Shaun_E

Has anyone upgraded to an adjustable bar and has one of these lying around?

Preferably complete with mounts and bushes.

1. The bolt holding my crank position sensor in place disappeared at a hillclimb about 5 years ago. I finally replaced the zip tie used to secure it at the beginning of this year!

2. Following a small electrical fire on the start line of the Manx classic a few years ago we replaced the main engine loom power feed with a bit of cooker cable purchased from a tiny hardware store in Port Erin and secured it with chocolate block connectors. This remained in place for a couple of years before I had the car rewired. I still carry some cooker cable in my spares kit 😬.

If you still have a Banner or similar battery then replacing with a Redtop 15 or equivalent will lose a couple of kg. Replace with one of these will lose quite a few more (at somewhat large expense though).

Wheels and tyres are another place for a big weight saving. Avon CR500 are a lot lighter than most road tyres and certainly lighter than A048R/R888 type tyres. Mag rims often come up for sale on here or you could try the 7Tips ones (see link above) or Image lightweight 3 piece.

Losing the windscreen (and therefore the wiper motor, etc.) is a big step forward but I guess you'd rather keep them! Likewise the heater.

Ti silencer such as Raceco would be good.

Hi Oliver - it was great to catch up with you at Penn.

Give Michael Calvert a call. His Xflow 7 weighs less than my Superlight 😳 and he has gone to great lengths to remove excess weight - he even trimmed the ends off lots of bolts . His car is a de-dion and weighs less than 510kg so your target on a live axle is definitely achievable.

Shaun

As above Richard A, Mark D, the Heads, Rob G, myself and Gill would all be excluded if a 235bhp limit was introduced (assuming Mark and I find our missing horses). This would also exclude CSR260s so that's Simon Jenks and James Moreton out as well. Steve Holland and Kevin Evans would be the only competitors remaining from this year!

The effect of this would therefore be to create a "class 4b" and move most current class 5 competitors into the new class 6 and we are back to the original problem . We could have a further class for Haybusas and sequential boxes but this really would start to dilute the competition.

If 4b (190 to 235) was really going to attract a lot of new competitors then I can see it as a possiblity - we might also see some class 4 move up.

That 189.9 bhp 1.9K is looking more and more attractive now 😬.

On the face of it there is a large power range for class 5 (190 to 250+) compared with class 4 (160 to 190) and class 2/3(125 to 160). I have always argued that perception is important and I can see that the perception is if you have 210bhp you won't be competitive in class 5. We do however have to balance this against the fragmentation of classes. The Hayabusas and sequential boxed cars are much quicker despite having a power deficit compared to big Ks and Duratecs which is why they are being moved to a new class. In the existing class 5 though, the power advantage get's less, the higher up the scale you go and in fact can count against you (especially in the wet). A well set up and well driven R400 would easily hold it's own against a 250bhp K - look at this year's class 4 times versus class 5 at a number of events for proof that power isn't everything. 😬

The problem now is the huge variety of Caterham's out there such that we can never cater for every model. The R300 is at the bottom of the class 4 power range but to put it in class 3 would be unfair to class 3 competitors. R400s find themselves in that position in 5 which is unfortunate. Limiting 5 to 230ish bhp would then put most of the existing competitors out of the class. Creating 5b + 6 + 7 would mean only 2 or 3 cars in each class which nobody wants. There will always be winners and losers - I think that if you are really serious about sprinting you will get the best car for the class you choose but otherwise just turn up and have some fun. I drove for the first couple of years in class 5 on CR500 tyres!

Oh and Chris - the only class 4 car to cross the line at Curborough at 100mph was Stuart and that was because he went so deep into Fradley he had an extra 20 yards of runway - either that or he has fitted Nitrous .

I use an Eezibleed. Just drop the tyre pressure to about 10psi before using it otherwise it can blow past the cap. I always wrap the master cylinder in a large rag before starting. When you remove the Eezibleed, the master cylinder reservoir will be brim full - I use a large syringe to remove the excess fluid before putting the cap back on.

You can also buy a tube to fit on the bleed nipple which has a 1 way valve on it - I got one from Halfords.

No - the date is for racing only and is not considered at MOT time.

is Gill setting her PB of 49.10s

My second timed run . Shame it was slower than the fastest class 3 times

My fastest run (T3) is . 50.93s.

I have run all 3 so have a little input to the discussion - my apologies for the long post.

Most people "upgrade" to Nitrons as they are a good quality adjustable damper (the Bilsteins do not have adjustable damping). Invariably the upgrade is made when the Bilsteins have been on the car for some time and may be past their best. The result is that fitting the Nitrons is a big improvement. Certainly when I fitted a set to my Superlight the car control was much improved (the ride was much firmer though). At the same time people tend to fit a stiffer spring than standard (250 or 225 lb/in fronts and 140 or 150 lb/in rears) as I did. Again this alters the ride/handling (not necessarily for the better if it is a road car). Damping has to be matched to the spring rates - the adjustable feature allows fine tuning of this. Once I found a set-up I liked I left it there.

A couple of years ago I upgraded to Ohlins 2 way adjustables. I reduced the front spring rate from 250 to 225 and the rear from 150 to 140. Ride improved a little but car control was much better - I felt much more confident with the car. IMO the Ohlins is a better damper and the valving was well matched to the spring rates (by Aurok the UK importer). Again, after a few events, I found a setting I liked and have not changed it since.

This year I had to change class in the sprint championship (due to an engine failure) and 2 way adjustables are not allowed so I borrowed a set of Bilsteins on standard springs. I am amazed at how good a damper the Bilstein is and the ride is so much better with standard springs. Where I can really notice the difference though is on the very fast bumpy corners (e.g. Folly at Castle Combe and Fordwater at Goodwood) - it is here that the Bilstein comes unstuck compared with the Ohlins. 90% of the time the Bilsteins are absolutely fine but on the very limit there are some shortcomings.

There isn't a straight answer but do not underestimate how good the standard springs adn dampers are - Caterham spent a long time getting to those settings and it works pretty well in most instances. If you want the best then Ohlins are excellent and will improve the control of the car but think carefully about the spring rates you want and get the damping set to match those springs. The Nitrons are a nice product and if you really want them I suggest you talk to Simon at 7 tips about the "Nitron by Aurok". For road use only there is another choice - Black Art Designs which would be worth looking at.

 

Edited by - Shaun_E on 30 Aug 2011 08:57:41

Fixed

Here.

 

Edited by - Shaun_E on 29 Aug 2011 16:52:03

My T3 :-)

Thank you all - it was a very enjoyable weekend.

is the driver's eye view.

220bhp K series is going to be £6k+

You will need:

throttle bodies (with airbox or large filter)

programmable ECU

VVC or MS2 head with extensive porting (VVC needs a blanking kit)

cams (at least BP285, more likely 1444)

Forged pistons

single tang rods (steel rods even better)

decent 4-2-1 exhaust

bearings, gaskets, etc.

bottom end balancing

add to that all the consumables and the labour and a rolling road session

 

You could convert to Duratec but I suspect that will be north of £10k unless you do the majority of the work yourself (the engine itself would probably be cheaper but it's the conversion and all the ancillaries that add up)

Hayabusa - maybe £15k for the complete engine and conversion?

Zetec or VX wouldn't be a sensible move for a K series as they are much heavier engines.

 

Unless the car is a "keeper" it would probably be cheaper and better to sell it and buy an R400.

We'll be there in the Bongo.

My final run . Wouldn't even have won me class 3 ☹️.

Somewhat belatedly, .

It is most likely to be fuel coming through the breather as described above but I had a more serious issue recently. I found that the outlet on the top of the tank next to the filler had cracked around the weld and fuel was spilling out of that. I sorted it with some Leak Fix.

Blimey Nick, you kept that quiet - and after all the work you just did on it.

Here.

Ah - I see you worked it out.

 

Edited by - Shaun_E on 4 Jul 2011 11:09:34

Had a great day today at Shelsley - blue sky and sunshine and very warm.

the quicker of the 2 at 31.78s.

I think the winners were:

Class 1 Paul Brown

Class 2 Matt Jenkins

Class 3 Richard Price

Class 4 Mike Sankey

Class 5 Mark Durrant

but I stand to be corrected.

Chris - as you know my new class 5 engine was down on power from what was expected. I am investigating every option. Talking to Steve at Track and Road, airboxes can have a major effect, expecially with cams that have a large overlap. It is usually pulse interference effects and the big car manufacturers spend millions on developing the right length inlet tracts to eliminate these effects. Just ask any Duratec R500 owner what effect the "quiet" airbox has on power! My plan is, as you guessed, to have a swappable system, mainly so I can prove on the rolling road if the airbox is a problem or not. If it is then I will continue with the swappable system, if not I'll just leave the airbox on. Anyway my existing airbox is very close to the 90mm trumpets so I would like to use one that sits further away - I was looking at your airbox at Gurston and it looked to be nearer the outside of the car so would hopefully give more clearance. If I can find my missing 20 horses I will be a happy man.