Life with a CSR (so far...)
Entry posted by David.Ashley.Poole
9,261 views
Hello L7Cers,
My name is David Poole and I am the new owner of a 2005 CSR 260. Well, six months owner.
Recently my thoughts kept drifting back to the Lotus 6 (1498 Laystall-Ford) that I owned when I joined the RN. It had a hood, but no side-screens or heater, and I loved it dearly. I drove it from the Britannia Royal Naval College, with my kit stuffed into the passenger seat, to my next posting, where I crashed it. But I had another Lotus 6 (1466 XPEG Laystall-MG) some years later, and then a Seven (1500 Crossflow) – all road cars.
I live in Weymouth, work from home and in London, so it was not much of a stretch to get the train to Caterham at Gatwick. They had a lot of nice cars, and let me drive a somewhat ratty 420R demonstrator. But I was not totally sold, and so I arranged a drive in a new 420R and new-ish 420S at Williams in Bristol. Now this was interesting, since the 420R had a six speed gearbox. But although I liked the R – and the six-speed - quite a lot (but did not like the S much) somehow I was still not bonded to either car. And then I saw that Chapman Cars in Kent had a 2005 CSR for sale. Now I have always thought that the CSR was the pinnacle of Caterham engineering, and had been looking for one for some time. How CC managed to produce such a sophisticated car was a mystery to me, and why they stopped making if after a few years was an equal mystery. But I could not resist… so I put down a deposit, arranged the train tickets, was collected at the station by Anthony Paine, and had a test drive. In the rain… and that, as they say, was that. And this blog is an attempt to document my progress, and also solicit advice from you chaps who are clearly more experienced with these cars than I.
And this is it… a 2005 CSR 260. Many owners, 20,000 Miles, built as a knockdown CSR 200 (kit) car, converted to a 260 by Caterham in 2007 with a 260 engine and six speed gearbox, and a Quaife ATB in 2008 when it had its first MOT. It has a very comprehensive service history and is in wonderful – almost like new - condition, but although the paint was great it was jolly dirty in the cockpit despite Chapman’s best efforts. When I test drove it the diff whined a bit, but it was nothing to complain about. After the high speed run down the M3 to Weymouth it was a different story, and it was howling like a banshee and had a lot of freeplay by the time I arrived. I initially thought that this was going to be a case of caveat emptor, since I could not imagine anyone being sympathetic to a Caterham owner complaining about a noisy diff (!). I was considering pulling it out and getting it rebuilt myself, but I thought that some advice from Anthony and Damien at Chapman would be useful… and the response was quite outstanding. They insisted that I brought the car back to them and let them have it rebuilt by Road and Race – and I then called Philip at R&R and after a chat he found a 3.14 CWP that he had in stock and he fitted that, new bearings and seals, and rebuilt it. He said that many of the original 3.48s had been manufactured by Hewland for racing and they were not too concerned about noise. It also had no preload…. But the rebuilt unit is totally quiet, the freeplay has gone, the ratio is ideal, and you can only hear a whisper from the ATB on corners when you have the sidescreens off. Philip clearly knows what he is doing.
I put this table together in Excel to see what the ratios look like in practice – and this is with the standard CR500 245/40R15 rear tires at 896 revolutions/mile. Max power is at 7500 and max rpm is 7800, and you can see what a beautiful set of ratios these are for this car.
Speed in gears RPM Final Tyre R/Mile 1 2 3 4 5 6
1000 3.14 896 8 11 13 16 19 21
2000 16 21 27 32 38 43
3000 24 32 40 48 57 64
4000 32 42 54 65 75 85
5000 40 53 67 81 94 107
6000 48 64 80 97 113 128
7000 55 74 94 113 132 149
7500 59 80 101 121 142 160
7800 62 83 105 126 147 166
Ratios 2.69 2.01 1.59 1.32 1.13 1.00
Percentage change -34 -26 -20 -17 -13
Next gear RPM at 7500 change 5604 5933 6226 6420 6637
Next gear RPM at 7800 change 5828 6170 6475 6677 6903
Sine then I have rebuilt the front suspension – I thought one of the Heim joints was rattling, but after I replaced them all it turned out to be the lower steering column hitting one of the exhaust primaries. But I did discover that one of the steering rack gaiters was torn and the rack slightly rusted, so I replaced it with the high ratio “race” rack, which turned out to be the same 2.0 turns lock to lock as the original. I thought it was going to be around 1.6, but a chat with Darren at CC parts cleared up that misapprehension. I also replaced the lower column, which was getting a bit ratty, and had not realized that the lower column sets the end-play in the upper column, which was grinding against the horn button slip ring. So this turned out to be the proverbial “n birds with one stone” deal. At the same time I swapped the original Momo 300 mm Team steering wheel for a 320 mm Jet, since the 300 mm wheel made the indicator and light stalks (I have the integrated cockpit) stick out like Ross Perot’s ears. As they say…
And over the summer – when I was grounded since the builders were in – I pulled the exhaust off and had it media (Aluminium oxide and the glass bead) blasted, and insulated the primaries with titanium wrap; replaced the windscreen, which had some dings; fitted a set of weather equipment from Thundersports (the car had never had any); and compounded and polished it with my random orbital polisher.
And then I tackled the on/off throttle transition problem that had plagued me – more or less – since I bought the car. It was always easy to promote a kangaroo hiccup if I was not extremely smooth in applying throttle, and I managed to compensate somewhat by pressing my foot against the side of the cockpit. In the past I had improved idle quality by changing to Iridium plugs, so I decided to try them in my CSR. And the results were pretty amusing – they irritated the car immensely, and it became almost undriveable. So I swapped them back to the originals and thought about it for a couple of days. Now the plugs were pretty black, but Damien said that the Cosworth engines typically run rich. But there is rich and rich, and I came to the conclusion that the ECU was running open loop and that probably the Lamba sensor was not – well – sensing. So I replaced it with a Bosch equivalent, and after 100 miles or so I presumed that the trim maps had been updated and the engine settled down to a very civilized behavior. So I put in the Iridium (TR7IX) plugs again, and it became even better, and now the transition problems have gone and it is a delight to drive.
Next year I plan to refinish the wheels since they are losing the paint on the inner tears 9but I am not sure about the color – originall or body colour, that is the Question), and replace the tires. I think I will stick to CR500s since they were designed for the car and I am not enthusiastic about modifying the front mudguards to take the larger section ZZS. And I am going to get the gearbox rebuilt when I investigate the rattle in reverse, which I think is the clutch. And that is about it, apart from bonnet stripes and a shift light – but I am unsure about the seats, which are not (quite) a pair, and I have been thinking about the Thundersports GT seats and would welcome comments on the choice.
So my conclusions? Chapman cars are a truly excellent company, and I have no hesitation in recommending them without hesitation. And the CSR? Pure magic. Great ride, wonderful feedback, more power than you (usually) need, best engine and gearbox ever, outstanding brakes and roadholding. I am bonded.
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