Nick

Back again; poxy computers!

I thought you'd like it! wink.gif What do you reckon it weighs?!

Not a Caterham or a Lotus admittedly, but an electric Tiger may be of interest!

as olden stories tellen us

Another disadvantage is that if timing becomes common practice at trackdays and insurance companies realise this, premiums could well rise and/or trackday cover will be excluded, which will subsequently only be available through specialist companies. Mr Pooper

I didn't fit the anti-cav tank myself so didn't see the various bits; however, the bill states: 71304 Oil/air seperator 111.80 71304C Oil/air tank pipe package 93.49 71306 Lower platform 3.75 71307 Upper bracket 3.75 I had problems with oil leaking from the various pipes, cured by liberal use of PTFE tape.

Over to you then Rob!

The wheel is one of a set of five I have just bought for trackdays. I was told it's a superlight wheel, ie 4.5 kg (?) rather than the slightly heavier minilight. What's the going rate? About UKP25/30 with a tyre? But for you, Rob, it would probably be double that! Why do you want a spare, haven't you just had dozens in your garage?! Cheers, Nick PS - I guess we should wait for Dave to respond? HURRY UP DAVE!

I have one good condition minilight 13" wheel going, complete with well worn (but not quite knackered) AO21R; fits de Dion 1.6K. I'm in Colchester, Essex - where are you? I was going to take it to Easytrack's airfield day at Bentwaters, Suffolk, on Saturday 14th October in the hope someone there would want it, thus avoiding delivery hassles. Edited by - Nick on 7 Oct 2000 21:23:45

Typical! I fitted one of these a few weeks ago! Edited by - Nick on 7 Oct 2000 19:20:41

Blah www.rhubarb7.freeserve.co.uk

I hope you all took notes, as there will be a short quiz after the interval...wink.gif

James, a dry sump involves pumping the oil to the engine from an extrenal container, rather than it being held within the crankcase (sump). This means the crankase can be reduced in size and sometimes, the engine can then be lowered, thereby lowering the centre of gravity. Moreover, it eliminates oil starvation that results from oil surge - with a normal sump, all the oil is forced to one side of the sump during heavy (eg race/track) cornering and braking. An anti-cavitation tank (the optional Apollo) is a header tank of oil that works with a conventional wet sump. It does nothing to reduce oil surge but does separate any air from the oil, so that during oil surge, air is not forced onto the engine, blowing away what oil may be there. A wet sump is the conventional system for holding an engine's oil, in which the oil is contained within the crankcase, underneath the engine. As for oil types, a good quality mineral oil is recommended for the first 500 mile running in period; thereafter, high quality synthetic oil, such as Comma SynerG or Comma SynerZ, or Mobil 1. Needless to say, these are more expensive than your average oils but you gets what you pay for. smile.gif Oh yes, the anti-cav tank holds about 7 litres of oil instead of the wet sump's 4 (I think), so oil changes get more expensive! I'm not sure of the dry sump's capacity but it may be between the two.

I have heard that apart from the obvious nightmare of really clouting your sump, it is possible to knock the sump drain plug loose with the consequence of rapid and complete oil loss. sad.gif

I appreciate your comments, but my position is that I have done a number of trackdays over two years as you are now doing them, ie without changing setup. I have driven a 7 that felt superb, and am interested to see if i can get mine to feel the same; it is precisely the subjective feel I am currently interested in, rather than outright speed; I am aware that the feel I like may well be slower, and then I shall possibly revert to my known settings, or a compromise. I am not a 'tinkerer' by nature but would like to improve the feel of my car; if it can be achieved relatively simply with a bit of help from the likes of Peter, I will be very pleased; if not, I know my original settings and so can easily revert and just carry on as before. All the best, Nick

Peter - ah, the voice of reason! After Hyperion's flat floor setup, the car felt pretty good - but still prone to a bit of understeer. At this stage, you suggested stiffer front springs, raising the rear ride height by 2 turns, and changing the rear arb from 4 (stiffest) to 2. I haven't touched the springs, but did raise the rear ride height by 2 turns. I posted this in the original thread but cannot remember if you saw it. I went for a drive after the adjustment and decided to raise by another 2 turns, although the platforms were nearing the end of available adjustment. Another drive, and things felt better. I then adjusted the rear arb from 4 to 2, having adjusted the length of the links to suit, so that the arb was not under tension at rest; hopefully I have explained that well enough! It all seemed much better: understeer had gone but it wasn't chronic oversteer. I was more aware of the rear of the car but wasn't sure if this was because it was too rear biased (in which case I could wind the rear down a bit) or because it was a new sensation that I simply wasn't used to. Also, there is only so much I can tell from the road rather than a track session. Later on, I drove along a bumpy road I know quite well but hadn't driven on for a while. I couldn't go as fast as before, as the car didn't ride the bumps so well, and occasionally there was a clonk from the rear that had never happened before; the car also tramlined more, although not horribly so. This led me to wonder if the adjustment to the rear ride height had affected the front castor, and also if perhaps I'd 'stretched' the rear shocks too much and the clonk was them over extending. Maybe you saw my reasoning, even if it was invalid! I have not touched the front, and following your advice, will not do so. I have not had the geometry checked since I raised the rear ride height. I am keen to follow a reasoned route and do not want to jump around. Reading your post, I see what you mean and appreciate your advice rather than just giving up on me! I thought I was being logical but can see now that that was not so - a little bit of knowledge is a dangerous thing. Do you think my perceived increased tramlining and lower speed on bumpy roads is actual? If so, could this, together with the clonking rear, be a result of my raising the rear ride height? I guess I should revert to how things were to re-assess? The trouble is, my back's playing up and so I can't do that - and you know how it is when you want to play but can't! Once again Peter, thank you for your help thus far, and for pointing out that I was straying. Any light you could shed on bumps and clonks would be much appreciated. Cheers, Nick PS - Good luck fine tuning that engine of yours - and then, no doubt, having to play around with your own suspension again! Edited by - Nick on 3 Oct 2000 15:14:28

Interesting stuff, thank you. My 7 was originally running pretty well on the bump stops - at rest! Hyperion raised the ride height so that, at rest, there was about 1 cm of travel before the bump stops. At Peter's suggestion, I raised the rear ride height, initially by 2 turns, then 4. This (as far as I can tell on the road) has cured my understeer problem but has resulted in more tram-lining (but not badly) and a bumpier ride (definitely slower on some roads). I wonder if 4 turns was too much and has upset the castor, and may also have 'strecthed' the shocks too long so that they are 'topping out' - my term for the opposite of bottoming out. Maybe I could drop the back by 2 turns, and then drop the front by 2 as well. To my thinking (and I stand to be corrected) this would give the same or similar effect as I have now, without changing the castor as much (I don't know how to adjust castor); one problem is that it would reduce suspension travel before the bump stops come into play. I shall leave the spacers alone. All good fun - I suppose! Cheers, Nick

Mike, I wish I'd got you to show me this at the weekend! Maybe it would be a good idea to get rid of it on mine, as my 7 was running on the bump stops until recently. I'll have a look when it's stopped raining! Why is it there? Cheers, Nick

Has anyone any experience of the Stack ST500 tach-timer thingy? The URL is http://www.stackltd.com/uksite/st500.html Hours of fun, or pants?! Thanks, Nick

In answer to my own post...! Bad form, I know, but I had one last go at searching and it didn't time out. If anyone's interested, Dave J in 'Wings and Stuff' said.... "I've just stripped the carbon , wings , dash , rear wings and nose off me superlite and stripped the GRP versions from kevins car . TOTAL WEIGHT SAVING = 237.12 Grams ( after I had washed all the ****e from me rear wings ). This will increase my power to weight ratio by .34 bhp/ ton"

A while back, somebody posted comparable weights of the fibreglass and carbon fibre bits. The search keeps timing out on me - can anyone remember the post? Thanks, Nick

Thanks Mike, I knew I'd heard something along those lines. Simon - your list is the same as mine!

Thanks for the various comments - keep them coming! Simon - what prompted Caterham to recommend the 1.8? Money aside, the 1.8 would seem the better bet - simply because 'there ain't no substitute for coobic inches'; but is it? The cars will get a lot of trackday use; no competition envisaged at the moment. The friend after the 1.6 currently has a 1.6Kss and has driven all types of Caterhams, Westfields, et al - but has never owned a 1.8. My friend after the 1.8 is new to 7s and currently owns an Elise 111. Edited by - Nick on 28 Sep 2000 13:51:36

A couple of friends are set to buy a 1.6 and a 1.8 Superlight. Has anyone any pearlies on the pros and cons of each car? I thought I read here recently that something about the 1.8 (the ECU?) was a bit bodged in comparison with the 1.6, but my searches keep timing out. Thanks for any comments. Nick

The following is a copy of one of Mike Bees' old posts, (thanks Mike!) and may help. I run the AO32Rs on my 1.6K ss at about 18 psi cold. Apparently, 23 front and 24 rear are good pressures to aim for when hot - so say Hyperion and a few others. Quote: A rather obvious but possibly overlooked point about tyre pressures: For a given situation there will be a tyre pressure that gives the optimum amount of grip from the tyre. Adding more pressure than this will reduce the grip, reducing the pressure from this will reduce grip. Ergo you can't have a general rule which says "increasing the front tyre pressures will cause less/more understeer" because it depends (a) on where you're starting from and (b) on loads of other factors. The best way to determine the tyre pressure for optimum grip (or more correctly to make optimum use of the tyre's width) is to use a pyrometer. Measure the temperature of the inside, centre and outside of the tyre. Plot them on a graph with temperature on the Y axis and position (inside, centre, outside) on the X axis. If the 3 points form a horizontal line then bingo you're heating the whole width of the tyre evenly. If they form a straight line but with the inside hotter than the outside or vice versa then the pressure is optimised but the camber and/or toe is causing a temperature gradient across the tyre. If they don't form a straight line then draw a straight line between the inside and outside temperature points - if the centre point is below this line then the middle of the tyre isn't doing enough work so more pressure required, if the centre point is above the line then the middle of the tyre is doing too much work hence less pressure is required. The requirements will change from venue to venue and day to day (even hour to hour) at the same venue.