Mike Bees

Can you describe the wishbone failure Graham? Cheers, Mike

Or for anyone who thinks that their Peugeot 306 is indeed a sack of intestines/ears/flaps/a-holes they can buy my P306 OFL for a ridiculous sum of money in order to satisfy their vanity. Better still I'm sure some speculative number plate wheeler-dealer will snap it up as it clearly has massive potential. Failing that I'll change my name by deed poll to Mr P306 OFL (thanks to Viz for that idea) and then I'll be really cool. Mike

"If you set up for the maximum grip senario then you're in trouble with any change in road surface, camber, rise & fall etc." I don't understand this. However you set it up there will be some changes of conditions which reduce the amount grip. Better to start from a higher point than a lower one. If you set it up substantially sub-optimally then in some circumstances the available grip will increase, but you won't know when/where/how long for - it'll be highly transient anyway. "Take rally driving as the extreme where the setup and driving style is orientated towards handling rather than grip?" A very different situation and a very different piece of machinery! Throwing a 7 around sideways is fun but it's not fast. And we don't often drive flat-out over rough/rocky/gravelly off-road stages. Mike

Maybe the BFG chart is telling you how to adjust the balance of the car, not how to get the optimum grip from each tyre... In theory Peter is right in that there must be an optimum pressure for a tyre in a given situation, and any other pressure will result in less-than-optimum grip. Sometimes it's worth accepting less-than-optimum grip for the sake of better balance, although I think there are often better ways of achieving balance than by reducing the grip at one end to match the other. Mike

"...the worst was a 2.8 Capri". Oh how many different situations that phrase could be applied to smile.gif Expect the significantly higher tyre losses in 4th gear than 3rd. Mike

Tim - how much for your hood (if Geoff doesn't want it - he asked first!). I'm after a cheap one (doesn't matter if it's not too pretty) to hack to fit over my Vx race rollover bar. S33VEN - there's a guy in Cambridge who will do mods, I got him to put an extra hole & flap (ooer) in my tonneau cover so it works with both the standard FIA rollover bar/brace and the Vx race version. You'll need to take the car to him and leave it there. DS Thompsett 27 Cave Ind Estate, Fen Rd, Cambridge (01223) 420622 Don't be put off by the appearance of the place (or the proprietor!), his work seems good. Also worth a try I'm told: Suffolk Trimmers Shepherd's Grove Industrial Estate Stanton Suffolk (01359) 250513 Mike

Depends... on... gearbox, gear ratio, diff type, diff ratio, engine speed... If you're talking about losses between the flywheel and the *road* then it's also dependent on tyre size/type/pressure as well (not to mention the road surface). There is no percentage figure that 'works' for all conditions. A further point to note is that losses on a rolling road tend to be higher than on a (real) road due to: * The rollers aren't flat, and there are 2 of them resulting in significantly lossy distortion of the tyre * Powerful cars have to be strapped down hard onto the rollers, resulting in even more of the above. * More powerful cars have to be strapped down hard and have 1-3 fat bastards sat on the back leading to even more of the above * Sticky stuff squirted onto the tyres to help them grip the rollers As a rule of thumb say 15-25% for all of the losses (the high end of that on a rolling road), of which a significant proportion is in the tyres themselves. Fun eh? Mike

There are various trimmers around who could certainly make one for you if you left your car and the old hood with them for a few days. I doubt that this would be cheaper than buying one direct from Caterham though. Mike

I'm told that the G-tech can be a bit optimistic since it doesn't compensate for the car 'squatting' under acceleration. There's a review of it at http://www.geocities.com/MotorCity/9190/g-tech.html, and a review of a more accurate device at http://www.geocities.com/MotorCity/9190/AC22.html Mike

Induction noise can be an issue, but it depends greatly on the state of tune of the engine. If your xflow is in a relatively standard form then a new 5 or 6" silencer should get you through noisy (105db) days at both Combe and Goodwood. Not sure about quiet (98db) days. Mike

If you're going to use it as a motorway hack then the 5-speed will be better. But the whole point of the 7 is that it's for *fun*, and the 6-speed box is much much much more fun (not because it's got 1 more gear but because the ratios are so much better - a cheaper alternative is to whip the 5-speed box out and get the ratios sorted). Mike

http://www.findit.co.uk/uk/cars/caterham/83479.htm http://www.findit.co.uk/uk/cars/caterham/83170.htm Go for the 6-speed box if you can. Mike

It *might* depend what era the chassis is from. In recent years you can swap to the FIA bar relatively easily (no drilling/sawing/filing required). The FIA bar does have up-and-under bolts which necessitate removing the rear spring/damper units to access the holes. The standard hood does fit over the FIA bar (although there is a 'tall' FIA bar available over which the standard hood does not fit). Mike

I see the thought police have been in and censored my reference to W ******* d. Mike

Shome confushion here me thinks. In the old days the bolt attaching the forward end of the radius arm had a nut on it (inside the cockpit). At some point this changed to using a threaded bush, and then recently changed back to using a nut. I have heard of the threaded bush variety coming loose and falling out. I put the torque wrench on mine from time-to-time and they show no sign of loosening at all. Iain says "the right radius bolt has sheered off completely" which implies a faulty or wrong-spec bolt, not a design fault. Mike

>>It's also an ali block and is vertualy as light as a K-series but should be more easily tunable up to the high 200's bhp - allegedly.<< Why? Mike

I'm still confused as to whether you're talking about getting the best performance out of the engine, or getting the best acceleration on a traction-limited surface... In respect of engine performance, 'stomping' the pedal to the floor in the space of a few nano-seconds might cause the engine to stumble very briefly, but after that it shouldn't make any difference. Mike

The Yamaha/Zetec 1.7 is being worked on for a W*******d installation (not by W*******d themselves as far as I know). There's a shortage of tuning parts around for it at present, like I don't think there are cams available. But then this is how the K-series started out, so the situation will change in time. Mike

Dominic - assuming you're not having to control wheelspin then just putting your foot to the floor should work as well as anything else. On a modern computer-controlled fuel-injected engine the ECU will supply the 'best' amount of fuel (and best ignition timing) for the combination of throttle position and rpm. At low rpm you find that you only get extra power up to a certain amount of throttle opening, after which the power stays (more or less) the same however much more you open the throttle. The ECU has this information stored in it and knows the optimum amount of fuel to supply in all conditions. Mike

With my 3 bar pressure reg. referencing to atmos. and 311cc/min injectors (~30% bigger than the standard 1.6/1.8K jobbies) my engine likes a pulse width of 1.9ms at a warm 1200rpm idle. I've just acquired some bigger injectors to allow me the luxurious and potentially short-lived option of using 9000+rpm. These are approx 380cc/min (from a Lotus Carlton!). Having scaled the map appropriately and popped them in it still idles quite happily although it seems to want a bit more fuel than before to idle nicely, maybe fuel wetting the ports or just inconsistent control of the injectors with a 1.5ms pulse width? Mike

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Maybe the new FB version has a power steering option... Mike

"However, Stewart's question regarded steering weight building up in the corner. This is because he is holding the front end in against the chassis natural tendency to understeer. Rear steering by raising the ride heights will sort this out." How can you be sure? His symptoms (too much self-centering) sound exactly castor-induced to me. Mike

Toe-out will make it 'sharper', more inclined to change direction. The way it loads up is dictated by the amount of castor. On a De Dion chassis you can adjust the castor by playing with the number of washes in front of/behind the legs of the lower wishbone. More castor (moving the wishbone forwards) gives more self-centering action (higher effort), but has the advantage of giving more camber with lock and also improves steering 'feel'. Mike

Just let the fuel pressure regulator reference to the atmosphere. Mike