SimonR300

A version of this worked for me. I broke the first copy of this made of oak, so I used a plank of hardwood in the end and drilled holes for all four wheel studs with a large hole in the center for the socket.

Thanks for your comments so far on your experiences. My conclusion is that Caterhams are generally black-flagged unless they back off past the noise meters. I've heard back from Caterham Parts who suggest I get a new collector, silencer, link pipe and 620 rear silencer which would be about £1700 I think. I'd like to have a car that I can take to all trackday venues without having to lift off at the meters. The limits can only get worse so whatever I spend on a solution needs to be well within current noise limits. I'd like to hear from anyone who has a rear exit/silencer to know which route you took and your success or otherwise. I'm not keen on the rear U-bend link pipe which seems to get very close to the ground. I found this photo of a 620R pipe which seems an improvement.... But it doesn't have the silencer.... I rather like the twin rear exit silencer found on some EU cars.

Has anyone been to Bedford and not been black flagged for drive-by noise? I was there on Saturday in a road car and was surprised at the number of cars being pulled in and spoken to. I hadn't realised that they photograph the offenders too. I saw a couple of Caterhams get pulled in. The Academy cars seemed to be ok, it was an R400 and Aurélien Chevalier's Superlight 20 that were close to the limit I think. I'm going back in May with my 175hp Duratec R300 which has a standard 7" silencer and separate cat still fitted, plastic plenum and airbox. It passed at Castle Combe with a 98dB static so will pass at Bedford (101dB), but the drive-by (87.5dB) may be an issue. Caterham don't seem to have any off the shelf solutions to noise and no longer stock the 485 rear silencers apparently. I spoke to BTB Exhausts who make the rear silencer with central outlet for the Palmersport Caterhams, but they run on gas so perhaps have more room under the tank. The guy I spoke to also runs a Caterham Cosworth and he fitted a rear silencer finding the rear outlet helped with the noise meters which can be on both sides of the car/track. I don't want to run into any noise limits at any trackday really. It seems the favourite choice is Raceco, but has anyone got some recommendations for a rear silencer? Simon

Hello d-j, I might be too late but here's my advice anyway..... I too have an ex-racer and use my car for sprints, hillclimbs and trackdays and have replaced all the seats and belts in the last year. If the car was raced with the belt sizes you have, it more than likely had crutch straps. Are you sure they are not still there? What seat do you have? 2nd thing to check is the expiry date of the belts. If you are not sure that the current belts have never suffered "an abrupt halt", replace them. The Schroth asm will be the yellow bit on one of the shoulder straps. As far as I can see, none of the racing 4 point harnesses have 2" shoulder and 3" lap belts. Which also suggests it was a 6 point harness originally. 2" shoulder straps will cut in to your shoulders too much without a Hans, best use 3" shoulders. The Sprint event regulations should tell you if you they are run under MSA/Motorsport Uk regs which will also determine if you need to use a Hans. A helmet with Hans posts too, obvs. The Hans does require the shoulder straps to be closer, another reason I think you had a full race 6 point Hans harness. The adjustable Hans has been discontinued, so yes you need the neck size and the angle. As already said, 20deg should be the one. If you use the Hybrid FHR then angle isn't an issue and you should use 2" shoulder belts with it. You are right to consider the shoulder to mounting point angle. There is plenty of info and regulation on that point. You should be ok as you are I think. Best thing is to read all the regs etc and buy a new harness. Schroth do a Caterham specific 6 point (with or without Hans 2' or 3") eg: https://caterhamparts.co.uk/seatbelts-harnesses/6490-schroth-6pt-rh-kit.html Hope that fills in some of the blanks!

If you are going to the trouble of splitting the engine and bell-housing, I would certainly renew the clutch plates as worn plates are likely to be the problem. Slave cylinders don't often fail. I would make sure you fit a remote bleed nipple on a length of hose if you haven't already got one. It certainly makes life easier than trying to get a tool on the bleed nipple that barely reaches the cutout in the bellhousing.

"As part of the lowered floor bits I have these two seat ali supports. I understand the runners sit on top of these (and they are installed in the cockpit not underneath) but what are the three holes in the bar and what are the four holes in the floor " What led you to understand that the seat supports do not go underneath? My R300 race car was built by DPR Motorsport with a lowered driver's floor with the two ali seat runner supports riveted to the underside of the floor with 3 rivets each. The same seat runners as yours were used with the 4 bolts going through the floor and more or less down the centre line of the 2 ali plates. This I believe gives extra thickness and strength to the floor panel to ensure that the bolts don't pull the nuts and washers through the single floor skin or bend the floor in the event of a major shunt. To have them inside the cockpit makes no sense to me and the plates are unlikely to be spacers. I would ask Caterham to be sure. I don't know why you have the four holes in the floor either. I sent my car back to DPR to fit a lowered floor on the passenger side which they did very well. I had to drill holes for the seat runners myself. I suspect your floor may be pre-drilled to take some version of a seat, they could be a distraction and probably best ignored. I laid a sheet of new corrugated cardboard precisely into the new lowered floor and then placed the Tillet seat with the runners attached into the cockpit. Once in the correct place, I applied some pressure which left a clear imprint in the cardboard where the bolt holes needed to be drilled. With the seat out, I just drilled through the cardboard, through the floor and got a pretty good result.

Caterham do still sell this alternative, although I suspect the nylon wedge should offer more protection. https://caterhamparts.co.uk/oil-system/4344-dry-sump-guard-r3-4-500.html I replaced mine a few months back with like for like. The old one was very bashed and you can see the amount of protection it gave, or didn't. (Ex-R300 Championship race car.)

I'm not sure what rj means, maybe a typo? "The new ones have to be pre-greased. They are not meant to be taken apart" The new bearings are pre-greased sealed bearings and are not meant to be taken apart. [CtrMint "I was thinking of taking the damaged one apart for interest."] I wouldn't bother as they are metal seals and will bend even more, tho' I believe you can pick plastic/rubber seals carefully out of a sealed bearing, (not recommended, just replace when worn). They are already lubricated and sealed for life, usually about 100,000 miles. Please call Caterham Parts to confirm. I replaced my rear wheel bearings a few months ago. The car came with worn out bearings which were the old twin bearing greased versions. They were replaced with what Caterham Parts now sell, albeit the sealed bearings were already installed into the housing. It looks like they may have stopped installing the bearings as the parts photos, https://caterhamparts.co.uk/71-hub-bearings only show bearings alongside the housing. [ CtrMint " I spoke with Derek at CC this morning and he has confirmed they should be installed in the carrier, as a result he is sending out a replacement set installed in the carriers." ] So you don't need to worry about the oven/fridge thing as yours will be assembled like mine were. I guess they are trying to save some costs but are finding that owners/fitters are having trouble doing the bearing install themselves. Not so relevant here but maybe of interest.....My front bearings are these https://caterhamparts.co.uk/hubs-and-bearings/355-wheel-bearing-kit-2003-onwards.html They look similar to sealed bearings when in the packet but are conical roller bearings and the two parts come apart like this.. and they do need grease on them. The rollers run on the inside conical face of the outer race which fits into the hub and the inner ring is held onto the stub axle with a large thrust washer and castellated nut. I think the uprated front hub kit now available may have sealed bearings.

I used a sheet of corrugated cardboard, cut from the side of a box probably. Having made a paper template, I laid the cardboard into the floor, making sure it could not move and once positioned, applied some weight to the seat with the runners attached. The rivnuts I'd fitted to the adjustable runners and/or the ali box section left a very clear imprint in the cardboard. I used a center punch and then drilled through the cardboard and the floor. I bolted my Tillett seats in from below. If you need to cover the old holes, you can buy some cut-to-order/size aluminium sheet and rivet in place with some suitable sealant, above or below the floor skin.

Another one for your diary Nicolas.... https://www.kophillclimb.org.uk/ 21/22 September 2019

You should find this helpful as it shows what I think you have at the moment. http://www.alcester-racing-sevens.com/side_impact_bar.htm As this site and TomB mention, the aluminium honeycomb is a gesture and works a bit like corrugated cardboard. They put the same material around some fuel tank as it helps with puncture type intrusion and resists bending as a sheet material. It might perform better if it was properly bonded into the sides of the chassis. The SIB that elie boone suggests is the next best thing and I believe will allow you to use the full doors. They do just bolt into place using existing chassis mounts and a longer bolt for the A frame which is all provided in the fastener kit. Best check with Caterham Parts and have your chassis number handy. The bar you've got does a better job of putting some more metal between you and whatever is trying to intrude, as it is higher up and bridges the massive opening between the windscreen and your shoulder. Part number 77856 more or less follows the same shape as the chassis tubes behind and doesn't close the gap. If you haven't seen this already, it might be of interest; https://www.pistonheads.com/gassing/topic.asp?h=0&f=101&t=1495828

Hi Les, Some shift lights have down change strategies too but I suspect that isn't available with the DRE. The point being that you could consider setting the first pair of lights to a point in the rev range that you don't want to fall below. So if you are in the power band you want they will stay on and as soon as you fall below the band, lights go off and you know to downshift. Then obviously the remaining two pairs can be your upshift lights. So with only those two sets available you will have to open the rpm gap to maybe 1000rpm to start with and then you might be able to close it to 750 - 500 rpm as you work out your reaction time needed. You have a bit of a plateau in your torque curve below 6000 rpm, so you could try setting the first pair of shift lights somewhere between 5300 and 6000 rpm, the next pair at somewhere between 7000 and 7750 and the change gear now at 8000 rpm, so if you are a bit late changing, you just run into the bhp plateau which I assume is closely followed by your soft cut/limiter. Simon

https://www.motorsportatthepalace.co.uk/ You could contact the MSA to see about getting a Nat B licence which is all you'd need I think for the Crystal Palace event. "There is no test requirement for taking out a Non-Race National B licence but the Association of Hillclimb and Sprint Schools (AHASS) offers a written examination that can count as an upgrade signature towards a Speed National A licence." https://www.msauk.org/Competitors/Competition-Licences http://ahass.co.uk/schools.html

I think generally shifts lights are positioned in line of sight so you don't have to take your eyes off the road to look at your tacho and therefore serve as a visual red line to avoid loosing power by running into the rev limiter (assuming there is one). Normally you would have a soft cut and a hard cut to the ignition. Although you can generally hear when to change gear, it is not usually accurate enough to protect the engine or avoid hitting a limiter. You can configure the lights to suit yourself, so yes, you could decide that your preference would be to change gear at max torque. Although it is too small to read the values, it looks like your bhp continues to rise and would do so a little if projected on from the rev limit. Usually the shift light is set for a gear change just before you hit the soft cut or rev limiter and probably a few (100-250rpm) revs below that to allow for reaction time. That will depend on how quickly the revs rise and of course they will rise quicker in 1st gear than top. (I don't know whether the DRE lights allow you to set a value for each gear, but some systems like Motec do.) The other point to consider is where your limiter is set to cut the ignition, common sense suggests that there is no point in revving the engine beyond the point where both torque and bhp are starting to drop off, even if mechanically it could handle it. I would suggest you work back in evenly spaced rpm gaps to somewhere close to where your torque and bhp graph lines cross (as the car won't stop accelerating at that point). So you end up with a ready, steady, change now series of lights moving from left to right. You'll have to experiment until you are happy with the rpm gaps based on how much time you want to react. For instance, assuming you can use all 5 lights, you might start by having the first light come on at say 1500rpm before the cut and space the others out evenly at 1500/5= every 300rpm. Or you could make the gaps varied or maybe bring the last two lights in together or maybe they will all flash when you need to change. Depending on your driving style, say on the road, you might already have your hand on the gear lever before the the first shift light comes on. Or if you are on a track and keeping both hands on the wheel is preferable, then think about the time it takes your hand to reach the gear lever to pull the next gear, can be under a second. You could watch a few onboard videos like this to get the idea. Jon Barnes has his lights set to have two reds at the end of a multi-coloured sequence which flash together when he really must change gear. It is just down to personal preference.

Justin, I discovered csfnet some years ago too, it's the best place to get the two part expanding foam. The mark-up from other suppliers is considerable. I have had a few expanding foam seat failures such as it shrinking after setting and having to buy some expanding foam remover after my father poured in too much mix into the bag I was sitting on. Richard's advice is spot on. Ideally you need your race suit, Hans and helmet on too. Just protect everything from over-expansion/spillage and spend the time with the cardboard. I won't use it anymore and only make bead seats now. You need to consider the advances in impact absorption provided by the bead material and the curve of your spine. It is difficult to maintain a good posture for your spine and neck in the car while the foam expands around you. A bead seat does give you some support. Racecar Engineering magazine published some research into spinal injuries in Formula cars that you might be able to find. Basically, the more the spine is curved and not in good alignment, the greater the chance of (mainly lower) spinal injury in an impact. The Tillett seats, if you are comfortable in them, at least keep your spine in a better position than you might end up with in a bag seat. Yes, it is the belts that hold you into the chassis thereby securing the foam/bead seat. http://www.realequipe.com/2011/09/real-race-seat-insert-for-caterham-racers/ http://www.caterhamr500.co.uk/2017/03/real-essentials-diy-bead-seat.html