ChrisC

I commented on these photos when they where posted on Facebook, recommending a replacement chassis loom, and a good inspection of the dash, switch and engine looms.  Given it looks like the solid brown wires are the wires that have over heated, the brown wires are the pre fuse power supply wires to everything electrical in the car (except the starter and alternator) so you have to expect anything could have been the cause.  If it is the solid brown wire that has overheated incorrect fuses won't be the problem.  That said, I noticed you seem to have a mix selection fuses from different brands, technically not a problem but it might mean the cars has had previous electrical problems.  Do you know the cars full history?

If it was my car, a replacement chassis loom would be they way I would go.  If that wasn't an option, I would still want the loom out, stripped the wires replaced and reassembled to gain piece of mind.  Those brown wires have a few joins where they split into multiple wires, it's highly likely your only seeing the obvious damage and there is more to be uncovered.

Your right, door (or side screens) off for IVA.  If there is a door it has to be double locked or it's a fail.  Hence all the faf with the mirror mounts on the screen.

Changed from 21 to 24 in 2017(ish).  If you have the screw on the top of the light ring, then it's 21mm,  two screws at the bottom of the light ring, 24mm.

I think the most important thing is to be present at the IVA, regardless of who is presenting the car. 

I have been through three IVAs, so by no means an expert, but I feel some PBC inspections identify work that's not needed for IVA, while forgetting to complete other identified and paid for work (not my car).  I have also sustained damage to the car while it was waiting for IVA at the dealer. 

My last IVA I didn't bother with the PBC until it was road registered.  This isn't for the faint hearted, I had a 200 mile round trip under time pressure, with a car that had never been tested further than my driveway.  Regardless it was still with CC assistance, where I borrowed some compliant parts.

If I where you I would PBC before IVA, taking the car to and from the dealer via a trailer on the day of the PBC. They fix anything identified before your IVA date, and fit any complaint parts needed days before the test.

Hi James, it sounds like our experiences are broadly the same, except I am not experiencing any hot issues, and it's your comments on other posts which has made me take a more scientific approach.   Fingers crossed there is a sweet spot. 

Without doubt a 420R can be made to run in stock form without major issues, mine does.  It was perfect before the decat at 1000 miles, no cold start issues, no hesitation.  Once it was decat was fitted I started getting minor cold idle problems, when the coolant temp was below 15c. Since my garage is rarely in that temperature range (its attached to the house and is the location for my boiler) it was such a mild inconvenience letting the car idle, which it does unaided, for 10 - 20 seconds before the coolant has time to heat I didn't fix it.  
Since it's such a frequent topic, and I suspect I am going to make matter worse when fitting the K&N panel filter, I thought it would be good to run a series of comparisons, and create a definitive setup guide, much like the Sigma 150 sweet spot.  To do this I have to revert back to a un-modified TPS because that's what most owners will have.(arrived yesterday from Caterham Parts).

I won't be getting my stock map modified at any well known tuners because next year I plan a RBTB conversion, so see little point, assuming all goes well.  The conversation will be done for the right reason, enjoyment, not to resolve problems.

What I am concerned about is rumours of a version 2 map introduced in 2021, so I might need volunteers at some stage.

If the time is spent, it is possible to get a stock 420r running without hesitation or cold start problems.   I am in the process of creating a blog post, but I am waiting for a stock unmodified TPS. 

I agree, "TPS sitting at 4.2" doesn't give enough information, is that voltage or throttle site.  The actual voltage will vary between Caterham model to model and MBE model to model, but in general the TPS throttle site should go from 0 at idle to 15 at full throttle in a smooth manor as the throttle is pressed.  Best to test this with the engine off ;-)

Some Sigma cars had a MAP sensor, with the hole open, pointing upwards near the ECU, so easy for water to ingress the sensor.  If the sensor isn't sensing atmospheric pressure you will get running problems.  I always recommend putting a small piece of hose on the sensor to create a u bend so the opening is pointing downwards,with a little length to prevent water strike.  It won't effect the sensor from detecting atmospheric pressure, but adds a little protection.

I think I would start with a spanner check of everything.  It could be as simple as the wheel touching the dedion tube (13" have a habit of doing that), or your exhaust hasn't been dragging on the ground.  
A preload check on the diff might give you a clue, but be careful of your equipments ability to compare clockwise and anti clockwise readings. This might lead you to a wrong conclusion (don't ask me how I know) 

The problem with noise, it's very difficult to diagnose.  

This is the Titanium version https://www.ecstuning.com/b-turner-motorsport-parts/turner-magnetic-differential-drain-plug-m22x15/027030tms01~a/

It's an interesting point, you can speak to RRT, there is no secret around the base oils, but the specific blend of additives used is obviously a secret for obvious reasons

There is a magnetic drain plug specifically designed for BMW diffs, so it has the same dimensions and seal, so no worries about clearance.  Not cheap, and comes either in aluminium or titanium. 
 

Not a fan of the Motul stuff, back in 2016 with my 360R, I switched at the first service to Motul from the kit supplied Commer, this increased the noise from the diff. At the time it was carbon plates, so it wasn't plate noise.   Personally now I use the RRT special blend, which reduces the noise.

Two year service interval with a magnetic drain plug sounds sensible for road use with the occasional trackday.

I remember that being a pain of a job, one of those jobs that just added unnecessary randomness as to how hard it would be.  But then my dad purchased the official special tool (it might have been a copy), it provided a leaver with a massive area to hit with a hammer, that pivoted on a drive shaft seal casing bolt.  It was a 5 second job each side after that. Are the good old days :)

The Caterham supplied nuts no longer come in a Ford parts bag, so I assume they are no longer using Ford to supply.  This is different to my September 2019 delivery kit, which was supplied with nuts from a Ford bag.  You can find cheaper supplies, but I was told by a Caterham tech of an instance where a hub nut failed before reaching the specified torque.  If that was to happen it would probably damage a wheel and I might get smacked in the face with a breaker bar, so given that I am happy to consider the extra price of the Ford part.

It depends on so much, but as others have said a stock (or de-cat) 420R with the side exit exhaust will pass under a 100db static, assuming the exhaust is in good condition.  Drive by noise has a few additional factors, like sensor location, how hard your driving, gear used and weather etc.  On a quiet track like Bedford, I tend to start the day short shifting, and let the revs rise as the day goes on.  At Bedford your get a Noise board if you get close to the limit.  But I have not had a problem there yet with my 420R.  I believe the only circuit that does cause a 420R drive by noise problems is Brands.  This will change as the exhaust burns through its packing, and unfortunately the stock exhaust needs a fair bit of modification to make it repackable. 
 

I suspect your going there to learn your car, and therefore won't be ten tenths straight away, so go and enjoy and don't worry about noise.  

Two things you will find in the archives of blatchat when bleeding the rears, is one jiggle the handbrake as the pedal is down, and two tap the caliper with a rubber mallet as the pedal is down. Both help to find that elusive last trapped air bubble.

Are you supposed to fit the shim to remove the angle?

https://caterhamparts.co.uk/fittings/6304-high-effort-brake-pedal-shim-use-with-30b045a.html

Hi Brett, then I strongly suggest you get a second opinion on the brake pedal.  The bake test during IVA is I think the hardest part to pass, there is little if any leeway or allowance for new braking components, yet no way of bringing them up to performance.   Have you attended a local club night? You could reach out to a local owner and even compare 420 pedal feel.  It will tell you what you need to know.  The performance will come, but the feel needs to be right. 

Brett, as you can see it's either, as designed, a bleeding issue, an undetected leak, the brakes need bedding in or a combination of all four.

Are you planning PBC before IVA, if you are then I would leave it the tech to decide, they have seen plenty of examples and will know if it's right or what's wrong.  If on the other hand (and I wouldn't recommend) your just going to drive to IVA before PBC then it might be worth getting a second opinion beforehand. 

Once it's passed IVA and the they have bedded in a bit you can make a decision. if you don't like the feel and want a firmer pedal, it's a simple procedure to change. 
 

My brakes to begin with had a firm pedal, but didn't bite as desired.  On the way to the IVA I had plenty of time to work them, fairly hard to the point I could smell them, to gain the pass.  From that point they have improved further.  I have confidence in them.  If I did more track work then I think I would go with the firmer pedal, but understand anyone taking that option for road uses.

Let's face it the CC development team and resources are limited, so obviously the 170 was the first priority (especially with the sigma loss and the new owners), then the increased product problems. When the ToDo list isn't full of higher priority problems then fixes might progress. 

Not sure this is going to help, but I think Tilletts have a higher seating position compared to standard leather seats.  I have had both recently, both with lowered floors, and I definitely seat higher in the Tillett.  The standard leather seat base actually touches the floor, so you are sitting on a thin layer of plastic plus the foam and leather, where as the Tillet doesn't touch the floor if you fit runners (or the box section), that's before you add any additional spacers. 
 

See now your talking 

Caterham use a Sirius product NE-2273 

http://www.ns-sirius.com/products.php?page=9&pmid1=1&pmid2=4&pmid3=&keyword=page=9&pmid1=1&pmid2=4&pmid3=&keyword=

It looks like JAL is using a unbranded version of the same, difficult to tell from the photos, but if the lens has NS-2273 printed on it then I think it would be a safe assumption it is.

Bit cheeky JAL using the Caterham 310R press launch car on the JAL website, because that car definitely didn't have JAL products fitted :).  

Oops sorry, I was only quoting CTRMint car, given what he had said before about not wanting to be a product tester.  
I still think I wouldn't cover the rad without knowing the full picture, and I am not sure as a owner there is a way you can get that. Then again as more owners find solutions, the unknown becomes the known.  

 

If this was my car, I wouldn't cover the radiator.  There is a CC fix for the 620 cooling issues, and I would look to have that applied.  The lambda adjustment is only used if the engine coolant  is warm enough, 60C for a 420R, so this may explain why your lambda fault was intermittent.  The problem with covering the radiator is your also covering the supercharger oil cooler, and as far as I know there is no temperature gauge for that oil.