rear I supposed. I placed an order for the CL pads, but were out of stock on essexparts, so I'm gonna go with the DS3000 after all.

I have not. I suppose i should.

OK - I just pulled the trigger on a set of CL RC6 for the rear (size 4035). Seems to have a high friction like the DS3000 but don't need so much heat to start working well. The RC6 have a friction coefficient around 0.50. I can't find any data on the delphi, so it's crapshoot in terms of where my balance will end up, but we'll see what happens. Will report back once I've tested them.

Looking at the images of the front pads for the AP racing 4 pots on CC parts site, it seems they are the ferodo DS performance. It is shown on the chart comparing to other Ferodo compounds. It seems it has similar friction to the DS2500 but with better cold bite for street applications.