Austin David

Heat shrink gates clamps are very nice too, but definitely not reusable.

The original intake isn't bad. How does inspection work up there? Is it a one-time event when they assign the registration? When you get around to turbo you'll want to gut the intake entirely (and maybe add an intercooler). As a naturally-aspirated car with 1/2 the weight it probably doesn't matter as much.

I took a lil test ride tonight, about 40 minutes each way in FREEZING 60* weather. The seats work great. They start getting warm after about 3 mins, and by about 15 we turned them down a little.

I've got the 4 seat-parts refit as planned, and driver side mounted. Definitely easier on the second set. And I did a "test run" in the garage. It's nice -- I wasn't in long enough to make it HOT, but definitely enough to confirm electrical. Warmup seems like ~ 3 minutes, which matches my expectation. Not as good as factory (since it's behind the bonded foam) but still pretty good, and very even / no hotspots. And it's invisible, apart from the switches. Wiring: - I ran a pair of dedicated lines from battery (positive fused 15A) back to the bulkhead, under the tunnel. I happened to have some braided loom. I also added a third trigger wire, which is hanging off a terminal tied to the fuse panel, hanging off the ignition supply fuse. I'd previously used this to fire a relay for the cig lighter + my added USB charging port. - those 3 lines run under the tunnel cover, along the brake lines & other wiring, and are tied to a terminal block on the top of the tunnel / under the cover, about where your center elbow rests. - the Caterham has a *lot* of space under the cover in that spot - I had so much space, I have no yet shortened any of the included harness wiring from the seat kits. I riveted down a couple extra ziptie holders, just to keep things snug. - added a clean terry rag to secure the control cans for the seats, to avoid rattling - for now, the switches are temporarily fed forward through the handbrake boot and just hanging out. More below - the wiring to the seats: it is presently run between the two mountpoints for the seatbelt, under the carpet. There's a forward mount for my 3-point belts, and an after mount for (I assume a 4+ point. My harnesses emerge from the carpet about there. - The seatback is behind the seat, and just plugs in. There's extra wire, and enough space for it between the seat and the bulkhead. The pan / butt section wiring pops out at center. This section of seat rests on the seat frame, and the wiring can avoid getting crushed by running out the outside of the seat frame, along the carpet/floor, to the back bt the hookup. Again plenty of room to tuck the wiring out of the way. In an SV chassis you might have more space, but in this S3 the seat is touching the carpet and hides that wiring just fine. When lifting the seat back out the wiring stays exposed with plenty of slack, and will be easy to unplug. Switches: I have not yet cut any leather. The tunnel padding feels pretty thick, like 1/2" (leather over ~1/2" pad over curved sheet aluminum). The switches are designed to mostly pass through a thin, flat panel. That tunnel area needs to stay pretty flush, so whatever I do needs to be pretty tight; I may end up making some sort of flush-mount fixture that can penetrate the leather and padding, back up to the aluminum structure, and secure the switches? If I mount on the tunnel (elbow area) it will have to be more than just "drill a hole". Another option I'm braining is mounting to the side of the seat; the side rails are mostly empty space and I think deep enough for the switch body + harness behind it. Unfortunately because of the thick padding, I can't use the flat area in the handbrake boot -- after the pad and internal tunnel structure, there's almost no free usable space.

Heated seats! It's literally freezing right now due to some awful cold front, injecting a false winter into our false autumn. 40s in the mornings, ick. I got this kit: https://leatherseats.com/shop/seat-comfort/seat-heaters/round-switch-seat-heaters/ because I like the round switch. The dual-seat switch doesn't fit in the washer bottle switch spot, so if I'm cutting holes I'ma cut round ones. My seats are the "signature" model. I have no idea how they compare to standard seats, and CF can come with heaters. This is not a "HOWTO" but I'll include enough photos and tips to get anyone going. The seat construction is ... interesting. I haven't done a lot of upholstery, I can just say this isn't the same as the Miata I refit. The two sections (back and seat) are similarly-built. In both cases the seat leather itself consists of large clear sections under the thighs and lumbar, and thinner ribbed sections at the butt and mid back. The large clear sections are just a layer of leather bonded to thin foam, over a thicker shaped pad. Those ribbed sections are a little more foam, but then they are spray-glued into the seat pan. This is obviously very annoying. The sides and edges of the material is sewn to a plastic strip, which is later (final assembly) glued to the pans. All stitching cuts are out of line of sight / under the seats, and easily repaired to look great. The heating elements MOSTLY fit thusly: horizontal under the thigh, and vertical at the back. Because the heater needs to have at least 12" of element, I went ahead and separated the glued section on the back, and trimmed about 1" of element from the back heater. There's about 18" of connector for each pad; on the back, the connector comes out the center / floor. For the bottom, the cable emerges toward the tunnel. Both will have to plug in under the carpet, with wiring routed up under the tunnel and probably forward (TBD) for power. To separate the leather from the sewn-and-glued edge, it's better to cut the stitching out. The glue broke cleanly about half the time, and not-clean the other half. All repairable with zip-ties, but if I'm tied it up anyway, better to keep it clean. On the pan, separate the front seam. The sides are held on with double-sided tape, it's very similar to scotch double-sided tape you can acquire from your favorite office supply store. it lifts right up, but has to be replaced to be useful (leather fuzz left behind). At this point the cover can be rolled back, the heater taped down to the shaped foam, and re-covered (see below) The back: there are zip-ties in a few places, cut most of them below where your shoulders would go. Cut the stitching at the bottom edge. The two side rails are just held in with tension, once you get the zip-ties free the molded back/pan comes off the rail, and the sides will slide loose. And the fun begins. Roll back the lumbar section. I had a little spray-glue at the edge of the lumber foam, then liberal glue between that ribbed section and the back pan. Very slowly separated the two, minimal tearing of the bonded section. I went up to the last rib, leaving the one intact / still glued to the back. I trimmed about 1" from the heating element for a test-fit to get coverage all the way to the bottom. Because the back was glued, and the heating pad doesn't normally get glued, I added a section of carpet tape (heavier double-sided) to the center of the heating pad, so it was secured on the taped sides plus my new center tape. Then I put three more strips of carpet tape on the center and sides of the pad, then pulled the seat material down over the back. For the lumbar section, it's taped more like "normal" with the heater taped to the foam, then leather pulled tight over that. The sides of the cover tuck back under the frame/pan and zip-ties get replaced. For the last bottom edge, I punched zip-tie-sized holes in the leather and drilled two holes in the pan, then lifted the lumbar foam enough to thread the ties back through. Five sets of these to get the edges and center, then pulled them all tight carefully to keep it straight. Note that my *first* attempt (the bottom section) was not as "clean", I tried to preserve the hidden stitching and ended up doing more work, for little value. The final product looks pretty good, I'll include more pics when I mount the switches. by "pretty good" I mean "you can't tell I monkeyed with them." The covers are nice and tight and apart from some new zip-ties in a spot that can only be seen with the seat frame unbolted.

The heater is definitely effective, but the air kinda leaks out pretty aggressively what with no doors. Or windscreen. I'm going with heated seats (similar kit linked above), updating my build blog with the actual procedure. Spoiler alert, it's a PITA because the seats are glued together, after being sewn up. But it's not as hard as installing a diff.

Redline is the go-to recommendation, but Royal Purple is also respected. Honestly for a NA car with half the weight, you probably won't be putting too much load on that geartrain so pretty much anything will be great.

3500 miles in, some answers. Mostly "stop thinking this behaves like a car." For "spirited" street use, 2/4 seems about right; 1/4 is pushy / understeer, 3/4 is a little extra fun / oversteer. I understand it's easy enough to induce oversteer at any setting, but 2/4 is natural. I have not tested the higher "S" mounting locations. There is very little body roll in this setting. Roll steer is there, but not significant; I sort of have to hunt for it, honestly. Certainly not enough roll action that I feel like I would want to add linkages to my rear arms.

When you can bleed it. Which might be *after* the parking brake goes in... which is pretty late in the Caterham process. The risk is that if you have to open a sealed system, you have to basically dump 1-2qts of fluid to bleed it again.

to be fair it's not a question of uncomfortable, but more comfortable. In SC we have protracted and unpredictable spring/fall cycles. Hard Winter is usually a few nonconsecutive weeks, wrapped by a series of false fall / spring events on both sides. I'm OK with gear for road trips, but this is 95% grocery-getter and I don't want to have to pull out "layers" just to run out and get the milk.

my booty gets cold, and is protected from the influx of tunnel-heat. This way I can toast my butt *and* my forelegs.

It's that time, in SC. For what it's worth the blower/core is pretty amazing but it takes a solid 10 minutes to warm up enough to make the core effective. When the engine is HOT I have to put the plunger mostly back in (minimal heat flow to the core), it gets hot in there. Did you ever run heaters in your seats? I have used a kit like this one for a different car: https://leatherseats.com/shop/seat-comfort/seat-heaters/dual-control-switch-seat-heater/ Installation (99 Miata) was not hard. My cat seats might be annoying tho -- the back is crimped on, but the bottom / pan is glued so I assume I'll have to basically unglue the cover, then hope to be successful stretching & reattaching it.

It came that way? Like a DRUM.

I added lighting to the rollbar uprights. I'm not 100% sold on these, but they were cheap and easy and they look pretty good. The mounts are temporary, if it ever stops raining I'll put some miles on them and see how they do. The goal is visibility, secondary I want them to not get in the way and work if I (shudder) have to use the hood. I actually made a much more complex setup, but went "quick n dirty" for this first pass. I used a set of 4-pin econoseal plugs to make a splice-in extension / harness, it goes between the tail lights and the chassis loom. The lights are spliced directly into this harness, fed up through the floor of the boot, then routed over to the rollbar. Wiring up the econoseal was the most annoying part of the project, honestly. The lights themselves are an amazon special, $11 run/brake/turn extension. I bought two of these, and wired the turn signal to the "right" side; in this mount it's the top 1/3rd of the strip. In daytime these are merely bright. I need to figure out if they're too obnoxious at night. in the pics below only the parking/running lights are on; the brakelight is BRIGHT.

Get yourself near Charleston, SC and you can sit in my S3. At 200# I think you'll be an S3 + lowered floors kinda guy. 100% agree you should sit in one first.

I'm surprised when I find someone who knows what it is. But yeah, always a conversation (or 3) when I stop.

At the suggestion of another builder, I secured the o2 sensor line with a bracket in place of one of the body rivets, beside the catalyst. My kit had a few leftover tie brackets and rivets, I just had to drill out a painted one. I also retaped some of the heat shield which got chewed up on that side.

I'm gonna try it disconnected, but I don't expect to learn much. It runs great in all cases except this "stab from idle," where it's noticably worse cold, but still always present.

it's the greatest car in the world, they gotta make you sweat it a little.

well dang, that's a great find! You gonna come tool around the BRP with us later this fall?

I was able to find a local source (Josh @ Rocky Mtn) but I also modeled and printed one today while I was sposed to be paying attention in meetings. The original unit is relatively weak, now that I've had to look at it. Hopefully the next one will live a bit longer, but this temporary stand-in oughta work well enough

I noticed my backup light lens was ... missing. No other evident damage. It looks like it just snapped off at the two screwposts, both sides were shorn at the screw head -- I had the clear "posts" left under the screws, but no lens, and no evident damage around it. Bulb and reflector are intact. I assume it happened while zipping around town on errands in the last ~ day. I have a photo of the car from a week ago showing the lens intact. I see a few posts like https://www.caterhamlotus7.club/forum/rear-fog-lamp-lens, seems this is not uncommon ... especially on the fuel fill side. I won't say mine's never gotten any fuel on it, but the break didn't show any chemical damage so idk. The lens wasn't particularly tight either, in fact I don't think I've put a screwdriver to the two cover screws.

Took me two mos in SC. You're very lucky!

Not sure. Mine already kisses the bonnet on the left rear corner, where the main harness plugs in.

If you're they type who would dump lights for weight, probably dump the cove too. Personally I'll use it, but definitely want to make sure it's not pressing on important wires