ashaughnessy

When I bought my car second hand from Caterham, the clock showed only about two hundred miles but Caterham told me it had done about 21,000. A full record of receipts and MOT certificates is the safest way to tell, IMHO. Anthony

As an interesting alternative view, my 1987 live axle supersprint weighs about 505Kg with an almost empty fuel tank. However, this is based on being weighed at the end of the race and once being told off for being underweight by 18Kg. From that, I calculated the 505Kg weight. I've since been told once that I was right on the weight limit. I'm currently getting the corner weights done, so if they tell a different tale, I'll post an update. The racing weight is with side screens, FIA bar and strut (and an extension hoop behind my head, perhaps about 2Kg), a small handheld extinguisher, no heater, no hood, no spare wheel, no carpets, no passenger seat, fibre-glass drivers seat, wet sump engine, no oil cooler. I've got two sets of wheels. Steel Wellers, 13x6 with A021Rs, weigh 13Kg each. Alloy KN wheels (the old 5 prong affairs that used to be common fitment) with A032Rs, also weigh 13Kg each. Both types of tyre in 185x60R13 size weigh (I think) 6Kg each (therefore wheels = 7Kg each). These were measured on a set of bathroom scales. Anthony

This last piece of advice is debatable. There have been lots of discussions in the past (here and in low flying) about alternative materials for A-frame bushes. It isn't a simple matter of just fitting a harder or tougher material, as the bush is designed to give some flex and a harder material gives increased roll stiffness. I wouldn't say the aforementioned poly bushes aren't suitable but you should be aware of the issues. Anthony

I'm changing from standard to 8% on the advice of Derek Moore at Caterham Midlands. He reckons 8% is the best compromise for a mix of road and track - good enough for the track and nice on the road.

I agree with what's been said - you'll get plenty of track days out of one set of pads. Changing them is easy, just like someone else said, EXCEPT - the last time I changed my pads I ended up with a long brake pedal. The secret (according to James Whiting) is to make sure the new pads are a snug fit when you put them in. If you lever the pistons back too far so that it's easy to put the new pads in, then you might find they won't "snug up" to the disk properly when you pump the pedal for the first time. The rubber seal inside the piston tends to draw it back. After James told me this, I took more care in refitting the pads and had a beautiful solid pedal. Anthony

I think you'd be lucky if anyone could tell you *exactly*, as everyone seems to have their own preference. This is a very common subject on this mailing list, and there is always some disagreement. Sorry. In cases like this, I prefer to go to a single source that I consider to be expert and ask them to make the choice for me. Try going to one of the more respected specialists like Classic Carriage, Arrowstar, etc. and ask them to choose for you. Anyway, if you search through the back postings in this list, there are several threads within the last few months on this topic. Anthony

From reading various postings about front brake material, I think the jury is out on green stuff - several people have said it's great, several have said it's not so great. Anyway. The advice I've been given by Caterham and by some others is to leave the brake lining material at the back as standard, as the rear brakes don't do enough work to justify a higher rated material. I've got standard on the back and Mintex 1144 at the front. Yes, when a wheel locks it's always at the front, but I don't find it difficult to avoid a lock up (at least on the track, with nice warm tyres). I usually think the brakes are quite nicely balanced front to rear. I don't know if you can get alternative drums, but if you leave the shoes with standard linings this probably indicates there isn't much need to go with an alternative drum. If the drums are pitted on their friction faces, I guess I would replace them, but I'd rather hear a more expert opinion. Drums are reasonably expensive, you'd have to buy them in pairs to make sure the brakes are balanced, and you'd also need to replace the shoes at the same time to match, so it adds up, but it depends how bad the pitting is. Anthony

Sorry, I don't have any answers for you, just want to add to your questions with my own. In Low Flying about two months ago, there was an article about a new airbox thing that Caterham have introduced specifically for the roller barrel throttles. How come the roller barrels are so much noisier? Anthony

Hopefully other more expert people will reply, but my two pence worth is: 1) The tyres cool down very quickly once you've finished fast lapping on the track. To measure the race temperature, you need to come straight into the paddock from a fast lap without any dawdling on the way. Measure the temperatures (and pressures) as soon as the car comes to a halt. 2) My tyres (Yoko A021R last year, A032R this year) increase pressure by between four and eight PSI from cold to hot, depending on the track, the weather, and which corner of the car the tyre is on. 3) Different tyres definitely have optimal operating temperatures, but I'm afraid I don't know what they are. 4) A valuable use for the pyrometer is to make sure the temperature is the same across the tread. This can indicate whether the pressure is correct (hotter in the middle than the edges might mean over-inflated, and vice versa) or whether the camber is optimal (hotter on the inside than the outside or vice versa). If I had a pyrometer I would definitely use it to check my tyre pressures, but you need a bit more expertise to judge other things from it, I think. My simplistic diagnosis of temperature differences across the tread might not be 100% correct. Anthony

Now I'm not saying this is the case with your car, but on my car (live axle crossflow) I used to think my back axle was leaking oil like a tap at track days because after every session the axle and rear chassis tubes were covered in oil. I finally figured out it was actually the engine spitting it out through the breather pipe which was pointed down just under the passenger footwell. From there, the oil would be flung towards the rear and end up all over the axle (and the track :-( Got a catch tank now, you'll all be pleased to hear. Easy to tell the difference, because engine oil doesn't smell like gear oil. Anthony

The factory's answer to this is to replace the side skins, at great cost :-) I don't have a better answer, though. Anthony

Just had my first race of the year with my new tyres, Yoko A032R (S compound) to replace my A021R. My best lap time this year was 3 seconds a lap better than my best last year at this circuit (Cadwell Club). The tyres are the only thing to have changed apart from using full-fat leaded 4 star instead of LRP. Pretty big difference. They felt very similar but with much sharper turn-in. Money well spent, I think. It was a fantastic race day, as well. Anthony

A big question. There are regular articles in low flying on this subject, try looking through the back issues. Regulations for track days depend on who is running them. If it's the L7 club, you'll need the FIA roll-over bar. Other clubs don't demand this. I don't think there are any other things you need apart from the FIA bar to go on a track day. Racing is another matter. You will probably need (not guaranteed accurate list): - FIA roll-over bar. - Fire extinguisher. - At least four point, preferably six point, harness. - Flush fitting fuel filler cap - Yellow tape wrapped round battery earth lead - Battery master switch - Possibly replace your ply-wood boot floor with ali honeycomb - Helmet, fireproof overalls. - Head restraint to stop your head hitting the roll-over bar in a crash (you may already have a seat with a head restraint) - Oil catch tank for the crankcase breather You will also need a race licence and you'll need to join whatever club is running the race series you want to enter. Other regulations will depend on the race series you enter. For example, in the 750MC Gold Arts series, you will need a non-reverse breather valve in the fuel tank, ballast to bring minimum weight of car+driver to 600Kg, control yokohama tyres, etc... Cars and Car Conversions also occasionally publish articles on converting your road car for racing. See their back issues. You'll probably also want racing boots (better feel) and fireproof gloves. Once you've got all this, then you'll start wanting a faster engine, bigger brakes, better suspension setup, etc. You will want to think about whether you're going to drive the car to the circuit or trailer it. Finally, you'll need a very large wallet. I did the same thing about three years ago with my supersprint and haven't regretted it. Anthony

I've got a live axle supersprint. I used to have the standard goodyear eagle but changed to Yoko A021R 185/60/13 about two years ago when I started racing. On the road they have a lot more grip than the goodyears, as you would expect. Can't remember the price, somewhere in the region of £50 per tyre. I found them slightly noisy though, they whine a little. They haven't lasted long. After two years and about ten races they're almost worn out. I've just fitted Yoko A032R in soft compound, again 185/60/13. Can't report on what they're like yet but every other car in my series (750MC GoldArts) uses them. Not surprising considering that the regulations only allow either A021R or A032R, but even before the regulations included control tyres almost all the cars were using these. If you go for these, don't buy from Caterham. I bought from DemonTweeks for about £50 per tyre + vat, compared to Caterham's price of £70 per tyre (don't know if that includes VAT). You get a choice of compound with A032R, hard, soft or supersoft. I went for soft because supersoft isn't allowed in the race. Anthony

If I got my car set up properly (if!) with the ride height set correctly and the corner weights set properly, that would be a good start. From there, could I use changes in front and rear ride heights to affect the handling in a predictable and useful way? E.g. if I get too much understeer could I raise/lower the front or raise/lower the rear to either get rid of it or compensate for it by loosening the back? At the moment, the only useful on-track set up options I have are the dampers and the tyre pressures. Anthony

Let's say I wanted to try this on my garage floor - far from level. Do I need to create four level pads on which to place the scales, or can I place the scales on the floor and put things on top of the scales to shim up each wheel so that each wheel' contact point with the scales is at the same level? I assume the latter, because the corner weighting is all about getting rid of imbalances caused by the car rocking about one of its diagonals. How accurately do you need to get the levels? E.g. to the nearest foot [:-)], the nearest half centimetre, the nearest millimetre, etc? What about problems caused by the car not settling correctly on the springs each time you jack it up to adjust it? How do you make sure it settles back to the correct rolling ride height each time? Anthony

After eleven years of black-handed ownership, having tried every trick, I reckon doing it by hand is the only answer. Power drills, etc., don't seem to make it any easier. I've tried Solvol (Autosol, Autochrome) which works well, Mother's is very good, and I've just discovered AutoGlym which works extremely well (better than Solvol). Takes me about two hours to do the whole car. Not my favourite job.

I once heard at a talk by Len Unwin that he reckoned oil coolers weren't much use on a seven. I used to have one (in my supersprint) mounted in the "official" place, in front of the radiator, and found that it significantly reduced my water cooling capacity (in other words, I overheated more often), especially when racing. Since I removed it the water temperature is more under control (though still a bit of a problem when racing). I've no idea what my oil temperature is, though. Anthony

This may sound obvious, but are you sure the gun is firmly attached onto the nipple? The oil gun I use relies on the pressure of pumping the gun to get a firm seal but a normal grease gun doesn't push against the nipple, the nipple needs to "snap" into the end of the grease gun. If you just place the gun against it, that's no good. You can tell its snapped on correctly because you'll need to pull hard (well, slightly hard) to get it off again. I don't know if the one from James Whiting is like mine (just push it against the nipple) or like a normal grease gun (snap it onto the nipple).

21psi for racing? Ah, but are you talking hot or cold pressure? With my A021Rs I use 25 psi hot for racing, which means anywhere between 18psi to 21psi cold depending on the track, the weather, and also which tyre it is (e.g. nearside warms up more than offside on a circular clockwise track). I spent a day setting up at Oulton Park and played with tyre pressures and 25 psi hot was the best setting. This was measured as soon as I came off the track so the tyres didn't get a chance to cool down at all, so they were pretty hot. Its amazing how much pressure they lose when they cool down. On that day, the rear nearside went down from 25 to 17.5 !

I just changed the pads on my "standard" old-fashioned calipers. I also rebuilt the calipers with new seals at the same time. After putting it all back together I had a long brake pedal. James Whiting says this is common and the answer is to make sure the pistons are in the right position before putting the pads in, i.e. it should be a tight squeeze to get the new pads in between the piston and disc. If you push the pistons too far back, then when you apply and release the brakes they'll be pulled back into the cylinder by a tiny amount, causing the long travel. I don't know if this happens with the AP calipers, nor whether it only applies when you've fitted new caliper seals or whether it always happens when you fit new pads. Worth bearing in mind though.

I have a 1987 supersprint. Am I correct in thinking it has a "leaded" distributor? Does this mean that my advance at tickover should be 10 degrees? This has always been something that worries me because there isn't a big label on the distributor saying "leaded". What kind of advance curve do I get with my leaded distributor? If the original poster had an unleaded distributor, why has he been running on leaded petrol until now? (I've always run on four star, I run nowadays on LRP, mostly because the 750MC rules say you can't use additives.) Anthony

I was changing my brake pads yesterday (1987 live axle car, triumph hubs). I noticed there weren't any anti-squeal shims. I remembered that I had some shims in a plastic bag somewhere. They'd been returned to me last time I had some work done in that area. It seems like the mechanic had deliberately not used the shims. Question - should I use the anti-squeal shims or should I leave them out? The car is used for racing - I don't know if this makes a difference. Anthony