Nigel B

I put a fair few miles on my car in September when I drove to Italy! I've just popped into the garage to check & I can confirm that I've covered 15,144 miles since I fitted the Tracsport. It's still near-silent & very effective! I've changed the oil a couple of times & it comes out completely clean, with a minimal blob of smooth metallic material on the magnetic plug. I'm very pleased with it.

Thanks for the replies everyone, interesting! My car is from 2017 Peter, so thankfully I have the earlier radiator, with the separate Mocal oil cooler. I was aware of the problems people have been having with leaking radiators, but thankfully it's not a problem I've had. I'd imagine lighter, silicone hoses would help from that point of view, putting a little less weight on the radiator. I wasn't aware of the modification using a 620 hose, I'll have a look at CtrMint's blog. Although I think I'd prefer a hose that's made entirely from silicone, if at all possible. I had a set of silicone hoses made up for my last Caterham by a company called Classic Silicone. They did a great job of replicating the original rubber hoses, so I'll probably contact them again. The coolant needs changing & I've had a slight, intermittent leak from the hoses at the rear of the engine for a while. I suspect it's just a hose clip loosening off, but it will need a closer look. It seems like a good opportunity to replace the rubber hoses with silicone while I have the system drained. Thanks again!

I found myself wondering recently why the radiator top hose on my 420R is a traditional rubber item, when all the other coolant hoses are silicone. Is there a specific reason Caterham fitted a rubber top hose? It’s long & quite a convoluted shape, so I was wondering if that would mean it would be difficult to make in silicone? Or is there another reason? Every other Duratec car I’ve seen is the same. I was contemplating getting a replacement made in silicone, but I can't help but feel there may be a reason for the original rubber construction that I'm missing. Or perhaps I’m over thinking it? Does anyone have any thoughts?

I agree with rgrigsby. The Range Rover driver probably assumes damage to the funny little kit car thing can be rectified with a three hundred quid filler & blow over job!

Actually Peter, you're right, I'm mis-remembering! Perhaps my rev counter under-reads a bit?

My 420 with a Caterham six speed, 13 inch wheels & a 3.62 diff sits at about those revs at 70, perhaps a couple of hundred rpm lower on a steady throttle opening. The car had a Titan LSD when I bought it, which I replaced with a Tracsport in 2020. I wasn't aware of any low speed noise or clunking with either diff.

I bought a spare fob for mine from Caterham a few years ago, but I gave up trying to pair it, using the instructions in the owners manual. I'll have another crack at it, following the advice on this thread. The car came with a spare fob, but it looked like the previous owner had backed the car over it & sure enough, it was as dead as a dodo!

Thanks for your post Paul! Was the process the same as the one described in the post I linked to above? Essentially, drill out the rivets & cut the end of the perforated internal pipe to remove the end cap? If so, how did you modify the end cap, to keep the perforated pipe in place after cutting? It hadn't occurred to me that I might need a heavy duty rivet gun, so thanks for that tip!

Hi Peter, Yes, it's annoying that they're not repackable as standard, but I suppose from Caterham's perspective, they get to save a few pennies on each silencer they make & it encourages owners to simply buy another when the packing material blows out. There are a few custom exhaust businesses locally, so I think I'll take it to one of them next week & see if they're willing to modify it. It looks like it should be possible. Fingers crossed anyway.

Hi James, Yes, I think that may well be the case. Having done a bit more Googling, I came across this thread from 2016. I think the silencer in question is from a Sigma car, but it does look very similar to mine. It's an encouraging thread! /forum/techtalk/can-standard-silencer-be-repacked-yes-it-can-see-post-8 Cheers! Nigel.

Hi Peter! I think the mileage is at about 20,500 right now. I've only recently noticed the resonance. I hope your R400 is running well. Colin, that's an interesting observation. I presume the groove is there to stop the end caps moving, in relation to the sleeve? Perhaps it won't be possible then? I might take it to a local exhaust fabricator next week & ask their opinion. Thanks for the input!

I've recently noticed I'm getting a little resonance from the exhaust, generally when the throttle is lifted during gear changes. Taking the silencer off & shaking it from side to side, I can feel the packing material sliding about. There clearly isn't as much in there as there used to be! I believe the silencer on my 2017 420 isn't repackable, but having Googled it, I have found a few references to people modifying them in order to make them repackable. From what I can make out, if the rivets at the forward end of the can are drilled out & the internal perforated pipe is cut with a dremel & cutting disc, the end cap can be removed. I'm assuming a modification to the end cap would then be required to keep the perforated pipe in place after the silencer has been repacked? Has anyone successfully managed to do this? I'm struggling a little to visualise exactly what is involved & whether I'd actually have the skills to tackle the job! Any advice (or ideally photos!) would be very much appreciated!

#544 Well, that question prompted me to head for the garage to check my mileage & I'm happy to report that I've covered 10,901 miles since the Tracsport was fitted, including one track day. Although I've never checked the preload, the diff is functioning exactly as it was when it was first fitted. It's quiet & unobtrusive & provides bags of traction & very progressive characteristics when traction is (finally!) overcome. I've changed the oil a couple of times & the oil comes out the same colour that it went in (in contrast to the black sludge that came out when the previous carbon plate Titan was fitted), with a minimal amount of smooth metallic material on the magnetic plug. I'm very happy that I made the change.

I'm looking to swap my 9/16" blue bar for a 1/2" orange one. If anyone has an orange bar that they'd like to sell or swap for a blue one, I'd love to hear from you. My car is a 2017 wide track S3. Cheers! Nigel.

Apologies in advance for the somewhat tongue in cheek response, but perhaps a short cockpit, live axle Seven is the answer?

& the pedal positioning.

#23 Here are a few photos of my car. There are three washers underneath the upper mounting bolt. It's in an awkward spot to measure, but I'd estimate they have a combined width of about 5 to 6mm.

DPR fitted a high effort pedal to my car last year when I was having the suspension set up. They did use washers rather than the shims & the pedal travel has been reduced considerably. I much prefer the feel. I'd go as far as to say it's the best modification I've made to the car & that's saying something, given I've also had RBTBs fitted! I'd assumed they'd fitted the washers as they'd run out of shims, so it's interesting to hear it's actually a deliberate modification.

I had a set of RBTBs fitted to my 420R 12 months ago by Luke Stevens, along with a custom remap by Steve Greenald. They’re Cosworth roller barrels, as opposed to the Caterham ones, but I believe they have damn near identical characteristics to the Titan/Caterham version. My last Caterham had twin webers & although I prefer the 420R in most respects, I found I really was missing the induction roar & the general character that comes with carbs. I think I’m echoing a lot of posters on this thread when I say that the roller barrels have certainly improved matters in that respect! The car has a deeper burble at idle & a ferocious howl at high revs. To my ear, it also sounds warmer & sweeter throughout the rev range. I found, with the standard set up, there was a point at around 4000rpm where I was getting what I’d describe as a slightly metallic, harsh sounding, resonant note from the exhaust. That has completely gone since I had the RBTBs fitted. It does have more of a tendency to pop & bang when you lift off, although dipping the clutch immediately stops that, if you need to be discreet. I was expecting a few down sides to the conversion. Perhaps worse fuel consumption & more noise whilst cruising on the motorway, but it doesn’t seem to be noticeably worse in either respect. Previously, from cold, the engine would turn over on the starter motor for quite a while before firing & it had a tendency to cut out for the first five minutes or so, before it warmed up. It now starts almost instantly & idles very smoothly from cold, with no tendency to cut out. I believe the cold running problems can be cured while retaining the standard intake set up, but getting rid of those tendencies was a nice bonus. It’s often said that roller barrels are better for track use, as they’re at their best at full throttle, but for more precise part throttle response, butterfly throttles are better. I’ve actually found the roller barrels are fine, whilst burbling around town on light throttle openings. It was probably the main thing that worried me before I had them fitted, but if anything, it’s better than the standard set up in that regard. I have heard that roller barrels are more prone to wear & that it’s important to ensure your air filter is in good condition with roller barrels because if small pieces of grit get trapped in the barrels it can cause problems. I haven’t had any problems in that regard so far, but perhaps it’s something to bear in mind. One advantage to Jenveys, of course, is they’re quite a bit cheaper. I suspect parts availability might be better with Jenveys too, as they’re a popular choice. I did seriously consider them, but I found myself drawn to the roller barrels, in part because of their historical association with Caterhams, the R500 K, etc. I don’t regret my decision, I’ve been really pleased with them. They’re the icing on the cake, for me. Gratuitous photo!

My 420R has RBTBs & the pedal isn't modified in that way. I haven't experienced any low speed kangarooing on a light throttle, in fact, if anything, the car is better in that respect than it was with the original plenum intake. You could potentially shorten the cable using a 'solderless nipple' & cut the pedal arm back to it's original length. However I can't help but feel this must have been someone's solution to a problem they were experiencing. Perhaps returning the pedal to it's original length would simply result in the return of the original issue? I think a bit of trial & error might be required!

That sounds like a nice spec. Perhaps Dreadnought thought fitting lowered floors was a bit too specialised for them? When I think back, I contacted Dreadnought about five years ago, when I'd had a slight 'off' & bent the steering arm & steering rack platform on my old Seven. (Oops!) They said then that they didn't do chassis work, so perhaps they regard lowered floors as chassis work? I ended up using Oakmere, the Caterham dealer in Cheshire. They were great & I've do doubt they would fit lowered floors, although obviously it's a bit of a jaunt from Edinburgh. They might be worth bearing in mind, if you can't find anywhere locally. I've also used the Car Tuning Clinic at Abbeyhill. They worked wonders with the Weber carbs on my last Seven & also changed the cam belt for me. I doubt they'd do lowered floors, mind you. Enjoy the car anyway! Perfect weather for it today.

Hi Stephen! Welcome & congratulations on acquiring your first Seven! I'm in Edinburgh too. For the past couple of years, I've been using Craig Moncrieff in Sighthill. He's actually a Lotus specialist, but he's very well regarded & understands Caterhams. I'm surprised Dreadnought said they didn't work on Caterhams any more. When I was last there, they had a wide variety of cars in the workshop, including a Lotus Elan & even a Bond Bug! Given they used to be Caterham's official service agent in Scotland & clearly have a lot of experience with Sevens, it seems like a strange move. What model of Caterham do you have? The local group are very active, although the meetings are quite a drive from Edinburgh. Nigel.

#8 Luke fitted a set of green injectiors & different plugs, to suit the RBTBs. Steve Greenald does a lot of mapping for Luke, so it's essentially a one stop shop, if you go there, with no need to visit Track N Road separately. As a bonus, there was all manner of tasty machinery in the workshop, including an original Lister Jaguar, a Caterham Levante & an Elan 26R. It's worth visiting, just to have a mooch around!

I had a set of roller barrel throttle bodies fitted to my 420R last year by Luke Stevens. Steve Greenald of Track N Road fame did the mapping. I'm delighted with the result. Before, the car would idle lumpily & cut out for the first five minutes or so. It would also turn over on the starter motor for a fair while before firing up from cold. Now it fires the instant you thumb the starter button & ticks over super smoothly without any tendency to cut out. It's smooth & docile around town, but also feels more muscular in the mid range & wild at the top end! (I was shocked, the first time I revved it out!) I'm sure Track N Road could improve matters, even with the standard intake fitted, but if you're ultimately thinking of fitting roller barrels, given mapping the car isn't a cheap process, perhaps it would be better to live with it until you're ready to get the throttle bodies fitted? (Or wait for Chris C's blog post) Good luck with whatever decision you make, they really are fabulous cars when they're properly sorted.

No, there are no anti squeal shims front or rear.