Mike Bees

And this is how not to do it: ---------------------------------------------------------- A friend of mine once built a canoe. He spent a long time on it and it was a work of art. Almost the final phase was to fill both ends with polyureathane expanding foam. He duly ordered the bits from Mr Glasplies (an excellent purveyor of all things fibreglass) and it arrived in two packs covered with appropriately dire warnings about expansion ratios and some very good notes on how to use it. Unfortunately he had a degree, worse still two of them. One was in Chemistry, so the instructions got thrown away and the other in something mathematical because in a few minutes he was merrily calculating the volume of his craft to many decimal places and the guidelines got binned as well. He propped the canoe up on one end, got a huge tin, carefully measured the calculated amounts of glop, mixed them and quickly poured the mixture in the end of the canoe (The two pack expands very rapidly). I arrived as he was completing this and I looked in to see the end chamber over half full of something Cawdors Witches would have been proud of. Two thing occurred to me, one was the label which said in big letters "Caution - expansion ratio 50:1" (or something similar) and the other that the now empty tins said "approximately enough for 20 small craft." Any comment was drowned out by a sea of yellow brown foam suddenly pouring out of the middle of the canoe and the end of the canoe bursting open. My friend screamed and leapt at his pride and joy which was knocked to the ground as he started trying to bale handfuls of this stuff out with his hands. Knocking the craft over allowed the still liquid and not yet fully expanded foam to flow to the other end of the canoe where it expanded and shattered that end as well. A few seconds later and we had a canoe with two exploded ends, a mountain of solid foam about 4ft high growing out of the middle, and a chemist firmly embedded up to his armpits in it. At this stage he discovered the reaction was exothermic and his hands and arms were getting very hot indeed. Running about in small circles in a confined space while glued to the remains of a fairly large canoe proved ineffective so he resorted to screaming a bit instead. Fortunately a Kukri was to hand so I attacked the foam around his hands with some enthusiasm. The process was hindered by the noise he was making and the fact he was trying to escape while still attached to the canoe. Eventually I managed to hack out a lump of foam still including most of his arms and hands. Unfortunately my tears of laughter were not helping as they accelerated the foam setting. Seeking medical help was obviously out of the question, the embarrassment of having to explain his occupation (Chief Research Chemist at a major petrochemical organisation) would simply never have been lived down. Several hours and much acrimony later we had removed sufficient foam (and much hair) to allow him to move again. However he still looked something like a failed audition for Quasimodo with red burns on his arms and expanded blobs of foam sticking everywhere. My comment that the scalding simple made the hairs the foam was sticking to come out easier was not met with the enthusiasm I felt it deserved. I forgot to add that in retrospect rather unwisely he had set out to do this deed in the hallway of his house (the only place he later explained with sufficient headroom for the canoe - achieved by poking it up the stairwell. Having extricated him we now were faced with the problem of a canoe construction kit embedded in a still gurgling block of foam which was now irrevocably bonded to the hall and stairs carpet as well as several banister rails and quite a lot of wallpaper. At this point his wife and her mother came back from shopping...... Oh yes - and he had been wearing the pullover Mum in law had knitted him for his birthday the week before. ---------------------------------------------------- Mike

Plenty of people have made seats that way Steve. It probably does take a bit of trial and error, but it's cheap even if you cock it up and have to do another. I'm told it's much cheaper to buy the foam directly than from DT etc. Here's some tips that were posted to the sevens mailing list earlier this week: ---------------------------------------- For this you just take a tough plastic bag (30 gallons worked best for me) and pour the two-part foam mix into it. Close with tape, put in the car and sit on it (it's warm and comfy). Just a word of advice: put some very thin plastic painter protection sheet all over your car including the footwell, and wear old clothes and a shower hat. This foam is just a nightmare to remove from the skin or the hair. Wear latex gloves during the operation. The law of ever-increasing entropy fully applies in these experiments... foam butt recipe ---------------- - remove all seat and carpetting from your side of the cockpit - leave the harness - cover the cockpit with plastic sheet for protection (push it in the footwell as far as you can as well) - in a big container, pour an equal amount of part A and part B of urethane foam. Usually that stuff expands by a factor 30 so work out how much you want... In my experience the best is to use two clean containers to measure about 3/4 liter of each part, then mix that in a larger container (5 liters). You have about 30 seconds before it starts foaming and expanding. Each part individually looks brown (one dark, one clear). When you mix them thoroughly it becomes creamy and starts frothing. That's the right time to pour the mix in the bag (on the ground) and close it with duct tape. - put the bag in the cockpit, working the sides so that it isn't all wrinkled. - you can put another sheet of plastic above the bag for further protection - sit on the bag, and make sure you can operate the clutch - don't do the mistake I once did: camber your back "in order to get better lumbar support in the future seat": this causes the muscles adjacent to the spine to protrude, resulting in a ridge in the seat just where the spine is. Very uncomfortable. Just relax in there. The result is a hard foam seat that I found extremely comfortable and that holds you in place really well. If I had the choice again, I would buy my Caterham with the cheapest seats (or no seat at all) and replace them with foam seats. Now, the next step is to make a custom carbon fiber seat. You can start with a foam seat, them sand the surface to remove inegalities and make it look good. When you are happy with the shape, then apply gelcoat and sand that to a smooth finish (220 grit, 400 grit, 600 grit, without skipping a step). Now wax it and apply PVA release, then make a mold of it (fiberglass & resin). From this mold you can make a carbon or kevlar/carbon seat by vacuum bagging.That's something I want to do sometime but I recently ran short of time with all the things to take care of with my move to Europe... Personally, I think the all-foam approach is good enough. It's pretty light, rigid enough. I raced with it and was pleased with how well I was held in place. I was told it is easy to cover the seat with headliner (the material used for trimming the cabin of trucks is very compliant and can be shaped at will even on the compound curves of a seat; the result looks really good). It's cheap enough to be remade if necessary. -------------------------------------- Another useful snippet: I found a supplier, Glassplies (01704 540626) in Kitcar magazine who sell this for approx. 5ukp/litre plus tax and carriage. This means that 13ukp worth should be enough for a seat. Mike

I'll give it a go sometime. It is what Phil Stewart recommended to me too... Mike

Do you mean the Indi-Seat kit? Or the 2-pack expanding foam DIY sort? Mike

Turbo Technics have a supercharger conversion for the 1.8K. I wouldn't want a turbo in a 7, the throttle response of even the best turbos is woefully short of what you get with a nicely tuned nat. asp. engine. A 7 is all about quick responses. Mike

I use Redline MT-90 (or is it MTL?) in gearbox. Basically any good quality good quality GL4 oil is good for the 'box, and EP90 or any GL5 synthetic diff oil will be fine in the diff (don't need friction additives for the Suretrac LSD). Mike

smile.gif Mike

Eddie is in the trade - but who cares as long as he gives you the price you want? Mike

£80k to build? What a load of cods! Mike

Rollover bat?

Minty's correct, you don't need any sort of rollover bat to compete in sprints or hillclimbs if your car is fully road legal. Mandating an FIA bar but allowing a 3-point inertia reel belt defies all logic as far as I can see. I wonder what proportion of track incidents involve a rollover, and what proportion of track incidents would have resulted in serious injury or worse if the driver had not properly strapped in. If you're not properly strapped in in a big rollover situation then I doubt the bar is going to do much for you anyway. Mike

When you say "most" track days, which clubs other than L7CoGB won't let you on the track without an FIA bar? I've not come across any. Mike

Keith - a special lightweight chassis was only introduced for the R500, prior to that all Superlights used the standard chassis (and possibly still do). Mike

blush.gif A generalisation of course... but it is true that CF has become a 'fashion' item (as evidenced by the amount of carbon fibre-lookalike crap that you can buy). I've nothing against it being used for genuinely worthwhile weight saving (I've paid enough money for CF boats and their equipment over the years!). The biggest gains are from using it for structural components - a CF De Dion tube would be very worthwhile, bagsy I don't have to test it to destruction though... Mike

The current Caterham catalogue quotes the Superlight at 485kg and the 'Roadsport' (i.e. non-Superlight K-series) at 550kg. There's never been anything like 110kg difference between a Superlight and a not-Superlight. Weight differences quoted by Caterham when the Superlight was launched were: leather adjustable seats +10.8 kg full windscreen + wipers +6.6 hood + full side screens +8.0 paint +2.5 spare wheel including carrier +11.5 tool kit (for above) +2.8 full carpet set +3.3 heater +3.9 tonneau +1.6 I think the 6-speed box is quite a bit lighter than the 5-speed. Mike

Julian - "Supersport" is just an engine upgrade. Tasty bits that the Superlight has which are (or where 3 years ago) options on a non-Superlight are: * 6-speed box (a "must" have) * Big front brakes with vented disks * Limited slip diff * Supersport engine Superlights also have carbon dash/wings/nosecone, no windscreen or weather gear, race seats with 4-point harnesses. Mike

EB - carbon bits 'n' bobs are a rip-off because they're fashion accessories. Mike

Hydrogen???? Are you sure you don't mean Nitrogen? Mike

Yes & no... http://www.se7ens.co.uk/ If a dealer has a Superlight for 16k then you should be able to get one a bit cheaper than that privately if you hang about for a bit. Early to mid winter is the cheapest time to buy. Alternatively you could look for a 1.6K 6spd Supersport and cross-grade it to a Superlight by pulling off the bits it shouldn't have and adding the bits it should. Mike

Pierre - it includes honeycomb panels for the sides, rear and bottom of the tank. I can't remember if there is one for the front of the tank as well. Mike

http://hometown.aol.com/DVAndrews/bghpage.htm

The CD-ROM (prices out of date now I think) lists: Bag Tank Rover Race - 489.36 Box - Bag Tank - 95.15 I don't know whether this can re-use your existing in-tank injection pump - if not then you're probably looking at another 100+ quid for a remote fuel pump. I can't find a price for the honeycomb tank protection kit, but I can't see it being more than 100quid (surely?!!!). All prices plus VAT. Mike

The 'race' tank is in the same place, but uses an ATL fuel-filled bag tank within an ali box. A much cheaper solution is to get the honeycomb fuel tank protection kit. Less effective in a crash than the bag tank, but good protection from flying debris. Mike

Pierre - leaks around the fuel pump (right hand end of the tank as you face the back of the car) are not uncommon on later injection cars. Mike

I'm so old & unhip I thought fridges were only supposed to be cool on the inside! Mike